Report on Eel Stock and Fishery in Sweden, 2003

APPENDIX II. EEL STOCK AND FISHERIES IN 2003 BY COUNTRY

Section Page

1 EEL STOCK AND FISHERY IN SWEDEN IN 2003 ...... 50 1.1 Data...... 50 1.2 Management...... 57 2 EEL STOCK AND FISHERY IN DENMARK IN 2003...... 58 2.1 Data...... 58 2.2 Management...... 61 3 EEL STOCK AND FISHERY IN IRELAND IN 2003 ...... 62 3.1 Data...... 62 3.2 Management...... 70 4 EEL STOCK AND FISHERY IN THE UNITED KINGDOM AND NORTHERN IRELAND...... 72 4.1 Data...... 72 4.2 Conclusions...... 77 4.3 Recruitment, stock and fishery trends in Northern Ireland ...... 77 4.4 Management...... 84 5 EEL STOCK AND FISHERY IN GERMANY IN 2003...... 88 5.1 Data...... 88 5.2 Management...... 102 6 EEL STOCK AND FISHERY IN THE NETHERLANDS IN 2003 ...... 103 6.1 Data...... 103 6.2 Management...... 110 7 EEL STOCK AND FISHERY IN BELGIUM IN 2003...... 112 7.1 Data...... 112 7.2 Management...... 115 8 EEL STOCK AND FISHERY IN FRANCE IN 2003 ...... 119 8.1 National level (Thomas Changeux, Gérard Castelnaud, Cédric Briand) ...... 120 8.2 Rhine-Meuse Basin district (Vincent Vauclin) ...... 128 8.3 Artois-Picardie District (Gilles Euzenat, Françoise Fournel, Jean-Louis Fagard, Cédric Briand)...... 133 8.4 Seine-Normandy district (Cédric Briand, Sarah Gimet, Marie-Noëlle De Casamajor) ...... 135 8.5 Brittany district (Cédric Briand, Thibault Vigneron)...... 141 8.6 Loire District (Aurore Baisez) ...... 155 8.7 Garonne district (Gérard Castelnaud, Gilles Adam, Laurent Beaulaton)...... 171 8.8 Adour District (Marie Noëlle De Casamajor)...... 183 8.9 Rhône Mediterranean Corsica (Thomas Changeux, Nicolas Auphan, Jean-Yves Menella, Raymonde Lecomte) ...... 195 8.10 Conclusion (Cédric Briand, Thomas Changeux, Gérard Castelnaud, Aurore Baisez, Marie Noëlle de Casamajor)...... 203 9 EEL STOCK AND FISHERY IN ITALY IN 2003...... 205 9.1 Data...... 205 9.2 Management...... 208 @#

1 Eel stock and fishery in Sweden in 2003

Country: Sweden Authors: Håkan Wickström1 and Håkan Westerberg2 Author address: 1National Board of Fisheries, Institute of Freshwater Research, SE-178 93 DROTTNINGHOLM, Sweden, [email protected]

2National Board of Fisheries, Box 423, SE-401 26 GÖTEBORG, Sweden, [email protected]

Reporting date and last reported year: September 2003, most data through 2002

1.1 Data

1.1.1 Trend in recruitment

1.1.1.1 Monitoring methodology, life stage, gear type

The amount (kg and sometimes numbers) of young eels (0+ and older) ascending several rivers along the Swedish coast (Rivers Göta Älv, Viskan, Lagan, Mörrumsån, Motala Ström and Dalälven). Viskan is the only river where “glass eels” are totally dominating. In the remaining rivers there is a mix of age classes, from 0+, 1+, 2+ and 3+ up to about 10+ in age. An additional recruitment series on glass eels comes from an experimental trawl fishery in the intake channel for cooling water at the Ringhals Nuclear Power Plant.

The Institute of Coastal Research within the Swedish National Board of Fisheries is since a number of years analysing the age and relative year-class strength of the recruits from Rivers Mörrumsån and Motala Ström.

1.1.1.2 Recruitment monitoring results

Recruitment data series from Sweden (all in kg, 2003 may be incomplete) 193 3879. 106.5 N/A 8 0 Yea Göta Dalälve Motal Viska Laga Mörrumså Rönne Kävlingeå 193 4775. 36.0 N/A r Älv n a n n n å n 9 0 Ström 194 1894. 684.0 N/A 190 530.0 0 0 0 194 2846. 321.0 N/A 190 5100. 1 0 1 0 194 427.0 14.0 454.0 N/A 190 340.0 2 2 194 1848. 283.0 1248. N/A 190 858.0 3 0 0 3 194 2342. 773.0 1090. N/A 190 552.0 4 0 0 4 194 2636. 406.0 1143. N/A 190 8700. 5 0 0 5 0 194 2452. 280.0 766.5 29.7 190 2000. 6 0 6 0 194 675.0 272.5 440.8 5.8 190 275.0 7 7 194 1702. 120.0 494.7 6.0 190 N/A 8 0 8 194 1711. 43.0 603.6 39.4 190 N/A 9 0 9 195 2947. 304.5 419.9 93.5 191 N/A 0 0 0 195 1744. 210.0 2713.0 281.8 1.0 191 5728. 1 0 1 0 195 3662. 324.0 1543.5 379.1 9.1 191 6529. 2 0 2 0 195 5071. 241.5 2698.0 802.4 70.0 191 20.0 3 0 3 195 1031. 508.5 1030.0 511.3 2.7 191 2828. 4 0 4 0 195 2732. 550.0 1871.0 506.9 42.6 191 N/A 5 0 5 195 1622. 215.0 429.0 501.6 14.1 191 N/A 6 0 6 195 1915. 161.5 826.0 336.1 46.8 191 N/A 45.0 7 0 7 195 1675. 336.7 172.0 497.2 73.2 191 N/A 4.5 8 0 8 195 1745. 612.6 1837.0 910.5 80.0 191 1465. N/A 9 0 9 0 196 1605. 289.0 799.0 552.4 29.0 93.0 192 800.0 N/A 0 0 0 196 269.0 303.0 706.0 314.8 665.5 143.7 192 1555. N/A 1 1 0 196 873.0 289.0 870.0 261.9 534.8 113.0 192 455.0 N/A 2 2 196 1469. 445.4 581.0 298.1 241.2 32.5 192 1732. N/A 3 0 3 0 196 622.0 158.0 181.6 27.5 177.8 34.7 192 4551. N/A 4 4 0 196 746.0 276.4 500.0 28.0 292.3 87.1 192 5463. 331.3 N/A 5 5 0 196 1232. 157.5 1423.0 216.5 196.3 48.5 192 3893. 357.8 49.0 6 0 6 0 196 493.0 331.8 283.0 24.4 353.6 6.6 192 4796. 581.1 445.0 7 7 0 196 849.0 265.5 184.0 74.4 334.8 398.0 192 47.0 211.9 0.0 8 8 196 1595. 333.7 135.0 117.1 276.8 85.7 192 756.0 4.5 0.0 9 0 9 197 1046. 149.8 2.0 24.7 80.4 29.8 193 5753. 268.0 147.0 0 0 0 0 197 842.0 242.0 1.0 12.0 45.3 141.1 53.3 193 2103. 316.0 N/A 1 1 0 197 810.0 87.6 51.0 88.0 106.2 139.9 249.0 193 7238. 408.0 N/A 2 2 0 197 1179. 159.7 46.0 177.0 107.1 375.0 282.3 193 6333. 303.5 N/A 3 0 3 0 197 631.0 49.5 58.5 13.0 33.6 65.4 120.7 193 6338. 236.0 N/A 4 4 0 197 1230. 148.7 224.0 99.0 78.4 93.3 206.7 193 1336. 53.5 N/A 5 0 5 0 197 798.0 44.0 24.0 501.0 20.2 147.2 17.1 193 2537. 24.5 N/A 6 6 0 197 256.0 176.4 353.0 850.0 26.4 89.6 32.1 193 8711. 0.5 N/A 7 7 0

197 873.0 35.1 266.0 532.6 75.8 168.4 10.8 8 197 190.0 34.3 112.0 505.2 165.9 61.4 56.1 9 198 906.0 71.2 7.0 72.5 226.0 36.5 165.7 0 198 40.0 6.8 31.0 513.1 78.0 72.8 49.2 1 198 882.0 0.5 22.0 472.0 90.8 129.0 40.0 2 198 113.0 112.1 12.0 308.4 87.8 204.6 37.6 3 198 325.0 33.9 48.0 20.7 68.0 189.9 0.5 4 198 77.0 69.7 15.2 211.5 234.1 138.1 0.0 5 198 143.0 28.4 26.0 150.9 2.5 220.3 8.6 6 198 168.0 73.5 201.0 140.9 69.8 54.5 84.8 7 198 475.0 69.0 169.5 91.9 191.7 241.0 4.9 8 198 598.0 N/A 35.2 32.7 44.0 30.0 0.0 9 199 149.0 N/A 21.0 42.1 21.6 72.5 32.0 0 199 264.0 N/A 2.0 0.4 161.3 151.0 N/A N/A 1 199 404.0 9.6 108.0 70.3 42.2 14.0 N/A 12.5 2 199 64.0 6.6 89.0 43.4 8.7 45.7 N/A 25.8 3 199 377.0 71.9 650.0 76.1 30.7 283.0 N/A 4.0 4 199 0.0 7.6 32.0 5.5 11.6 72.4 N/A 2.9 5 199 277.0 17.5 14.0 10.0 2.8 51.9 N/A 13.5 6 199 180.0 7.5 8.1 7.6 31.7 148.0 10.4 19.4 7 199 N/A 14.7 5.5 5.0 62.6 12.9 24.0 15.3 8 199 N/A 15.5 85.0 1.8 49.5 84.2 11.4 22.2 9 200 N/A 12.4 270.1 14.1 13.0 1.0 N/A 5.0 0 200 N/A 8.2 177.5 1.8 26.8 19.3 13.7 34.5 1 200 693.0 58.6 338.8 26.2 102.0 37.4 27.0 19.3 2 200 261 126.7 19 44.13 31.7 9.1 3

Recruiting eels 8990,0

7990,0

6990,0 Göta Älv Dalälven Motala Ström Viskan 5990,0 Lagan Mörrumsån Rönneå 4990,0 Kävlingeån kg

3990,0

2990,0

1990,0

990,0

-10,0 1900 1920 1940 1960 1980 2000 year

Experimental catch of glass eels in the intake of cooling water to the Ringhals Nuclear Power Plant

50 glass eels/hour, average per night

CPUE 30

0 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 year

1.1.1.3 Development during the last season

In River Viskan the recruits still continues to ascend the trap as late as in the beginning of October this year (2003). Due to warm conditions the ascent commenced early in the season this year. The catch in River Dalälven was the best since 1977. From River Motala ström the manager reports on an unusually low catch and propose that a change in the flow regime might have influenced the ascent. River Göta Älv is back to more normal levels as during the 1980’ and 90’.

1.1.2 Re-stocking

The Baltic Sea and a number of lakes are stocked annually with either imported and quarantined elvers (from River Severn, UK) or with medium-sized yellow eels from the Swedish West Coast. During the last 13 years about 2.2 million individuals were stocked annually.

Year Elvers Yellow eels Total 1990 684 000 820 655 1 504 655 1991 294 900 937 761 1 232 661 1992 300 000 1 123 133 1 423 133 1993 572 000 980 914 1 552 914 1994 1 709 400 1 009 833 2 719 233 1995 1 494 370 850 949 2 345 319 1996 2 427 030 1 060 620 3 487 650 1997 2 458 326 1 084 831 3 543 157 1998 2 131 985 948 805 3 080 790 1999 2 349 825 991 001 3 340 826 2000 1 335 770 667 909 2 003 679 2001 846 765 428 175 1 274 940 2002 1 374 686 256 168 1 630 854

Stocking in Sweden

4 000 000

Yellow eels 3 500 000 Elvers

3 000 000

2 500 000

2 000 000

numbers of eels 1 500 000

1 000 000

500 000

0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 year

1.1.3 Trend in fishery

1.1.3.1 Life stage concerned

Yellow eels are the main targets for the commercial fishery along the Swedish West Coast and in the Baltic Sea and most freshwater fisheries migrating (mostly silver) eels are the targets.

1.1.3.2 Description of fisheries, information sources, gear types

EU-logbook is kept by all licensed fishermen with a boat >10 m, for the other licensed fishers a monthly “Coastal Fishery Journal” are the information sources in marine/brackish waters. In freshwater a similar system (monthly or in smaller lakes yearly journals) is used. In addition a parallel source of information is the sales notes that are delivered directly to the Board of Fisheries from the wholesalers on the landing market. This data includes landings also from non-licensed fishermen.

Effort data are included in the logbook/journal systems.

The yield is nowadays given per landing district or in the case with logbooks per fishing area (ICES).

1.1.3.3 Data series on fishing yield

Marine catches Coastal districts West Coast South Coast East Coast Total 1985 1116 2000 123 286 39 448 2001 195 107 123 425 2002 222 106 183 511

Freshwater catches Lake Vänern Vättern Mälaren Hjälmaren Other lakes Total 2001 25 0 38 23 32 118 2002 22 0 34 18 29 103

2500

2000 The Baltic Sea Skagerrak-Kattegat Freshwater s 1500 onne t

1000

500

0 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 Year

1.1.3.4 Recent development in fisheries and market

Catch, effort and CPUE 600 000 120 000 550 000 500 000 100 000 450 000 80 000 400 000 E

kg 350 000 60 000 300 000 E & CPU 250 000 40 000 200 000 20 000 150 000 100 000 0 1994 1995 1996 1997 1998 1999 2000 2001 2002 Landings (kg) Logg-books (kg) Effort-fykes (*10^-2) CPUE-fykes (*10^6)

Since about 1997 also the remarkable stable catches from the Swedish West Coast have fallen.

Monitoring of yellow eels in Halland County (West Coast) 1.8 1.6 aug 1.4 april 1.2 1 0.8 CPUE 0.6 0.4 0.2 0

6 0 6 82 88 97 978 980 9 984 986 9 99 992 994 99 998 000 1 1 1 1 1 1 1 1 1 1 1 1 2 ye ar

However, CPUE data from one area along the Swedish West Coast do not show any clear trends.

1.1.4 Trend in the stock

1.1.4.1 Monitoring of the stock.

The Institute of Freshwater Research has initiated a survey of silver eels this year (2003). Samples from the commercial fishery in eight lakes (freshwater) are collected. In another study large samples are collected from the Öresund area where most eels leaving the Baltic Sea have to pass. In addition to the traditional data on stage, length, weight etc. most eels will be aged and a proportion also analysed with respect to the Sr/Ca-ratio in their otoliths. Sr/Ca-ratios will be used to determine the life histories of the silver eels, with emphasis of being stocked or not.

The Institute of Coastal Research has recently included eels in the marine environments in their Data collection programme.

1.2 Management

In a PM from 2000 the state of the European eel and the eel fishery was analysed, mainly from a national perspective. In 2003 the first steps towards a Swedish Eel Management Plan were taken. An outline of this plan will be discussed with different stakeholders in December 2003. This plan describes the situation and the problem. It also proposes and discusses possible actions to be taken. A population model for the Swedish eel stock is being developed and will be used to assess the effect of different management actions on escapement and the eel industry. The model results will be used when ranking actions in order of priority.

One obvious step already discussed is an increased minimum legal size in the yellow eel fishery along the Swedish West Coast (Skagerrak-Kattegatt). A quite reasonable increase in size should increase the silver eel escapement quite considerable.

1.2.1 Management measures currently in effect

Recently the minimum legal size in the Baltic Sea and in the large lakes where the Government manages the fish stocks was increased from several different sizes to 600 mm.

A decrease of the number of fyke-nets allowed, to maximum six for non-commercial fishermen and 600 for commercial ones.

Fishing with fyke-nets is forbidden during January-March.

Trammel net fishery for eels is banned from 1 Jan 2004.

Gears have to leave free passage in 1/3 of any river or other migration route.

2 Eel stock and fishery in Denmark in 2003

Country: Denmark Authors: Michael Pedersen Author address: Vejlsøvej 39, Dk-8600 Silkeborg: [email protected] Reporting date and last reported year: October 2003 and 2002

2.1 Data

2.1.1 Trend in recruitment

2.1.1.1 Monitoring methodology, life stage, gear type

Recruitment monitoring takes place at two pass traps catching ascending yellow eel at Tange Hydro power station and Harte Hydro power station. Additionally scientific sampling is done, by electro fishing stream sections in a small brook, calculating the no of eel *m-2 . (More details in - Monitoring of eel recruitment in Denmark in Dekker 2002).

2.1.1.2 Recruitment monitoring results

Harte Hydropower station Vester Vedsted brook 2 m / 15 600 eel

y 500 t 12 i 9 400 300 6 Kg on dens

i 3 200

at 0 100 1 1984 1 1994 1999 9 9 opul 7 8 0 9 9 P 7 2 7 2 7 2 7 2 196 197 197 198 198 199 199 200

Figure 1 and 2. Recruitment indicies

The glass eel fisheries by the Waddensea stopped in the late 1980s because there was only few glass eels to catch. The pass trap at Harte Hydropower station is nowadays probably the best monitoring place reflecting size of the recruitment to Danish waters in the Kattegat area. In Vester Vedsted brook, situated by the Waddensea, we only found few (pigmented) glass eels ascending the brook since we started monitoring in 1995.

Year Tange Harte Vester Vedsted brook (kg) (kg) density 1967 500 mean max (season) 1968 200 eel/m2 eel/m2 1969 175 1970 235 1971 59 1973 117 1974 212 1975 325 1976 91 1977 386 1978 334 1979 291 2,8 6,5 1980 93 522 7,0 13 1981 187 279 7,8 13 1982 257 239 1983 146 164 1984 84 172 1985 315 446 1986 676 260 1987 144,5 105 1988 251,5 253 1989 353,6 145,1 1990 367,2 101,3 1991 433,5 44,2 1992 53 40,4 1993 93,3 26 1994 311,7 35,2 1995 83,1 22,9 2,6 2,6 1996 56 6,7 4,6 6,8 1997 390 9,1 0,7 1 1998 28,9 17,7 0,3 0,4 1999 346,3 15,3 0,4 0,5 2000 87,9 18,9 0,6 0,7 2001 239,0 11,4 0,6 0,8 2002 278,2 17,0 0,5 0,6 Table 1. Recruitment data

2.1.2 Trend in fishery

2.1.2.1 Life stage concerned:

Yellow eel and silver eels

2.1.2.2 Description of fisheries, information sources, gear types

Danish coastline

Along the Danish coastline in Kattegat and Øresund and Belt Sea, huge poundnets exploit migrating silver eels during autumn.

In Fjords, Bays and shallow water mainly yellow eel are taken during the summer, by use of fyke nets, baited hooks and small poundnets.

The information sources on yield are from eel traders. The traders are obliged to report to the ministry of fisheries from where the yield data is retrieved.

2.1.2.3 Effort

• The countrywide effort is most probably decreasing. There is no statistics readily available concerning the no of fishermen or no of gear to give an indication of the effort except on Roskilde Fjord.

• Roskilde Fjord

• In Roskilde Fjord, Sealand, a gear survey was made in August 2003. The survey was made by counting the number of gears from a small helicopter while flying over the Fjord. The total number of fykenets recorded was 485 and the total number of pound nets was 147. Only professional fishermen are allowed to fish with poundnets.

Fyke net licence marks are different if you are professional or recreational fisherman. A licence identity in 2003 survey showed that 72 % of the fyke nets belonged to recreational fishermen and only 28 % to the professional fishermen, suggesting that the unrecorded recreational fishery is important.

In the 1950s about 2000 fyke nets were recorded in Roskilde Fjord, increasing to 7000 during the 1970s and hereafter dropping to 485 in 2003.

The number of pound nets registered in the 1950s were ca. 500, increasing to 800 in the 1970s and herafter dropping to 146 in 2003.

2.1.2.4 Data series on fishing yield

The officially statistics reflect decreasing yield since the 1960s, however, selling on the black market is part of the fishermen culture. More or less constant prises due to large amount of farmed eel released in the market and low catches makes the fishermen sell as much as possible on the black market to increase their income by avoiding taxes.

In some areas the fishery is probably not sustainable. For example on Roskilde Fjord (125 km2) landings are almost exclusively small eels below 45 cm. Despite female silver eels (> 45 cm) are never seen, sex ratios of yellow are found to be ca. 50 % females, suggesting that the stock is exploited very hard. F-values from a survey in 1990 have been calculated to be between 0.22 - 0.80 per 1.5 cm length interval for the population above legal size. (Pedersen 1997). The official catch is in recent years was 10 – 14 tons/year and a rather small part of the total landings ca. 600 tons/year.

6.000

) 5.000

ons 4.000 (t 3.000 eel

d of 2.000 el i

Y 1.000

0 1920 1930 1940 1950 1960 1970 1980 1990 2000

Figure 3. Total Danish official catch

Year Silver Yellow Total 1990 834 734 1568 1991 724 642 1366 1992 687 655 1342 1993 523 500 1023 1994 509 631 1140 1995 408 432 840 1996 381 337 718 1997 375 383 758 1998 306 251 557 1999 380 307 687 2000 382 218 600 2001 446 225 671 2002 365 217 582

Tabel 2. Total Danish official catch of silver and yellow eel.

2.1.2.5 Recent development in fisheries and market

There is no recruitment of new eel-fishermen and the mean age of the active fishermen are quite high, so the number of professional fishermen is decreasing. The fishermen have difficulties surviving on the income from fishing. In general there is a shift from fulltime eel fishermen toward parttime or recreational fishermen.

2.2 Management

There is currently no national management plan.

2.2.1 Management measures currently in effect

1. Minimum legal size of yellow eel (see Moriarty 1996)

2. Restrictions on number of fyke nets to be used for recreational fishermen and they are not allowed to sell the catch.

3. Countrywide re-stocking program to enhance fisheries, with imported glass eels from southern Europe.

3 Eel stock and fishery in Ireland in 2003

Country: Republic of Ireland Authors: Russell Poole Author address: Marine Institute, Furnace, Newport, Co. Mayo [email protected] Reporting date and last reported year: Sept. 2003, data for 2002/2003 Contributors to the Report: Aidan Barry SWRFB John Conneely NWRFB Paula Cullen NUIG Denis Doherty ESB – Ballyshannon Pat Doherty ERFB Greg Forde WRFB Paddy Gargan CFB Gerry Gough ESB Seamus Hartigan Galway Fishery WRFB Kieran McCarthy NUIG Milton Matthews NRFB Tom O'Brien ESB – Parteen Brian Sheerin SRFB Frank Sheridan DoCMNR Rebecca Walsh ShRFB

3.1 Data

3.1.1 Trend in recruitment

3.1.1.1 Monitoring methodology, life stage, gear type

Monitoring of elver migrating at Ardnacrusha (Shannon), Cathleens Falls (Erne) and for the Feale, Inagh and Maigue Rivers and monitoring of bootlace eel migrating at Parteen Dam (Shannon).

3.1.1.2 Recruitment monitoring results

Monitoring is carried out at six fixed stations by the ESB and fishing is also undertaken by the ESB/Shannon Regional Fisheries Board in the Shannon Estuary for glass eels (Table 1). Indications are that recruitment remains low although catches in 2003 were higher at all stations except for the Feale. Figure 1 presents the historical elver monitoring for the Erne and the Shannon (Ardnacrusha).

All glass eel and upstream migrating juvenile eel trapped in the monitoring programme (Table 1.) were transported overland and stocked into the catchments. An additional 441kg 91.3 million) and 188kg (0.6 million) glass eel were transported from the estuary to the upper catchment of the Erne system in 1999 and 2000 respectively.

Erne

5.0 275 4.5 250 4.0 225 4) ) 200 199 t 3.5 9- ( 175 h 3.0 c

t 150 197 a

2.5 f

C 125 2.0 o 100 % ver l 1.5 E 75 ex (

1.0 50 d n 0.5 25 I 0.0 0 965 968 971 974 977 980 983 986 989 992 995 998 001 1 1 1 1 1 1 1 1 1 1 1 1 2 Year

Shannon

8.000 400 375 7.000 350

325 94)

) 6.000 300 19 t

( 275

79- h 5.000 250 c

t 225 19 a 4.000 200 f C 175 o

3.000 150 % ( ver l 125 E

2.000 100 ex

75 d n 1.000 50 I 25 0.000 0 5 8 1 4 7 0 3 6 9 2 5 8 1 196 196 197 197 197 198 198 198 198 199 199 199 200 Year

Figure 1. Historical data for catches of elvers at Cathleen's Falls on the Erne and Ardnacrusha on the Shannon.

Table 1: Glass eel, elver and bootlace (Parteen) catches (kgs) from 1985 to 2003 (nf = not fished).

Shannon Shannon Sh. Estuary Year Erne Ardnacrusha Parteen River Feale River Maigue Inagh River Glass Eels 1985 400 1093 984 503 1986 700 948 1555 1987 2300 1610 984 1988 3000 145 1265 1989 1800 27 581 1990 2400 467 970 1991 500 90 372 1992 1400 32 464 1993 1700 24 602 1994 4400 287 125 70 14 1995 2100 398 799 0 194 1996 647 332 95 0 34 140 1997 1087 2120 906 407 467 188 616 1998 723 275 255 81 8 11 484 1999 1246 18 701 135 0 0 416 2000 1074 39 389 174 0 120 43 2001 699 27 3 58 2 18 1 2002 113 155 648 116 nf nf 37 2003 693 378 873 36 72 111 147

In Ireland, commercial fishing for juvenile stages is illegal and capture is restricted by law to that needed for enhancement under special authorisation by the Regional Fisheries Boards. Fisheries for brown and silver eel take place both in freshwater rivers and lakes and in tidal areas.

3.1.2 Fisheries for yellow eel

3.1.2.1 Life stage concerned

In Ireland, the yellow eel stage is often referred to as brown eel.

3.1.2.2 Description of fisheries, information sources, gear types

Brown eel are caught mainly in lakes either by fyke net, or by long-line, with additional fisheries in rivers and tidal waters. There is also some baited pot and trap fishing.

Reliable information on fishing effort is not available but it is thought that the brown eel fishery supports approximately 130 part-time fishermen. Table 2 details the number of licenses issued in 2002 in each Fishery Region. The number of licenses, however, does not reflect the number of fishermen and not all licenses are actively fished.

3.1.2.3 Data series on fishing yield

Reporting of eel catches is not a requirement of many eel licenses and in some cases eel fishermen fail to make accurate returns. Reported catches may be as much as 50% lower than the actual catch. The Regional Fisheries Boards collate the returns from the fishermen and report the catch data to the Marine Institute. Table 3 gives brown eel catch for each fishery region for 2001 and 2002. While historical data is lacking, is generally felt that catches have fallen in recent years.

Table 2. Number and type of licenses (inc. silver eel) issued in 2002 in each Fishery Region.

______Fishery Region Type Number Comment ______Eastern Longline 7 Fyke 18 Coghill 9 Southern Fyke 5 140 nets Pots 26 442 pots Coghill 2 South Western Longline 3 not fished Fyke/Pot 6 Shannon Longline 8 capped @ 10 Longline 31 to ESB Fyke 8 Fyke 19 to ESB Coghill 6 Coghill 34 to ESB Western Longline 1 Fyke 20 2 are for tot 60 nets x 1m high Trap 1 Coghill 27 North Western Longline 26 or fyke option Coghill 2 on trial basis Northern Longline 29 Rep., capped @ 32 Longline 20 On Erne in North Fyke 13 20 nets/licence Total 321 ______

Table 3. Declared Irish Catches (kgs) for 2001 and 2002.

______2001 2002 Region Brown Silver Brown Silver ______Eastern 14,000 2,500 16,000 4,300 Southern 8,555 0 4,800 50 South Western 552 0 972 0 Shannon 16,053 24,107 15,849 24,079 Western 8,949 9,363 3,922 12,980 North Western 13,913 1,384 10,983 1,194 Northern 4,743 28 8,911 31 Total Catch 66,765 37,382 61,437 42,634 Approx. Value €324,387 €159,878 (@€5.28) (@€3.75) Overall Total Catch 104,147 104,071 Overall Value €484,265 ______

3.1.3 Impact of fisheries on the stock

General

There is only sparse information on the impact of fisheries on brown eel stocks and silver eel production. It is also difficult to separate the impact of dropping recruitment, either natural or stocked. A number of examples have been reported on where fisheries have been shown to impact on brown eel stocks or where poor recruitment has had an influence on stock structure these are summarised below and the original reference is cited. It should be noted, however, that the impact of levels of recruitment or commercial fishing on stock size or stock characteristics has not been quantified.

Erne (Matthews et al. 2001)

There were three examples of changing stock structure demonstrated in the Erne system; one by poor recruitment, one by over-fishing and one which showed the result of previous stock enhancement.

Analysis from a comprehensive fyke net survey of over 56,000 net-nights along with length and age data demonstrated that areas of poor recruitment in the upper catchment (Annalee-Dromore & Ballinamore Lakes) suggested that natural recruitment to these lakes was negligible. Evidence for local depletion of eel stocks through commercial fishing was apparent, particularly in the Narrows, Lwr L. Erne, where CPUE fell progressively from 4.9 to 2.4kg per 10 nets per night over the three years of the study.

The relatively small size of many of the lakes (<100ha) in conjunction with lower stock densities means that they are unable to support fulltime fisheries. These lakes are consequently fished on an intermittent basis and many may not be fished for several seasons.

Shannon (McCarthy & Cullen 2000)

Declining fyke net CPUE in L. Derg, the lowermost lake, can largely be attributed to reduced recruitment. The impact of brown eel fishing, at current levels of effort, on the composition of the brown eel populations in the Shannon lakes is generally felt to be low (see Section 1.3 for details).

Corrib (Moriarty 2001)

The potential yield of the Corrib catchment eel fishery could be as much as 520t. However, while such an attainment may be possible in the future, the present status of the fishery is one of limited catches, declining stocks and poor recruitment. Without a considerable change in recruitment any development based on increased stocks is unlikely.

Surveys were carried out in the catchment in 1967, 1990 and in 2001. In the southern basin (nearest the sea) the catch in 1990 was less than half that of 1969 and large eels had become very scarce. CPUE in the northern basin was more or less the same, medium and larger sized eels were more plentiful and smaller eels were fewer over the same time period. Assuming that fyke net CPUE is proportional to the stock density, it would appear that the stock in the southern basin has fallen to less than half its 1960s value while the northern basin is more or less unchanged.

Survey data, length and age, showed clearly that the brown eel fishery, while making a substantial contribution to the total Corrib catch was not having a detectable adverse effect on the silver eel catch in spite of the observations of falling stocks in the southern basin. The data from the Galway Weir silver eel fishery showed that the brown eel fishery alone could not be held responsible for the reduction in silver eel catches. The decrease in the number of large brown eel in the South Basin, however, could well have been as a result of fyke net fishing

Lady's Island, Co. Wexford. (Moriarty 2002)

The fyke net fishery in Lady’s Island Lake has been in progress since the 1960’s. The current yield is estimated as 3 tonnes.

The lake is a very unusual waterbody: essentially a lake, it is changed to a tidal lagoon by the artificial breaching of the sand bar – which takes place in most years in spring. The water is shallow and very productive. Inflowing streams are small and few. Since they do not have a significant salmonid population, the eel is suitable for management solely as an eel fishery. The water of Lady’s Island Lake is saline and, when the breach is open, tidal. An argument is made in favour of treating it as a freshwater lake so that eel fishing can be controlled by Authorisation from the Eastern Regional Fisheries Board.

A sample taken in August 2002 showed that the catch was composed largely of small eels of 100g (quarter pound) or less. Comparison with an unexploited stock, in the South Sloblands Channel, indicated that fishing, at the current rate, had an impact on the population. The catch per unit of effort and the size distribution of the catch provide grounds for restricting the fishing effort to the current level of three boats.

3.1.4 Fisheries for silver eel

3.1.4.1 Life stage concerned

3.1.4.2 Description of fisheries, information sources, gear types

Silver eel capture takes place during the downstream migration in autumn and winter, mostly at fixed stations or 'weirs'. Some fyke netting near lake outflows also takes place.

The primary methods used on the larger systems such as Shannon, Corrib and Erne are coghill nets. Regulation of these fisheries is more straight forward and consequently data is more robust.

Silver eel fishing effort has been dropping over the past few years with many private fishermen and small privately owned fishing weirs closing or ceasing to operate. The main silver eel fisheries are owned either by the state (Galway Weir – Corrib) or by the ESB (Shannon).

3.1.4.3 Data on fishing yield

The catch for 2001 and 2002 for each fishery region is given in table 3.

The silver eel fishery does not impact directly on the standing crop within a catchment. It is not known what the impact of the Irish silver eel fisheries is on the global stock.

3.1.4.4 Recent development in fisheries and market

The silver eel fishery in Ireland would appear to have been more affected by drops in market prices in the last few years than has the brown eel fishery.

Since 2001 the ESB has embarked on a programme of transporting silver eels captured in the Shannon silver eel fishery around the dams and releasing them for onward migration to the sea. In 2001, 1,278kg (5.3% of catch) and in 2002, 3,884kg (15.4% of catch) were released as part of this conservation measure.

3.1.5 Trend in the stock

Currently in Ireland, the best indicators of trends in stock are provided by the elver indices data for Shannon (Ardnacrusha) and Erne and the silver eel data for the Shannon, the Corrib (both exploited systems) and for the Burrishoole system (unexploited).

3.1.5.1 Monitoring of the stock

In these three fisheries, eel catch and eel size is monitored for the coghill net fisheries on the Shannon and the Corrib. In the Burrishoole the entire silver eel migration is trapped in 'smolt traps', the eels are counted and measured and a sample of otoliths are also taken.

3.1.5.2 Data series on fishing yield

Historical silver eel data is available from a number of fishing stations (Table 4). Data for Galway Weir (Corrib) is based on commercial coghill nets and the Burrishoole data is for total trap counts from a research facility.

Table 4. Historical data for Irish silver eel fisheries.

Year Galway Weir Burrishoole Year Galway Weir Burrishoole (t) (number) (t) (number) 1971 4567 1987 15.0 2713 1972 3144 1988 8.5 3283 1973 5087 1989 16.5 flood 1974 4642 1990 12.1 3121 1975 6530 1991 7.0 2902 1976 16.5 4595 1992 7.2 3670 1977 11.3 5362 1993 7.1 2570 1978 15.3 1412 1994 8.3 3570 1979 19.7 5196 1995 8.2 5102 1980 20.9 3550 1996 4.1 2251 1981 20.6 4702 1997 7.3 2578 1982 31.3 4234 1998 4.6 2956 1983 13.0 1548 1999 6.1 2969 1984 14.0 1034 2000 7.95 2631 1985 11.4 1958 2001 6.84 3875 1986 7.5 1856 2002 5.81 2863

Shannon

Brown Eel

Surveys of brown eel carried out since 1992 have provided evidence of changes in the Shannon stock that reflects variation in previous natural recruitment and re-stocking levels (McCarthy & Cullen 2000). Declining yields as demonstrated by CPUE in L. Derg, the lowermost lake, can largely be attributed to reduced recruitment (Figure 2) although this change in CPUE may also have been influenced by poor fishing efficiency and changes in fishing upstream of L. Derg. Longline results, however, confirm this decrease in CPUE. It is anticipated that this reduction in stock will also become evident further upstream. The impact of brown eel fishing on the composition of the brown eel populations in the Shannon lakes is generally felt to be low and there has been little inter-annual variation in length frequencies (McCarthy & Cullen 2000).

Figure 2. Variations in overall average fyke net CPUE recorded for Loughs Derg and Ree during yellow eel fishing seasons of 1992-1999 inclusive (taken from McCarthy & Cullen 2000).

Silver Eel

The annual downriver migrations of silver eels have traditionally been exploited in the River Shannon and the three commercial eel weirs, owned by ESB since 1937, have continued this practice with varying success (Fig 3a&b). Analysis of the catch statistics for these weirs and commercial data concerning quantities of eels of different size grades sold from the Shannon fishery has provided a great deal of scientific information on long term eel populations trends. In many respects the overall pattern of change, with steadily declining silver eel catches at Killaloe/Clonlara but relatively steady catches at Athlone mirrors the results obtained by monitoring the Lough Derg fyke net CPUE yellow eel catches versus those in upper catchment lakes. Changes in sex ratios of silver eel catches also indirectly provide information on population dynamics. The high overall predominance of female eels in the fishery upstream of Parteen reflects on a relatively low population density throughout the lakes. There is evidence of a decline in the small percentage of males, which form the "very small" boxed eel category in commercial eel sales statistics, has declined from 1992 onwards.

Figure 3a. Trends in the annual catches of silver eels made at the commercial eel weirs of Athlone (1984/'85 – 1998/'99), Killaloe and Clonlara (both 1984/'85 – 1999/'00) along with regression analyses for Killaloe and Clonlara data sets (taken from McCarthy & Cullen 2000).

60 ) s 50

40 h (tonne

tc 30 a C 20

0 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Fishing season

Total Killaloe Athlone

Figure 3b Silver eel catches from the Killaloe eel weir (1981 to date), Athlone (1984 to date) and the Shannon system (1966 to date). Note that in the case of the Athlone data catches recorded between 1984 and 1998 inclusive were made at a single eel weir operated by ESB. All subsequent data refers to a series of at least six licence holders fishing in the vicinity of Athlone.

Corrib

The Galway Fishery comprises an weir with 14 coghill nets. These are fished throughout the dark moon phases and may be lifted during periods of very water. The fishery was purchased by the state in 1978 and has been fished consistently since then. Fishing effort may have increased in later years. The downward trend in silver eel catch ( Figure 4) therefore probably reflects accurately the decreasing stock in the greater Corrib catchment and falling silver eel escapement.

A study of the Corrib Catchment Eel Fishery (Moriarty 2001) concluded that while fyke netting may have had an impact on size frequencies in the lower Corrib, falling recruitment was probably a more likely cause of changes in stock.

Commercial Silver Eel catch Galway Fishery 1976 - 2002

35 30 25 20 15 Tonnage 10 5 0 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Year

Figure 4. Annual silver eel catch in the commercial Galway Fishery, Corrib System, for 1976 to 2002.

Burrishoole

The Burrishoole System in the West of Ireland is an oligotrophic river and lake system with a catchment area of 8,949 ha. The eel population is unexploited and the total silver eel production is trapped in downstream Wolf type traps.

Catches of silver eel between the years 1971 (when records began) and 1982 averaged 4,400, fell to 2,200 between 1983 and 1989 and increased again to above 3,000 in the '90s (Figure 5). There was an above average catch in 1995, possibly contributed to by the exceptionally warm summer. The catch in 2001 of 3875 eel was the second highest recorded since 1982. The average weight of the eels in the catches has been steadily increasing from 95 g in the early 1970s to 215 g in the 1990s (Figure 5). The increase in average weight has been caused, at least in part, by a change from a predominantly male sex ratio to more than 60% females in the more recent years (Poole et al., 1990).

Burrishoole Silver Eel Number Weight 8000 300

7000 250 6000

200 ) m r 5000 g e ( b t

4000 150 h m ig e Nu 3000

100 W 2000 50 1000

0 0

1971 1973 1975 1977 1979 1981 1983 Y1985 ear1987 1989 1991 1993 1995 1997 1999 2001

Figure 5. Annual silver eel catch in the Burrishoole System for 1971 to 2002.

3.2 Management

There is currently a National Review underway which has a draft management plan.

Introduction

Increasing awareness of the value of eel fishing and considerable concern for the status of stocks led to a decision by the Irish Minister for the Marine and Natural Resources to establish an Eel Review Group in 2002. The Group was tasked with addressing four Terms of Reference with ultimate aim of presenting him with clear, realistic and costed proposals for the sustainable development and regulation of the eel resource. Much of the emphasis in the report lies in developing policy that will support conservation and enhancement of the fishery and the eel stock. The report focuses on the lack of reliable and detailed data and makes recommendations for the improvement of the collection of eel fishery statistics. The following is a brief summary of the draft contents of the report.

Review of the Management of the European eel resource in Ireland

Fishing for glass eel and elver is carried out under special authorisation. The catch is used largely for re-stocking open waters and has been used in the past as seed for aquaculture. Yellow eel are caught mainly in lakes either by fyke net, or by long-line, with additional fisheries in rivers and tidal waters. Silver eel capture takes place during the downstream migration in autumn and winter at fixed stations or 'weirs'. The officially reported catch is in the order of 100t per annum but inadequate reporting and illegal fishing makes this difficult to quantify accurately. Regional fisheries and management issues are summarised, with reference to N. Ireland and the aquaculture situation.

International aspects of European eel management

Recent worldwide declines in eel populations have caused serious concern and has prompted the formulation of management plans in many regions. ICES/EIFAC have advised the EU that the European eel stock is outside safe biological limits and that an action plan is urgently required. The EU has begun the process of drawing up such a plan, implementation of which will be a national responsibility.

Management plan for the Irish eel resource

While primary legislation exists for the control of the eel fishery, a number of amendments or additions to improve the efficiency of fishery protection and quality of reported catch data are proposed. This chapter covers the existing fisheries for glass eel and elver, brown and silver eels and proposes a plan for stock enhancement. Given the concern over declining recruitment and reduced stocks, fishery development can only take place supported by proven enhancement. Factors limiting eel production and survival including hydrobarriers, access upstream and water quality are discussed. Reference is made to common links between N. Ireland and the Republic and recommendations are made for the Erne, L. Neagh and for joint implementation between North and South authorities.

Eel culture is not currently practiced in Ireland but given suitable economics and adequate supply of seed, this may become viable in the future. Currently market price is low and processing is limited to a few small operations. Public perception, regular supply of top quality raw material and export into niche markets at low prices are limiting factors. It is recommended that value added processing and branded good quality product are essential for the survival of the eel fishery.

3.2.1 Management measures currently in effect

Each Regional Fisheries Board has a local eel management plan or policy. These broadly aim to improve the regulation of eel fisheries and in many cases also include aims towards enhancement of fisheries through upstream transport of glass eel or elvers. The Management of Eel Fishing Bye-Law No.752, 1998, capped the number of longline licences that a Regional Fisheries Board may issue for long line fishing for eels in any district. In addition to the above, the Fisheries (Amendment) Act 1999 delegated authority to the Regional Fisheries Boards to issue authorisations for the use any fishing engine for the capture of eels including any long line, as it sees fit. Many Fisheries Boards are now promoting the use of fyke net over long-line in a effort to reduce mortality of released undersize eels. The Electricity Supply Board also has statutory responsibility for fisheries regulation and stock enhancement and conservation in waters under it's control.

References

Anon. (2003). Guidelines on the operation of small-scale hydroelectric schemes and fisheries. Central & Regional Fisheries Boards (in press).

McCarthy, T.K. & Cullen, P. (2000). Eel fishing in the River Shannon: Eel population changes, fishery management options and fishery conservation issues. A synthesis report on the River Shannon Eel Management Programme 1992-2000. Report prepared for EFB Fisheries by NUIG; 21pp.

Matthews, M., Evans, D., Rosell, R. Moriarty, C. & Marsh, I. (2001). Erne Eel Enhancement Programme. EU Programme for Peace & Reconciliation Project No. EU 15. Northern Regional Fisheries Board, Donegal; 348pp.

Moriarty, C. (2001). Maintenance and development of the Corrib Catchment eel fishery. Report commissioned by the Western Regional Eel Fisherman's Assoc.; 34pp.

Moriarty, C. (2002). The eel fishery of Lady's Island Lake, Co. Wexford. Report commissioned by the Eastern Regional Fisheries Board; 18pp.

Poole, W.R., Reynolds, J.D.R. & Moriarty, C. (1990). Observations on the silver eel migrations of the Burrishoole river system, Ireland, 1959 to 1988. Int. Revue Ges Hydrobiol. 75 (6); 807-815.

4 Eel stock and fishery in the United Kingdom and Northern Ireland

Mike Pawson1, Brian Knights2, Miran Aprahamian3; Robert Rosell4 & Tony Bark, Beth Williams and Heidi El-Hossaini5

1 CEFAS, Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk NR33 0HT. Tel: +44 (0) 1502 524330, Fax: +44 (0) 1502 513865, email: [email protected]

2 University of Westminster, School of Biosciences, 115 New Cavendish Street, London W1M 8JS. Tel: +44 (0) 171 911 5000, Fax: +44 (0) 171 911 5087, email: [email protected]

3 Environment Agency, NW Region, Richard Fairclough House, Knutsford Road, Warrington WA4 1HG. Tel: +44 (0) 1925 653999, Fax: +44 (0) 1925 415961, email: [email protected]

4. Department of Agriculture and Rural development for Northern Ireland, Agriculture and Science Div., Newforge Lane, Belfast BT9 5PX. Tel (028) 90255506, Fax: (028) 90255004, email: [email protected]

Division of Life Sciences, King’s College London, 150 Stamford Street, Waterloo, London. SE1 9NN. email: [email protected]

Contributions from Malcolm Beveridge, FRS Freshwater laboratory, Faskally, Pitlochry, Perthshire, Scotland, UK PH16 5LB and Peter Wood, UK Glass Eels, Gloucester, England

4.1 Data

4.1.1 Trends in recruitment

Information and data for 2001 presented in the report of the last WGEEL meeting to ICES/ EIFAC (ICES, CM 2002/ACFM:03) are updated below. Licence sale and catch return data for glass eels/elver and for yellow/silver eel fisheries are derived from the Environment Agency (EA), other catch and economics information is derived from Customs & Excise export-import data for Great Britain. Analysis of the latter has short-comings, but gives useful information and provides proxy estimates of recruitment and of home and international market trends (Knights, 2001; Knights et al, 2001).

Figure 1 indicates that glass eel/elver catches remained relatively constant between 2000-02 at ~5-8t per year, i.e. about 20% those of the late 1970s-early 1980s. CPUEs (kg per licensed dip net, Fi. 2) were also depressed by about 20%, despite the large increases in licence sales and fishing effort between 1996-2000, when prices were up to £200/kg because of high demand for farm seed stock from China. Catches, licence sales and CPUE were depressed in spring 2000 because of fishing site restrictions due to foot-and-mouth disease regulations. Effort has not increased subsequently as catch values have stabilized because of falling demands from China (due to increased farm efficiency and survival rates and impositions of local controls to prevent overproduction).

Table 1 Glass eel/elver export import data 1972-2003

MAFF/NRA/EA Customs&Excise Licence estimates Exports sales CPUE CPUE No.of Year t/yr t/yr dipnets kg/net £/net 1972 16.7 1973 28.2 1974 57.5 1975 10.5 1976 13.1 1977 38.6 1978 61.2 1979 67 1980 40.1 32.8 1367 24.0 121 1981 36.9 1303 1982 48 30.4 1288 23.6 187 1983 16.9 6.2 1537 49 1984 25 29 1192 24.3 162 1985 20 18.6 1026 18.1 245 1986 19 15.5 917 16.9 330 1987 21.3 17.7 1162 15.2 384 1988 21.4 23.1 918 25.2 861 1989 20.6 13.5 1087 12.4 804 1990 20.9 16 1169 13.7 986 1991 1.1 7.8 960 8.1 625 1992 5 17.7 969 18.3 1335 1993 5.73 20.9 1000 20.9 1959 1994 9.5 22.3 1058 21.1 1304 1995 11.9 1530 1996 18.8 23.9 1682 14.2 1480 1997 8.7 16.2 2450 6.6 821 1998 11.2 20.1 2480 8.1 1113 1999 18 2207 8.2 1012 2000 7.6 2100 3.6 £/net 2001 5.4 838 6.4 can't be calculated 2002 1.5 5.1 899 5.7 > 2000 because of * 2003 19 (~10 ) Biscay imports *10t according to P.Wood, UK Glass Eel

The catch in 2003 appears to be over twice that of 2002. French catches were relatively low because of cold water temperatures/high river discharges. It is possible that higher prices in England and Wales stimulated higher effort. Data on licence sales are not yet available to assess this possibility. An increased 2003 catch has been confirmed by Peter Wood (UK Glass Eels) but he has put the catch figure as nearer to 10t, due to an error in Customs & excise data. Knights (2002) has suggested that recruitment is intimately related to long-term cycles of ocean climate factors that affect the survival of leptocephali, rather than fishing mortality. If, as predicted, recruitment success is correlated with ~25-30 year cycles of the North Atlantic Oscillation, we may be entering a period of Sargasso Sea cooling and changes in N. Atlantic currents that more closely resemble those of the peak recruitment years in the late 1970s-early 1980s.It is however too early to say definitively whether 2003 marks such a turning point.

As in other recent years, the values of exports often appeared relatively low for glass eels/elvers and the overall value of imports exceeded those of exports. It is suspected that some shipments had already been paid for in France and that Customs and Excise values only represent shipment costs. Shipments to the Far East were ~16.1t and ~12.6t respectively in 2002 and 2003. Demand from European farms via the Netherlands, Denmark, Sweden and Greece again appeared relatively low, reflecting the decline in European farming because of competition from the Far East. Small

volume sales to Eastern European markets (presumably for re-stocking) have continued, including continuing shipments to Latvia, Lithuania and Estonia. Although obviously not recorded in export data, shipments of ~1t were also made to N. Ireland in 2002 and 2003 for re-stocking the L.Neagh fishery (Table 3).

4.1.2 Studies of recruitment and fishing mortality at Leighton Moss RSPB Reserve

Studies at this bird reserve on the NW coast of England, begun in 1997, were continued in 2002, carried out voluntarily by David Mower (Royal Society for the Protection of Birds). Direct comparisons with previously reported results on trapping of recruits are not possible, because experiments were conducted to assess the effects of wedging open the tidal sluice downstream of the trap. This resulted in marked increases in trap catches on selected high tides, illustrating that this structure is a migration barrier. In 2002, 3640 elvers were trapped, of which ~1500 were attributable to the wedging. This compares with 5667 elvers in the best year (1999) and 856 in the worst year (2001).

Two commercial fishermen caught 77,100 glass eels/elvers downstream of the tidal sluice over 18 nights in March and April. However, limited data support previous conclusions that such fishing mortality has no significant impact on the number of elvers reaching the reserve trap.

4.1.3 Yellow/silver eel fisheries and economics for 2002

The total GB catch (i.e. minus N Ireland catches) for 2002 is estimated to have been ~122t, with 1952 fyke nets licensed (Figs. 3). Thus the decline in catches from peaks in the mid-1990s has continued, although licence sales have been relatively constant over the last 5 years. CPUEs (in kg and £/fyke net licence) have consequently fallen too (Figure 4). The catches from other instruments, such as moveable traps, are believed to have followed the same trends. Only two fixed (silver eel) traps have been licensed. Reports from eel fishermen are that eels may be sparser in some waters but that the main reason for poor catches is that they have reduced their fishing effort because of very variable demand and low prices paid by dealers (commonly <£1.50/kg, if they are prepared to buy). Figure 5 shows that the average export value has been <4/kg since 1997, similar to values pertaining in the early 1980s. Given changes in the value of the £ since then and relative increases in boat, fuel, netting and other costs, returns are very poor. Anecdotal evidence suggests that many fishermen only continue fishing because of earnings from by-catches. Eel merchants and processors claim low prices are due to (a) declining home (and mainland Europe) consumption and (b) competition from farmed live eels for smoking and farmed frozen eels for other dishes, exacerbated by periodic overproduction in volatile international markets. Ringuet et al. (2002) estimate that European aquaculture production increased from almost nil in 1970 to >10,000t in 2000, whilst European eel fishery landings fell from 20,000t to 10,000t over the same period. In more recent years, increased production and cheaper labour costs in the Far East have severely impacted prices, exacerbated by periodic overproduction. China, for example, now supplies over two thirds of world production (Ringuet et al.2002). This is illustrated by increases in cheap frozen imports into England and Wales, plus subsequent re-exports (Section 2.1.5).

Table 2 Yellow & silver eel export data for England & Wales

Total Catch Export exports returns value Fyke net All Y&S Year tonnes tonnes £thousand £/kg N licences methods 1979 162 CPUE CPUE kg/instrum £/instru 1980 196 670 3.41 ent ment 1981 229 759 3.31 1982 273 850 3.11 1983 270 888 3.29 1523 1984 283 922 3.26 2085 1985 283 1012 3.57 2624 177 583 1986 274 1190 4.35 1994 136 442 1987 381 60.41 1869 4.91 2168 108 386 1988 456 280.58 2992 6.56 2443 137 597 1989 376 80.63 1699 4.52 2041 176 862 1990 277 48.74 1016 3.66 1589 187 1225 1991 358 38.26 1724 4.82 1704 184 832 1992 234 35.63 1383 5.92 1724 175 639 1993 232 46.62 1442 6.22 1859 210 1012 1994 384 86.79 1920 5.00 2647 135 802 1995 514 103.76 2484 4.83 2648 125 776 1996 540 100.51 2532 4.69 2752 145 725 1997 526 68.04 1956 3.72 2602 194 938 1998 306 58.31 1126 3.68 1825 196 920 1999 294 1012 3.44 1670 202 752 2000 113 345 3.05 168 617 2001 207 771 3.72 1916 176 606 2002 122 50 445 3.65

108 402 4.1.3.1 Frozen yellow/silver eel imports

In 2002, ~183 t of frozen eel were imported, compared to ~84 t in 2000 and ~310 t in 2001. The proportion of frozen New Zealand wild-caught eels declined, with 62% of imports (cf 76% in 2001) deriving from farmed production in China, Taiwan and Vietnam. The average price was £2.72/kg, compared to £3.10/kg in 2001. Re-exports then totaled ~58 t, with ~48 t going to the Netherlands at £3.44/kg, i.e. slightly less than the export value of fresh wild-caught eel of £3.65/kg.

4.2 Conclusions

The above review suggest that;-

- There is no substantive evidence that glass eel recruitment has fallen further below the low levels pertaining in the 1990s

- Demand for glass eels/elvers as seed stock for aquaculture in the Far East (and also in Europe) has fallen to stable levels and is unlikely to increase again

- Demands for re-stocking have increased, especially in the Baltic countries, although high prices discourage large purchases

- Yellow and silver eel fisheries continue to decline in England and Wales, as elsewhere in Europe. Home (and European mainland) consumption continues to decline and over half of European demand is now met by farmed and frozen eel. Economic factors appear to be the principal cause of declining fisheries rather than shortages of eels due to poor recruitment or overfishing.

4.3 Recruitment, stock and fishery trends in Northern Ireland

In Northern Ireland, there are two important stock units for which there are data.

4.3.1 Lough Neagh

L. Neagh/R. Bann comprises a 400 km2 lake-based production system which produces circa 95% of the total Northern Ireland catch. Annual data are available on elver/glass eel stocked and trapped naturally in the River Bann on their way upstream. Annual commercial production figures are divided into outputs of yellow eels (line or draught net catch) and silver eels (caught in traps in the River Bann when migrating downstream from Lough Neagh). Data since the 1960s have been provided by the Lough Neagh Fishermen's Co-Operative Society. Current annual outputs are around 500-600 t in total. Models based on input/output relationships with a 17-18 year lag were presented to ICES/EIFAC in Working Papers 1999 and 2000.

Catches of glass eel and elver, additional stock purchases, yellow and silver eel catches are updated from previous reports in Table 2. Glass eel data are plotted in Figure 6 and yellow and silver eel catch in Figure7.

4.3.1.1 Glass eel and elver data for 2003

Good conditions in spring 2003 permitted fishing of glass eels in the Bann Estuary before their ascent into the traps at the tidal head. The total catch recorded to May 2003 consisted of 941 kg taken as glass eel and 69 kg takes as ascending pigmented elver. Further catches of elver were taken up to August but totals are not yet available. It is possible that the high take of glass eel has reduced the subsequent ascending elver catch.

Table 3. Lough Neagh fishery summary data for Northern Ireland report

Year Glass Additional Total Yellow eel Silver eel Total catch eel+elver purchases kg recorded catch kg catch in kg (yellow + catch kg input silvers kg) 1936 7333 7333 1937 9000 9000 1938 8000 8000 1939 6333 6333 1940 9000 9000 1941 10000 10000 1942 7000 7000 1943 6000 6000 1944 5333 5333 1945 5667 5667 1946 7000 7000 No data 1947 to 1958 1959 1960 7409 7409 1961 4939 4939 1962 6740 6740 1963 9077 9077 1964 3137 3137 1965 3801 0 3801 236759 329564 566323 1966 6183 0 6183 284773 332800 617573 1967 1899 0 1899 327282 242727 570009 1968 2525 0 2525 382327 204618 586945 1969 422 0 422 368677 238327 607005 1970 3992 0 3992 516505 237345 753850 1971 4157 0 4157 610909 233309 844218 1972 2905 0 2905 509091 124945 634036 1973 2524 0 2524 562482 162400 724882 1974 5859 0 5859 587905 178873 766777 1975 4637 0 4637 576355 187527 763882 1976 2920 0 2920 481886 144873 626759 1977 6443 0 6443 455350 236691 692041 1978 5034 0 5034 544695 280727 825423 1979 2089 0 2089 702609 341164 1043773 1980 2486 0 2486 668945 245273 914218 1981 3023 0 3023 681545 228691 910236 1982 3854 0 3854 705759 209891 915650 1983 242 0 242 662709 203636 866345 1984 1534 1335 2869 807673 165891 973564 1985 557 3639 4195 616668 135055 751723 1986 1848 5935 7784 522359 129855 652214 1987 1683 4584 6267 503777 121345 625123 1988 2647 2107 4754 503236 150982 654218 1989 1568 0 1568 643395 152436 795832 1990 2293 0 2293 613232 123600 736832 1991 677 0 677 578868 121382 700250 1992 978 786 1764 533241 148036 681277 1993 1525 0 1525 535150 90327 625477 1994 1249 772 2021 597418 95200 692618 1995 1403 686 2089 659050 138000 797050 1996 2667 33 2700 594045 112291 706336 1997 2533 70 2603 554750 109418 664168 1998 1283 17 1301 531968 104545 636514 1999 1345 1167 2512 556214 113055 669268 2000 563 150 713 486595 101964 588559 2001 315 0 315 451309 84000 535309 2002 1092 1007 2099 432314 91382 523695 2003 1010 1333 2343

Figure 6 History of Lough Neagh glass eel and elver inputs

Elver Supply to Lough Neagh 12000

10000 Bought in (imported) Bann trap & transport)

) 8000 g

(K 6000 rs e v l

E 4000

2000

0 36 39 42 45 60 63 66 69 72 75 78 81 84 87 90 93 96 99 02 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 Year

Figure 7 Lough Neagh Commercial Catches, Updated to 2002

Lough Neagh Eel Catches 1200000 Yellow Eel 1000000 Silver Eel

Kg 800000 n

i 600000 h c t 400000

Ca 200000

0 5 7 9 1 3 5 7 9 1 3 5 7 9 1 3 5 7 9 1 196 196 196 197 197 197 197 197 198 198 198 198 198 199 199 199 199 199 200 Year

Figure 8 Pooled commercial sample, Lough Neagh, 2003, Ungraded catches.

Lough Neagh commercial sample 2003

y 30 c n 20 que e

r 10 f 0 30 34 38 42 46 50 54 58 62 66 70 74 78 82 86 length class (2cm interval)

Figure9 Monthly Length Frequency of Lough Neagh Commercial eels – 2003

(2cm Length Class intervals)

MAY

12 10 8 6 4 2 0

8 30 34 38 42 46 50 54 58 62 66 70 74 7 82 86

June

12 10 8 6 4 2 0

0 8 30 34 38 42 46 50 54 58 62 66 7 74 7 82 86

JULY

14 12 10 8 6 4 2 0

0 4 8 2 6 0 4 8 2 6 0 4 2 6 3 3 3 4 4 5 5 5 6 6 7 7 78 8 8

August

12 10 8 6 4 2 0

4 4 2 6 0 4 8 6 30 3 38 42 46 50 5 58 6 6 7 7 7 82 8

Figure 10a. Input – Output relationships, Lough Neagh, part 1

Lough Neagh eel fishery - Correlation between recorded Elver+glass eel input and eventual total catch with varying lag in years, data from 1965 to 2002 1

0.8

)

R 0.6 ( n o i 0.4 at el r r

o 0.2 C

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 -0.2

Lag from input to catch in years

Figure 10b. Input – Output relationships, Lough Neagh, part 2

Lough Neagh - Output for input( t-18)

1200000 ) g K

n 1000000 i tch

ca 800000 l a u

an 600000 tal to 400000 t (=

e y = 72.944x + 459512 m R2 = 0.6499 ti t 200000 u p t u o 0 0 2000 4000 6000 8000 elver input in Kg (t-17 to t-19) running average

4.3.2 Yellow eel data for 2003

The number of boats (two man crews) fishing Lough Neagh continues to decline and the maximum this year is of the region of 110 to 130 boats. Low market prices are now beginning to affect effort. The decline in boats over the past decade (from 180-200 boats to 110-130) represents a possible effort reduction, but there has also been increased efficiency of fishing gear over that period, with those boats operating draft nets moving to hydraulic rope haulers rather than manual labour. There is also a trend toward more draft net fishing and less long-line fishing.

4.3.3 Further data becoming available as a result of new research

As a result of the employment of a research assistant to provide fishery management information for both the cooperative and government fishery managers, additional data will become available over the next three years. The length frequency of eels in the 2003 is presented in Figure 8. Figure 9 shows the monthly progression of length frequency in the yellow eel catch, with no obvious differences or cropping effects with progression through the season. There is also clear evidence (not presented here) of differing size selection by differing long-line baits. There are plans to assess total silver eel emigration and escapement starting in October 2003.

4.3.4 Anticipated future changes in the Lough Neagh stock

Over the past decade, there has been a slight decline in total output, but not on the same scale as the post-1980s recruitment decline. It is not yet evident that there has been any significant reduction in CPUE, (annual catch per boat) as boat numbers have fallen as total catch has fallen over the past decade. Precise data on the decline in boat numbers is not yet available.

The recruitment decline from the mid-1980s onward should begin to show soon as decline in output, if assumed age and growth relationships are correct. There are positive correlations between input of glass eel/elver and total catch with time lags of 16 to 22 years, peaking at a lag of 18 years (Figure 10a, 10b), and this relationship has strengthened since first noted in 1999 (Rosell, Working Paper to ICES/EIFAC meeting, Silkeborg 1999). Over the range of stock input recorded of 1000 to 7000 kg total to Lough Neagh (40,000 Ha), a linear regression is the best fit to the input-output relationship (Figure 10b). Updated age data for Lough Neagh commercial samples should become available shortly, but it is assumed that the 18 year lag is the average time taken by a female to reach the marketable size of circa 42cm from entry as glass eel at circa 70mm. Current Lough Neagh catches may have been protected from the effects of the 1980s natural recruitment decline by purchase of large quantities glass eel from elsewhere (River Severn) between 1984 and 1988. If the 18 year lag input/output relationship is correct, a reduction in the fishable stock is anticipated from 2006 onwards.

Other long term trends in the Lough Neagh Fishery include:

• a shift in catch emphasis from silver to yellow eel (due to effort shift and market forces), and

• a switch from male dominance to female dominance in catch sex ratio (presumed to be due to lower stock densities affecting sex determination).

4.3.5 The Erne System

The Erne is a cross-border catchment in SW Northern Ireland, shared with the Irish Republic, comprising two large lakes of 145 km2 and with a total productive water area of 330 km2. . Elver passes have operated since construction of a hydropower station in the 1950s. Since the 1970s, elvers have been trapped and transported to the upstream lakes and, since 1998, distributed throughout the catchment. There are annual data on elver catch since the 1970s (updated to 2003 in Figure 11). An EU-funded survey documented the status of the populations in 1995-2000. Annual production has fallen recently due to market forces and reduced prices. Total full-time summer season fishing is now down to an estimated 4 boats, with a mix of long-lining and fyke netting. There is no updated catch information available at the time of this report.

Silver eel escapement is likely to be severely compromised by the hydroelectric power station.

With dwindling fishery effort, and local government re-organisation affecting fisheries departments, it has been difficult to obtain collated effort data and catch returns for the Erne system since 2000.

Figure 11 Erne glass eel + elver lifts at Cathaleens Fall Power Station, Ballyshannon

Elver supply to Lough Erne

5000

4000 Glass eel fishery Trap box at power station

Kg 3000 n i h c

t 2000 Ca

1000

0 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 Year

4.3.5.1 General Lough Erne trends:

• This is one of very few elver/glass eel recruitment stations not to show the 1980s decline in recruitment (Figure 11). Effort changes in the glass eel trap and transport operation past power stations may be a factor in this absence of a trend.

• Fishery yield has declined markedly in recent years as fishermen have gone out of business (due to low prices)

• Glass eel recruitment is insufficient to stock system to anything like its potential yield

• Silver eel escapement is likely to suffer very high mortality in power turbines

4.3.6 Scotland

No data are available for Scotland. There remains some small research activity at the University of Strathclyde into fish pass design and eels, with specific reference to issues on the River Clyde (Ms Caroline McGillvary).

There remains no commercial yellow eel fishing as far as is known, although it remains to be determined whether two long-established traps in Fife are still in operation. There are anecdotal reports of some sporadic fishing for elvers in the northwest.

Data on eel abundance is beginning to be recorded by Trust biologists and input to the SFCC datbase. However, the data are very approximate (unummerated in tens) and not universally recorded.

Information has recently been included on the website: http://www.frs-scotland.gov.uk/FRS.Web/Delivery/display_standalone.aspx?contentid=791

4.4 Management

4.4.1 Establishment and Implementation of Biological Reference Points for the Management of the European Eel, Angullia anguilla L.

The bases for this project, DEFRA-funded 4 year R&D project (2002 – 2006) were introduced to WGEEL in 2002, an up-date is given below, plus a project Overview flow-chart. The contract is being carried out by Tony Bark, Beth Williams and Heidi El-Hossaini of King’s College London, with inputs from Brian Knights (University of Westminster) and Geoffrey Kirkwood (Imperial College).

4.4.1.1 Main Project Objectives:

• To develop, program and test models for population dynamics, stock assessment and management strategies.

• To research and develop methods for establishing biological reference points (BRPs as limits and targets) to inform practical and sustainable management of eel stocks and fisheries within appropriate management units in England and Wales (with potential for application elsewhere in Europe and to anguillids in other continents).

• To develop recommendations for appropriate decision structures, management approaches and harvest strategies, within the context of the precautionary approach.

• To specify data requirements and practical monitoring options for assessing compliance of eel stocks with BRPs.

• To provide a practical demonstration of the application of BRPs and monitoring approaches in test catchments.

4.4.1.2 Field work in 2002

Summer field work resulted in >5000 eels being caught by electric fishing from three catchments, the Lower Severn (Gloucester), River Wnion in Wales and the Rivers Piddle/Frome in Dorset. The data collected will be used in the parameterisation of the model and once analysis and ageing had been completed over the winter months will provide an idea as to what data needs be collected in the summer of 2004. At least one new catchment will be surveyed next summer to increase the variety of catchments and locations for which detailed data are known to expand the geographical application of the model.

Establishment and Implementation of Biological Reference Points for the Management of the European Eel, Angullia anguilla L.

Project Overview

Manager/End User

Selects river from GIS computer package

Data input by user.

Biological: GIS Total n Bare minimum Length Frequency data Sex ratio requirements Levels of recruitment vary depending Anthropogenic: Catch data on the catchment Physical barriers in question. Environmental: GIS data layers Environmental Quality Index

Data collected from Model Parameters Field Work

INPUT

Fortran Program

OUTPUT

Biological Reference Points

Stock Status

Traffic Light Principle?

Management Options

4.4.1.3 GIS development

The Geographical Information System is being developed, with variables such as nitrate levels, altitude, distance from tidal limits, level of exploitation/recruitment being added, and will be at a functioning stage by early 2004.

4.4.1.4 Modelling Population Dynamics

A stochastic length-based matrix model is being developed to consider the population dynamics of the European eel. Recruitment, growth, natural mortality, sexual differentiation, and emigration are the key biological processes accounted for. The model also accounts for the anthropogenic effects of fishing and includes an environmental quality index that may be affected by changes in habitat quality or water quality.

Due to the lack of knowledge regarding the oceanic phase of the life cycle and hence no feasible spawner-recruit relationship, a mean recruitment with stochastic deviation must be assumed. Temporal trends may be incorporated into the recruitment function to simulate the widely hypothesised declines.

As the model accounts for immigration into UK freshwaters and as this occurs before sexual differentiation, a function must be established which determines the differentiating proportions of males and females. This is assumed to be based on the ratio of the biomass of undifferentiated eels to the carrying capacity biomass of undifferentiated eels. A number of functions are currently being investigated to determine which would be optimal.

Due to a lack of quantitative time series data, model parameters are difficult to determine accurately. Although current parameters used may be ‘best guess’ estimates, inaccuracies tend to proliferate within the model. Unless better data sets become available, it is possible that the model would be more appropriately used as a qualitative guide rather than a quantitative one.

The aim of the model is to determine the status of a given population with regard to pre-defined reference limits or targets. From a modelling perspective, the optimal BRP to be used would be silver escapement biomass. This is difficult if not impossible to measure in practice, however. From a biological perspective, the optimal BRP would be framed in terms of length-frequency distributions. This is more difficult to interpret mathematically. More investigation is required to determine which BRPs will be used.

4.4.2 Management in England and Wales.

A new national system of licence duties for eel fishing (other than by rod and line) has been advertised, together with revisions to byelaws. The revisions are in line with the National Eel Strategy and the byelaws reflect international scientific advice on the status of eel stocks in Europe.

The byelaws aim to:

• Rationalise the licensing system and methods of fishing

• Confine elver exploitation to those areas where they have been historically exploited. This follows ICES advice of no expansion of the fishery.

The consultation phase has just been completed (end of August). In total, 19 objections to the proposals were received for both England and Wales. A response will be made to each objection, which will give evidence in support of the proposals and request that the objection is retracted. All the objections will be included in the submission to Ministers to request approval of the proposals. It is intended that the new duties will apply from January 2004.

As part of its National Eel Management Strategy, the Environment Agency plans to produce handbooks for practising fishery managers, on re-stocking (with reference to preventing disease transfers) and on the use of passes.

o "Guidelines for the stocking of eel and elver (Anguilla anguilla)" is a collaborative project with Kings College London, and aims to produce guidelines on best practice for the re-stocking of eel and elver (Anguilla anguilla) for Agency officers and other organisations involved in fisheries management. It will critically review published and unpublished literature on eel and elver re-stocking in Europe. It is hoped that the draft guidelines will be submitted for discussion to the WGEEL meeting and be available by the end of 2003.

o "Fish Pass Design for Eel and Elver (Anguilla anguilla)" is being carried out by D. Solomon & M. Beach with the aim of producing design criteria and costs for eel and elver fish passes and traps. The project will critically review published and unpublished literature on eel and elver passes, taking into account the issues of hydraulics, exit, entrance and approach, installation, robustness, maintenance and location, and also literature on the swimming speed of eel and elver and factors affecting it. Design criteria for eel and elver passes will be produced, taking into account their installation, and specific designs shown that may be needed for passes situated at gauging stations, at total exclusion tidal barrages and at tidal flaps. Design criteria will also be given for traps, which can be incorporated into fish, passes. Designs will need to ensure that they do not compromise the function of the original structure specifically passes at sites used to measure flow. It is hoped that the guidance notes will be available in a form suitable for a user manual, by March 2004.

There have been some discussions with Dr Alex Haro, of the U. S. Geological Survey, Biological Resources Division, in Massachusetts who has been working a similar generic eel pass design and operation "manual" with Jacques Boubee (New Zealand) and Antoine Legault (France). It would widen the scope of the Agency report to include other species of eel so that a single set of reports are produced that cover Europe, N America and Australasia.

o Screening Guidelines – The aim is to produce an update of the Dr. D. Solomon review (NRA R & D Technical No. 1), produced in 1992. The updated review should provide guidance on the best method of screening eel (as well as other fish) from intakes. It is hoped that this will be produced before March 2004 and is being funded by The Environment Agency, English Nature and the Countryside Council for Wales.

(d) It is now compulsory for all fishermen to make catch and effort returns, however within England and Wales no single database for the recording of these data exists. It is hoped that a national database will become available in 2004.

References

Ibbotson, A., Smith, J., Scarlett, P. and Aprahamian, M. (2002). Colonisation of freshwater habitats by the European eel Anguilla anguilla. Freshwater Biology 47: 1696-1706.

Knights, B. (2001) Economic Evaluation of Eel and Elver Fisheries in England and Wales (Module C). Environment Agency R&D Technical report W2-039/TR/2, 42pp.

Knights, B. (2003) A review of the possible impacts of long-term oceanic and climate changes and fishing mortality on recruitment of anguillid eels of the Northern Hemisphere The Science of the Total Environment 310, 237-244.

Knights, B., A. Bark, M. Ball, F. Williams, E. Winter, and S. Dunn (2001). Eel and elver stocks in England and Wales – status and management options. Environmental Agency, Research and Development Technical Report W248. 294 pp.

Ibbotson, A., Smith, J., Scarlett, P. and Aprahamian, M. (2002). Colonisation of freshwater habitats by the

European eel Anguilla anguilla. Freshwater Biology 47: 1696-1706.

Ringuet, S., Muto, F. & Raymakers, C. (2002) Eels: their harvest and trade in Europe and Asia. Traffic Bulletin 19, 80-

106.

5 Eel stock and fishery in Germany in 2003

Country: Germany Authors: R. Knoesche Author address: Institute of Inland Fisheries, D-14476 Gross Glienicke, [email protected]. Reporting date (sept. 30th 2003) and last reported year: 2002

5.1 Data

5.1.1 Trend in recruitment

5.1.1.1 Monitoring methodology, life stage and gear type

Pigmented young eel, scientific monitoring at eel ladders with traps in the river Elde (tributary of the Elbe) and river Warnow (Baltic sea)(LEMBCKE 2003); Glass eel, commercial catches for re-stocking at Herbrum/Ems (SCHUCHERT 2000; SCHMEIDLER 1957) (Table 2, Figure 1)

Table 2: Glass eel catches for re-stocking in German waters in the river Ems at Herbrum

Jahr kg 1951 719 1975 10312 1928 102 1952 1516 1976 3785 1929 598 1953 3275 1977 2172 1930 813 1954 5369 1978 1819 1931 1955 4795 1979 2774 1932 1956 4194 1980 3195 1933 1957 1829 1981 962 1934 1958 2263 1982 674 1935 1615 1959 4654 1983 392 1936 1960 6215 1984 352 1937 1961 2995 1985 260 1938 1962 4430 1986 102 1939 1963 5746 1987 10 1940 429 1964 5054 1988 16 1941 594 1965 1363 1989 5 1942 992 1966 1840 1990 30 1943 1989 1967 1071 1991 9 1944 1968 2760 1992 6 1945 1969 1687 1993 20 1946 600 1970 683 1994 70 1947 1438 1971 1684 1995 23 1948 1640 1972 3894 1996 2 1949 1182 1973 289 1997 9 1950 875 1974 3669

12000

10000

8000 r y / l e e

s 6000 a l G

g k 4000

2000

8 1 4 7 0 3 6 9 2 5 8 1 4 7 0 3 6 9 2 5 8 1 4 7 4 4 5 6 7 8 8 8 9 9 9 92 93 93 93 94 94 9 95 95 96 96 9 97 97 97 9 9 9 1 1 1 1 1 1 19 1 19 1 1 1 1 1 1 1 1 1 1 19 19 19 19 1

Figure 1: Glass eel catches in the river Ems at Herbrum

5.1.2 Trend in fishery

Germany had no relevant eel immigratiion for the last 20 years. The immigration rate was even low before 1980. Thus, re-stocking is the main recruitment source for the German eel stocks since about 100 years (Table 3 - 5 , Figure 2 - 4).

Table 3: Eel re-stocking in Germany 1908-1965 (sources: RÖHLER 1939; 1942; statistics)

pc. Glass pc. Glass eel 1933 15,3 5,0 40,3 eel/ha bootlace/ha equiv./ha 1934 14,5 5,0 39,5 1900 1935 18,4 5,0 43,4 1901 1936 18,4 5,0 43,4 1902 1937 19,1 5,0 44,1 1903 1938 24,6 5,0 49,6 1904 1939 26,3 5,0 51,3 1905 1940 1,1 5,0 26,1 1906 1941 7,3 6,6 40,3 1907 1942 5,8 6,3 37,5 1908 1,7 1,7 1943 19,4 5,0 44,4 1909 8,2 8,2 1944 4,7 5,0 29,7 1910 17,0 17,0 1945 0,0 0,0 0,0 1911 18,8 18,8 1946 8,8 8,3 50,4 1912 12,4 12,4 1947 20,9 8,3 62,6 1913 19,4 19,4 1948 23,9 8,3 65,6 1914 18,0 18,0 1949 17,2 8,3 58,9 1915 1950 12,8 8,9 57,0 1916 1951 10,5 8,3 52,2 1917 1952 22,6 7,8 61,7 1918 1953 55,4 55,4 1919 1954 85,1 85,1 1920 1955 70,4 70,4 1921 1956 71,8 71,8 1922 1957 25,9 25,9 1923 1958 33,0 33,0 1924 2,9 2,9 1959 67,9 67,9 1925 4,1 4,1 1960 90,6 90,6 1926 6,6 6,6 1961 43,7 43,7 1927 10,5 10,5 1962 64,6 64,6 1928 18,3 4,6 41,4 1963 83,8 83,8 1929 16,8 5,6 44,6 1964 73,4 73,4 1930 19,4 5,0 44,4 1965 19,5 19,5 1931 22,5 5,0 47,5 1932 21,4 5,0 46,4

100

70 a

/h 60

40 Glass eel equiv. 30

9 35 44 920 1908 1911 1914 1917 1 1923 1926 1929 1932 19 1938 1941 19 1947 1950 1953 1956 195 1962 1965

Figure 2: Eel re-stocking in Germany 1908-1965 (1 bootlace = 5 Glass eels) (total area 120,000 ha)

Table 4: Eel re-stocking in East Germany 1950-1989

glass eels glass eel 1971 8085 11705 227 (kg) bootlace (kg) equiv./ha 1972 10493 37380 340 1950 0 18063 38 1973 8941 6305 237 1951 0 18942 39 1974 12001 50730 406 1952 0 11371 24 1975 10132 61709 382 1953 735 30019 81 1976 13833 50770 452 1954 0 21705 45 1977 12857 57302 441 1955 3284 25000 134 1978 13123 59303 452 1956 1600 25000 92 1979 13070 30215 390 1957 360 26444 64 1980 13241 20380 373 1958 1900 34000 118 1981 8730 54413 332 1959 3555 38548 169 1982 10160 46548 351 1960 4577 15978 148 1983 8400 45500 305 1961 2536 36602 140 1984 10500 34100 334 1962 4741 15140 150 1985 1995 22395 97 1963 6835 13886 200 1986 7925 198 1964 3960 16465 133 1987 8754 219 1965 9275 19410 272 1988 8878 222 1966 7275 25703 235 1989 4764 119 1967 7589 18810 229 1968 8447 29485 273 1969 6456 46995 259 1970 9155 14965 260

Figure 3: Eel re-stocking in East Germany 1950-1989 (1 bootlace = 5 Glass eels)

500

450

400

350 a h / . 300 v i u q e

l 250 e e

s 200 a l G 150

100

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 195 195 195 195 195 196 196 196 196 196 197 197 197 197 197 198 198 198 198 198

Table 5: Eel re-stocking in Brandenburg 1990 – 2002 (total area: about 60,000 ha)

reported kg year area, ha bootlace advanced farm eel glass eel 1990 20514 3550 74 2156 1991 18742 672 157 3695 1992 38342 2120 50 4954 1993 45990 2541 133 7663 1994 46493 2467 180 7223 1995 9925 2075 220 7631 1996 8994 160 1556 16473 1997 54853 126 2787 39553 1998 60193 0 3867 38734 1999 60042 8 6171 29712 2000 54155 0 7357 28198 2001 55071 0 3440 37954 2002 55291 0 5896 23492

900

800

700

a 600 h / v. 500 equi 400 ass eel

gl 300

200

100

0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Figure 4: Eel re-stocking in East Germany 1950-1989 (1 bootlace = 5 glass eels, 1 adv. farm eel = 3.5 glass eels)

The re-stocking rate in East Germany increased significantly after World War II. The mean rate between 1960 and 1989 amounted 272 glass eel equivalents/ha. After 1990 the mean re-stocking rate in Brandenburg remained at the same level – 245 glass eel equivalents/ha but with a decreasing tendency (for the reasons see Table 7). The mean re-stocking rate in Mecklenburg-Vorpommern (about 65,000 ha) 1995 – 2000 was 162 glass eel equivalents/ha with a constant tendency.

This ensures a significant additional silver eel emigration, as the eel stock model for the East Germany and Brandenburg waters is showing (Table 6 and 7).

Table 6: Eel stock model for East Germany 1960 – 1989 (time lag between re-stocking and catch: 7 years)

re-stocked (mean): 272 glass eel equiv./ha mean yield (reported): 4,57 kg/ha year weight (g) M *) n F =0,17 1 0,3 0,70 272 2 8,13 0,27 83 3 29 0,19 60 4 65 0,15 49 5 105 0,13 42 6 153 0,12 37 yield 7 209 0,11 32 pieces/ha kg/ha 8 264 0,10 23 5,41 1,43 9 316 0,09 17 3,93 1,24 10 362 0,09 13 2,89 1,04 11 400 0,09 9 2,13 0,85 total 14,36 4,57 *) LORENTZEN-formula * 0,164 (WGEEL-Rep. 2001, P. 33)

Table 7: Eel stock model for East Germany 1960 – 1989 (time lag between re-stocking and catch: 7 years) re-stocked (mean) 245 glass eel equiv./ha mean yield (rep. last 5 yrs.): 2,28 kg/ha F= M-Corm. = year weight (g) M n 0,17 0,12 *) 1 0,3 0,70 245 2 8,13 0,27 75 3 29 0,19 54 pieces/ha kg/ha 4 65 0,15 44 6,48 0,42 5 105 0,13 31 5,27 0,55 6 153 0,12 22 yield 3,72 0,57 7 209 0,11 16 pieces/ha kg/ha 2,61 0,55 8 264 0,10 11 2,63 0,70 9 316 0,09 8 1,91 0,60 10 362 0,09 6 1,40 0,51 11 400 0,09 5 1,04 0,41 total 6,99 2,22 18,09 2,09 *) Stomach analysis (n = 120): Summer stocks of cormorant eat 32 weight-% of eel; 2480 breeding pairs = 4960 adult birds + 4960 juveniles a 100 resp. 75 days = 868.000 cormorant-days * 0,45 kg/d * 0,32 = 125 t eel a Ø 187 g (= 2,09 kg/ha)Approximately 9 silver eels per hectare (= 1,08 mill. pieces from all East German waters) could escape at the high re-stocking rate 1960 – 1989 and no or moderate cormorant predation (= 43 % of the potential escaping at F = 0). This figure is reduced to 5 at substantial cormorant predation (1990 – 2002). When F = 0 the number of ecapees would increase to 10 (= 53 % of the potential escaping at F = 0 and Mcorm. = 0).

5.1.2.1 Description of fisheries, information sources, gear types

A substantial eel fishery exists in the lake areas of Mecklenburg-Vorpommern, Brandenburg, Schleswig-Holstein and Niedersachsen (144,000 ha). The main fishing gears are different types of trap nets and double fyke nets.

The river eel fishery is located in the lower stretches of the big rivers Rhine, Weser, Elbe and Oder. The most river fishermen are fishing with small fyke nets. In the river Rhine some fishermen use twin stow nets (Schokker). In the river Elbe two fishermen run 3 otter board stow nets near Stendal (one) and Gorleben (two). In the river Oder one fisherman runs one otter board stow net.

A substantial coastal eel fishery (mainly silver eel) exists in the shallow Bodden waters of the Baltic sea with pound nets.

Effort: There is only a few information about fishing effort. The response of the fishermen to the eel yield decrease is different. In Brandenburg the fishing effort on eel remained nearly constant during the last decades (Figure 5). A study in 5 West-Brandenburg districts (11,000 ha) 1999 showed a trap net fishing effort of 12.5 trap nets per 100 ha (KNÖSCHE & RÜMMLER . An effort of 6.1 trap nets per 100 ha was estimated in an other study in Schleswig- Holstein 2002 (14,500 ha) (KNÖSCHE 2003). The fishing effort in Mecklenburg-Vorpommern (55,800 ha) was 2001 3.3 trap nets per 100 ha (HILLER & WICHMANN 2003). 10 trap nets per 100 ha are used in three large lakes (4770 ha) in Niedersachsen.

o It seems to be realistic, if the mean fishing effort in the German inland waters with commercial eel fishery (200,000 ha) is assumed to be 7…8 trap nets per 100 ha.

o There is no information about the fishing effort in the Baltic coastal waters and in the estuaries of the rivers Elbe and Weser.

1.4

1.2

0.8

0.6

0.4

0.2

0 trap nets gill nets seines E-fishery

Figure 5: Fishing effort with different gears in 122 Brandenburg lakes after/before 1990

• Yield: There are some yield reports. But it is difficult to evaluate them. The East German reports until 1989 can considered exactly because the allowance of the fishermen depended from the delivery of catches. An over- reporting was impossible. The West German and the East German (after 1990) reports must considered more or less to low (how much ?).

Figure 6 shows the East German inland fishery eel yield (120,000 ha) until 1990, Figure 7 the reported yields in Brandenburg and Mecklenburg-Vorpommern (122,000 ha) since 1991, Figure 8 the reported yields in Niedersachsen and Figure 9 in Schleswig-Holstein.

800

700

600

) 500

400

eel yield (t 300

200

100

0 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990

Figure 6: Eel yield in East Germany 1949 – 1990

5 Brandenburg

4 Mecklenburg-Vorpommern

eel yield (kg/ha) 2

0 1990 1992 1994 1996 1998 2000 2002

Figure 7: Reported eel yield in Brandenburg and Mecklenburg-Vorpommern 1991 – 2002

10.00

9.00

8.00 Steinhuder Meer weighted mean 7.00

6.00

5.00

4.00 yield (kg/ha) 3.00

2.00

1.00

0.00 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Figure 8: Reported eel yield in Niedersachsen (10,135 ha)

7.00

6.00

5.00

4.00

3.00 yield (kg/ha) 2.00

1.00

0.00

7 9 0 2 3 5 7 8 0 2 -4 5 6 9 9 9 9 9 0 0 1 9 9 9 9 9 9 9 0 0 4 1958 1 1 1 1 1994 1 1996 1 1 1999 2 2001 2 9 1

Figure 9: Reported eel yield in Schleswig-Holstein (15 – 17,000 ha)

The eel yield in the Bodden waters of Mecklenburg-Vorpommern is shown in Figure 10.

1400

1200

1000 ) a h / 800 g k (

d l 600 e i Unknow n disease Y 400 (toxic substances ?)

200

0 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Figure 10: Reported eel yield in the Bodden waters of Mecklenburg-Vorpommern 1960 – 2002

The longest yield report comes from the 750 ha lake Grimnitz north east of Berlin (Table 8; Figure 11).

Table 8: Eel yield of the lake Grimnitz (kg/ha)

1900 1,53 1926 8,81 1952 1,52 1978 10,89 1901 1,66 1927 9,21 1953 2,03 1979 11,04 1902 2,13 1928 7,52 1954 1,84 1980 12,48 1903 1,18 1929 11,20 1955 2,72 1981 14,71 1904 1,45 1930 9,57 1956 2,77 1982 12,92 1905 2,57 1931 10,04 1957 2,78 1983 11,96 1906 4,75 1932 7,86 1958 3,39 1984 14,06 1907 4,79 1933 4,65 1959 4,67 1985 15,71 1908 1,38 1934 6,82 1960 4,38 1986 12,73 1909 3,57 1935 5,69 1961 6,20 1987 13,41 1910 8,01 1936 1962 3,44 1988 12,54 1911 7,27 1937 1963 7,12 1989 15,45 1912 8,00 1938 1964 3,15 1990 10,54 1913 7,96 1939 4,77 1965 2,65 1991 7,51 1914 6,67 1940 2,94 1966 7,02 1992 11,13 1915 6,52 1941 2,57 1967 6,51 1993 2,53 1916 7,75 1942 1,95 1968 11,29 1994 1,86 1917 5,47 1943 3,16 1969 12,09 1995 1,23 1918 15,32 1944 1970 13,26 1996 0,38 1919 8,38 1945 1971 12,18 1997 0,17 1920 8,42 1946 1972 13,64 1998 0,04 1921 6,19 1947 1973 12,66 1999 0,18 1922 9,16 1948 1974 13,06 2000 0,31 1923 9,46 1949 1975 8,76 2001 0,09 1924 8,93 1950 1,27 1976 10,61 2002 1925 8,32 1951 1,65 1977 12,58

18,00 extreme cormorant predation 16,00

14,00

12,00 ) a h / 10,00 g k 8,00 yield ( 6,00

4,00

2,00

0,00 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010

Figure 11: Eel yield of the lake Grimnitz

Is there information on the impact of this fishery on the stock is reported in Table 6 and 7. There are no significant differences in CPUE at two or three subsequent otter board stow nets (mouth width 32 m, longitudinal distance < 1000 m) in the river Elbe (width 200…220 m) what indicates a rather low catch rate (KÖHTKE, pers. comm.).

5.1.3 Trend in the stock

Yellow and silver eel are monitored using CPUE of a eel trap at a weir in the river Eider (1850 – 1962) (Table 9, Figure 12) and of a otter board stow net in the river Elbe (1966 – 2002) (CE constant) (Table 10, Figure 13).

Table 9: Eel yield (=CPUE) at the stationary eel trap Achterwehr (r. Eider/Schleswig-Holstein)

year Yield (pieces) 1878 18696 1907 11156 1936 15968 1850 21272 1879 25417 1908 21709 1937 15705 1851 13590 1880 25165 1909 13955 1938 10736 1852 22705 1881 23628 1910 23135 1939 10364 1853 15885 1882 20065 1911 19287 1940 8910 1854 17180 1883 23628 1912 20386 1941 4509 1855 17676 1884 25180 1913 14571 1942 4211 1856 10974 1885 23695 1914 31485 1943 4441 1857 16119 1886 22403 1915 16938 1944 1858 15145 1887 19949 1916 22257 1945 6250 1859 21746 1888 29708 1917 29434 1946 8187 1860 19499 1889 28809 1918 16408 1947 4525 1861 17582 1890 12988 1919 15828 1948 2442 1862 12116 1891 22489 1920 23601 1949 5082 1863 13094 1892 16981 1921 8569 1950 3544 1864 16501 1893 25103 1922 12554 1951 3425 1865 17939 1894 26859 1923 11918 1952 2428 1866 15656 1895 28860 1924 14772 1953 1880 1867 19153 1896 26955 1925 9316 1954 5010 1868 22755 1897 26801 1926 12913 1955 2613 1869 16029 1898 23699 1927 12900 1956 1736 1870 19767 1899 33883 1928 7712 1957 4482 1871 13463 1900 18658 1929 4963 1958 3001 1872 16031 1901 22715 1930 13629 1959 3388 1873 18128 1902 14112 1931 5526 1960 5498 1874 15374 1903 21758 1932 13392 1961 8658 1875 20091 1904 15224 1933 10339 1962 7630 1876 22447 1905 13868 1934 16300 1877 26501 1906 14600 1935 19876

Table 10: CPUE of the otter board stow net near Gorleben (r. Elbe)

CPUE (kg/stow year net day) 1966 15,9 1967 11,9 1968 7,5 1969 13,0 1970 12,7 1971 6,7 1972 5,4 1973 4,3 1974 5,8 1975 9,7 1976 5,8 1977 11,0 1978 13,0 1979 10,2 1980 16,5 1981 12,3 1982 10,7 1983 9,5 1984 8,2 1985 5,1 1986 15,6 1987 1988 1989 1990 1991 1992 6,1 1993 5,2 1994 10,2 1995 10,9 1996 4,1 1997 3,0 1998 4,4 1999 3,6 2000 3,5 2001 3,5 2002 10,2

100

35000

30000

25000

s/yr) 20000 ce e i d (p l 15000 e i y

10000

5000

0 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970

Figure 12: Eel yield (=CPUE) at the stationary eel trap Achterwehr (r. Eider/Schleswig-Holstein)

18,0

16,0

14,0

12,0 net day) 10,0 stow l/ 8,0

UE (kg ee 6,0 P C 4,0

2,0

0,0 1965 1970 1975 1980 1985 1990 1995 2000 2005

Figure 13: CPUE of the otter board stow net near Gorleben (r. Elbe)

Figure 12 and 13 show that the eel stock does naturally fluctuate by a factor of about 4.

101

5.2 Management

There is no national management plan for eel stocks and fisheries in Germany.

A special task group was founded for the preparation a national management plan and a co-ordinated research program in Brandenburg and Mecklenburg-Vorpommern is running.

References

HILLER, J. & WICHMANN, T. (2003): Auswertung von betriebswirtschaftlichen Rahmendaten der Binnenfischereiunternehmen Mecklenburg-Vorpommerns mit Seen- und Flussfischerei 2000 und 2001. Fischerei & Fischmarkt in M-V 3(2): 24 – 37.

KNÖSCHE, R. & RÜMMLER, F. (1999): Fischereientwicklungsplanung des Gebietes Potsdam-Brandenburg. Forschungsbericht Inst. F. Binnenfischerei.

KNÖSCHE, R. (2003): Agrarstrukturelle Entwicklungsplanung (AEP) „Binnenfischerei Schleswig-Holstein“ – Seen- und Flussfischerei. Abschlussbericht Inst. F. Binnenfischerei.–

LEMBCKE, R. (2003): Etablierung eines langfristigen Glas- und Jungaalmonitorings in Mecklenburg-Vorpommern. Fischerei & Fischmarkt in MVP 3(1): 14 – 23.

RÖHLER, E. (1939): Bericht über die Aalbrutgewinnung im Frühjahr 1939. Fischerei-Zeitung 42(26):305.

RÖHLER, E. (1942): Die Beschaffung von Aalbesatzmaterial in zwei Kriegsjahren. Fischerei-Zeitung 45(3): 15.

SCHMEIDLER, E. (1957): Entwicklung des Glasaalaufstiegs in der Ems, seine zeitliche Begrenzung und die auf ihn wirkende Wassertemperatur. Z. Fischerei N.F.

SCHUCHERT, W. (2000): Sind die Aale noch zu retten? Blinker Nr. 11: 96 – 100.

102

6 Eel stock and fishery in the Netherlands in 2003

Country: Netherlands

Authors: Willem Dekker1, Jan van Willigen1 & Jan Klein Breteler2

Author address: 1 Netherlands Institute for Fisheries Research, PO Box 68, 1970 AB IJmuiden, the Netherlands [email protected] 2 Organisation for the Improvement of Inland Fisheries PO Box 433, 3430 AK Nieuwegein, the Netherlands [email protected]

Reporting date and last reported year: August 2003, most data through 2002

6.1 Data

6.1.1 Trend in recruitment

6.1.1.1 Monitoring methodology, life stage, gear type

Monitoring of glass eel, immigrating through the sluices at Den Oever, sampling by means of lift net, scientific effort. See Dekker 2002 for details.

6.1.1.2 Recruitment monitoring results

100 moving average annual index 10

0 1995 2000 number of glass eel per lift net haul, April 22u00.

0 1940 1950 1960 1970 1980 1990 2000

Figure 6.1-1 Long-term trend in the glass eel catches in the experimental fisheries at Den Oever

103

Table 6.1-A Number of glass eel caught per lift net haul. All observations in a year have been corrected for time of day and month of sampling, and averaged. Decade Year 1930 1940 1950 1960 1970 1980 1990 2000 0 12.71 6.90 22.48 40.06 28.11 3.57 1.70 1 12.10 13.61 38.81 18.01 23.53 1.08 0.55 2 18.77 87.93 88.13 31.65 14.95 2.82 1.13 3 13.12 13.33 126.48 24.13 9.83 2.84 1.47 4 37.26 19.87 39.80 26.59 13.37 4.75 5 27.34 81.92 34.97 14.57 6.85 6 6.24 7.25 19.52 27.86 15.33 7.80 7 5.85 16.20 30.57 61.49 6.03 12.53 8 16.00 5.28 52.02 20.73 40.87 4.23 2.23 9 33.94 5.27 29.13 17.64 55.03 2.95 3.43

6.1.1.3 Development during the last season

100

1980

75 day me of i r t o

ed f 50

ust 2003 adj ,

25 Number per haul average since 1938

2002 0 Mar Mar Mar Mar Mar Apr Apr Apr Apr May May May May May

Figure 6.1-2 Short-term trend in the glass eel catches in the experimental fisheries at Den Oever The winter was severe (not very), but lasted quite long. When glass eel finally arrived, a few weeks of very nice weather occurred. Very first glass eel caught in Den Oever on March 20, 2003 (Feb 21, 2002).

Long term monitoring at 10 stations (other than Den Oever): see table below, and Dekker 2002 for details. At these stations, sampling is much less intensive as at Den Oever, but otherwise, the same methodology is used. Sampling in IJmuiden has been done by research staff. There has not been a single glass eel caught, while procedure and effort was as it always has been. If the situation does not improve, it will clearly be impossible to keep motivation up. Elsewhere, fishermen and volunteers have run the glass eel sampling, and have moved to more favourite, nearby places when catches decline to zero. A less labour demanding sampling gear is urgently required, but research for alternatives has not been continued.

104

10000 Otheense Kreek Bath Krammer Stellendam Katwijk IJmuiden Den Oever, sluices Den Oever, ship lock Harlingen Nieuwstatenzijl Termuntenzijl Lauwersoog 1000

100 index (% of 1990-1999 average) 10

1 1970 1980 1990 2000

Figure 6.1-3 Long-term trends in the glass eel catches in the experimental fisheries at various places along the Dutch coast In the northern provinces of the Netherlands, a detailed monitoring programme for glass eel and other migratory fish has been running over the years 2001-2003, using an identical procedure, but sampling just before high tide every fortnight. End-report is to be expected in early 2004. Although this programme has contributed to our knowledge of immigration opportunities along the coast, and has supported local water management in optimising sluice operations, its long-term continuation is not quite certain.

105

Table 6.1-B Annual indices of glass eel recruitment at places in the Netherlands, other than Den Oever. Annual indices are expressed as the mean catch per lift net haul, at whatever time in the night. Most hauls are made in the evening, just in the dark k ijl z -zijl r, og

n en o a

n t ve se Kree d ck n ge n n ide

i Oe u mmer ip lo

year Othee Bath Kra Stellen Katwijk IJm Den sh Harl Nieuwstaten Termu Lauwers 1969 47.3 1970 31.5 1971 15.4 N/A 1972 4.1 N/A 1973 13.1 32.8 1974 22.8 119.3 1975 13.9 66.8 1976 11.3 73.1 14.4 1977 42.1 159.2 28.4 1978 42.1 131.7 83.9 1979 27.3 176 66.2 1980 45.1 101.5 80.3 1981 47.3 113.9 55.1 1982 11.3 20.8 17.4 1983 14.3 15.6 15.1 1984 3.8 11.4 7.1 1985 8.7 1 25.2 1986 6.4 4.7 1.3 1987 9.8 7.7 52.0 1988 7.6 3.5 0.5 1989 4.4 1.6 12.1 1990 0.3 11.3 4.7 5 1991 5.9 0.1 1.7 5.1 2 0.3 6.3 1992 12.3 0.3 9.9 8.2 2.5 14.8 0.4 7.3 1993 17.5 0.3 5.2 13.5 1.6 1.4 20.8 1994 14.6 0.5 2.7 15.1 3.6 16 2.2 22.5 1995 0.5 15.7 0.3 3.2 27.1 13.1 27.8 6.8 3 11.6 1996 1 26.8 0.7 0.4 25.4 4 10.2 29.7 24 6 34.4 1997 0 40.4 0.4 2.5 10.9 1.3 10.2 12.4 21 10.6 20.9 1998 0.7 18.3 0.6 0.9 38.8 1.2 6.5 15.4 19.9 1.1 9.9 1999 1.2 23.1 0.6 1 101.3 1.6 5.6 12.7 11.8 7.5 15.1 2000 0.7 20.1 0.8 5.6 8.8 1.5 4 2.8 23.3 5.7 6.6 2001 0.5 1.2 0.1 0.9 8.1 0.4 1.5 1.8 16.1 0.8 1.7 2002 0 13.6 0.4 3.7 9.8 0.05 1 2.2 35.3 0.9 3.4 2003 0 7.0 0.1 0.4 11.8 0 4.7 3.8 25.5 0.4 1.2

6.1.2 Trend in re-stocking

Glass eel and young yellow eel have been used for re-stocking inland waters since time immemorial, mostly by local action of stakeholders. Although a minimum legal size for capture, holding and transport of eels is set in a byelaw, the existing practice of short-range transports has never been prosecuted. Since World War II, the Organisation for the Improvement of Inland Fisheries has organized a re-stocking programme, importing glass eels from France and England, and buying yellow eel from commercial fishermen fishing in the Waddensea. Data on re-stocking quantities are listed in tables xxx and xxx. Average weight of the young yellow eel amounts to approx. 33 gr.

106

Table 6.1-C Re-stocking of glass eel and young yellow eel in the Netherlands, in millions re-stocked 1940 1950 1960 1970 1980 1990 2000 young young young young young young young glass yellow glass yellow glass yellow glass yellow glass yellow glass yellow glass yellow eel eel eel eel eel eel eel eel eel eel eel eel eel eel 0 5.1 1.6 21.1 0.4 19.0 0.2 24.8 1.0 6.1 0.0 2.8 1.0 1 10.2 1.3 21.0 0.6 17.0 0.3 22.3 0.7 1.9 0.0 0.9 2 16.9 1.2 19.8 0.4 16.1 0.4 17.2 0.7 3.5 0.0 1.6 3 21.9 0.8 23.2 0.1 13.6 0.5 14.1 0.7 3.8 0.2 1.6 4 10.5 0.7 20.0 0.3 24.4 0.5 16.6 0.7 6.2 0.0 5 16.5 0.9 22.5 0.5 14.4 0.5 11.8 0.8 4.8 0.0 6 7.3 23.1 0.7 8.9 1.1 18.0 0.5 10.5 0.7 1.8 0.2 7 7.6 1.6 19.0 0.8 6.9 1.2 25.8 0.6 7.9 0.4 2.3 0.4 8 1.9 2.0 16.9 0.8 17.0 1.0 27.7 0.8 8.4 0.3 2.5 0.6 9 10.5 1.4 20.1 0.7 2.7 0.0 30.6 0.8 6.8 0.1 2.9 1.2

6.1.3 Trend in fishery

Eel fisheries occur in coastal areas and all inland waters. Only a minor part of these waters is actively managed under governmental control. Latest guestimates of production are:

Area Annual yield (t) Monitoring /statistics IJsselmeer 350 Yes / yes Rivers Rhine and Meuse 150 Yes / no Other inland waters 375 No / no SE Delta, Zeeland 75 No / no Waddensea 40 Yes / no Along west coast 30 Yes / no Indoor aquaculture 4000 No / yes

IJsselmeer

• Life stage concerned: yellow eel, 10 % is silver eel

• Description of fisheries, information sources, gear types

Former estuarine area, 1820 km2, closed off from the sea in 1932. Lake eel fisheries, using fykenets (most), eelboxes and longlines. Governmental management, auction statistics, research sampling and surveys. Fishermen’s organisation has become co-responsible for management in last decade, and has instituted internal obligation to land catch at auctions. Results are not public.

• Effort. Number of fyke nets rose from an estimated 5000, to 45,000 in mid 1980s (counted, and subsequently licensed), in late 1980s reduced to 60 % and additional constraints in time and space. Subsequent co- management, by which the quantification of effective fishing effort is now rather obscure.

• Yield

107

5000

4000

3000 ons (t)

ngs at aucti 2000 Landi

1000

0 1900 1920 1940 1960 1980 2000 year

Figure 6.1-4 Landings of yellow and silver eel (combined) from the Zuiderzee/IJsselmeer area. In 1932, the estuarine area was closed off from the Waddensea by a dike Table 6.1-D Landings from the IJsselmeer area, in tonnes per year. Only landings recorded at the auctions are included; other landings are assumed to represent a minor and constant fraction. Year 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 0 324 620 1157 838 3205 4152 2999 1112 641 472 363 1 387 988 989 941 4563 3661 2460 853 701 573 381 2 514 720 900 1048 3464 3979 1443 857 820 548 353 3 564 679 742 2125 1021 3107 1618 823 914 293 4 586 921 846 2688 1845 2085 2068 841 681 330 5 415 1285 965 1907 2668 1651 2309 1000 666 354 6 406 973 879 2405 3492 1817 2339 1172 729 301 7 526 1280 763 3595 4502 2510 2484 783 512 285 8 453 1111 877 2588 4750 2677 2222 719 437 323 9 516 1026 1033 2108 3873 3412 2241 510 525 332

Personal communication during summer 2003 indicates a fall in yield during early summer. In past years, prices were good, but this year that does not compensate for the decline in catch volume.

• Impact of fisheries on the stock

Instantaneous fishing mortality F of the fully recruited length classes is in the order of 1.0 (Dekker 2000). Although F values have been calculated on an annual basis, the extreme overexploitation in combination with the lowering quality of the market statistics, have made an up-to-date calculation rather superfluous. All information indicates the extreme overexploitation is continued. Major efforts to reduce the fishing intensity have indeed reduced mortality somewhat, but reductions have not been adequate to derive an sustainable F-level.

108

Waddensea and coastal areas.

Fisheries on the North Sea are obliged to report catch and effort, including eel, since 1995. Total marine catches landed in the Netherlands are listed in table xx, by country of origin of the vessel.

Table 6.1-E Landings of eel in the Netherlands from marine areas, listed by country of origin of the landing vessel. Unit = kg. year BE DE DK FR UK NL N/A Total

1995 6,925 2 - 2 - 38,163 - 45,092

1996 3,184 - - - 309 30,719 - 34,212

1997 1,622 24 - 38 41 25,679 - 27,404

1998 1,566 4 - 2 23 20,256 - 21,851

1999 1,690 - - 3 7 24,307 - 26,007

2000 1,783 25 - - 18 20,055 16 21,897

2001 791 - 461 - - 34,342 729 36,323

2002 902 - - - - 26,961 1,320 29,183

6.1.4 Trend in the stock

The IJsselmeer eel stock is surveyed, independent of the commercial fisheries. Since about 1950, 8-m beam trawl surveys have been operated, targeting either eel (2 mm mesh), or coarse fish (16-20 mm mesh) with a by-catch of eel. The dedicated eel trawling has been replaced in about 1980 by a 3-m beam trawl, with a 300 V DC electric field between the sledges of the beam (only 2 mm mesh). Additionally, market sampling provides information on the stock status too. A combined analysis of all information available has yielded detailed information on the composition and abundance of the stock; see figure below, derived from Dekker 2003.

109

>= 35 cm

30-35 cm

150

25-30 cm

100

150

20-25 cm

100

15-20 cm

10-15 cm

< 10 cm

0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Year

Figure 6.1-5 Trends in abundance over the 20th century: estimated catch of a 2-mm mesh 8-m beam trawl operated for one hour, summed over 5-cm length intervals. In 1932, the estuarine area was transformed into a fresh water lake. Since 1937, a minimum legal size for exploitation has been set at 28 cm length.

6.2 Management

The Ministry of Agriculture, Nature Conservation and Fisheries (now: A, N and Food Safety) has compiled a report, describing the decline of the stock and a long list of potential causes; suggestions for remedies are given. Neither the existing situation nor the remedies have been quantified. Major emphasis is placed on international coordination, by the European Union. Major focus in impacts is on hydropower and habitat loss, with fisheries in a double role: as existing impact and as ultimate beneficiary.

110

This report is intended as Fact Sheet, with options for subsequent approach. Next step will be political decision making, which is to be expected in summer 2003.

Dekker W. et al. 2002. Aal, de stand van zaken. Knelpunteninventarisatie. Ministerie van Landbouw, Natuurbeheer en Visserij, Directie Visserij. Den Haag, maart 2002.

Dekker, W. (ed.) 2002. Monitoring of glass eel recruitment. Report C007/02-WD, Netherlands Institute of Fisheries Research, IJmuiden, 256 pp.

111

7 Eel stock and fishery in Belgium in 2003

Country: Belgium

Authors: Claude Belpaire

Author address: Institute for Forestry and Game Management, Duboislaan 14, B-1560 Groenendaal-Hoeilaart, Belgium [email protected]

Reporting date and last reported year: October 2003, most data through 2002

7.1 Data

7.1.1 Trend in recruitment

7.1.1.1 Monitoring methodology, life stage, gear type

Monitoring of glass eel, immigrating through the sluices at Nieuwpoort on river Yser, sampling by means of handnet, scientific effort. See Dekker 2002 for details.

7.1.1.2 Recruitment monitoring results

1000 100

900 90

800 Total year catch 80

700 Max daycatch 70

600 60

500 50

400 40 Total year catch (kg) Maximal daycatch (kg) 300 30

200 20

100 10

0 0 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002

Fig 1. Maximal daycatch and total biomass of glass eel caught per year at Nieuwpoort (1964-2003).

112

Decade Year 1930 1940 1950 1960 1970 1980 1990 2000 0 795 252 218,2 17,85 1 399 90 13 0,7 2 556,5 129 18,9 1,4 3 354 25 11,8 0,539 4 3,7 946 6 17,5 5 115 274 15 1,5 6 385 496 27,5 4,5 7 575 472 36,5 9,8 8 553,5 370 48,2 2,255 9 445 530 9,1

7.1.1.3 Development during last season

50 l u a 40 eel / h s as l

g 30 f er o

mb 20 Nu

0 3 3 3 3 3 3 3 3 3 3 /0 /0 /0 /0 /0 /0 /0 /0 /0 /0 2 3 3 4 4 5 /0 0 /03 /0 /03 /04 /0 /04 /0 0 27 6/ 13 20 27 3 10 17 24 1/ Date

Fig 2. Daycatch (numbers per haul) of glass eel caught at Nieuwpoort in 2003 .

During 2003, fishing was organised on 18 nights between February 27th and May 5th. Total yield was 2168 glasseel for a total weight of 539 gram. Best catches were performed between April 15th and 18th. Very first glasseel caught in Nieuwpoort on March 3rd, 2003.

7.1.2 Status of the stock and trends

In Flemish water bodies (rivers, canals, polder water courses, ponds) fish stocks are assessed by the Institute for Forestry and Game Management using standardised procedures. A dataset of 1332 locations fished during the period 1996-2002 showed very low eel occurrences especially in riverine systems (rivers and brooks 18% of eel presence, canals 50%, closed water bodies (ponds old river arms) 91%). Where eels are present abundance is usually low (rivers, brooks and canals 1-5 ind/100m, closed water bodies > 15 ind/100m) (Belpaire et al., 2003).

113

Fig 3. Catches of eels in running waters by electrofishing (1996-2003)(Belpaire et al., 2003)..

Some historical data on eel stocks during the period 1925-1934 showed that the stocks were very important in some polder water courses in the west of Flanders (90-470 kg/ha)(Vrielynck et al., 2003). Nowadays eel stocks in these waters are in the order of 1 to 30 kg/ha. Other historical data on eel fisheries can be found in Vrielynck et al. (2003)

Tab 2. Estimates of eel densities and proportion of eels in the fish population in some water courses in the west of Flanders, period 1925 – 1934 (Vrielynck et al., 2003). ..

Eel densities kg/ha Weight % Year Ijzer 168 49,0 1925 Kanaal Nieuwpoort - Duinkerke 272 53,6 1925 Veurne - Ambacht 470 25,2 1936 Venepevaart 90 26,1 1934 Lokanaal 324 50,7 1925 Ieperlee 220 36,4 1925 Grote Beverdijk 119 35,0 1925 Bergenvaart 225 35,7 1925

A trend is also available from studies by the University of Louvain on the River Scheldt. Eel densities in the Scheldt estuary were recorded during the period 1991 – 2002 by analysing eels in the cooling water intake of the Doel power station and by a follow up of the fyke net fisheries. The numbers of adult eel (50 – 70 cm) per fyke net per day decrease from 1998 to 2002 and the numbers of pre adult eel (20 cm) per 103 m3 cooling water showed a declining trend. Overfishing is a possibility to explain declining catches of eel in the estuary but overfishing does not explain decreasing eel numbers in the cooling water as predominantly small eel are entrapped by the intake.

114 estuarine ee l abundance

2 016

Fig 4. Trends in abundance of estuarine eels in River Scheldt (1991-2002). Data from University Louvain , Belpaire et al.(2003).

7.2 Management

There is no national management plan for eel stock and fisheries in Belgium.

In Belgium, by means of a new Royal decree, the government adopted a new PCB standard for fish and fisheries products. According to this, the sum of the seven marker PCBs (polychloorbiphenyls PCB28, PCB52, PCB101, PCB118, PCB138, PCB153 en PCB180) may not exceed 75 µg/kg on product basis (Belgisch Staatsblad, 2002a). In Flanders, a monitoring network for measuring PCB concentrations in eels has been set up in recent years. According to the results of the analysis of 1057 eels from 244 locations in Flemish canals, rivers and closed water systems, this standard is exceeded at 80% of the sites. In some cases, mean concentrations of the sum of the seven marker PCB exceed 6700 µg/kg on product basis (Goemans and Belpaire, 2002). As a consequence of these results, the Flemish Minister for Environment has banned the taking of eels from public inland waters in Flanders until 2006 (Belgisch Staatsblad, 2002b). Moreover, the use of a number of fisheries devices specialised for catching eels like fykes and liftnets is now prohibited in most of the Flemish rivers and canals (Belgisch Staatsblad, 2002c).

Indirect effects of such bans due to contamination are likely to increase the production of silver eels by reducing fishing mortality. However, studies are needed to quantify these unintentional effects, and must also take account of the low quality of contaminated eels as potential spawners.

115

Figure 5 : Exceedings of PCB concentrations in eels in Flanders. Legal maximum for fisheries products is 75 µg/kg (Goemans et al., 2003).

Habitat restoration objectives

Migration obstructions

A very high number of migration barriers like sluices, weirs, dams, watermills, drainage pumps, siphons… are located on Belgian water courses. Inventories are being made in most of the catchments in Flanders and Wallonia. In Flanders, at this moment 3 000 km on the 20 000 km waterways (15%) have been inventoriated. 1 050 potential migration barriers have been located and were included in a database related to an interactive website (http://vismigratie.instnat.be/). On the river Meuse Wallonia has 15 dams. At the moment 11 of them are equipped with fish ladders.

Presence of these obstructions are considered as one of the major causes of the fact that normally structured riverine eel populations in Flanders are restricted to areas nearby the sea.

The Benelux decree on the free migration of fish species in the hydrographic river basins of Benelux countries (1996) aimed to guarantee the free migration of fish species in all water courses by 2010 (Benelux, 1996). In Flanders as well as in Wallonia high efforts are taken to build fish ladders or to resolve migration obstructions. At this moment in Flanders 24 (2.3%) barriers have been resolved recently, either by constructing fish passes or simply removing the barrier. The aim is to resolve all of them by 2010.

Yellow eel habitat

In addition to the low accessibility for a migrating species as the eel, yellow eel habitat has been heavily influenced by poor water quality and structural habitat degradation for many years. However considerable efforts have been made in water purification programs (especially in Flanders where a lot of rivers and brooks where for a long time not viable for eels due to poor water quality), resulting in a general increase in water quality. Projects aiming to ameliorate general habitat quality of water ecosystems (restoration of natural river banks, river basin management, restoring meanders, … ) are believed to result in an increase of the eel habitat area.

116

Hydroelectric power stations

In contrast to the efforts taken for restoring habitats and enabling free migration of fish, some new initiatives are actually taken to install hydroelectric turbines on Belgian watercourses. This was triggered by the recent European legislation (European Directive 2001/77/EC) on the promotion of electricity produced from renewable sources in the internal electricity market, asking for more green power to be produced.

This is particularly the case in Flanders where, at the moment 7 hydropower turbines are active, but on 19 localities hydropower stations are in preparation. The possibilities to construct turbines on another 150 places is envisaged (Belpaire et al., 2002). These stations have all small capacity. Small capacity power stations ususally have no or minor energetic gain but may induce considerable ecological damage. Also in Wallonia hydropower stations have impacts on local eel populations, e.g. on the river Meuse 6 dams are equipped with turbines for producing hydroelectric energy. Only one of them is equipped with a fish deflector

Prognoses made for new plants in Flanders reveal an estimated immediate mortality of ±17% per site. The cumulative effect of a hypothetical situation with 5 consecutive hydroelectric power plants would result in a mortality rate of over 60% without taking into account the postponed mortality.

It is expected that these new initiatives will put new threats on silver eel escapement (Belpaire et al. 2002).

References

- Belgisch Staatsblad, 2002a. 16 April 2002 - Koninklijk besluit tot wijziging van het koninklijk besluit van 19 mei 2000 tot vaststelling van maximale gehaltes aan dioxines en polygechloreerde bifenylen in sommige voedingsmiddelen (6 March 2002)

- Belgisch Staatsblad, 2002b. 25 May 2002 - Ministerieel besluit houdende een tijdelijk meeneemverbod van paling in alle openbare wateren en een tijdelijk meeneemverbod van alle vissen op bepaalde openbare wateren (19 April 2002)

- Belgisch Staatsblad, 2002c. 25 May 2002 - Ministerieel besluit houdende een tijdelijk verbod op het gebruik van de palingfuik en het kruisnet in de grensscheidende Maas en de niet-bevaarbare waterlopen en kanalen in de provincies Oost-Vlaanderen en West-Vlaanderen (19 April 2002)

- Belpaire, C., De Charleroy, D., Coeck, J., Janssens, L. and Monden, S., 2002. Flemish plans for hydropower turbines : additional loss for eel spawning stock? ICES/EIFAC - Working Group on Eel (Nantes, 2-6 September 2002)

- Belpaire, C., Goemans, G., Van Thuyne, G., Verreycken, H. and Maes, J., 2003

Eel Fisheries and Management in Flanders, Belgium: Status and Trends

American Fishery Society Annual Meeting, Quebec, 10-14 augustus 2003

- Benelux, 1996. Decree on the free migration of fish species in the hydrographic river basins of Benelux countries. Committee of Ministers of the Benelux Economic Union, Document M (96) 5, The Hague, April 26th, 1996

- Directive 2001/77/EC of the European parliament and of the council of 27 September 2001 on the promotion of electricity produced from renewable energy sources in the internal electricity market

Official Journal of the European Communities 27.10.2001 L 283/33

- EC, 2001. Council regulation (EC) No 2375/2001 of 29 November 2001 amending Commision regulation (EC) No 466/2001 setting maximum levels for certain contaminants in foodstuffs. Official journal of the European Communities, 6.12.2001, L 321/1

- http://vismigratie.instnat.be/

Internetsite and database on the localisation and status of fish migration barriers in Flanders. Ministery of the Flemish community.

117

- Goemans, G. and Belpaire, C., 2002. New Belgian standard for fish and fisheries products leads to catch and release obligation for eel (Anguilla anguilla) by fishermen in Flanders. Workshop on PCBs, Brno, 2002

- Goemans, G., Belpaire, C., Raemaekers, M. and Guns, M., 2003.

Het Vlaamse palingpolluentenmeetnet, 1994-2001: gehalten aan polychloorbifenylen, organochloorpesticiden en zware metalen in paling. Instituut voor Bosbouw en Wildbeheer IBW.Wb.V.R.2003.99 190p.

- Vrielynck, V., Belpaire, C., Stabel, A., Breine, J. and Quataert, P. , 2003. De visbestanden in Vlaanderen anno 1840- 1950. Een historische schets van de referentietoestand van onze waterlopen aan de hand van de visstand, ingevoerd in een databank en vergeleken met de actuele toestand. Instituut voor Bosbouw en Wildbeheer and Afdeling Water, AMINAL.

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8 Eel stock and fishery in France in 2003

Country: France Cédric Briand, Thomas Changeux, Gérard Castelnaud, Aurore Baisez, Marie Noëlle de Casamajor

With contributions from

Authors Authors address Gilles Adam DIREN Aquitaine, Service Eau et Milieux Aquatiques,l 95, rue de la Liberté - 33073 Bordeaux Cedex- FRANCE [email protected] Aurore Baisez Table de bord anguille du bassinde la Loire (Logrami) Université de Rennes 1 UMR Ecobio Bat 5 , 1 avenue du Général Leclerc35 042, Rennes Cedex- FRANCE [email protected] Laurent Beaulaton Unité Ressources Aquatiques Continentales. , Cemagref, Groupement de Bordeaux, 50, av. de verdun, Gazinet 33612 Cestas cedex.- FRANCE [email protected]

Cédric Briand Institution d'Aménagement de la Vilaine, 56 130 La Roche Bernard- FRANCE [email protected] Gérard Castelnaud Unité Ressources Aquatiques Continentales. , Cemagref, Groupement de Bordeaux, 50, av. de verdun, Gazinet 33612 Cestas cedex.- FRANCE [email protected] Thomas Changeux Conseil Supérieur de la Pêche, Immeuble "Le Péricentre", 16, avenue Louison Bobet, 94132 Fontenay-sous-Bois Cedex - FRANCE [email protected] Marie Noëlle De Ifremer , Laboratoire Halieutique d'Aquitaine , Technopole Izarbel , Maison du Parc , 64210 Casamajor Bidart - FRANCE [email protected] Gilles Euzenat Délégation Régionale Nord ouest, Station salmonicole, Rue des fontaines, 76 260 EU - FRANCE Françoise Fournel [email protected] Jean-Louis Fagard Sarah Gimet DIREN Ile de France - Service de Bassin Seine-Normandie, 18 avenue Carnot - 94 234 CACHAN Cedex [email protected] Antoine Legault Fish Pass, 8, allée de Guerlédan, ZA Parc Rocade Sud, 35 135 Chantepie Pascal Laffaille [email protected] Sébastien Manné Conseil Supérieur de la Pêche - Délégation régionale n°3, 23, rue des garennes - 57155 MARLY - FRANCE [email protected]

Jean-Yves Menela MRM Rhône migrateurs, Port fluvial, Chemin des Ségonnaux, 13 200 Arles Nicolas Auphan [email protected] Vincent Vauclin Conseil Supérieur de la Pêche - Délégation régionale n°3, 23, rue des garennes - 57155 MARLY - FRANCE [email protected] Thibault Vigneron CSP, délégation régionale de Rennes, 84, rue de Rennes, 35 510 Cesson Sevigné, France [email protected]

Reporting date and last reported year: August 2003, depending on places, data from 1999 to 2003

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8.1 National level (Thomas Changeux, Gérard Castelnaud, Cédric Briand)

8.1.1 Freshwater from estuarine limit (Thomas Changeux)

8.1.1.1 Numbering of freshwater fishermen by category

The administration distinguishes two categories of fishermen, (1) commercial and (2) recreational. Most of the recreational fishermen are anglers, but some are allowed to use other fishing gears such as traps, lift-net or deep line, in limited number. Among professional, freshwater and marine fishers in estuary are distinguished (table 1).

category Sub-category number Recreational Total about 2 000 000 Recreational 1 262 735 Gear fishermen 6 855 Other (closed waters) about 730 000 Professional Total 776 Fluvial 580 Marine 196 Table Fr. 1. Number of fishermen by category in French freshwater in 2000

8.1.1.2 Fishing methods for eel

The regulation distinguishes between angling and all other fishing techniques.

8.1.1.3 Angling

This technique is admitted with up to four fishing rods. It is authorised all year long during daylight. A particular fishing, without hook is called bobbing (Vermée), and is authorised at night (see regional reports).

The proportion of fishers targeting eels is not known at the entire country scale. An investigation performed in the Loire-Atlantique department from a representative sample of 821 associative recreational fishers, allowed estimating to 29 % the proportion of fishers having targeted the eel once in 2000. This level is though to be a maximum as the Loire- Atlantique is one of the most favourable place for eel fishing in France.

8.1.1.4 Fishing gears

Glass eel scoop net

The scoop net (1 à 2 mm mesh size) is the unique legal tool to catch glass eel. The size is limited to 50 cm diameter and only by hand for amateur fishermen. It is limited to 1.20 m diameter for professional fishermen (by hand only in Adour river, or fixed on the boat and pushed in the Loire and Gironde estuaries).

Traps

Traps and eel pots are well diversified and widespread in France. They comprise eel pots (40 mm entrance diameter, mesh size 10 mm), fyke nets, and fish traps (mesh size 27 mm). The amateur fishermen can use one to six eel pot according to the department rules. Professional fishers are allowed to use from 50 to 100, rarely beyond. This fishing technique is also authorised all year long, except in departments where it is forbidden during pike perch closed season (mid-January to mid June).

Deep lines

The deep lines are set up permanently and withdrawn periodically. For amateur, the number of hooks is limited to 18, sometimes less according to local regulations. This kind of gear is also authorised for commercial fishermen. This technique is usually forbidden during pikeperch closed season (mid-January to mid June).

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Lift nets

The regulation in force distinguishes lift nets types using mesh size and surface. The most used (mesh size > 27 mm and surface < 16 m²) do not target eel. Lift net with 10 mm mesh size that target eel and little cyprinids are less numerous and often of limited size. The majority of lift net are used from boat. Some are lifted from the bank. The lift nets are used most often by recreational fishermen. Fishing is usually forbidden during pikeperch closed season (mid-January to mid June).

Silver eel nets

A few coghill or similar nets are admitted in rivers (Guideau from Loire), or placed at the outlet of ponds (Braie, Manche or Tézelle). Complex local fisheries also exist in the Somme basin. Specific authorizations and closure dates regulate silver eel fishing.

8.1.1.5 Specific rules

Before 1984 law on fishing, the eel was considered as a noxious species in salmonid streams (1st category). This status justified dispensatory measures favouring its elimination. These measures still persist in actual regulation because they are difficult to change in reason of socio-economic interests.

Fishing for eel may be authorised on the fluvial public domain (DPF), with specific licences, even if locally, the use of fishing gears is not judged necessary to the rational exploitation of resources1. Eel pots targeting eel are admitted during the closure of fisheries in 2nd category rivers2. Nominative authorisations can be delivered for silver eel dispensing to apply the weekly closure3, as an exceptional measure and according to local custom4. This last rule ceases apply since the order of July, 2nd, 2003.

Contrarily to most of other species, eel fishing can be authorised night and day5. The mesh of 10 mm can be used to catch eel, as applies for species possibly causing biological imbalance6. The fish with bundle is forbidden except for adult eel ; the attracting light also, except for glass eel fishing7. Lastly, there is no size limit8.

In opposition, the eel can benefit, as an amphidromous species, of specific measures proposed by the Comity for management of migratory species (COGEPOMI), as those proposed in the decree 16/02/94. This same decree precises, in article 13 that fishing for glass eel, is as a principle forbidden. However, it may be authorised, for a limited period on the Atlantic, Channel and North sea estuaries. But, it remains forbidden, from Saturday 18 h to Monday 6 h9. Lastly, costly specific amateur and professional taxes are necessary to fish for glass eel10.

1 R.* 235-6 of rural code

2 R.* 236-45 of rural code

3 prévue au R.* 236-21 of rural code

4 R.* 236-37 of rural code

5 R.* 236-19 of rural code

6 R.* 236-36 of rural code

7 R.* 236-42 3° of rural code

8 R.* 236-23 of rural code

9 R.* 236-22 of rural code

10 R.* 236-1 of rural code

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8.1.1.6 Number of fishermen targeting eel

In the absence of precise data on the number of anglers targeting eel, only the fishermen using fishing gears are numbered in the following part.

8.1.1.7 Free waters domain

The free waters are defined by legislation by contrast with closed water which are isolated from the framework. The administration distinguishes three domains in the free waters : the public fluvial domain (DPF), the non domanial streams, and specific domains.

The DPF assembles 11 000 km of navigation of timber floating streams associated with 40 000 ha of great lakes. The fishing rule is administered by state which only admits the use of fishing gears on some great streams, estuary and marshes as long as this exploitation is « compatibles with rational exploitation of natural fish resources »11.

The streams and pieces of water, that do not depend of DPF or of the private domain of estate, are called non-domanial streams. There, fishing gears and nets are sometimes authorised for anglers from associative organisations (AAPPMA)12. The order from 24/12/1987 enables this kind of fishing in 37 departments (figure 1). Specific domains, such as some large inland lakes13, or some close waters or fish ponds, apply specific rules for historical reasons.

8.1.1.8 Glass eel stage

The counting of glass eel licence fee in 2000 allows to evaluate the number of fishermen in fluvial domain as 432 commercials and 425 amateurs (table 2). Commercial fishers, who comprise 196 marine fishers, exert mainly in the estuaries of DPF, whereas amateur practise also in streams and non domanial ponds (for example the Gironde). The numbering of glass eel fishermen in specific domain is poorly known, but those are certainly limited because these sites are far from the sea.

8.1.1.9 Yellow eel stage

Potentially, all commercial and amateur using gears in the DPF have access to yellow eel. On a sample of 406 commercial fishers, 40,9 % declare that they target eel. This number is close to the 37% obtained for the 1996 year in a national study led from a representative sample of 180 commercial fishers. Extending to the total number, one can estimate that 317 commercial fishers target yellow eel with some persons exerting out of the DPF (table 2). Identically, on a sample of 3 888 amateur fishermen from DPF, 54.9 % target eel. This leads to a global estimation of 3 763 amateur fishers (table 2).

An inquiry led by departmental brigades of the CSP allows to estimate that more than 15 877 associative anglers were targeting yellow eel in 2000 using other fishing gears such as eel pot and deep line (table 2). Those were preferentially located in the Atlantic departments (figure 1).

Lastly, we count about 200 yellow eel fishers in specific domains, essentially the Brière marsh.

8.1.1.10 Silver eel stage

Silver eel is fished seasonally by 29 commercial fishermen (table 2) whereas at least 233 associative fishers benefited from special authorisations on non domanial streams and 20 on the streams of the Charente. Last, 10 fishermen with undetermined status are allowed to fish in the fisheries of the specific domain of the Somme basin.

11 R.* 235-14 (1°) du code rural

12 R.* 236-34 pour les professionnels et R.* 236-30 pour les membres d’AAPPMA

13 R.* 236-51 du code rural qui cite le Lac de Grand-Lieu et le Marais de Brière en Loire-Atlantique

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8.1.1.11 Technical recommendations concerning the monitoring of fishing effort in freshwaters

Adding the number of fishers of various status targeting the three stages (table 1), we obtain close to 800 commercial, more than 20 000 amateurs and more than 200 fishers without determined status. This counting may lead to count twice the same fisher, but is though as a reliable method to trace fishing effort.

However, for a clear vision of the fishing effort targeting eel in the freshwater of France, the large number of anglers targeting yellow eel is lacking. A first inquiry in the Loire-Atlantique allows to think that, from their numbers, their fishing mortality may be close to the one of fluvial commercial fishers. An investigation at the Loire scale will be carried on next years. An inquiry at the France scale would be necessary to estimate their impact.

The large number of fishers using fishing gears (15 000 individuals) can be monitored through a sub sample using a common form.

# # # # # # # # # # # # # #

# #

Nombre d'adhérents AAPPMA untilisateurs d'engins ciblant l'anguille jaune Pêche aux engins possible sur cours d'eau et plans d'eau non domaniaux 2 000 # Oui (37) # 1 000 Non (59) # 200

Figure Fr. 1. Departmental repartition of the number of amateur fishermen targeting yellow eel from a CSP inquiry. In grey, departments where fishing gears are authorised.

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DOMAIN PUBLIC FLUVIAL DOMAIN1 NON DOMANIAL SREAMS AND SPECIFIC PONDS DOMAIN

STATUS PROFESSIONNEL AMATEUR ASSOCIATIVE AMATEUR WITH UNDETERMINE WITH FISHING FISHING GEARS D STATUS GEARS Glass eel Engine Large net Little net Not precised Place and Total estuaires 432 Total estuaires 425 Inconnu number Adour Adour 133 et Courants Landais 186 Loire 86 Loire 147 Charente 3 Gironde et Charente 99 Gironde2 203 Yellow eel Gear Hoop net, eel pot, fyke net Hoop net, eel pot, Hoop net, eel pot, tendin, ramée, deep Hoop net, eel pot, deep lines lift net and deep lines, lift net. lift net deep lines, lines fouëne (fork)

Place and Total DPF1 Total DPF 3 763 Total >15 877 Total 204 number + listed sites3 ≈ 317 Restricted to some places4 ≈15 877 Brière 200 Somme 4 Silver eel Gear Dideau, verveux et braie Braie, hoop net5 Anguillère, braie, hoop net5 Fixed trap

Place and Total DPF1 29 Total >20 Total >233 Total 10 number Lac de Léon Charente >20 Charente 20 Somme 10 et Courants landais 2 Eure et Loire 1 Loire 11 Indre 50 Maine 1 Loire-Atlantique 60 Rhône 4 Vendée 117 Somme 1 Vilaine 2 Lac de Grand Lieu 8 TOTAL 778 >20 318 >214 Table Fr. 2. Estimation of the 2000 of fluvial fishers targeting eel, according to the place where they exert and the targeted stage14

8.1.2 Brackish water and freshwater under tide effect (Gérard Castelnaud)

8.1.2.1 Inland fisheries monitoring methods of CRTS and CSP

The marine professional fishermen in coastal areas, estuaries and tidal part of rivers in France are monitored from1993 by the Centre Régional de Traitement Statistiques depending from the Direction des Pêches Maritimes et de l’Aquaculture (DPMA). The river professional and amateur fishermen in rivers apart from estuaries (and in lakes) are monitored from 1999 by the CSP in the frame of the « suivi national de la pêche aux engins et aux filets » (SNPE). These two monitoring system are based on compulsery declarations of captures and effort using similar fishing forms collected monthly.

8.1.2.2 Glass eel production

14 1 DPF : public fluvial domain; 2 From which 70 on the DPF ; 3 R.* 236-34 ; 4 R.* 236-30 (Figure 1) ; 5 R. 236-37 or 21.

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Figure Fr. 2. The glass eel fishery areas in France

Glass eel fishery in France is limited to the estuaries (brackish water) and to the lower part of rivers under tide effect (freshwater). In 1999, the production of glass eels was estimated at 255 tons, with a turnover of 35.2 millions euros (Table Fr. 2). In the whole French basins (Figure Fr. 2). The historical analysis of the series of captures concerning the principal catchment areas of the Atlantic coast highlights a fall of the glass eel productions starting in the eighties.

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ANNEE 1970 1979 1986 1989 1999 2000 Production MP (t) 450 1175 300 225 180 Production PF and river 895 675 110 30 16,6 non-pro f(t) Total Production (t) 1345 1850 500 520 (3) 255 196,6 Mean price /Kg (€) 2,75 5,65 61 138 120 Total value (M€) 2,74 10,44 12,5 30,5 Number MP(1) 648 964 850 886 936 970 (4) Number PF and river non- 2424 2588 4000(2) 1512 761 671 professionnals Number marine non-pro f 2055 109 Origin of the data Popelin (1971) CIPE (1982) Desaunay et Castelnaud Castelnaud Castelnaud Aubrun et al (1989) (2002) et al (2003) (1988) Castelnaud et al (2003) Table Fr. 3. Estimation of the total glass eel production and the number of fishermen in France from 1970 to 2000 15

This decrease of glass eel abundance is particularly illustrated by the marine professional fishery ; the captures decrease as confirmed by the corrected results from CRTS (Table Fr. 3) for 2000 (180 t) and 2001 (90 t), while the real effort has certainly increased in the nineties and now remain stable ( Table Fr. 4).

2000 2001 2002 Contingents de licences 1137 1137 1137 CIPE Total licences délivrées 980 970 920 Repartition timbers "basin" NORTH 20 18 16 NORMANDY 32 30 32 NORTH-BRITTANY 38 37 38 SOUTH-BRITTANY 38 29 23 VILAINE 160 145 134 LOIRE 235 225 219 VENDEE 239 242 237 CHARENTES 142 146 142 GIRONDE 105 98 98 ARCACHON 33 36 34 ADOUR 71 71 71 TOTAL 1113 1077 1044

Table Fr. 4. recent evolution of the number of glass eel licence for marine fishermen. Source CNPMEM.

15 (1) unknown number of marine non-professional fishermen to be added (for 1986, see 2)

(2) marine non-professional fishermen included

(3) comprising 110 t from marine non-professional fishermen

(4) number of licences delivered

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8.1.2.3 Yellow and silver eel production

Yellow and silver eel fishery in France is almost concentrated in estuaries and lagoon (brackish water) and in the lower part of rivers (freshwater).

The production of yellow and silver eel in french rivers including estuaries has been evaluated at 302 t in 1999, with a value of 3 millions euros (Castelnaud, 2000); 220 river professional fishermen and 110 marine fishermen are involved (a big part is also concerned by glasseel fishery). Around 500 marine professional fishermen harvest 900 t of yellow eel in the whole Méditerranean coastal lagoon, including Corsica, in 1999, with a value of 5.4 millions euros.

8.1.2.4 Socio-économic state of the coastal fishery

A socio-economic study of the coastal fishery in the Bay of Biscay was carried out in 2000 in the frame of the Pecosude project. The survey concerned 248 commercial fishermen representing 20% of the whole population. Seven classes of fishing boats were built. Nineteen surveys concerned the class of « pure glass eel boat » and 36 the class of “estuarine boat”

The fishing fleet is old (24 y.), the boats are 8m long, have 4.8 tjb de jauge, 65 kw of mean power. For the « pure glass eel boat », the glass eel production represents 79% of the turn-over and 56 % for the “estuarine boat”. Others classes of boat are seeking for glass eel like “trawlers”, “scrappers”…

With 132.7 t declared, the glass eel production in the Pecosude report is classified in 1999 at the second place in value of the ressources of the Bay of Biscay, after the sole. If we refer to the estimated landings (Castelnaud, 2002), the glass eel reach the top (Table Fr. 3).

It certainly appears from the results of this study that the future for the glasseel fishermen is very poor.

8.1.3 Management

In France, the Decree n° 94-157 (16 February 1994) and n° 2000-857 (29 August 2000) organises the management of migratory species by hydrographical districts (art 1-4). The management units are called comity for management of migratory species (COGEPOMI). The report is organised to follow these hydrographical districts.

A management plan is written down every five years. It applies to all waters comprised upstream from the transversal limit to the sea, as long as migratory species are present. This management plan determines conservation and management measures, re-stocking operations, fishing restrictions for both recreational and professional fishery, fishing season, logbooks distribution and content (Art 2).

The COGEPOMI is in charge of monitoring the plan, recommending technical programs and funding necessary for the plan. It can propose recommendations necessary to the application of the plan beyond the transversal limit of the sea (Art 5).

8.1.4 References

CASTELNAUD G., 2000. Localisation de la pêche, effectifs de pêcheurs et production des espèces amphihalines dans les fleuves français. Séminaire national sur les poissons migrateurs amphihalins GRISAM, GIP hydrosystèmes, Paris, 27 et 28 mai 1999. Bull. Fr. Pêche Piscic. (2000) 357/358, 439-460.

CASTELNAUD G., 2002. Caractéristiques de la pêcherie civellière du golfe de Gascogne. Contrat Européen N° 99/023EC/DG FISH (DG XIV). Historique des captures de civelles, intensité actuelle de leur exploitation, variation de leur capturabilité par la pêche professionnelle maritime et indices de colonisation sur la bassin versant de l’Adour. Cemagref, Groupement de Bordeaux, 32 p.

CASTELNAUD G., GUÉRAULT D., DÉSAUNAY Y. and ELIE P., 1994. Production et abondance de la civelle en France au début des années 90. Bull. Fr. Pêche Piscic., 335, 263-288.

CASTELNAUD G., CAUVIN G., 2002. Site atelier de la Gironde. Caractéristiques des petites pêches côtières et estuariennes de la côte Atlantique du sud de l'Europe. Rapport final, contrat européen PECOSUDE n°99/024 ED/DG FISH (DGXIV). Cemagref, Groupement de Bordeaux, 58 p

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CASTELNAUD G., CHANGEUX T., GRANDPIERRE A., 2002. Bilan sur la production des pêches professionnelles et amateur aux filets et aux engins dans les eaux intérieures françaises au début du XXIème siècle. (à paraître).

8.2 Rhine-Meuse Basin district (Vincent Vauclin)

8.2.1 Recent Trend

8.2.1.1 Trend in recruitment

No data

8.2.1.2 Trend in fishery (Glass eel)

No data

8.2.1.3 Trend in fishery (Yellow eel/Silver eel)

No silver eel fishery.

Only two professional fisherman exploit the European eel (amongst other fish) on the French course of the upper Rhine in Alsace.

Twenty-seven amateur fishermen are allowed to use gears such as hook nets or eel pots on the river Ill, the main "100 % French" tributary of the Rhine.

These gears are not allowed on the Moselle, the main international tributary of the Rhine that has a part of its course in France, nor on the Meuse (which shares a common estuary with the Rhine in the Netherlands).

There are no data on the quantities of eel caught by rod and line in the French part of this basin, apart from two surveys carried on in 1999 and 2000 on a 100 km section of the Rhine and the Grand Canal d'Alsace where night fishing is allowed (until midnight) from may to September. The study dealing with year 2000 has led to an estimate of 700 kg of eels caught by night by anglers, the CPUE being 12 times higher than for daylight fishing. This appears to be very small (0,4 kg/ha/year) compared to the 1997-2001 average eel biomass found on a sampling site situated in the study area (22 kg/ha) and on three other sampling sites located downstream of the study area on the Rhine, that showed respectively eel biomasses of 43, 58 and 234 kg/ha (VAUCLIN, 2002). The study related to the year 1999 (BOHN, 1999) had given an estimated 960 to 2000 kg of eels caught at night, which is higher than in 2000 but in the same order of magnitude. These contrasted results are not representative of a true evolution in the patterns of eel exploitation by rod and line between the two years, but rather of differences in the surveys protocols.

8.2.1.4 Time series

8.2.1.5 Recent development /fisheries and market

8.2.1.6 Fishing mortality

8.2.1.7 Trend in the stock

A synthesis on a number of surveys by electrofishing carried on the basin from 1981 and 2000 has been realized by MANNE (2001). This includes 1270 locations, each being fished from 1 to 40 times on the covered period. The eel is present on all the Rhine sub-basin whereas it is not found upstream of the middle reaches of the Meuse (Verdun) and of the Moselle (Bayon).

128

Charleville-Mezieres

Verdun Metz

Nancy Strasbourg

Epinal Colmar

Mulhouse

Figure Fr. 3. Map showing the distribution of eel on the Rhin-Meuse basin (Presence= circle /Absence= star). Observations by electrofishing from 1981 et 2000)

(Source Manné S., 2001)

It is absent from a number of tributaries of these rivers, especially in the upper reaches and from all the Vosges mountains.

An analysis restricted to 65 locations sampled every year since 1993 (Reseau Hydrobiologique et Piscicole = RHP) shows that the densities are higher on the Rhine (1,3-5 individuals/100 m2) than on the Moselle (0,4-1 individuals/100 m2) or on the Meuse (0,2-0,8 individuals/100 m2), and that the eels are on average bigger at the most upstream locations, in a given river.

129

0,9 0,8 0,7

2 0,6 >600 mm 0,5 500-600 mm 0,4

Ind/100 m 0,3 300-500 mm 0,2 <300 mm 0,1 0 1993 1994 1995 1996 1997 1998 1999 2000 Années Figure Fr. 4. Trend in eel CPUE between 1993 and 2000 on the Meuse (4 stations fixes du RHP) (Source Manné, 2001)

2,00

1,50 2 >600 mm 1,00 500-600 mm 300-500 mm Ind/100 m 0,50 <300 mm

0,00 1993 1994 1995 1996 1997 1998 1999 2000 Années

Figure Fr. 5. Trend in eel CPUE between 1993 and 2000 on the Moselle (7 fix stations) (Source Manné, 2001)

The CPUE of electro fishing has been divided by two from 1993 to 2000 on the Meuse (from 0,7 to 0,35 ind/100 m2), especially for the bigger eels (L > 60 cm), but shows no consistent evolution on the Moselle. It has increased from 1,5 to 2,2 on the same period on the Rhine, with differences between size classes : the eels of less than 30 cm long have disappeared and those longer than 50 cm have increased, the 30-50 cm size class being relatively stable.

In 1986, the Rhine was heavily polluted by Sandoz factories (organochlorates) dowstream of Basel (Switzerland). This directly killed 400 tonnes of fishes of the upper Rhine, compsed of 90 % of eels. A monitoring started in 1987 to evaluate the evolution of the fish populations. Four sampling sites situated near Strasbourg confirm the above evolution of the size classes of eels in the Rhine. The extinction of the "< 30 cm" size class and the increasing number of large fish (> 50 cm) class could be caused by a fall in re-stocking or by a decrease in natural recruitment. The first hypothesis seems likely as re-stocking seem to have taken place mainly in the first years after the Sandoz accident. Unfortunately, lack of real data on these practices weakens our interpretation.

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3,00

2,50

2 2,00 >600 mm 1,50 500-600 mm

Ind/100 m 1,00 300-500 mm

0,50 <300 mm

0,00 1993 1994 1995 1996 1997 1998 1999 2000 Années Figure Fr. 6. Trend in eel CPUE from 1993 to 2000 on the Rhine basin (9 fixed stations) (Source Manné, 2001)

4 3,5 3 2,5 > 600 mm 2 500 - 600 mm 1,5

Ind/100 m2 1 300 - 500 mm 0,5 < 300 mm 0

7 8 9 0 2 3 4 5 6 7 8 9 0 8 8 8 9 9 9 9 9 9 9 9 9 0 9 9 9 9 9 9 9 9 9 9 9 9 0 1 1 1 1 1 1 1 1 1 1 1 1 2 Années

Figure Fr. 7. Trend in eel CPUE from 1987 to 2000 on the Rhine basin, for 4 fixed stations concerned by the Sandoz accident = longer serie (Source Manné, 2001)

8.2.2 Management

8.2.2.1 Geographical limits

The French part of the Rhine-Meuse basin includes the middle and upper courses of the Meuse and the Moselle (which also flow through Germany and the Netherlands) and 12 % of the Rhine catchment area, including 185 km of the Rhine upper course which materializes the border between France and Germany..

8.2.2.2 History of management plan

A migratory fish management plan has been designed for the period 1995-1999. It has not been updated since then.

8.2.2.3 Management objectives

The first management plan included very few recommendations concerning the eel, but one of the objectives was defined for this species : "the maintain of an economical resource exploitable by professional and sport fishermen without any re-stocking". No specific measures where proposed.

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8.2.2.4 Management measures

8.2.2.5 Fishery

8.2.2.6 Habitat

8.2.2.7 Migration

A multi-specific fish pass was installed on the first (most downstream) dam of the Rhine (Iffezheim) in 2000 (11 meters high). It does not include a specific "rampe" for eels. There are 9 other hydroelectric dams of the same dimensions upstream of Iffezheim on the franco-germanian course, and 10 more in Switzerland until the natural falls of Schaffhausen.

Twelve weirs have been equipped with fish passes from 1992 to 1996 and in 2001on the middle course of the river Ill, of which 11 include a specific "rampe". A great number of other obstacles remain unequipped for fish migration on the river Ill, and on its six main vosgian tributaries( between 20 and 100 on each).

The middle courses of the Meuse and the Moselle are not equipped with any efficient device for fish migration, in spite of a large number (> 50) of weirs and dams.

8.2.2.8 Re-stocking

Very few is known on eel re-stocking on the basin. Re-stocking has been operated on the upper Rhine by managers from Germany following the Sandoz accident (1986), but these operations seem to have ended around 1992, though no written document are available on that. Only two re-stocking operations were carried on in France, for experimental purposes.

One was made in march 1989 and comprised 500 kg of elvers (1,25 million individuals) which were marked by tetracycline chlorhydrate. A significant number of marked eels have been recaptured every year since then. In 1996- 1998, 63 eels were marked in a sample of 474 caught by electro-fishing (12 %). Overall, 179 eels coming from this re- stocking have been recaptured by electro-fishing, in a total sample of 2 261 eels (CLAUSS and MEUNIER, 1998). The second operation was realised in 1990 with 475 kg of elvers marked with fluoresceïne. It apparently gave poor results, as only one eel was recaptured in 1997 (MEUNIER and DUFOUR, 1999).

8.2.2.9 Monitoring

Apart from the information derived from electrofishing samples (RHP network, see above) or from other general fish population surveys, there is only one monitoring carried on, located at the Iffezheim dam fishpass on the Rhine. The fish migrations have been monitored since the pass began to operate in June 2000, by a trap and a video-control device. None of these methods give a reliable estimation of the eel passages, because they were primarily designed for salmon and sea-trout. Nevertheless, a modification of the settings could be realised in the next years to adjust the video-control to a better eel counting. Between 230 and 368 eels have been recorded each year but real figures are more likely to approach several thousand individuals, according to some direct observations made at night in June 2000.

8.2.2.10 Is target conforming to the 30% SPR rule

8.2.3 Réferences

BOHN P., 1999. Pêche de nuit à la ligne dans le Rhin et le Grand canal d'Alsace. Evaluation de l'effort et du prélèvement par pêche à la ligne en 1999. Conseil Supérieur de la Pêche, 10 p + annexes.

CLAUSS T. and MEUNIER, F., 1998. L'alevinage Sandoz en demi teinte. Eaux libres N°24. "L'anguille dans le rouge", Rennes, pp 34-35.

MANNE S., 2001. Réseau Hydrobiologique et piscicole (RHP). Synthèse des données du bassin Rhin-Meuse, année 2000. Conseil Supérieur de la Pêche, Délégation régionale Champagne-Ardenne, Lorraine, Alsace 47 p + bibliographie et annexes.

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MEUNIER F., DUFOUR S., 1999. Biologie de l'anguille, Anguilla anguilla dans le Rhin alsacien : croissance, développement sexuel, acquisition de l'argenture. Université de Paris 7 - MNHN, Rapport de fin de contrat Conseil Supérieur de la Pêche, 9 p + figures.

VAUCLIN V., STORCK F., MANNE S., 2002. La pêche de l'anguille à la ligne sur le Rhin et le grand canal d'Alsace en 2000. Conseil Supérieur de la Pêche, Délégation régionale Champagne-Ardenne, Lorraine, Alsace 18 p + annexes.

8.3 Artois-Picardie District (Gilles Euzenat, Françoise Fournel, Jean-Louis Fagard, Cédric Briand)

8.3.1 Recent Trend

8.3.1.1 Trend in recruitment

In 2002 and 2003 severe flood on the Somme shortens the series

1999 2000 2001 2002(?)

23000 37100 266 203

Table Fr. 5. Yellow eel and glass eel trapping on the fluvial eel ladder from the Somme (30 km from the estuary).

(source David DHENNIN, Conseil Général de la Somme, David DUFRESNE, Fédération de Pêche de la Somme, unpublished data.)

8.3.1.2 Trend in fishery (Glass eel)

No data available

8.3.1.3 Trend in fishery (Yellow eel/Silver eel)

8.3.1.4 Time series

No times series available

8.3.1.5 Recent development /fisheries and market

Status-quo for glass eel fishing effort.

8.3.1.6 Fishing mortality

No time to collect data for the glass eel fishery.

The Somme is also a place for traditional silver eel fishing. The river is 192 km long with 600 km on the whole watershed. There is one professional fisherman on the lower Somme and 8 in the upper Somme. The catches are 1 tons for the lower Somme and were though to be of a magnitude of 20 (1990 CSP estimation) to 10 tons (management plan 1995-2000) on the upper Somme.

No data on amateur fishery. A particular and efficient fishing using bobbing “Vermée=worms” is allowed at night, all year, in 2nd category streams (most of them), during the period corresponding to the open fishing in 1st category.

8.3.1.7 Trend in the stock

32 sites have been electrofished between 1983 and 1989. They showed a good density close to the sea (10-20 eels/100 m²). These densities decreased to less than 5/100 m² past 50 km upstream from the sea and eel were absent from 5 points of sampling.

133

In the Wateringues, 19 electrofishing stations have been sampled from 1995 to 1998. Eel densities were <5 eel/100 m² in canals and Wateringues rivers

8.3.2 Management

8.3.2.1 History of management plan

Management plan 1995-2001, not yet renewed. Only about the Wateringues and the Somme rivers. The same plan is to be reconducted because not realised, except ladder and partial monitoring on the Somme

8.3.2.2 Management objectives (Major content)

Management was defined by river. In near all rivers, no management aimed for eel.

• Restore free migration on the main axis in the fist time and on the tributaries in a second time.

• Trap the eel up-run at the Abbeville dam to estimate fluxes

• Monitoring of anguillicola crassus

• Develop logbooks on the upper Somme (not continued)

• Develop amateur fishery

• Maintain professional fisheries

• Limit poaching

• Adapt input and output fluxes

8.3.2.3 Management measures

8.3.2.4 Fishery

Somme

No fishing limit for glass eel fishery. 12 professionals in estuary for a total catch of 2 to 5 tons (data = management plan 1995-2001). A control and elimination of illegal fishing has been set up in the Somme basin as a management measure.

A recent decree act (2002-965) forbids amateur fishery with nets for silver eel (6 persons 0.3 T/ year).

8.3.2.5 Habitat

No data on habitat restoration. Habitat destruction of the lower Somme during the flood defence program operated in 2001-2002

8.3.2.6 Migration

9 eel ladders on the lower Somme river, and 2 traps.

Several ladders programmed on coastal rivers : Authie, Canche, Wimereux, in parallel of the salmonid restoration programme.

8.3.2.7 Re-stocking

Somme actions were planned for the 1995-2001 management plan, but nothing done.

134

8.3.2.8 Monitoring

8.3.2.9 Is target conforming to the 30% SPR rule

8.4 Seine-Normandy district (Cédric Briand, Sarah Gimet, Marie-Noëlle De Casamajor)

8.4.1 Recent Trend

8.4.1.1 Trend in recruitment (trap monitoring)

A yellow and glass eel trap is associated with a salmon trap. The station is located in EU, on one of the branch of the Bresle river, 3 km from the sea. It only catches a fraction -unknown- of the whole eel population. The access was ameliorated in 2003 putting bundles 15 metres downstream from the pass outlet. There is no glass eel fishery on the Bresle. The annual catches have decreased from 1994 (of a factor 6). The recent increase is due to the local modification of accessibility to the bottom of the eel ladder.

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 M 1 74 11 0 14 25 8 28 0 2 88 M 2 30 45 46 383 227 84 164 11 100 746 Jun 1 251 81 1807 10208 1209 328 482 27 223 4547 Jun 2 2620 691 801 788 1318 242 522 904 446 2259 Jul 1 3893 9702 995 563 381 617 47 1254 1195 2653 Jul 2 12227 3836 2279 687 1169 321 541 901 381 2787 A 1 8032 3810 1359 1502 2206 633 2016 1295 728 2608 A 2 496 2618 1502 1385 1765 238 1860 1355 605 2311 S 1 121 755 289 131 2055 531 805 81 369 628 S 2 22 94 38 13 73 457 805 32 21 O 1 1 44 17 8 4 92 92 78 10 O 2 5 7 5 2 58 2 105 56 37 N 1 0 0 0 0 0 0 0 34 275 N2 0 D1 2 D2 27772 21694 9138 15684 10490 3553 7467 6028 4394 18627

Table Fr. 6. Yellow eel and glass eel trapping on the Bresle river eel ladder (Normandy) source Données Conseil Supérieur de la Pêche - DR 1 - Station salmonicole Eu. F. FOURNEL / J.L. FAGARD / G. EUZENAT.

135

94 95 96 97 98 99 00 01 02 03

Figure Fr. 8. Annual catch for eel on the Bresle river.

1500 Effectif par 24 heures

1250

T°C de l'eau 1000

750

500

Marées 250

0 AVRIL MAI JUIN JUILLET AOUT SEPT. OCT. NOV.

Figure Fr. 9. Number of eel per 24 h ours on the Bresle river, 2003 data

8.4.1.2 Trend in fishery (Glass eel)

Year 1996 1997 1998 1999 2000 2001 2002

Production declared (kg) 3941 2867 1722 1718 1093 719 887

Nb. Of declaration 18 31 31 25 20 21 32

Table Fr. 7. Glass eel fishery production in the seine Normandy basin, the production corresponds to 32 licences for 2001 (source CLPMEM, Basse-Normandie)

With the objective of a good management and a limitation of the access to the resource, the CIPE decided, to limit to 32 licences the fishing of glass eel (what currently represents 38 fishermen on the Normandy littoral).

The total value of sales of glass eel is about 300 to 600 k€ for Normandy littoral (2 to 4 tons declared by the commercial fishing on average each year for prices which varies from 70 to 2300 €/kg). The glass eel is captured in estuaries by boats equipped with rectangular or square scoopnets which mouth is 1,5 m large in its maximum dimension. The main activity stands in river Orne estuary (40 % of the trips), Bay of Veys (35 % of the trips) and accessory in the Risle-Seine

136

(20 % of the trips). Fishing takes place at night, with rising tide and is supported by strong coefficients. These last years, the legal activity had to face clandestine fishings. The vigorous action of the police forces had largely contributed to reduce this drift.

8.4.1.3 Trend in fishery (Yellow eel/Silver eel)

Most of Yellow end siver eels are captured in the maritime domain, downstream the transversal limit of the sea. The fishery uses passive gears similar to coghill placed in the Seine river. The catches varies from 5 to 10 tons annually (commercial value of about 35 to 50 F/kg). In fluvial domain, only a few professionals capture less than one ton of eel per year. Theoretically silver eel fishing is prohibited in accordance with article 14 of decree 94-157 since the season 1999.

8.4.1.4 Time series

8.4.1.5 Recent development /fisheries and market

8.4.1.6 Fishing mortality

Bobbing (fishing rod without hook) is not widespread in Normandy, where it is restricted to some watersheds. However, this fishing is allowed in the north of France (Artois Picardie). In the Cotentin marshes and Douve rivers, a recent study tried to evaluate fishing mortality. The method used coupled a CPUE indice with an indication of effort (frequenting).

The Douve is 65 km long, the fishing effort is concentrated in the lower part of the river. The mean catch was 4.9 eel /h; the mean number of fishermen was 0.4 / km, for a mean fishing duration of 2.6 hours. The CPUE was 12.9 +/-9.5 (SD). Annual catch was calculated as 24 168 eels (+/-4446) for a total weight of 2852 kg (+/-525). An estimation of local stock was conducted as 40 ha x 150 kg/ha =6 tons for upper reaches and 130 ha x264 kg/ha=34 tons (Baisez, 2001). Relative to the whole biomass, the exploitation rate was calculated as 7.1 %, however other calculations show the production may exceed local production, when estuarine bay is not taken into account (Michelot, 2002).

8.4.1.7 Trend in the stock

The population of the Orne river has been described by Legault (1998). Densities from 0 to 40 ind/m². Density divided by 4 between 1990 and 1996. No information was avalable on the RHP stations in time for the report .

8.4.2 Management

8.4.2.1 Geographical limits

The Seine-Normandy basin covers a 97 000 km2 area including 55 000 km of river and more than 600 km of sea coast. Regarding the 30 principal tributaries of the Channel there is only left 10 true estuaries : the bay of Veys (Vire, Aure, Douve and Taute rivers) the Orne river estuary and the Seine-Risle ensemble. On the western limit of the area, the bay of Mont St-Michel is shared with the region of Brittany (Sée and Sélune belongs to Seine-Normandy, Couesnon to Brittany). At the eastern side of the area, Bresle depends administratively on Seine-Normandy but constitutes the limit with the Picardy area and the Artois-Picardy basin.

8.4.2.2 History of management plan

Migratory fish Management plan 2001-2005

8.4.2.3 Management objectives

Avoid the collapse of the stock ;

Enforce the police ;

Maintain commercial and non-commercial eel exploitation on some sections of some rivers ;

137

Evaluate runs on several rivers (building of trapping stations) – very large plan ;

Restore free movement up and down ;

Improve Water and habitat quality.

Figure Fr. 10 Management objectives for Seine Normandy basin. Source : Migratory fish Management plan 20012005.

Restore migration

The basin water management scheme (SDAGE) approved in 1996 recommend to improve the river continuity t by openning the sluices and destructing the useless dams.

- On the Norman coastal rivers:

* In Low-Normandy: the priority relates to the good management of the crossing works (water supply and maintenance).

* In High-Normandy: the stress must be laid on the application of the decree of 18 of April 1997 which implies to equip or to open about 200 works before 2002. This task ambitious as regard to the current rate/rhythm of realization (up to 80% of assistance of the water agency, the local communities and the State).

- On the axis Seine / Yonne / Cure: To finish the equipment of crossing with broad spectrum (all species) already envisaged in the plan preceding Andresy (6 MF), Chatou (10 MF), Suresnes (20 MF). To carry out crossing with the stopping of Installations out of right bank (8 MF), to envisage the same operation with Port-Mort (8 MF) and Méricourt (15 MF) out of left bank and the equipment of the dam Bougival.

- On the other major axes, actions of installation, restoration and equipment of the works in devices of crossing will have to integrate the safeguard of eel, species considered as today very vulnerable on a European scale.

138

* Aube : to ensure freedom of movement of eel each installation appropriateness.

* Marne : to ensure migratory control. Works of crossing in Bonneuil and Ferté (8 MF on the whole). Installation appropriateness to ensure freedom of eel movement.

* Oise : Access to the upstream part of the basin of Oise is apparently difficult for eel according to the results of the RHP national electrofishing network 1997, the operations of equipment of works in devices on crossing will thus comprise adapted devices.

The sum of the costs (approximate) quoted here and which milked in very large majority with the restoration of freedom of movement, goes to more than 26 million € without counting an operation like the " restoration " of Yères in estimated Seine-Maritime 46 million €. High-Normandy without the axis the Seine represents more of the 2/3 of this amount 18 million €. the Seine axis asks for this plan 5,5 million of € and Low-Normandy which completes its equipment of crossing there requires 2,3 million €.

8.4.2.4 Management measures

8.4.2.5 Fishery

No reduction in fishing effort. The fishing with worms at night (Vermée) is allowed in 2 to 3 rivers of haute Normandy and in parallel with the quite committed fight against the poaching of glass eel on the littoral (particularly in the low Seine) and which must be continued mainly against the illicit networks of marketing on all the basin, the local regulation on fishing will tend to preserve all the phases of the life cycle of eel with the prohibition of eel fishing of silver eel and the non extension of the night fishing for this species. The number of glass eel fishing licences is limited to 32 on the Norman littoral. The possibilities of reduction of the period of glass eel fishing on this side 134 current days will be examined with integration of the effective periods of non fishing (inadequate coefficients of tide, raises decadal).

8.4.2.6 Habitat

Seine program, water quality enhancement, and the eel may benefit from these programs

8.4.2.7 Migration

A report evaluates migration obstacles. A database has been constructed taking an inventory of dams. In a first approach, 5191 dams and weirs were inventoried. 11142 with possible crossing, 1153 with seasonal blocking and 1836 with no possible crossing. The density was one dam every 5.2 km on the department where the inventory was complete. This number leads to an extrapolation of 8000 dams on the whole district, on which 6200 located on the main streams.

Only 5 % of these dams have a clearly defined use.

- 23 large dam with multiple aim (drinking water, navigation, flood control).

- A little more than 100 dams for navigation

- 274 hydroelectric sites

139

Figure Fr. 11 Streams classified by the L 432-6 of the environment code for free circulation. Pale blue : not classified, deep blue decree alone, red=classified by decree and order. (Source : Seine Normandy management plan)

To date 4 decrees (03 August 1904 modified by that of 25 of March 1991, 23 of February, 1924, 27 of April 27

8.4.2.8 Re-stocking

8.4.2.9 Monitoring

8.4.2.10 Is target conforming to the 30% SPR rule

8.4.2.11 What is missing in regional management plan ?

ASSESSMENT OF THE PLAN 1995-2000 - ANALYSIS OF BLOCKINGS

The plan 1995/2000 included 178 recommendations concerning the environment (96) migrating stocks (27) and their exploitation (55). The 178 recommendations were noted from 0 to 1 following their degree of realization estimated by the local experts (CSP, DIREN, AESN, CRPM, SNS...) each year since 1996. For each couple stream/species the sum of the notes gave thus the number of recommendations filled and made it possible to calculate a percentage of realization. The total assessment is established with less than 30% of realization at the end of 1999.

The positive points relate to primarily the mediums, the recommendations on stocks or the exploitation being followed very little effects. A notable exception however on the exploitation, relates to the fight against the poaching which according to all actors' was effective and seems to bear its fruits, the means devoted to this field by the higher council of fishing (CSP) and the maritime businesses were it is significant since 1996.

The principal points of blocking were identified in a remanent way since 1996:

- at the level of the management of the environments: the deficit of control of work to sit the operations of re- establishment of freedom of movement and their control, the practices of maintenance of rivers not adapted to the

140

requirements of functionality of the rivers in High-Normandy, physicochemical quality still far away from the lawful objectives to much of places,

- at the level of the inventory control : the lack of knowledge at sea, estuary and river, but more especially misses it posting of the managers (which must manage?) ,

- at the level of the management of the exploitation: lack of data in maritime field on the fished quantities, the strict application of the regulation, the acquisition of the fresh water beams.

8.4.3 References

Anonyme, 2002. Barrages, entraves à la dynamique biologique des rivières - Recensement des problèmes majeurs en Seine Normandie - Corrections et remèdes possibles (maitrise d'ouvrage DIREN de bassin.

Legault, 1998. L’anguille sur le bassin versant de l’orne, Rapport Fish-Pass, 40 p.

Michelot, E. Prelevement d’anguilles par pêche à la Vermée sur le bassin versant de la Douve en 2002. Rapport Conseil supérieur de la pêche, 10P.

8.5 Brittany district (Cédric Briand, Thibault Vigneron)

8.5.1 Recent Trend

8.5.1.1 Trend in recruitment

8.5.1.2 Experimental fishing

No time series, experimental fishing done on the Vilaine and the Aulne are thought to depend on local fishing conditions. No trend available

8.5.1.3 Eel trap monitoring

The Vilaine (Atlantic) the Frémur (Channel), and Rophémel (Channel) pass are monitored by IAV and Fishpass.

1996 1997 1998 1999 2000 2001 2002 Janvier 0 0 38 travaux 0 crue et travaux 20 Février 0 186 8 23 5 crue et travaux 6 Mars 0 3 277 86 3 194 332 10 2 234 Avril 499 818 41 805 947 610 25 378 5153 74 996 44 892 Mai 612 558 116 730 1 485 742 649 476 248 629 154 223 626 Juin 207 243 41 223 37 537 189 643 38 947 5 391 3 216 Juillet 6 678 5 466 2 184 7 202 8 528 772 376 Août 126 590 159 776 1 725 192 398 Septembre 117 121 829 132 160 4 161 Octobre 399 56 travaux 4 401 124 11 26 Novembre 1 575 135 travaux 3 586 crue travaux 146 Décembre 166 64 travaux 4 221 crue travaux 27 Total 1 328 680 209 653 2 474 193 888 032 303 603 235 599 52 128 Table Fr. 8 : glass eel numbers estimated on the Vilaine eel trap from 1996 to 2002 (Briand,et Fatin, unpublished).

141

1996 1997 1998 1999 2000 2001 2002

Janvier 0 0 65 travaux 0 crue et travaux 25

Février 0 95 30 0 15 crue et travaux 26

Mars 0 1 890 236 66 67 86 430

Avril 1 284 1 342 7 548 3 001 206 836 691

Mai 6 747 1 634 13 714 7 812 4 945 1 781 272

Juin 4 770 1 622 2 676 5 841 2 074 1 619 313

Juillet 1 413 725 524 813 699 228 704

Août 282 486 280 264 1 717 1 098 642

Septembre 234 330 750 135 537 467 696

Octobre 361 373 travaux 455 6 283 475 846

Novembre 454 2 160 travaux 57 crue travaux 2 459

Décembre 100 236 travaux 0 crue travaux 111

Total 15 645 10 893 25 823 18 444 16 543 6 590 7 215

Table Fr. 9: yellow eel numbers recorded on the Vilaine eel trap from 1996 to 2002 (Briand,et Fatin, unpublished)

142

Piége Pont es omnes Frémur

600

500

400

300

200

100

0 1997 1998 1999 2000 2001 2002

Figure Fr. 12. Evolution of the recruitment indice , Nb of recruit/km² watershed from 1997 to 2002. (source Antoine Legault, Fish Pass)

1,2

1,0

0,8 ascenseur BJ piège montée PEO 0,6 rophemel

0,4

0,2

0,0 1996 1997 1998 1999 2000 2001 2002

Figure Fr. 13. Evolution of catches in three stations of north Brittany from 1997 to 2002 (dtat presented as an indice of the maximum catch. (Source Antoine Legault, Fish Pass)

143

8.5.1.4 Trend in fishery (Glass eel)

8.5.1.5 Time series

Decade Year 1970 1980 1990 2000 0 120,3 25,4 12,6 1 44,0 83,3 25,3 12,8 2 54,7 74,7 25,3 11,1 3 77,7 67,7 28,2 8,9 4 80,3 45,7 28,2 5 86,3 38,7 25,4 6 66,0 37,3 24,9 7 85,7 39,8 20,8 8 122,0 33,8 18,5 9 136,3 33,5 15,7 Table Fr. 10.Time serie for the Vilaine fishery

200,0 180,0 ) s

n 160,0 o T 140,0 s (

he 120,0 tc 100,0 l ca ta 80,0 y to r 60,0 e h s i 40,0 F 20,0 0,0

5 9 1 5 7 9 1 3 71 73 7 77 7 8 83 8 87 89 91 93 95 9 9 0 0 05 9 9 9 9 9 9 9 0 0 19 19 1 19 1 1 19 1 1 19 19 19 19 1 1 20 2 2 Années

Figure Fr. 14.Trend in catches of the Vilaine fishery, line = smoothed data.

144

14 000

1987-1989 12 000 1990-1999 2000-2002 2003 10 000 ery (kg) h s i f

8 000 e h t

f o 6 000 catch 4 000 Total

2 000

0 Nov Dec jan feb March Apr

Figure Fr. 15. Intra seasonal catches of the Vilaine fishery.

The fishing season ended the 23 March, because of fishing regulations. The catch was the second lowest recorded in the serie. The additional recruitment estimated after the fishing season was 430 kg (Briand, unpublished). This year, like in 2001 there was a severe overflow. The years of important flood are often years of very bad catches, possibly because of a reduced attraction of the Vilaine panache, with an Increased concurrence from the Loire.

8.5.1.6 Recent development /fisheries market

200,0 200 s 180,0

at 160,0 bo 150 140,0 120,0 nb of /

h 100,0

c 100 t

a 80,0 Price/kg €

al c 60,0 50 40,0

Annu 20,0 0 0,0 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 Historical record Marine authority Briand et al., in press Nb fishing licence Price / kg € Figure Fr. 16. Total catches, licence number and price, historical record (Elie and rigaud, 1984; Castelnaud et al., 1994, Briand et al., in press).

145

8.5.1.7 Fishing mortality

The Vilaine fishery is regulated since 1998 with the objective to obtain an escapement target of 700 kg (see ICES 200/EIFAC 2002). Various limitations, based on temperature and escapement estimations have been experimented. Additional experimental trips have also been conducted from 1999 in estuary, and aim at increasing the number of recruits passing the dam.

Those regulations did not permit to attain the target, because of the constant fall in recruitement. Recently, these measures failed because they were calculated on a possible total escapement, and as the fishing period has been reduced of more than one month, the population dynamic (recruitement, settling, mortality) has to be taken into account within this month. The increase in experimental fishing and the reduction of catches has possibly led to a decrease in the estuarine yellow eel population.

Fishing Fishing regulation Fishery Estimated Total Exploitation Fluvial Fluvial closure catches late recruitment rate recruitmen recruitment (kg) recruitment (kg) t (trap) (experiment (kg) (kg) al fishery) (kg) 15 Apr 22 402 1 510 23 912 6,3% 443 30 Apr 22 656 250 22 906 1,1% 69 6 Apr temperature <12 °C 17 923 876 18 799 4,7% 700 2 Apr temperature <12 °C 15 320 700 16 020 4,4% 292 198 15 Apr temperature <12 °C 14 198 250 14 448 1,7% 82 54 30 March Stock estimation 8 164 300 8 464 3,5% 59 23 March Stock estimation 15 851 90 16 001 0,6% 15 84 23 March Stock estimation 8 939 230 9 369 2,5% 83 206 Table Fr. 11. Stock estimations and management of the Vilaine glass eel fishery (Briand,et Fatin, unpublished).

g) 800 k ( l 700

ee 600 s

as 500 gl t 400 n e 300 m t i

u 200 r c

e 100 r l a

i 0 v u l 8 F 999 1987 198 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1 2000 2001 2002 2003

Sluice operation Passe Ladder additional transport during fishing season

Figure Fr. 17. Recruitment towards freshwater (fluvial recruitment) in the Vilaine

8.5.1.8 Trend in fishery (Yellow eel/Silver eel)

The analysis of catches of fishers using fishing gears was performed on the Vilaine for the period 1991-2001. The analysis shows that for regular fishermen, the CPUE was correlated with recruitment with a lag of four years for eel pots and five years for lift nets (Briand and Changeux, unpublished). This analysis confirms the increase in yellow eel population observed through electrofishing (Briand, unpublished).

8.5.1.9 Time series

No time series avalable

146

8.5.1.10 Recent development /fisheries and market

8.5.1.11 Fishing mortality

The production was calculed for the Golfe du Morbihan, a bay covering 14 674 ha, south of Brittany. For a fishery exerted by 9 fishing team. The production was evaluated as 1.2 kg/ha/year (Briand, unpublished). In the absence of age evaluation, the total mortality per size class of 50 mm was used as management proxies to compare with previous studies. Three sites were selected for the Golfe : a natural reserve (pen en Toul), and two other places (Auray and Truscat). The mortality was also calculated with the same method for other estuaries and lakes whose size data were reported in the litterature (LEE and LASSERRE, 1979; SCHAAN, 1993; ADAM, 1997). )

m 1,60

50 m 1,20 s as

l 0,80 c

e 0,40 z i

s 0,00 per

( 1 1

Z B A D C 02 90 0 0 91 6 90 at 91 76 y 76 ' oul re re' c re a re 76 T r Loi Loi us Loi hon Au hon Loi hon 7 hon n c c c c e Tr a n ca ca c ca Pe Ar Ar Ar Ar

Figure Fr. 18. Mortality per size class of 50 mm calculated for data in the range 300-350mm to 650-700mm.

8.5.1.12 Trend in the stock

An analysis was performed at the regional level, with RHP stations, and at the basin scale in the Aulne and the Vilaine.

8.5.1.13 Regional level

Densities are low (<3 ind 100 m2) on 60 % of stations. Larger densities are observed (>10 ind. 100 m2) on stations next to the sea and without obstacles. Among 29 RHP stations, 20 present a downward trend. Among these stations, the 4 stations the most sensible to variation that is with a large eel density present a significant downward trend (T test P<0.1). Nine stations present a non-significant upward trend (T test, p>0.1). The increase is linked with habitat amelioration. One station presents a significant upward trend (T test P<0.01). This increase is liked with the amelioration in water quality.

On at least four locations, the downward trend cannot be linked with obstruction or glass eel fishery. It is thus probably the direct consequence of the decrease in recruitment.

147

4 2.0 B

3 1.5

e e 2 1.0

1 0.5

0 0.0 0 1 2 3 4 5 6 7 8 9 0 1 2 99 99 99 99 99 99 99 99 99 99 00 00 00 90 91 92 93 94 95 96 97 98 99 00 01 02 1 1 1 1 1 1 1 1 1 1 2 2 2 19 19 19 19 19 19 19 19 19 19 20 20 20 ANNEE ANNEE

Figure Fr. 19. Evolution of eel density (log dens (eel /100 m²+1). A) on 4 oif the most downstream station of the Brittany RHP network. B) On the whole network, 29 stations, GLM Ldens=constant+year N: 322, R² = 0.75, P <0.001. (Source Vigneron and briand, unpublished)

Figure Fr. 20. Eel density in 2002 in Brittany, arrows, recent trend, red croos = major obstacle, red star RHP stations with no eel. (Source : Vigneron and Briand , unpublished).

148

8.5.1.14 Vilaine

The dam of the Vilaine watershed was quoted from a grid elaborated on the Loire river (Steinbach, unpublished).

Figure Fr. 21. Classification of the effect of dam, from no problem (blue) to total obstruction (red). Black corresponds to unevaluated dam (Source : Fuentes, 2003).

It was possible to model eel densities against the cumulated quotation of dams located downstream from the sampling station.

350

300

250 ) ² aval m DON 200

100 ISAC /

N Vilaine é ( t i 150 Oust s n

e régression 2 D 100 Dens=exp(-0,028*noteba+3,949)-1

- 0,0 20,0 40,0 60,0 80,0 Somme notations barrages

Figure Fr. 22. Theoretic repartition of eel density per age against cumulated sum of the dam quotation (source Fuentes and Briand, 2003).

It was also possible to evaluate the effect of the Vilaine axis restoration in 1999 from 1998-2001 electrofishing operations. The data were well fitted by the model.

149

Figure Fr. 23. Theoretic repartition of eel density per age against cumulated sum of the dam quotation (plain line 2001, dotted line 1998), blue 0.3 eel.m-2,, green 0.1 eel.m-2,, yellow 0.05 eel.m-2 (source Fuentes, 2003).

Figure Fr. 24. Theoretic repartition of eel density per age calculated from cumulated sum of the dam quotation in 2001, blue 0.3 eel.m-2,, green 0.1 eel.m-2,, yellow 0.05 eel.m-2,, and management objectives blue > 30 eel.m-2, green eel present. (source Fuentes, 2003)

It was finally possible to estimate the effect of dam on migration and management objective (figure 24).

150

8.5.1.15 Aulne

The density in the Aulne basin was analysed in 2002 and 2003 (LAFFAILLE P. et al., 2003). The eel was caught in less than 17% of EPA with a mean density of 12,3 +/- 36,9 eel.100m-² (min=0 and max= 132,8).

A geographical analysis shows that eel is only abundant in the most downstream tributaries Douffine (mean 43 ind. 100 m-2) and Guilly Glaz (32 eel. 100 m-²). More upstream, on the Aulne canal eel density decrease to a mean value of 6 eel.100 m-2. They diminish further is the upper reaches to a mean value of 1 eel. 100 m-2.

An analysis of the glass eel fishery show that for a guest estimate of recruitment 4 T, the fishery only catches 200 kg to 500 kg for a mean number of fishing night of 64 on the period 1997-1999. The mean efficiency of the fishery was calculated as 1 % of the estuarine stock per night per boat.

A large escapement leads to very poor densities on the Aulne watershed because a large number of dams blocks migration.

20 Densités (ind.100 m-²) 10

0 0 50 100 150 Distance à la mer (km)

Figure Fr. 25. Eel densities (nb.100m-²) related to distance to the sea (km). Non parametrical regression was used to adjust the data Lowess (f=0,8).

151

10 KM RIVIERE D’ARGENT

RIVOAL

BRASPARTS ELLEZ DOUFFINE KERGAEREC ROSNOEN

GUILLY AULNE RIVIERE GARVAN GLAZ

AULNE VERNIC CANAL CANAL DE PLEYBEN STER NANTES A PIERRE BREST C’HANN GOANEZ JACQUES CHATEAULIN

SPEZET -2 COATIGRAC’H d>30 ind.100m CHATEAUNEUF d<30 ind.100m-2 CRANN ROZVEGEN d ≈ 0 ind. 100m-2 3 FONTAINES PONT AL Barrages C’HLAON

Figure Fr. 26. Eel densities repartitions (d, Nb. 100 m2) on the Aulne basin from the sampling of 2002 and 2003.

8.5.2 Management

8.5.2.1 History of management plan

Management plan 2001-2005

8.5.2.2 Geographical limits

The management plan concerns the Brittany region

8.5.2.3 Management objectives

8.5.2.4 General objectives

- Avoid the collapse in the stock,

- Maintain commercial and non-commercial eel exploitation, taking into account the international distribution,

- Management of glass eel and yellow eel fishery in such a way as to maintain or increase spawner production

- Escapement of silver eel from each watershed comprising estuaries and coastal areas,

- The escapement must comprise silver eels of sufficient quality to participate to the spawning phase

- Because estuarine and marine habitats are relatively preserved from Anguillicola crassus, the preservation of estuarine and marine stock is considered as a priority.

8.5.2.5 Management targets and specific objective

The objective are :

152

- Population. To obtain an eel density of 0.3 eel.m-2 on the riffles of half of the basin surface (for example 120 km from the Arzal dam). Elsewhere, the eel must be present in every streams.

- To manage the glass eel and yellow eel fisheries in such a way to maintain or increase silver eel escapement.

- Increase escapement in the Vilaine. For the Vilaine, an escapement target is fixed by the Cogepomi each year, as a percentage of the whole stock. For 1999-2003 the target researched was 700 kg. A date of closure of the fishery is calculated from model based on intra and inter-seasonal trends.

- Reduce hydro-electric related mortalities. A model simulating downstream migration from environmental conditions will be developed . In each watershed, technical measures will be proposed, and a management protocol depending on water flow will be elaborated to every hydroelectric dam in the duration of the next plan

- Habitat quality restoration.

- Transport : While waiting for technical solution in places where the number of dam is too large, an intra-basin transport can be considered. Transport from 15 March, re-stocking 4-5 eel.m-2. Evaluation and database needed.

- Migration : remains a major objective

8.5.2.6 Monitoring objectives

- An effort should be done to study and monitor littoral populations (Golfe du Morbihan, Mont Saint Michel Bay)

- Determine the regional silver eel production

- Evaluate the densities for whole Brittany with for objective the research of factors limiting colonisation and spawner production

- Monitoring of the Aulne and Vilaine glass eel fisheries, and upstream colonisation to set the regional management of glass eel fisheries.

8.5.2.7 Management measures

8.5.2.8 Fishery

The fishery has been reduced of 15 days in April for all glass eel fisheries.

The management is to have an escapement target of 700 kg of glass eel towards the watershed for the Vilaine Fishery. The fishery has been reduced of one month and a week. Additional catches for transportation were recently adopted during the fishing season.

8.5.2.9 Habitat

Some habitat restoration, very limited at the Brittany level, effect on eel unevaluated

8.5.2.10 Migration

In Brittany, five of the six mains obstacles have been equipped with eel fish ladder :Rophémel (Rance), Arzal (Vilaine), Ville Hatte l'Arguenon, Kernansquillec (Léguer), Ponts-Neufs and Pont Rolland (Gouessant). The remaining blocking dam are Guerlédan (Blavet), and the Gouët drinking reservoir. 57 eel-pass and multi specific pass have been built. 10 are in project, the equipment continues. On the Vilaine the effect of the dam construction has been monitored

153

8.5.2.11 Re-stocking

Experiment done in the Vilaine.

8.5.2.12 Monitoring

The monitoring of the escapement target of the vilaine is done by fishery monitoring, marking recapture operations and trap monitoring. The result are presented each springtime for the COGEPOMI, they are also presented to the Sage Vilaine board.

The monitoring of yellow eel population against management objective has been performed by electrofishing in the Aulne, Vilaine and Frémur basin. No monitoring is done in the other basins.

A method allowing to reduce the fishing labor is in development (Heron electrofishing equipment Lafaille et al., unpublished; Martin pêcheur electrofishing equipment Briand et al., unpublished).

8.5.2.13 Is target conforming to the 30% SPR rule

8.5.3 References

ADAM G., 1997. L'anguille européenne (Anguilla anguilla L. 1758) : dynamique de la sous-population du lac de Grand-Lieu en relation avec les facteurs environnementaux et anthropiques. TH.

BRIAND C., FATIN D., FEUNTEUN E. and FONTENELLE G., In press. Estuarine and fluvial recruitment of European glass eel in a fished Atlantic estuary. Fish. Man. Ecol.

CASTELNAUD G., GUÉRAULT D., DÉSAUNAY Y. and ELIE P., 1994. Production et abondance de la civelle en France au début des années 90. Bull. Fr. Pêche Piscic., 335, 263-288.

ELIE P. and RIGAUD C., 1984. Etude de la population d'anguilles de l'estuaire et du bassin versant de la Vilaine : examen particulier de l'impact du barrage d'Arzal sur la migration anadrome (civelles), proposition d'amélioration du franchissement de cet obstacle. Cemagref/Université de Rennes, Rennes.

FUENTES Y. en prep. Etat des lieux des poissons migrateurs sur le bassin versant de la Vilaine et définition des potentiels de colonisation, Rapport FDPPMA d'Ille et Vilaine, 52p.

LAFFAILLE P. & LAFAGE D., en préparation. Organisation spatiale des stock d’anguille de l’Aulne, rapport final. Rapport de Université de Rennes pour la Fédération du Finistère pour la Pêche et la Protection du Milieu Aquatique selon un financement contrat de plan état-région.

LAFFAILLE P., LAFAGE D., AUBERT C., 2003 Organisation spatiale et évaluation de l'état des stocks d'anguilles du bassin versant de l'Aulne, bilan de la première année d’investigation. Rapport de Université de Rennes pour la Fédération du Finistère pour la Pêche et la Protection du Milieu Aquatique selon un financement contrat de plan état-région.

LEE T.-W. and LASSERRE G., 1979. Analyse de la structure et estimation du stock d'une population d'anguilles d'un réservoir à poissons du Bassin d'Arcachon. Bulletin d'Ecologie, 10, 139-145.

SCHAAN O., 1993. L'exploitation des anguilles sub-adultes (Anguilla anguilla, L.) dans les estuaire de la Loire et de la Vilaine ; Méthode d'estimation des captures par age, ENSA, Rennes.

154

8.6 Loire District (Aurore Baisez)

8.6.1 Recent Trend

8.6.1.1 Trend in recruitment

8.6.1.2 Experimental fishing

No experimental fishing but it is planned to measure the influx on the Loire estuary by P. Prouzet (IFREMER) on the Adour model extrapolation in 2004 (Indicang Inter-reg IIIb).

8.6.1.3 Eel trap monitoring

There are 24 eel trap monitoring on the Loire and the Sèvre Niortaise.

Figure Fr. 27. Eel trap location on the Loire basin.

All the data are compiled by the Loire coordinator (Loire Eel Board) but each trap has been monitored by different structures.

155

800 000

600 000 s r e

b 400 000 m

Nu 200 000

0 0 0 984 986 988 990 992 994 996 998 0 002 1 1 1 1 1 1 1 1 2 2 Years

Enfreneaux (estuary trap), Parc Marais poitevin

Figure Fr. 28. Numbers of glass eel and elvers on the Enfreneaux trap an estuary pass on the Sèvre Niortaise (Source: Parc du Marais Poitevin).

We observe a decrease from 1984 to 2000. An increase was noticed in 2001. Nevertheless the data are not regular and it is not easy to determine a tendency. To have a time series on the trap, an eel trap survey has been set up in 2001 by the Loire Eel Board on the Sèvre Niortaise which is managed by the Parc du Marais Poitevin.

Number of elvers counting on the trap

5 abbés (Legault & Parc Poitevin)

Apremont (Legault & Dupé) 100 000 80 000

St Félix (Logrami) r e

b 60 000 Boisse m

Nu 40 000

Boule d'or (Legault & Parc Poitevin) 20 000

Massigny (Legault & P arc Poitevin) 0 9 00 01 02 95 96 97 98 9 994 003 Ribou (Chatard FD 49) 1 19 19 19 19 19 20 20 20 2 Years Figure Fr. 29. Numbers of glass eel and elvers on the downstream trap (Source : cf references).

In the downstream sites, a general trend seemed to be shown by the graphics. A decrease was observed during 1995- 1996. Most of the traps show an increase of the recruitment from 1997 to 1999. Until those date, some survey have been stopped because of technical problems.

St Félix is a trap restored in 2003 on the Erdre River (Loire tributary) close to the sea (60km). This installation opens a hydrographical system which is 975 Km². We could notice that from the 4th April to the 19th July 2003, 102 000 glass eels and elvers had crossed the dam and could colonise this system (Viallard, 2003).

156

Number of ye llow e els on the trap

1600 1400 1200 Chardes

r 1000 e

b Decize (Logrami) 800 m

u Poutès (Logrami)

N 600 Vichy (Logrami) 400 200 0 8 84 86 88 90 92 94 96 00 19 19 19 19 19 19 19 199 20 Yea rs

Figure Fr. 30. Numbers of yellow eels on the upper trap of the Loire (Sources : cf references).

On the upper part of the Loire, most of the surveys are not especially made for eel (salmon trap), but the trap managed to count the eel (yellow). For information, Poutès Monistrol is situated at 860 km from the sea,

8.6.1.4 Trend in fishery (Glass eel)

Three basins studied, the Lay, the Loire and the Sèvre Niortaise.

Glas s eel caught by profes ional (Lay )

) 20 000 g k (

h 15 000 g 10 000 cau l e 5 000 ss e a l

G 0 94/95 95/96 96/97 97/98 98/99 99/00 00/01 Years

157

Glass eel caught by profesional (Sèvre Niortaise)

) 25 000 g k (

t 20 000 h g 15 000 cau l 10 000 e

ss e 5 000 a l

G 0 94/95 95/96 96/97 97/98 98/99 99/00 00/01 Years

Figure Fr. 31. Glass eel fisheries in the Lay and the Sèvre Niortaise (Sources : Affaires Maritimes and Parc du Marais Poitevin).

Caught of Glass eel fisheries (tonnes)

90 80 70 60 50 40 30 20 10 0 1998 1999 2000 2001

Figure Fr. 32. Glass eel fisheries in Loire (Sources : Affaires Maritimes).

8.6.1.5 Time series

The fisheries in Loire have started at the beginning of the 1920th. The historical trend was provided by IFREMER (Desaunay et al, 1987). The most recent data come from logbooks analysis 2001. Recent data from administration still have to be collected.

158

Loire

s 900 e i

er 800 h s

i 700 f

l )

e 600 s e

s e 500 s nn a

l 400 (to G

f 300 o

t 200 h

g 100 u a 0 C 0 0 5 00 05 15 20 35 40 50 55 70 85 90 10 25 45 6 65 7 80 95 00 3 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20

Figure Fr. 33. Time serie for the Loire fishery (Sources : Desaunay 1987)

8.6.1.6 Recent development /fisheries market

Figure Fr. 34. Localisation of the fisheries Glass eel sectors

Two kinds of fishermen are regulated, the professionals and amateurs; some others can be commercial. Since 1995, some measures have been taken to control the number of person authorised to catch glass eel in the Loire. The goals for the new management plan are to maintain or reduce the number of fisherman. In the facts the main objective is the status quo. The Loire estuary fishery is regulated by sectors, and to each sector is attributed a quota of licences.

159

Catégorie maximum Secteur de 1995 1996 1997 1998 1999 2000 2001 pêche de pêcheurs de licences

Marins pêcheurs 240 licences CRPM 218 225 ? 236 235 234 232 estuaire de la Loire timbre "civelle" Loire

ZONE MARITIME Marins pêcheurs 240 licences CRPM 138 163 225 235 238 239 240 Pays de la Loire bassin Vendée timbre"civelle"Vendée

50 autorisations: limite Professionnels transversale à celle de fluviaux (en Loire) ? ? ? ? ? ? 31 salure des eaux

LOTS 14 et 15 Professionnels 50 licences spéciales fluviaux "civelle" 41 42 41 43 45 45 42 estuaire Loire 100 licences spéciales Marins pêcheur s "civelle" (parmi les 240 100 100 100 100 100 100 100 (zone mixte) licences "CRPM")

50 licences spéciales Professionnels "civelle" ( même quota fluviaux 41 42 41 43 45 45 42 LOT 13 que lots 14 et 15)

estuaire Loire 65 licences spéciales Marins pêcheurs civelle attribuées parmi 65 65 65 62 65 65 57 les 100 des lots 14 et 15 (partie amont de l'ancienne zone mixte) Professionnels en eau quota non défini. douce d'origine 0 0 0 0 0 0 3 maritime 3 en 2000-2001

SEVRE 15 licences spéciales Professionnels "civelle" (parmi les 50 fluviaux 10 10 10 15 15 15 15 nantaise des lots 15,14 et 13)

Table Fr. 12. Commercial fishermen on the Loire basin.

160

Secteur de pêche Catégorie maximum 1995 1996 1997 1998 1999 2000 2001 de pêcheurs de licences

LOTS 14 et 15

Amateurs aux engins estuaire Loire 200 licences "civelle" et filets sur le DPF 104 108 109 109 108 83 74

(zone mixte)

LOT 13

estuaire Loire 200 licences "civelle" Amateurs aux engins (même quota que lots et filets sur le DPF 104 108 109 109 108 83 74 14 et 15) (partie amont de l'ancienne zone mixte)

SEVRE 20 licences "civelle" Amateurs ADAPAEF 0 0 6 9 10 10 10 nantaise (sur les 200 des lots 15,14 et 13)

Table Fr. 13. Amateur fishermen on the Loire basin.

Mean price (€)/kg on Loire

250

200

150

100

3 9 9 94 95 96 97 98 98 9 99 00 01 9 9 9 19 1 19 19 19 19 19 1 1 20 20

Figure Fr. 35. Trend in price for glass eel in the Loire (Source : Conseil Supérieur de la Pêche de Loire Atlantique).

The price of the glass eel varied between 50 to 200 euros by kilogram. Since 1997, the price seemed to be around 100 to 150 euros excepted in 2001 when it was very high.

8.6.1.7 Fishing mortality

The fishing mortality is not actually studied but some studies are to be started with the INDICANG programme to estimate the fishing mortality of the glass eel influx.

8.6.1.8 Trend in fishery (Yellow eel/Silver eel)

8.6.1.9 Time series

No time series but under work.

161

8.6.1.10 Recent development /fisheries and market

The leisure fisheries using traps (nasses, bosselles) are submitted at CSP control. A general conclusion has been given by T. Changeux (CSP). We present only the departmental variation of the number of authorisation. We notice that the departments close to the sea are more concerned by this technique (Figure Fr. 36).

Figure Fr. 36. Number of amateur fishermen using fishing gears on the Loire basin.

The same analysis has been made for angling (Figure Fr. 37). The repartition of the number of fishermen does not depend on the eel repartition because this species is not always the target. Until 1995 and 2001, we notice a decrease of the fisherman number around 14,6 % due to the reduction of the Salmon and trout.

162

Figure Fr. 37. Number of anglers on the Loire basin.

About 69% of eels are caught in an accessory way. (source : Changeux T. (Conseil Supérieur de la Pêche) and M.L. Gianneti (Logrami), in the Loire Atlantique (Department 44), by a postal survey of 833 fishermen.)

Concerning professional fishermen, there is a traditional fishing technique named” Guideau”. In total, 14 guideaux exploit the silver eels along the Loire river between the french departmentLoir et Cher (41), the Maine et Loire (49) and the Loire Atlantique (44). This guideau is a fixed net, maintained in front of the current and moved from a boat. The mouth of the net has a surface from 45 to 50 m² (9-10 m large and 5 m high) with a 27m long end. The mesh is 160 mm wide on the mouth of the net to 10 mm at the end.

8.6.1.11 Fishing mortality

Fishermen catch 13% of the silver influx (source : Feunteun E. and P. Boury). Between 400 000 to 600 000 eels could from the silver eel escapement target of the Loire at angers.

8.6.1.12 Trend in the stock

There is a decrease of the eel distribution on the Loire basin area. Those data have to be validated because the cartography is an extrapolation from scattered sampling (source : RHP data, Conseil Superieur de la Pêche)

163

N Modification of the area repartition *

Laval Regression of the area Le Mans Orleans repartition since Chancerel, 1994*

Angers Tours Nantes Bes

Bourges

Chateauroux

Poitiers

Population density Data Conseil Limoges Supérieur de la Pêche (Chancerel, 1994) Clermont-Ferrand

Strong (> 12 individuals/100m2) Saint-Etienne Mean (5 à 12 individuals/100m2) 2 Small (1 à 5 individuals/100m ) Le Puy Very small (<1 individuals/100m2) Without eel

* According to the abundances coming from the Sampling site of the National hydro- biologic and fishes Network (CSP) in 2000

Figure Fr. 38. Decrease in the Loire distribution area.

8.6.2 Management

8.6.2.1 Geographical limits

The Loire is the largest structure (28 french départements) and 9 regions : Pays de la Loire, Basse Normandie, Poitou- Charentes, Limousin, Centre, Bourgogne, Auvergne, Rhône-Alpes and Languedoc –Roussillon.

61 28

53 72 45 89

44 49 37 58 18

36 85 86 71 79

23 87 69 17 63 42 16

15 43

164

The management comprises the Loire basin which covers 117 000 km² and coastal streams from vendee and the downstream part of the Sèvre Niortaise for an additional surface of 15 000 km². The plan extends from the upper zone of the Loire, since unclimbed dam to the downstream zone, estuary and salt water if necessary. The total represent 100 000 km of river and tributary.

8.6.2.2 History of management plan

The first management plan was from 1996 to 2002. It has been revised in 1999. Management measures taken by the Cogepomi are listed beyond :

8.6.2.3 Management objectives

- The maintenance of the eel repartition area on the continental zone, even if the level of density is low (less than 50 individuals by hectare on all the Loire catchment area as far as the first blocking dam.

- The maintenance or progress of the yellow eel population with a density sufficient to authorise exploitation by professional and leisure fishermen on the exploited area comprising ( the Loire from estuary to Bec d’Allier, The downstream Vienne, the Maine, the downstream Sèvre nantaise, the Sèvre niortaise, the Erdre, the Loire estuary and the Grandlieu Lake.). upstream from this limit, the eel is not exploited.

- A catch effort compatible with a sufficient target to contribute to the stock replacement.

8.6.2.4 Management measures

8.6.2.5 Fishery

Diminution of fishery duration of 15 days in some sectors of the estuary. Interdiction silver eel fisheries on water mills (2003). Slight increase of fishing effort in some places but no more licences delivered. Status quo elsewhere

8.6.2.6 Habitat

A particular effort is made to restore favorable habitat for eel, especially the Loire annexes disconnected since the dredging of the Loire.

165

8.6.2.7 Migration

Figure Fr. 39. Loire watershed migratory network state (Sources : Plan de gestion des Poissons Migratoires, Bassin Loire 2003-2007)

An analysis of the state of the hydraulic migratory system was done. The main axis is relatively free but the secondary tributaries are difficult to cross. At the basin level, each dam has been expertised in order to determine the eel crossing possibilities.

166

Figure Fr. 40. Dam and crossing ability for eel on the Loire watershed (Sources : Conseil Supérieur de la Pêche Plan Loire).

In France, the rivers can be classified for migration (code of environment article L 432-6). Depending on the river status, the installation of the fish pass for eel is obliged or not (Figure). The change of classification is a long procedure. Once finished, there is 5 years to restore the migratory axis. The classification has been proposed in several rivers (See map and management plan for detail)

167

Laval Le Mans Orléans

Blois

Angers Tour Nantes

Bourges

Chateauroux Nevers

Poitiers Moulins OCEAN Montluçon ATLANTIQUE Guéret

Roanne

Limoges

St-Etienne

Passe à poissons obligatoire pour tout ouvrage nouveau (art L 423-7) avec liste d’espèces comprenant l’anguille (art L 432-6 1er et 2ème alinéas) Le Puy avec liste d’espèces ne comprenant pas l’anguille (art L 432-6 1er et 2ème alinéas)

Figure Fr. 41. Proposition for regulation of migration on the Loire basin, the two shades of green indicate if the eel is comprised.

In the second management plan the objectives are to facilitate the migration until the major dam on the upper part of the river:

Buzay,

Saint Félix sluice on the Erdre,

Blois and Decize dam (middle Loire),

La Haye Descartes dam on the Creuse tributary,

Châtellerault dam on the Vienne tributary, reopening of the downstream reaches from the Mayenne, Sarthe and Loir,

The Rochepinard dam on the Cher, the Guétin and prise d'eau des Lorrains at the bec d'Allier, the hydroelectric dam of Poutès-Monistrol on the upper Allier, the Enfreneaux dam in theSèvre Niortaise estuary.

168

BASSIN axe or dams Dams or system Price (K€) Allier 11 dams 610

Sioule 9 dams 150

Allier Dore 5 dams 300 Allagnon 12 dams 610 S/TOTAL 1 670 Decize Re-management + 350 Loire Amont control station Arroux Arroux effacement + pass 140 S/TOTAL 490 Blois: mobil dams effacement or 3 500 à 11 000 equipment Loire Moyenne Belleville post dams in Right 910 bank S/TOTAL 4 410 à 11 910 Savonnières: partie pré-dams and pass in 110 piscicole right bank Cher Rochepinard Artificial river 690 partie piscicole Tours–Bigny: 6 pass Canoe Kayack, 1 830 ouvrages alosa and eels S/TOTAL 2 630 Châtellerault pass for aloses + 910 control station Bonneuil pass for aloses + ? dévalaison Saint-Mars pass for aloses + ? dévalaison Pont de Lussac Mixt pass e for big 230 place Vienne Gouex pass for fish 30 Charight bankes pass for eels ? Les Roches pass for eels ? Jousseau pass for eels ? Creuse: alose et 3 structure +station 720 saumon (Descartes) Creuse: alose 14 passs for fish 460 Gartempe 26 structure to put in 720 place or getting better S/TOTAL 3 070 Table Fr. 14. program for restoring of the free migration on the Loire

169

8.6.2.8 Water quality

8.6.2.9 Re-stocking

The management plan recommends transportation only when no other solution are available and only for intra basin transport

8.6.2.10 Monitoring

All actions are monitored and managed by the Loire eel board. This system has to be continued and with the goal of surveying each stage:

- estuary recruitment,

- Fluvial recruitment,

- Yellow sedentary population,

- Production of the silver eel for reproduction.

The Loire eel Board takes into account the environment parameter like the characterization of the habitat (potential surface), the hydrology, the water quality etc…

8.6.2.11 Is target conforming to the 30% SPR rule

8.6.3 References :

Trap monitoring

Ribou = Chatard N., (2001). Analyse de la structure de la population d’anguilles Anguilla anguilla (étude otolithométrique) et des flux migratoire dans la rivière Moins. Rapport Fédération pour la pêche et la protection du milieu aquatique de Maine et Loire, 55 pages.

Poutès = EDF (2002). Suivi de la dévalaison des saumoneaux et monté des saumons au droit du dams de Poutès Monistrol sur l'Allier., EDF: 25.

Decize = Logrami (2002). Suivi de la population de migrateurs du dams de Decize au printemps. LOGRAMI: 13.

Vichy = Logrami non publié (2002). “Suivi du dams de Vichy.”.

St Félix = LOGRAMI, Viallard J. (2003). Mesure de la colonisation du bassin versant de l'Erdre par la passe à anguille du dams de Saint Félix (Nantes, 44), Logrami: 55 pages.

Autres = Legault com pers.

Enfreneaux, 5 abbé = Parc Marais Poitevin =

BERTIGNAC M., 1984. Etude d'une passe à civelles et des manœuvres d'ouvrage à la mer - applications au bassin de la Sèvre Niortaise. PNR Marais Poitevin. 68p.

AUBRUN L., 1985. Amélioration du franchissement des dams par l'anguille - expérimentaions dans le bassin de la Sèvre Niortaise. 65p.

MESTIRI F., 1987. Etude de l'efficacité des passes à civelles dans le Marais Poitevin. Diplôme d'agronomie approfondie spécialité halieutique. 86p.

FILLEUL A., 1995. Etude de la migration de l'anguille dans le Marais Poitevin. Fish Pass/PNR Marais Poitevin. 38p.

170

DAMIEN J.P., 1996. Suivi et analyse de la dynamique migratoire de l’anguille dans le Marais Poitevin. Rap. MST Imacof/PNR Marais Poitevin. 55p.

ROSI R., 1998. Suivi de la migration anadrome de l'anguille dans le Marais Poitevin. PIMP. 12p.

BEAUBEAU N., 2000. Suivi de la migration anadrome de l'anguille dans le Marais Poitevin. PIMP. 20p.

MARTEAU ML., 2001. Suivi et analyse de la migration de l'anguille dans le Marais Poitevin, rapport de stage IAE, P.I.M.P, 37p.

BROSSARD A., 2002. Suivi et analyse de la dynamique migratoire de l’anguille dans le Marais Poitevin. Rap IUT Tours. 50p,

PARC INTERREGIONAL DU MARAIS POITEVIN, 2003. Réseau de suivi et de surveillance de la population d'anguille du bassin de la Sèvre Niortaise et des bassins associés, 56p.

8.7 Garonne district (Gérard Castelnaud, Gilles Adam, Laurent Beaulaton)

8.7.1 Recent trend

8.7.1.1 Trend in recruitment

8.7.1.2 Experimental fishing

The Gironde survey consists in a monthly sampling of 24 stations (surface + deep) distributed along 4 transects. This monitoring aims at evaluating the abundance variations of the juveniles of fish and crustacean and the adults of small species.

density (glass eels / 1000 m3)

density 14

0 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Figure Fr. 42. Glass eel abundance from experimental fishing 1991-2001

No trend is indicated by the curve of abundance, from 5 to 7 glass eel / 1000 m3 (Figure Fr. 42).

171

8.7.1.3 Eel trap monitoring

A lot of eel ladder have been constructed, but few provide an evaluation of crossing. The Tuilière dam has been equipped since 1989 with a multi specific fish lift comprising a control system. Two specific eel ladder (ramp and brush) have been installed in 1997, with operational counting in 2000/2001.

50000

40000 s

ille 30000 u g n

a 20000 b N 10000

3 5 0 89 90 91 92 9 94 9 96 97 98 99 0 01 02 9 19 1 19 19 19 19 19 19 19 19 19 20 20 20 Ascenseur rampe anguilles

Figure Fr. 43. Eel crossing of the Tuilière dam (MIGADO), ascenseur = eel lift, rampe anguille= eel ladder

The number of eel crossing at the Tuilière dam is particularly low for eel as they should be hundreds of thousands individuals to form a large enough colonization target (Figure Fr. 43). On the Golfech site, a similar experiment allowed the crossing of 19 000 eels in an eel ladder while 267 crossed in a fish lift in 2002.

8.7.1.4 Trend in fishery (Glass eel)

8.7.1.5 Method

Beside the recent involvement of CRTS and CSP (sustained by the professional fishermen association), the Cemagref collect his own data of capture and effort, from a sample of cooperative fishermen. The results presented here for the period 1978-2000 are from Cemagref.

8.7.1.6 Time series

The maximum for pibalour in 2000.in the estuary is in January, like in 1999 (Figure Fr. 44).

172

10 Zones 2 à 6 8

0 Novembre Décembre Janvier Février Mars

Figure Fr. 44. CPUE per month of cooperative fishermen in the estuary, pibalour, 2000 (kg/. pibalour/day of fishing).

Hand scoop net catches occurs only in February (0.8 kg) on the Garonne in 2000 (not shown on the graph) while they are absent the same month on Dordogne-Isle. The maximum for both hand scoop net and pushed net is in March on Dordogne-Isle (Figure Fr. 45).

2,5 T : Zones 10 à 13 D : Zones 7 à 9 2 D : Zones 10 à 13

1,5

0,5

0 Novembre Décembre Janvier Février Mars

Figure Fr. 45. Hand net (T) and pushed net (D). CPUE per month of cooperative fishermen for Garonne and Dordogne-Isle, 2000 (in kg/net/day of fishing and kg/pushed net/day of fishing).The CPUE for pibalour in estuary remains at the previous level but decreases for the two others “métiers” (Table Fr. 15).

CPUE par campagne de Métiers Zones de pêche pêche Tamis * 7 à 13 1,5 Drossage *** 7 à 13 1,7 Pibalour ** 2 à 6 6,6 * in kg/net/day of fishing ** in kg/fishing team. pibalour/fishing day *** in kg/équip. drossage/fishing day

Table Fr. 15. CPUE for 2000 of cooperative fishermen » for « hand net » and « pushed net » in the Garonne and theDordogne-Isle and for « pibalour » in estuary.

173

capture (t) cpue (kg/day) year pibalour PRO tamis PRO tamis NONPRO drossage PRO total pibalour 1977-1978 26.7 83.3 107.8 217.8 12.8 1978-1979 28.0 89.7 116.2 234.0 14.0 1979-1980 45.8 167.3 217.1 430.2 25.4 1980-1981 45.5 78.3 150.6 274.4 14.9 1981-1982 49.6 36.6 36.5 122.8 10.9 1982-1983 49.5 25.8 26.9 102.2 12.7 1983-1984 30.5 26.0 26.0 82.6 17.6 1984-1985 16.3 11.7 11.8 39.8 8.1 1985-1986 26.3 13.6 14.4 54.3 8.8 1986-1987 31.9 25.0 28.6 85.5 13.5 1987-1988 25.4 6.7 6.7 38.9 9.3 1988-1989 37.5 15.6 17.3 70.5 7.1 1989-1990 28.6 8.6 9.0 46.2 5.6 1990-1991 36.0 9.6 14.5 60.0 8.5 1991-1992 17.0 8.0 12.8 37.8 4.5 1992-1993 29.6 11.6 21.7 62.9 8.9 1993-1994 34.6 6.5 12.4 53.5 9.2 1994-1995 47.5 9.6 18.9 75.9 7.9 1995-1996 21.4 1.5 4.2 2.2 29.4 4.7 1996-1997 33.0 3.6 6.4 7.9 50.9 6.3 1997-1998 14.1 0.4 1.0 1.7 17.2 3.8 1998-1999 40.6 0.8 2.7 7.5 51.6 8.9 1999-2000 21.2 0.1 0.3 3.4 25.1 6.6

Table Fr 16 : Total eel captures by type of gears and category of fishermen, CPUE for the Gironde basin (1978-2000).

174

(1) captures (t) (2) CPUE (kg / day)

500 30 drossage PRO (1) 450 tamis NONPRO (1) tamis PRO (1) 25 400 pibalour PRO (1) CPUE pibalour (2)

350 20

300

250 15

200

10 150

100 5

0 0 1977-1978 1978-1979 1979-1980 1980-1981 1981-1982 1982-1983 1983-1984 1984-1985 1985-1986 1986-1987 1987-1988 1988-1989 1989-1990 1990-1991 1991-1992 1992-1993 1993-1994 1994-1995 1995-1996 1996-1997 1997-1998 1998-1999 1999-2000

Figure Fr. 46. Cumulated capture of glass eel for professional and non professional fishermen, CPUE on the Gironde basin for1978-2000 (Cemagref).

The CPUE followed the same trend than total catches in early eighties. Nowadays we are in a stationary situation for the abundance index, with low catches (Figure Fr. 46 and Table 16).

The total production for the Gironde basin in 2000 is 25,1t with a value of 3 464 k€.

8.7.1.7 Recent development / fisheries market

8.7.1.8 Fishing mortality

8.7.1.9 Trend in fishery (Yellow eel / Silver eel)

8.7.1.10 Time series

No silver eel are targeted on the basin. The maximum of the CPUE is in spring on the estuary with a second in November this year 2000. On the Garonne this maximum is in October and in June on Dordogne, with a shorter season than in estuary (Figure Fr. 47).

175

6 Zones 2 à 6

5 Zones 7 à 9 Zones 10 à 13 4

0 Jan Fév Mars Avril Mai Juin Juil Août Sept Oct Nov Déc

Figure Fr. 47. Yellow eel hook net catches, 2000. CPUE per month of cooperative fishermen in the Gironde with pot (in kg/pot/month). (zone 2 to 6 estuary, zone 7 to 9 Garonne, zone 10-13 Dordogne)

The CPUE and the total catches have decreased in 1988-1989. The total catches continue in the same sense, while the trend of CPUE seems to change but do not recuperate the previous level. This is due to the decrease of the number of fishermen and the change in the fishing tactic that masks the real trend of abundance (Figure Fr. 48).

The total production of yellow eel in the Gironde basin in 2000 is 21.4t with a value of 235.4 k€.

(1) captures (t) (2) CPUE (kg / pot / month) 500 2,0 nasse NONPRO (1) nasse PRO (1) 450 1,8 CPUE (2)

400 1,6

350 1,4

300 1,2

250 1,0

200 0,8

150 0,6

100 0,4

50 0,2

0 0,0 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Figure Fr. 48. Cumulated catch of yellow eel for professional and non professional fishermen, CPUE on the Gironde basin for1978-2000 (Cemagref).

176

8.7.1.11 Recent development / fisheries market

Among the population of 184 professional fishermen composed of 101 marine fishermen and 83 river fishermen, 149 fish glass eel with pibalour, hand scoop net and pushed scoop net.

The socio-economic study of the European contract “Pecosude” was based on a sample of 10 marine fishermen and 10 river fishermen representing 10 % of the total population. The sampling was planned according to a typology of the fishermen activity

The marine fishermen are very dependant of glass eel because this specie represents 72,5 % of their turn over while it represents 38.5% for the river fishermen. The turnover of this category is determined also by two others species: marine lamprey (29%) and allis shad (28%).

8.7.1.12 Fishing mortality

8.7.1.13 Trend in the stock

Data from the RHP hydoelectric network of the CSP, were used in the Garonne basin downstream from the major dams (Figure Fr. 51). It corresponded to 53 stations : Charente 10 stations ; Dordogne 13 ; Garonne 28 ; Leyre 2. The results on eel density are shown on Figure Fr. 49

Figure Fr. 49. Observed densities et and eel repartition in grey 0 à 0.05 eel/m² ; in green 0.05 to 0.95 eel/m² ; R = area for re-stocking in eel and juvenile eels (CSP - COGEPOMI Garonne 2002)

177

8.7.2 Management

8.7.2.1 Geographical limits

The limits of the basins are fixed by the décret n° 94.157 du 16 février 1994 (J.O. du 23 février 1994) ; the basin correspond to the FAO definition of inland waters and comprise estuaries.

The basins concerned

- Garonne

- Charente

- Seudre

- Leyre

- étangs médocains

8.7.2.2 History of management

The previous management plan concerned the period 1995-2000 ; it has been linked with the present plan launched for the period 2003-2007.

8.7.2.3 Management objectives

The objectives of the present management plan are :

- to realise a statement on the status of the species in the whole Garonne basin and a study about eel fishery to complete the official moinitoring which concern only a part of amateurs fishermen and not anglers

- to improve the crossing of dams for the upstream and downstream migration

- define targets of colonisation of the basin and escapement of silver eel

- to monitore the prevalence of Anguillicola crassus on the basin

- to set up a management board for the regional management administrations.

8.7.2.4 Management measures

The COGEPOMI wants that the proposed biological studies on the basin would be examined by the GRISAM to b e accepted.

8.7.2.5 Fishery

Salt limits have to be defined in some tributaries to facilitate police controls. Cooperation between marine and river fishing guards has to be developed with special measures concerning eel fishermen and poachers. The reduction of the fishing pressure on all stages and for all categories of fishermen will be defined. No new authorisation to fish silver eel will be delivered. The settlement of obliged commercial points is necessary to limit illegal market.

8.7.2.6 Habitat

All measures to avoid drying of small tributaries and to guaranty a minimum level of discharge in the basin, according to the SDAGE, have to be taken.

178

8.7.2.7 Migration

The level of crossing possibilities for migratory species has been defined on the rivers qualified as “axes bleus”; Liste 1 of rivers where the restoration actions are in process; Liste 2 of following rivers to be restored in priority (Table 17).

Axe bleu Liste 1 Liste 2

Bassins Linéaire total 72 km 28 km

Charente et Seudre Linéaire ouvert 100 % 100 %

Nb obstacles 0 4

franchissables 100 % 100 %

Bassin Dordogne Linéaire total 740 km 223 km

Linéaire ouvert 71 % (529 km) 47 % (105 km)

Nb obstacles 77 150

franchissables 61 % 82 %

Bassin Tarn-Aveyron Linéaire total 423 km 59 km

Linéaire ouvert 41 % (174 km) 0 %

Nb obstacles 104 15

franchissables 66 % 13 %

Bassin Garonne Linéaire total 746 km 223 km

Linéaire ouvert 66 % (494 km) 0 % (1,5 km)

Nb obstacles 103 57

franchissables 61 % 44 %

Côtiers Aquitains Linéaire total 52 km 246 km

En partie sur le Linéaire ouvert 16 % (8 km) 21 % (52 km) COGEPOMI Adour Nb obstacles 8 20

franchissables 50 % 10 %

Table Fr 17. Level of crossing possibilities for migratory species on the rivers « axes bleus « (Mission Poissons Migrateurs Adour Garonne, mars 2000).

These crossing possibilities in rivers « axes bleus « are based on salmon ; they have to integrate specifically the eel species. It is necessary to improve and create specific equipments of dams for eel, to monitor the progress in equipments and evaluate the efficiency of eel crossing.

179

On the Garonne basin, a first evaluation of the number of dam has been realised, both for upstream and downstream eel circulation (Figures Fr 50 and 51).

Figure Fr. 50. Number of dams non-equipped for upstream migration (CSP – COGEPOMI Garonne 2002). Blue =transparency, green = 0 to 5 / 100 km, yellow =5 to 10; orange = 10 to 25; red > 25.

180

Figure Fr. 51. Number of dams non-equipped for downstream migration (CSP – COGEPOMI Garonne 2002)

181

8.7.2.8 Water quality

Even if some improvement in water quality have been performed, it is necessary to equip cities with water treatment plants in connection with the WFD.

8.7.2.9 Re-stocking

The Lot, Aveyron and Tarn rivers were restocked in the eighties. Recently, from 1996 to 1998, 410 kg of glass eels have been introduced in Ariège, Garonne, Lot and Dordogne river.

Re-stocking have to be performed inside the same basin, in the areas without parasites. The process has to be controlled by CSP and MIGADO, in connection with fishermen associations.

8.7.3 References

BEAULATON, 2002. Analyse des indicateurs halieutiques de la civelle dans le bassin de la Gironde et dynamique des flux. Mémoire de DAA Spécialisation halieutique. Cemagref Groupement de Bordeaux, ENSA de Rennes, 58p. + annexes.

CARRY, L., SAGE, D., GRACIA, S., DELEZAY, B. 2003. Etude du rythme de migration des espèces amphibiotiques et holobiotiques de la Dordogne au niveau de la station de contrôle de Tuilières au cours de l'année 2002. Rapport MIGADO.

GIRARDIN M., CASTELNAUD G., BEAULATON L., 2002. Surveillance halieutique de l'estuaire de la Gironde - Suivi des captures 2000 - Étude de la faune circulante 2001. Rapport pour EDF CNPE du Blayais/ Etude Cemagref, groupement de Bordeaux, Cestas. n°74, 204 p

COGEPOMI Garonne, 2003. Plan de gestion des poissons migrateurs du bassin de la Garonne pour la période 2003- 2007.

TEYSSIER F., GAYOU F., FILKZINGER P., GALLAY E., LEMOINE A., TAILLEBOIS L. 2002. Plan de gestion des poissons migrateurs amphihalins Garonne-Dordogne-Charente-Leyre-Seudre. Situation et propositions. CSP Délégation Régionale Aquitaine, Midi-Pyrénées. 30p. + annexes.

182

8.8 Adour District (Marie Noëlle De Casamajor)

8.8.1 Recent Trend

8.8.1.1 Trend in recruitment

Quality of recruitment

The works in progress on isotopic proportions of otoliths on glass eels on the basin of Adour and the whole of Europe. The aim was to characterize the paths of migration used during the oceanic crossing and to try to find if glass eel come from only a single area of reproduction or from different area of reproduction in the Sargasso sea. Complementary works from various samples sites would be necessary to determine the fluctuation of the conditions of migrations between site and years.

Works on glass eel quality of recruitment on the basin of Adour will make us possible to know the structure and the genetic variability of the populations of A. anguilla of the south of the Bay of Biscay and to better understand the effects of the contaminants xenobiotic on these populations. They would have help us in particular to :

- obtain a better knowledge of genetic resources of these populations in the basin of Adour ;

- lay out bio-markers of exposure of the populations to the pollutants and thus of quality of the resource ;

- the description of the effects of some contaminants on physiology (short term) and resources genetic (long term) and to compare the effects of the contaminants according to habitats.

8.8.1.2 Trend in fishery (Glass eel)

Historical analysis of glass eels catches on the basin of Adour and their analysis of variability over the recent period: 1985-2002

20 ) ie t r so / g 15 (K CPUE 10

0 1928 1930 1967 1969 1971 1973 1975 1980 1985 1987 1989 1991 1993 1995 1997 1999 2001

1927/ 1929/ 1966/ 1968/ 1970/ 1972/ 1974/ 1979/ 1984/ 1986/ 1988/ 1990/ 1992/ 1994/ 1996/ 1998/ 2000/

CPUE moyenne CPUE Mini CPUE Maxi

Figure Fr. 52.Variations of the glass eels catches by exit of 1927 to 2002.

The historical series of glass eel fluctuations of catches in the basin of Adour show a fall of the catches from the beginning of the Eighties (figure 52) related to the decrease of production of yellow eel by the beginning of the Seventies. In the basin of Adour, this period was marked by some modifications of agricultural practices : increase in the cereal cultures, increase in drainage and irrigation, increase in the use of chemical products. This figure 53 shows

183

that the variability of the glass eel captures over the recent period (1985 - 2002) seems especially related to the fluctuations of hydro-climatic conditions.

4.5

3.5

2.5

1.5

0.5

0 87/88 88/89 89/90 90/91 91/92 92/93 93/94 94/95 95/96 96/97 97/98 98/99 99/00 00/01 00/02

Moyenne Tamis poussé Tamis à main

Figure Fr. 53.Variations of glass eels captures per type of fishing gears over the recent period.

14 0.5 0.45 12 0.4 10 0.35

8 0.3 0.25 6 0.2

4 0.15 0.1 2 0.05 0 0 1 2 3 4 5 6 7 8 9 0 1 2 9 9 9 9 9 9 9 9 9 0 0 0 9 9 9 9 9 9 9 9 9 0 0 0 1 1 1 1 1 1 1 1 1 2 2 2

/ / / / / / / / / / / / 90 91 92 93 94 95 96 97 98 99 00 01 9 19 19 19 19 19 19 19 19 19 1 20 20 Poids capturé PF(T) Poids capturé PM(T) Poids capturé PA(T)

Figure Fr. 54 – Fluctuations of glass eels catches for fluvial fishermen during recent period.

(Sources Ifremer/SNPE)

8.8.1.3 Time series

For the majority of sampling date, surface density of glass eels weakest corresponds to 0. The average density highest is observed on 16 of January (2,8 g/100m3) with a maximum of 4g/100 m3 and a minimum of 1,5 g/100m3. The density of glass eels remain low on average over the season between 0 and 1,8g/100m3). The season 2001/2002 was caracterised by very low densities.

184

Table Fr. 18. Descriptive statistical parameters of the density of glass eels at the bottom (expressed in g/100 m3 ) according to the exits for marketing year 2001/2002.

Densité fond maximum minimum mean SD Nb transects 21/11/2001 2,562 0,05 0,672 0,81 8 05/12/2001 1,187 0 0,489 0,471 8 11/12/2001 5,122 0,468 1,533 1,557 8 18/12/2001 0 0 0 0 8 03/01/2002 4,099 0,326 1,891 1,19 8 09/01/2002 5,515 0,281 1,949 1,82 8 16/01/2002 7,53 1,55 3,336 1,836 8 22/01/2002 0,25 0 0,112 0,124 6 05/02/2002 1,58 0 0,534 0,505 8 21/02/2002 0,426 0 0,177 0,197 6

Table Fr. 19. Descriptive statistical parameters of the density of glass eels at the surface (expressed in g/100m3) according to the exits for marketing year 2001/2002.

Densité surface Maximum minimum mean SD nbre transects 21/11/2001 0,261 0 0,074 0,11 8 05/12/2001 0 0 0 8 11/12/2001 0,206 0 0,07 0,098 8 18/12/2001 0,229 0 0,059 0,097 8 03/01/2002 3,708 0 1,224 1,168 8 09/01/2002 1,844 0 0,857 0,606 8 16/01/2002 4,025 1,584 2,861 0,946 8 22/01/2002 0,168 0 0,049 0,077 6 05/02/2002 1,307 0,106 0,474 0,37 8 21/02/2002 0,702 0 0,326 0,31 6

8.8.1.4 Recent development /fisheries market

8.8.1.5 Fishing mortality

The principal results showed shifted effects of the air temperature and tide coefficient on glass eels catches. A predictive model of CPUE makes it possible to describe the environment influencing the CPUE like a linear function of the level of rain, of the cosine of lunation, the tide coefficient of the previous day and the level of flow of the Adour river of two days before the last.

The first approach to estimate biomass uses a sinusoidal model of the speed of the water flow to establish a stochastic model of the density variations observed according to the current velocity of flood, a given day. The estimates of biomass provided by this method are generally precise and not very sensitive to the division of the water column. The second approach connects measurements of the observed glass eels concentrations to the initial local concentration via a statistical model obtained by aggregation of the local concentrations: the goal here is to express the biomass of the glass eel run in terms of the initial concentration. The estimates provided this latter way are generally of the same order of magnitude as the preceding ones.

Mono and bi-dimensional hydrodynamic models are used for estimating the glass eel biomass ; they are also used in a behavioural model which allows the simulation of glass eel groups trajectories which stick to the bottom as soon as the current moves towards downstream with an intensity of more than 0,3m/s. They remain at the bottom as long as the daylight persists.

Stochastic modeling and estimate of gass eels flows

185

A protocol of glass eels sampling flux transported by the flood tide in the Adour estuary and two methods to estimate the biomass of daily flux and of its variance adapted to the constraints imposed by the sampling design are presented (figure 54).

This protocol is based on the simultaneous captured of glass eels situated on the surface and in full water along three longitudinal transects. This method is usable in estuary whose width does not exceed 400 meters approximately. These captured are done behind the dynamic face of tide in fixed station and during all the flood.

Figure Fr. 55.Descriptive diagram of the materials of taking away and positioning used.

The first estimated method developed uses a sinusoidal model speed, to establish a stochastic model of variation of the density observed (in g/100m3) according to the current velocity of flood, a day given. The volume of water sampled is divided into 6 zones of calculation (corresponding to the 3 transects of surface and the 3 bottom ones). The calculation of the biomass is carried out for each subfield starting from a formulation taking in account the average density on a zone and the integral speed during the flood. An approximate formula of the coefficient of variation is proposed, by taking constant the variance of the term of error in time for the model binding the densities at the speeds.

186

Saison de migration 1999/2000

1800 1600

n 1400 e

(

ée 1200 m i 1000

800 asse est

m 600 o i

B 400

200

0 26-nov-99 06-déc-99 16-déc-99 26-déc-99 05-janv-00 15-janv-00 25-janv-00 04-f évr-00 14-f évr-00 Dat e s

Biomasse estimée (en kg) Poids capturé (en kg)

Figure Fr. 56. Representation of the evolution of the estimated biomass of glass eels and to their weight captured by the professional fisheries in maritime zone: season of migration 1999/2000

The model provides orders of magnitude of daily rates of exploitation of whose medians for the seasons of fishing 1998/1999 ; 1999/2000 and 2000/2001 lie between 6 and 26%.

A second method suggested connects measurements of concentrations into glass eels (= densities) observed to the initial local concentration, via a statistical model obtained by aggregation of the local concentrations, in order to express the biomass of a flow going up of glass eel according to this initial concentration. This method is particularly sensitive to initial distribution of the concentration which is assumed of Gaussian type.

Bathymetry of estuary and hydrodynamic modeling - Calibration of the model of estuary circulation

The unidimensional hydrodynamic model was implemented : bathymetric screens, introduction of a curvilinear axis. It makes possible to simulate, according to a longitudinal axis, a mean velocity on the unit of the water column (figure 57). It constitutes the base of the model of the transport equation of glass eels and the behavioral model.

0.8

0.7

0.6

0.5 s / vitesse mesurée e m 0.4 ess t vitesse canal vi vitesse bathy 0.3

0.2

0.1

0 Station 1 station 1bis station 2 station 3 station 4 station 5

Figure Fr. 57. Comparisons of current speeds measured on the ground with those calculated by the hydrodynamic model when Adour is assimilated to a channel (speed channel) with taking into account bathymetry (speed bathy)- (22 of 1998 – débit : 95,41 m3/s – coeff : 83 – BM : 10h20 – PM : 16h40).

187

The two-dimensional model, resulting from the system of Navier-Stokes equations, makes possible to generate current dissymetries in the cross section as well as the height variations of water. It deals with the problem of the islands and the junctions (figure 58).

The hydrodynamic simulator couples model 1D and 2D to avoid crippling costs of calculation. Under these conditions, only the zone of interest is treated into two-dimensional; the remainder of the field of calculation is then regarded as unidimensional and allows the initialisation of simulation.

Figure Fr. 58. Calculations speeds to the accesses of an island by the model 2D.

A graphic interface " Erreka " was developed by the UPPA-LMA and the calibration of the model corresponding to the estimate of the friction coefficients was carried out starting from the campaigns of courantometry carried out by the IFREMER-LHA. The adequacy between the actual values and simulated was good.

Figure Fr. 59. Joint variation in the time (x axis) speeds measured and calculated (y axis) in a fixed point (the curve in blue represents measured speeds while red corresponds it at the calculated speeds).

We note, however, a smoothing of the speeds variation simulated compared to those observed and a spreading out of the tidal wave with for consequence of the numerical variations preceding the current fluctuations observed (figure 59).

Development of a deterministic model of the behavior of glass eels

This model is used as a basis for a simulator of the behavior which uses for longitudinal transport, the unidimensional hydrodynamic model. The simulator is generated by injection of glass eels groups (concentration 50g/100m3) in a mesh of the hydrodynamic model located at the mouth corresponding to a volume of 200m thickness, width equal to the river one and height equal to the water column one at the time of the injection. Various simulations were tested and show coherent diagrams of propagation with the observations. Those make possible to explain majority of the cases of fluctuations for density met at the time of the campaigns in fixed stations or mobiles behind the face of the dynamic tide (Figure 60).

188

Figure Fr. 60. Example of simulation with hydrodynamic conditions the 21/01/2000 At 2 o' clock in the morning.

8.8.1.6 Trend in fishery (Yellow eel/Silver eel)

8.8.1.7 Time series

8.8.1.8 Recent development /fisheries and market

8.8.1.9 Fishing mortality

Yellow eels 12 25 Production Pêcheurs 10 20

8 N om

15 bre de pê onnes) 6 on (t i

cheur 10 oduct r s P

5 2

0 0 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 Figure Fr. 61. Evolution of the production of yellow eel Annéande denu captmureber of fishermen in marine zone of the Adour estuary.

We do not observe increase in the effort of yellow eel fishing on all parts of the Adour river. On the contrary, the captures and the number of fishermen tend to decrease during last years (figure 61 & 62)

189

120 1000 900 100 800 s r 700 u

80 ) e g

h 600 K c ( s pê 60 500

400 id de Po e

r 40 300 b

m 200 o 20 N 100 0 0 1999 2000 2001 2002

Nb pêcheurs fluviaux Poids (Kg)

Figure Fr. 62. Evolution of production of yellow eel and number of professional fishermen in Adour river.(source SNPE)

8.8.1.10 Trend in the stock

Intensity of colonization and production of yellow and silver eels in the catchment area of Adour and Gaves

The data base used comes from observations resulting either from piscicultural diagnoses carried out since 1977, or of the Pisces and Hydrobiological Network (RHP) of the CSP set up in 1994, or of the Eel Network developed by MIGRADOUR since 1998. Observation taken into account in the analysis must have a location known to be characterised according to the classification of Huet. Fished surface must be estimated. The data of abundance must be able to be treated according to the estimate method of the most probable settlements (successive captures). The collected observations interests 6 parts of the Adour basin.

BV1 (Adour upstream of the nozzle of Gaves and affluents of left bank - surface 6260km²) ;

BV2 (Midouze - surface 3155 km²) ;

BV3 (gave of Joined together Pau and gaves - surface 2800 km²) ;

BV4 (gave of Oloron -surface 2630 km²) ;

BV5 (Bidouze - merry - surface 1085 km²) ;

BV6 (Nive - surface 1030 km²) (figure 63).

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Figure Fr. 63. Division of the catchment area of Adour and Gaves for the eel study.

The data are treated by Factorial Analysis of the Multiple Correspondences, it make possible to show the existence of a gradient of densities and sizes on the scale of the river: stronger densities downstream and bigger sizes upstream. With the scale of the various under-basins slopes, a heterogeneity of the densities was observed.

A cartographic representation makes it possible to visualise the intensity of colonization on the whole of the catchment area of Adour and Gaves. The classes of densities are defined on the whole of the piscicultural inventories, but by taking account types of zones defined according to the classification of Huet.

The cartographic analysis highlights the importance of the factor " distance to the sea ". The under-basins short slopes to which the sources are close to the sea like those of Nive or Bidouze have the strongest densities with a gradient of densities slightly decreasing upstream. For the other more distant basins, the densities are generally lower with a strongly decreasing gradient of densities of the downstream upstream. Some, like the basin of the gave of Pau, have a distribution of the densities strongly influenced by the negative effect of the stoppings on the upstream migration of eel. Others, as the catchment area of Midouze presents a reversed gradient (stronger densities upstream) which could be induced by pollution of origins chemical and organic.

The temporal variability of the densities on the catchment area of Adour and Gaves is highlighted. The most recent period of inventories (1997-2001) corresponds to the strongest densities whereas the intermediate period (1988-1991) is characterized by the lowest densities (figure 64).

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Figure Fr. 64. Representation of the densities of eels per year on the unit of the Adour basin after elimination of fishings of the Network Eel.

It is however very difficult in the current state of the investigations to conclude on an unspecified tendency from the evolution from the densities on the basin of Adour since 1977 but the sampling design of the under-basins slopes was modified many times. It will thus be necessary to consider the temporal profiles of evolution of the densities, not by piscicultural zones, but by stations of inventories.

We can advance, at most, that the densities currently observed are not lower than those which one could count at the end of the Seventies. That does not make it possible to conclude however on a stability of the eel biomasses since the evolution of the zones colonized by this species was not undertaken within the framework of this study.

Silver eel

Measurements of effectiveness of the discharge system of the hydroelectric station of Halsou on Nive during the three last years (2000 to 2002) were carried out for the downstream migration of silver eels. An estimate was carried out starting from these data, over a 4 months season between September to December. A number of eels in migration was evaluated, ranging between 1500 and 2000 individuals for Nive (Gosset et al., 2002).

8.8.2 Management

8.8.2.1 History of management plan

8.8.2.2 Geographical limits

The rivers of the basins of Adour and the coastal rivers whose mouth were located in the departments of the Landes and Pyrénées-Atlantiques, other than Bidassoa, are covered by the board of management of migratory fishes of the Adour basin (COGEPOMI Adour). The presidency of this committee is taken by the prefect of the Aquitaine area or its representative.

The decree n° 94.157 of February 16, 1994 applies to the rivers and the channels flowing to the sea, as well upstream of the limit of salinity of water as in their parts ranging between this limit and transverse limits of the sea, in their affluent and tributaries of a tributary as in the water levels with which they communicate, in so far are there fish migrating belonging to the following species:

8.8.2.3 Management objectives

Studies

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• To consolidate and perennials the "network eel" (followed colonised surface, relative abundance, prevalence of the parasite Anguilicola crassus...) ;

• To make a study for a better knowledge of the exploitation of eel by the fishermen, in complementarily with the notebooks of fishing of the CSP ;

• To support the studies to improve downstream migration of the species ;

• To carry out complementary studies in order to define objectives of colonization and reproductive potential (minimal downstream intensity of subadultes necessary to contribute to the maintenance and/or the increase in the European eel population) ;

• To carry out a study on evaluation (surface, state, operation) of Barthes.

8.8.2.4 Management measures

8.8.2.5 Fishery

This plan of management recommends that all the limits of salinities of water are definite and those already existing possibly specified, in the event of difficulties of interpretation. In this waiting, agreements between the qualified administrations will be able in certain places to be used as a basis for the application of the regulation and to constitute the base of the file of sasine of the Ministry concerned.

• It is required that it is not made recourse to the transaction, as so far as the rate of continuation was significant.

• It is appropriate to support the cooperation between the maritime authorities and the brigades of CSP in order to avoid the effects of "border" between the mediums maritime and river.

• It is recommended that very fisherman condemned for an infringement relating to the police force of fishing concerning the migrating eels sees his licence concerned suspended for one duration subjected to the appreciation of the administrative authorities, starting from the date of judgment. The same recommendation is made for the maritime medium, but by taking account specificity of the professional licence of the Interprofessional Committee of the Fishermen in Estuary (CIPE).

• It is recommended to study the installation of points of collection and obligatory places of sale for the marketing of the amphihalins.

• No new authorization for the eel fisheries of avalaison must be delivered.

• The number of licences which can be delivered by the association of the coastal fishermen of Mimizan is currently fixed at 50. It is asked that no new additional licence is allotted.

• Article R. 235-6 of the Rural Code authorizes the attribution of licences for the fishing of eels to the members of the departmental association approved of fishermen amateurs to the machines and the nets on water of the public domain, including, when the use of machines and nets is not considered to be necessary to the exploitation of a batch, the Committee asks that this derogatory mode not be used.

8.8.2.6 Habitat

The contracts of river set up on various rivers aim at the improvement of the quality of water, but can also propose specific actions migrating fish.

 the plan of management insists on the importance to reach, the qualitative aims laid down by the SDAGE on the rivers concerned. It will be in particular very attentive with the continuation of the efforts engaged by the communities as regards cleansing to put itself in conformity with the European directive relating to urban waste water, in particular for the agglomerations of Dax on the axis Adour and Orthez on Gave of Pau

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the plan of management announces the paramount interest and the urgency to preserve the wetlands by maintenance of the wet meadows, protection of Barthes and installation of control programs of these spaces.

8.8.2.7 Migration

The indicators of opening of the rivers and the crossability of the obstacles are based on Atlantic salmon (species having the best capacities of crossing of the obstacles) and do not relate to in particular the species eel. Moreover, the percentages of opening and crossability do not take account of the real effectiveness of installations. In particular, the cumulated effect of the various obstacles (delays with the migration, being able to become crippling) is not evaluated.

Significant efforts remain to engage for the opening of the basin to the upstream migration and the downstream migration of the eel, and to measure the effectiveness of this improvement of the crossability for various migrating species (master keys traps or of counting, marking of mass, telemetry, mortality cumulated with the dévalaison...). It is asked that the committed efforts are continued on the priority axes (Gaves, Nives and rivers coastal) and reinforced on three plans :

to improve operation of existing installations ;

to carry out specific installations for the species eel ;

to reduce mortalities to the dévalaison of the works.

Classification of the rivers

The plan of management requires that the coastal currents Landais and the basin of the ponds are integrated into list I of the "blue axes" of the Master development plan of Water Adour

It is required that is carried out, as soon as possible, the revision of the classifications L 432-6 on the whole of the basin and that complements of classification or new draftings are proposed to raise discontinuities of classification, the statutes different according to bank and the problems of interpretation.

It is required that the lists of species are proposed, on the rivers where they are missing, or supplemented with taking into account more particularly of the species eel.

8.8.2.8 Re-stocking

In a palliative way, transfers of glass eels could be carried out inside the same basin. A schedule of conditions relating in particular to the spot of taking away and discharges, the organization and framing, will have to be established before any realization. The basins slopes little or not affected by the parasite Anguillicola crassus will be preferred. The absence of obstacle to the dévalaison (turbines) will be a determining factor. These transfers will be the evaluation object of their impact on the eel stock.

8.8.2.9 Monitoring

Of the relevant and reliable indicators on the level of each species, but also with regard to the quality of the mediums and the accessibility of the axes will be defined and followed annually within the framework of a dashboard. A working group must be set up on this subject and to allow the definition of the control of work, as well as the contents of the dashboard, in particular according to the requests of the financial and scientific partners.

It is required that is presented annually at the COGEPOMI a synthesis of the infringements and taken actions pursuant, supplemented by the actions at law carried out by associations and CSP.

An assessment of the follow-up of the financings of the operations will be presented annually at the COGEPOMI. The Regional Directions of the Environment concerned will take care on it.

The Board of management wishes that its action be able to be relayed in a durable way by a local executive relay, prolonging the missions ensured by the Adour Institution over the period 1999-2002; it will follow with attention reflections led by this partner on the redefinition of his competences.

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8.8.2.10 Is target conforming to the 30% SPR rule

8.8.3 References

AMARA M., CAPATINA-PAPAGAGHIUC & TRUJILLO D., 2002. Hydrodynamical modelling and multidimensional approximation of estuarian river flows., comm.sous presse, 7 p.

BARBIN, G. P. and W. H. KRUEGER. 1994. Behaviour and swimming performance of elvers of the American eel, Anguilla rostrata, in an experimental flume. Journal of Fish Biology. 45 : 111-121.

BRU N., 1998. Etude de quelques méthodes d'estimation non paramétriques de courbes. Application à l'évaluation de flux de civelles d'anguille. Thèse de doctorat, Université de Pau, 161p.

CASAMAJOR (De) M-N, 1998. Comportement migratoire de la civelle d'anguille (Anguilla anguilla L.) dans l'estuaire de l'Adour en fonction de la variabilité des conditions environnementales. Thèse n°98PAUU3017, 64p.

CASAMAJOR (De) M.-N., Bru N. et P. Prouzet, 1999. Influence de la luminosité nocturne et de la turbidité sur le comportement vertical de migration de la civelle d’anguille (Anguilla anguilla L.) dans l’estuaire de l’Adour. Bull. Fr. Pêche Piscic. (355) : 327 – 347.

CASAMAJOR (de) M.-N. & P. PROUZET, 2002.- Campagne de pêche de la civelle sur l'estuaire de l'Adour en 2000/2001. Rapport interne Ifremer, 9p.

CASAMAJOR (de) M.-N. & P. PROUZET, 2003.- Campagne de pêche de la civelle sur l'estuaire de l'Adour en 2001/2002. Rapport interne Ifremer, 12p.

GADET A., 2002.- Rôle de l'hydrodynamisme estuarien sur le comportement migratoire des civelles d'Anguille (Anguilla anguilla) dans l'Adour. Rapport de stage ESA, 86 p.

GHARBI S., 2002.- Intéractions entre l'écosystème estuarien de l'Adour et son bassin versant. Espaces sous pression des différents usages anthropiques. Mémoire de DESS, Univ. Montpellier III, 144 p.

LECOMTE-FINIGER R. & A. YAHYAOUI., 1989.- La microstructure de l'otolithe au service de la connaissance du développement larvaire de l'anguille européenne Anguilla anguilla.- C.R. Acad. Sci. Paris, 308 (Serie III) : 1-7.

PROUZET P. (coord), 2002.- Historique des captures de civelles, intensité actuelle de leur exploitation, variation de leur capturabilité par la pêche professionnelle maritime et indices de colonisation sur le bassin versant de l’Adour.- Rapport DG XIV N°99/023, 147p.

PROUZET P., MARTINET J.-P. ET CUENDE F.-X., 1994.- Les pêches professionnelles dans les estuaires de la Loire et de l’Adour.- Repères Océan, (6)., 78 p.

PROUZET P., SANCHEZ F., DE CASAMAJOR M.-N., BRU N. ET DROUILHET R. , 2000. Impact de la pratique du tamis poussé en zone maritime de l’Adour sur l’abondance des civelles et sur leur pêche. Rapport IFREMER DRV/RH. Contrat Pesca Aquitaine et MAP, 86 p.

8.9 Rhône Mediterranean Corsica (Thomas Changeux, Nicolas Auphan, Jean-Yves Menella, Raymonde Lecomte)

8.9.1 Recent Trend

8.9.1.1 Trend in recruitment

A monitoring from 1993 to 2002 on Vacares and Imperiaux lagoons shows no special trend (CRIVELLI com. pers.). BARRAL (2000a) has select 5 potential sites for the implementation of glass eel traps along the Mediterranean coast of France and Corsica Island. One new trap will be installed during season 2003/2004, for the monitoring of the recruitment in the Camargue (La Fourcade) (BARRAL 2000a). Two other traps will be constructed during season

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2004/2005 on two Mediteranean tributaries (Siagne (Alpes-maritimes) and Hérault (Hérault)). From 2 to 3 are planed in Corsica island on Golo, FiumOrbo and Tavignano.

8.9.1.2 Trend in fishery (Glass eel)

No glass eel fishery allowed. Poaching is observed episodically, but limited to the communication canals between lagoons and the sea (CSP, 1998).

8.9.1.3 Trend in fishery (Yellow eel/Silver eel)

The inland fisheries are of two types with regard to the salinity of the water: freshwater fishery and brackish water (lagoon) fishery.

The freshwater fishery is numerically dominated by anglers (409 000 individuals) who don’t specially target eel. Even if there eel captures had never been assessed, they may be of low importance compared with the captures of other fishermen. Since 1988, in the large rivers of the Rhône basin, en mean of 57 professionals and 710 amateurs were allowed to use fishing gears. Most of them have declared to the national monitoring of fishing gear users (SNPE-CSP).

The number of professionals was stable during the last decade. In a sample of 48 professionals, 15 (31%) target eel at least once a year, but only 4 to 5 devote more than 50% of their fishing sessions to eel using large fyke-nets (gangui, cerf-volant) downstream Lyon and in the estuary.

The number of amateur has decrease from 800 to 700 during the last decade. In a sample of 446 amateurs, 103 (23%) target eel at least once a year but none devote more than 50% of their fishing sessions to eel using eel pots (limited to 6) or lift nets.

Most of the catch are made of yellow eels because no specialize gear, such as “guideau”, is admitted. Silver eels are only accessory catches in October for the few specialized professional fishermen.

From 1988 to 2001, the mean capture of eel is estimated to 12,7 t/year (7% of a total catch weight of 176 t/year): 11,9 t/year for professionals and only 0,8 t/year for amateurs.

The lagoon professional fishery target eel using multiple trap fyke-nets (capétchade, trabaque). With a total declared catches close to 1 000 t in 1992 (which is an uder estimate of the true catches), the lagoon fishery apears as the most important compare to freshwater one (Table 9.1). In 1998, the estimated catches were at the same level (900 t following VERGNES et al. 1999), suggesting that the productions were declining, as BARRAL (2000a) shows in the study of declarations. In 2002, a survey limited to the lagoons of Languedoc Rousillon, estimated that 177 professional boats made a total catch of 740,5 t (Table 9.2). This suggests that even if they are rising down, the lagoon fishery productions are still high.

City of administration Eel catch (t) Bastia (Nothern Corsica) 46 Martigue (Provence) 471 Sète (Languedoc) 187 Port-Vendres (Roussillon) 237 Total 941

Table Fr. 20. Declared eel catches in 1992. Source: Quartiers des affaires maritimes in BARRAL (2000).

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Lagoon Nb boat Eel catch (t) Marette 4 3 Or 4 9 Medar 4 7 Ponant 12 17 Salins 5 35 Palavas 32 100 Pierre Blanche 4 8 Ingrill 14 112 Valras 5 6 Tau 40 250 Gruissan 23 58 Bage Sigean 19 105,5 Salse 11 30 Total 177 740,5

Table Fr. 21.Estimated eel catches of Languedoc-Roussillon lagoons in 2002. Source: CRLR 2002

Time series

Freshwater fishery: there are no clear trends in the catch since 1988 because most of the variability relies on the activity of a few professional fishermen who are not working regularly from one year to another.

Lagoon fishery: all the declared eel catches are declining since 1991 (time series of Bastia,, Martigues, Sète and Port- Vendres in BARRAL 2000a).

8.9.1.4 Recent development /fisheries and market

The price of eel has decline tremendously in 1999 (-50%), certainly as e consequence of the arrival of eels from Asian fish farms (BARRAL 2000a). In 2002, the eel market is signalled to be less favourable in Languedoc (CRLR, 2002). The price from the fisherman is 4 Euros/kg.

8.9.1.5 Fishing mortality

Has never been estimated.

8.9.1.6 Trend in the stock

There is no monitoring of sea and lagoons stocks.

The freshwater stock is followed by two means: (1) electro-fishing in small to medium rivers and (2) Capture per unit of effort calculated with SNPE data for large rivers .

Electro-fishing: the last synthesis at the basin level was made by GERLIER et al. (2000) on 1998 data collected over 132 locations The presence of eel is limited by the obstacles to upstream migration. This explains the very low level observed upstream in coastal tributaries such as Têt, Orb or Touloubre. It explains also the relatively good densities observed in Corsican rivers. In the Rhône basin eel is episodically caught even in the more upstream stations (Saône and Doubs river). But only the main rivers and the proximal reaches of the tributaries are well colonized with a density of more than 19 ind./1000 m². As usual, density decreases and mean length increases going upstream. Looking at the Mediterranean stations, where the densities is over 19 ind./1000 m², we see a strong decreasing from 1995 to 1997 followed by a relative stability up to 1999. Since 1999, we can see a clear increasing of the densities, especially in the smaller size class (Figure 65). These trends are observed also in the Corsican Island (Figure 66).

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Densité d'anguille par classe de taille (en mm) pour la région méditerranéenne continentale 450 400 350 300 250 [600-1200[ 200 [450-600[ 150 [300-450[ 100 [150-300[ Densité en individu/ha 50 0 1994 1995 1996 1997 1998 1999 2000 2001

Figure Fr. 65. Evolution of eel density in 10 electro-fishing stations situated in mainland Mediterranean with the distinction of length class from 150 mm. Source: CSP 2003.

Densité d'anguille par classe de taille (en mm) pour la Corse [600-1200] [450-600[ 1600 [300-450[ 1400 [150-300[ 1200 1000 800 600 400 200 Densité en individu/ha 0 1996 1997 1998 1999 2000 2001

Figure Fr. 66.Evolution of eel density in 6 electro-fishing stations situated in Corsican Island with the distinction of length class from 150 mm. Source: CSP 2003.

CPUE (in kg/day) has been studied from1988 to 2001. Amateur’s CPUE are easier to use because they rely on large sample of fishermen. The higher CPUE are observed downstream Lyon, in Lower Rhône and Rhône delta for amateur as for professionals. The mean weigh increases with distance from sea. The observed trends can be classified into three patterns.

(1) The Rhône delta pattern (Figure 67), showing a strong decrease from 1989 to 1992, and a little increase in 1999.

(2) The mainstream pattern (Upper and Lower Rhône (Figure 68))

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(3) The distant reaches pattern (Doubs, Upper and Lower Saône (Figure 69)), shows a continuously decrease of the CPUE from 1990 to 2000., were after a strong decrease in the first three years we observed a small but continuous increasing trend since 1994.

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 Captures annuelles d'Anguille en Rhône deltaique cpue_pro(Ang)Rd 20.3537 168.6 0 0 62 7.00681 0 5.29705 CPUE ama (kg/j) 0.7 0.6 cpue_ama(Ang)Rd 0.53633 0.57286 0.24365 0.14106 0.00966 0.04987 0.0042 0 0 0 0.5 0.4 0.3 0.2 0.1 0 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Année

Figure Fr. 67. CPUE calculated from amateur fishing gear users declarations in Rhône delta. Source: CSP-SNPE.

1988 1989 1990 1991 1992 1993 1994 1995 1996 cpue_pro(Ang)Rav Captur45.7927es annuelles d'42.5Anguille25 en Rhône0 aval0 143.864 0.59322 0 CPUE ama (kg/j) 0.5 cpu0.45e-ama(Ang)Rav 0.4533 0.1876 0.13602 0.03762 0.06189 0.05751 0.10274 0.08991 0.12375 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001

Année

Figure Fr. 68. CPUE calculated from amateur fishing gear users declarations in Lower Rhône. Source: CSP-SNPE.

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1988 1989 1990 1991 1992 1993 1994 1995 Captures annuelles d'Anguille en Saône aval cpCPue_UEpro (Aamnga)S (kavg/j) 0.081885 0.150233 0.020158 0.018315 0.040295 0.011146 0.016985 0.027462 0.06

0.05 cpue_ama(Ang)Sav 0.051496 0.048565 0.034039 0.028217 0.022852 0.029049 0.022828 0.020238 0.04

0.03

0.02

0.01

0 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 Année

Figure Fr. 69. CPUE calculated from amateur fishing gear users declarations in Lower Saône. Source: CSP-SNPE.

8.9.2 Management

8.9.2.1 Geographical limits

It comprises all the watersheds of coastal tributaries from Span to Italy and the Island of Corsica. The upper course of Rhône, upstream Geneva Lake, belongs to Switzerland.

The boundary between inland and sea administration is the water salty limit??.

8.9.2.2 History of management plan

A migratory fish management plan has been designed for the period 1995/1999. It has not been updated since then. One is about to issue for 2003/2007.

8.9.2.3 Management objectives

The objectives of the first plan, from 1993 to 2000, focus on Shad. The distribution of this species, limited downstream Avignon in 1994, had to reach the river Ardèche close Montélimard (LEBEL et al. 2001). This main objective, limited to shad, has been completed when started the transitory phasis from 2001 to 2003. The new plan from 2003 to 2007, which is about to be approved, will include eel on the bassis of several studies wich were realized during first plan on the Rhône and on Mediterranean tributaries (upstream migration only).

8.9.2.4 Management measures

8.9.2.5 Fishery

No actions in the first plan. The next plan suggests centralizing the organization the maritime fishermen like in the other part of the country (CIPE membership). The idea of a minimum size limit is proposed by the COGEPOMI. The proposal is simply for a 20 cm length wich correpond to the 10 mm mesh size selectivity.

8.9.2.6 Habitat

No special habitat action for eel but restoration of wetland, data exist but not available in time

8.9.2.7 Migration

Three important locks were modified (Beaucaire, Avignon, Caderousse), and five large fish passes were constructed on Rhône River, Ardèche, Gardon and Cèze.

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For next plan, thirty basins have been investigated by BARRAL (2000b), with an estimation of eel fish pass ability for 62 obstacles.

8.9.2.8 Re-stocking

No important re-stocking action is included in the old or in the coming plan. The price of the glass and bootlace eel make stocking a very expensive technique.

An investigation on re-stocking actions performed by anglers and fishermen shows a majority of bootlace re-stocking, with a break from 1989 to 1995 to prevent dissemination of A. crassus (BARRAL 2000a, FEUNTEUN).

The observed trends in main river pattern has to be interpreted regarding the re-stocking actions during these last years before to conclude on this point.

8.9.2.9 Monitoring

The plan retain monitoring using : fish ladders, fish sampling network whith electrofishing in freshwater habitats. CPUE from fishing gear users.

The plan points out lack of data at sea and in the lagoons.

8.9.2.10 Is target conforming to the 30% SPR rule

The exploitation of silver eel is limited (only one fisherment in the Rhône river).

No research on the density of the stock without exploitation.

8.9.3 Réferences

BARRAL M. 2000a. Etude préliminaire à la mise en place d’un tableau de bord anguille sur le basin Rhône- Mediterranée-Corse. Association Migrateurs Rhône Méditerranée, Décembre 2000, 93 p + annexes.

BARRAL M. 2000b. Fiches signalétiques des différents obstacles expertisés. Association Migrateurs Rhône Méditerranée, Décembre 2000, 85 p.

CSP 1998. Aspects du braconnage de la civelle en méditerranée française : application de la circulaire du 19/11/1997. Rapport du Conseil supérieur de la pêche, Délégation régionale n°8, 19 p.

CSP 2003. Réseau hydrobiologique et piscicole, synthèse des résultats pour les régions Languedoc-Roussillon, Provence-Alpes-Côte d’Azure et Corse : campagne 2000 et 2001. Conseil supérieur de la pêche, DR8, 46 p.

CRLR/Cépralmar 2002. Suivi des petits métiers.

FEUNTEUN E. (l’anguille du Rhône aval - Etude préalable à l’élaboration d’un protocole de suivi et de restauration – rapport université de Rennes – 107 p + annexes)

GERLIER M., BEAUDOU D., ROCHE P. 2000. Réseau hydrobiologique et piscicole (RHP), synthèse des données du bassin Rhône Méditerranée Corse, campagne 1998. Conseil supérieur de la pêche, 61 p. + annexes.

VERGNES L., BRON L., DECORPS M., ROMEYER D. 1999. Projet de réhabilitation de l’anguille dans le bassin Rhône-Méditerranée-Corse. Etude socio-économique. Rapport DIREN Rhônes-Alpes/ISARA, 315 p + annexes.

LEBEL I., MENELLA J.I., LE CORRE M. 2001. Note : Bilan des actions du plan migrateur concernant l’alose feinte (Alosa fallax rhodanensis) sur le bassin Rhône-Méditerranée-Corse. Bulletin Français de la Pêche et de la Pisciculture, 362/363, 1077-1100.

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8.10 Conclusion (Cédric Briand, Thomas Changeux, Gérard Castelnaud, Aurore Baisez, Marie Noëlle de Casamajor)

8.10.1 Glass eel

The glass eel fisheries have reduced the commercial fishing pressure in the Vilaine, Charente and Loire (in local places).

Regarding to the rules in force in freshwaters, glass eel fishing suppose that there is no minimum size, and that mesh size lower than 10 mm may be used, that fishing at night is authorized etc. The economic importance of glass eel fishing, implies that this activity is difficult to regulate. The number of glass eel licensees remains stable in fluvial domain. It would be necessary to respect at least the weekly no-fishing night provided by law. However, the poaching for glass eel is regular, despite more than 50 anti-poaching operations per year. The best way now to deal with this problem seems to be an increased control of the trading channel.

A management by quantitative escapement target could be achievable in places where obstructions (dam) occur. When estuaries are not obstructed by dams (Adour, Loire), the current development of quantitative assessment of recruitment and exploitation rate in the Adour could form the basis of reference points for future management. The research project has developed the analysis of the effect of environmental factors on glass eel catchability. It has also developed sampling, estimation and simulation tools of the abundance of the glass eel flux in an open estuary. These tools will be tested and applied to estimate the glass eel flux in other estuaries (Gironde, Loire) (INTERREG project). In other (non monitored) estuaries, the development of management proxies could help to have a consistent management of glass eel fisheries.

There is a large discrepancy in regional approaches for transport. In some places experiments are being done. The efficiency of the measure to restore the stock is debated

8.10.2 Yellow eel

The long continental life duration of yellow eel stage implies that all mortalities affecting the eel will have a large effect. Concerning fishing mortality, exploitation occurs both in fresh and brackishwater, where it can be controlled by the COGEPOMI.

In freshwater, the dispensatory measures allowing the use of fishing gears, even if those gears are not judged necessary to the rational eel resource exploitation, can be eliminate because they no more correspond to the eel actual situation.

In marine waters, where the eel fisheries are not monitored a central regulation should be developed. As for the glass eel fishery, the large illegal fishery is a real problem.

The regional management plan report that a large effort has been done concerning migration for instance in the Seine Normandy basin, where a large effort is planned to reopen migration routes. There is a regional discrepancy in management plans. A quantitative assessment of the effect of the habitat restoration is still lacking. However, the recent development of database of dam and of models allowing to simulate the cumulated effect of dam on eel densities (Vilaine example) could help to construct a quantities proxies at the French level. A coordinated work from both scientific and manager could help to obtain an idea of the effect of this restoration.

Whereas on the Atlantic coast (Loire, Brittany, Gironde, Adour), the eel appears as a priority for management, the management plans in Artois Picardie, Rhine Meuse, water districts have not been renewed probably because of the recent scarcity of eel in these regions.

An assessment of eel distribution in rivers at the national level has been approved by the scientific board of the GRISAM (Changeux 2002). This project, based on the CSP data set (electrofishnig samplings, fish pass counting, and CPUE from CSP-SNPE) consist in a multiscale modeling of eel abundance, using simple explanatory variables such as to be able to extrapolates stationary and reaches results to the entire framework.

8.10.3 Silver eel

Recently, the Decree 2002-965 2 july 2002 (article 9), modifies the le R*236-37 that provided Nominative authorizations for silver eel fishing outside from fluvial public domain (DPF). Moreover, in the article 8, this text limits

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to 6 the total number of eel pot per fisher on the DPF. The exploitation rate of the professional fishery on the Loire was calculated to be of 13 %. However, silver eel professional exploitation is not widespread in France.

Several work are being done to study the effect of pollutants in eel. The kinetic of accumulation on contaminants within the trophic chain has to be studied, along with the chronology of biocontamination by microdosage in calcified tissues. The conclusion from the eel national group meeting was that the effect was supposed to be large but indices of mortality could not be provided.

8.10.4 Management

For all these stages, the Cogepomi and management plans organize management actions at the basin level and large efforts have been done to reduce mortality. However, the effect of these measures is hindered by the fall in recruitment and overall, yellow eel populations tend to decrease in the Channel districts, Brittany, Loire, and Dordogne districts.

COGEPOMI may be a reactive and efficient management units, working in a similar framework as the one proposed by Dekker (2003). However, the reference targets proposed by the ICES (30 % SPR) are clearly not evaluable at the regional level. Up to now, except in local cases, there has not been any possible management with precise targets and evaluation of the effect of the measures taken.

References

Dekker, 2003. A conceptual management framework for the restoration of the declining european eel stock. AFS symposium 20p

Changeux 2002. Répartition de l’anguille dans les eaux courantes à l’échelle de la France. Réponse à l’appel à proposition de recherche 2002 du GRISAM. 10 p.

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9 Eel stock and fishery in Italy in 2003

Country: Italy

Author: Eleonora Ciccotti

Author address: Dipartimento di Biologia Università di Roma “Tor Vergata” Via della Ricerca Scientifica snc 00133 Rome Italy [email protected]

Reporting date and last reported year: August 2003, most data through 2002

9.1 Data

9.1.1 Trend in recruitment

• What is monitored? Life stage, information source, exploited or not, gear type

Glass eel stage, fishery at the Tiber estuary, exploited (now yield is too low, in practice only monitored), fykenets.

• Recruitment monitoring results

Period 1974-2003: total catch per season t 12 10 8 6 4 2 0 96/97 98/99 00/01 76/77 78/79 80/81 82/83 84/85 86/87 88/89 90/91 92/93 94/95 02/03 74/75

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Season kg 74/75 11000 75/76 6740 76/77 5930 77/78 3570 78/79 8440 79/80 8199 80/81 4000

81/82 4000 t0,3 82/83 4000 0,25 0,2 83/84 1800 0,15 0,1 84/85 2500 0,05 85/86 200 0 86/87 7400 96/97 97/98 98/99 99/00 00/01 87/88 10500 94/95 95/96 01/02 02/03 88/89 5500 89/90 4424 90/91 835 91/92 611 92/93 472 93/94 534 94/95 261.5 95/96 126.2 96/97 95.23 97/98 133 98/99 58 99/00 74.4 00/01 35.484 01/02 20.58 02/03 19.61

2,00 1,80 1,60 average 12 years season 2002-2003 1,40 1,20 1,00 0,80

daily cpue (kg/net)daily 0,60 0,40 0,20 0,00 7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 112 119 126 133 days

In the Tiber estuary, during last winter (season 2002-2003) as well as in the last three seasons, fyke net installation was difficult because of river discharge and weather conditions, therefore monitoring was discontinuous. On the whole, the lowest yield has been recorded. In a second monitoring station (river Marta estuary), also, low catches were recorded.

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9.1.2 Trend in fishery

9.1.2.1 Life stage concerned

Adult eel, yellow and silver depending on the site and on the season.

9.1.2.2 Description of fisheries, information sources, gear types.

Low course of the Tiber river, urban stretch (organic pollution, eutrophication) from the estuary to the first dam (circa 37 km). Some professional fishermen (3 cooperatives + some single), organised with barges and boats. Main target is (was) eel, gears are fyke nets (two designs, circular or half moon shaped, with or without bait), in rows of 10, number per day 400-600.

One of the three cooperatives working on the low course of the Tiber, duration of season ranging between 8 and 3 months, depending on the season (weather, floods, problems of the fishermen).

9.1.2.3 Data series on fishing yield

Period 1982-2002: catch per year

35 t 30 25 20 15 10 5 0 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 year

9.1.3 Trend in the stock

No monitoring for the stock. Some information on quantitative aspects can be drawn from trends of national productions referred to lagoon and freshwater environments (ISTAT, 2002).

• Data series on fishing yield

2.500 Coastal lagoons 2.000 Inland waters

1.500

1.000

500

3 5 7 9 1 989 991 99 99 99 99 00 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1 1 1 1 1 1 2

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Year Coastal lagoons Inland waters 1969 1.975 494 1970 1.653 647 1971 1.737 376 1972 1.653 344 1973 m 589 1974 1.483 639 1975 2.223 663 1976 2.020 576 1977 1.798 592 1978 1.617 555 1979 1.689 665 1980 1.655 543 1981 1.740 530 1982 1.531 494 1983 1.564 449 1984 1.598 452 1985 1.353 782 1986 1.469 665 1987 1.515 750 1988 1.601 426 1989 867 376 1990 768 320 1991 754 343 1992 714 370 1993 473 309 1994 419 321 1995 592 527 1996 516 448 1997 401 326 1998 397 269 1999 346 288 2000 210 329 2001 221 217

9.2 Management

• Is there a national management plan for eel?

There is no national management plan, nor foreseen in the near future.

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