and Labrador Region Stock Status Report 2004/039

48

3Pn 3Psa 3Psb 47 SPM 3Psc 3Psd 3Pse

3Ps 3L Subdivision 3Ps 46 4Vn 3Psf 3Psg Background 3O 45 In the Northwest Atlantic, cod are distributed from 3Psh Greenland to Cape Hatteras and are managed as 12 4Vs stocks. The 3Ps stock off southern Newfoundland 60 59 58 57 56 55 54 53 extends from Cape St. Mary’s to just west of Burgeo Bank, and over St. Pierre Bank and most of Green Bank. Summary The distribution of 3Ps cod does not conform well to management boundaries and the stock is considered a • Stock status was evaluated from complex mixture of sub-components. These may include fish that move seasonally between adjacent commercial landings (1959 until 31 areas as well as fish that migrate seasonally between March 2004) and log-book data inshore and offshore. The extent to which the different (1997-2003) in conjunction with components contribute to the fisheries is not fully understood. abundance indices from Canadian (1972-2004) research vessel trawl Cod from this stock generally grow faster than those surveys, industry trawl surveys from areas further northward. At least 50% of the females are mature by age 5 (~53cm) in recent cohorts, (1997-2003), and sentinel fixed compared to age 6 (~58cm) among cohorts present in gear surveys (1995-2003). the 1970s-early 1980s. Exploitation rates were estimated

Catches from this stock have supported an inshore from sequential population fixed gear fishery for centuries and are of vital analyses (SPA) and tagging importance to the area. Fish are caught offshore by experiments. mobile and fixed gear and inshore by fixed gear. Spanish and other non-Canadian fleets heavily exploited the stock in the 1960s and early 1970s. • Two strong year classes (1997- French catches increased in the offshore throughout the 1980s. A moratorium on fishing initiated in August 1993 1998) are well represented in the ended in 1997 with a quota set at 10,000 t. The TAC 2003 catch and these are likely to was increased to 20,000 t for 1998 and to 30,000 t for dominate the fishery in the coming 1999. Beginning in 2000, the management year was changed to begin on 1 April. An interim quota of 6,000 t years. However, these are was set for Jan.-Mar. 2000. The TAC for 1 April 2000 to followed by weak recruitment 31 March 2001 was set at 20,000 t, but this was (1999-2001 year classes), and reduced to 15,000 t for the next four management years to 31 March 2005. current catch levels are unlikely to be sustainable in the long-term unless recruitment improves.

November 2004

Newfoundland and Labrador Region Subdivision 3Ps cod

• Spawner biomass estimates for 1 • At fixed annual catch options January 2004 from two sequential ranging from 10,000 to 20,000 t for population analysis formulations the 2005/06 and 2006/07 used to illustrate the uncertainty in management years, both SPA stock size ranged from 88,000 t to formulations indicated that spawner 130,000 t. Spawner biomass biomass will decline further by 1 estimates from both formulations April 2007. At a catch option of are the highest in their respective 5,000 t both of these SPA time series (i.e. since 1977). formulations indicated a small increase in spawner biomass by 1 • The age structure of the recent April 2007. spawner biomass is unusual and comprises a much higher proportion of fish that are maturing The Fishery at younger ages than in the past. Younger spawners are less The stock was heavily exploited in the effective at producing recruitment; 1960s and early 1970s by non-Canadian consequently, although the fleets, mainly from Spain, with catches spawner biomass is high, the peaking at 84,000 t in 1961 (Fig. 1). current reproductive potential of the stock is lower than in the past. After the extension of jurisdiction in 1977, catches averaged around 30,000 t until • There are no explicit management the mid-1980s when fishing effort by objectives for this stock. France increased and total landings Consequently, only catch options reached about 59,000 t in 1987. Catches considered to be informative for then declined gradually to 36,000 t in fisheries management were 1992. evaluated in the current assessment. The TAC in the four A moratorium was imposed in August management years ending 31 1993 after only 15,000 t had been landed. March 2005 was 15,000 t and the Although offshore landings fluctuated, the catch options considered in this inshore fixed gear fishery reported report were 5, 10, 15, and landings around 20,000 t each year up 20,000 t. until the moratorium (Fig. 2).

• Both SPA formulations used to The fishery reopened in May 1997 with a illustrate stock trends indicated TAC of 10,000 t. This was subsequently that spawner biomass will decline increased to 20,000 t for 1998 and to in the next management year 30,000 t for 1999. In 2000 the (2005/06) for all catch options from management year was changed to begin 5,000 to 20,000 t. However, the on 1 April. An interim quota of 6,000 t was estimated spawning biomass at 1 set for the first three months of 2000. For April 2006 will be considerably 1 April 2000 to 31 March 2001 the TAC greater than the recommended was set at 20,000 t, and for the next four biological limit reference point management years ending 31 March (Blim). 2005 the TAC was set at 15,000 t.

2

Newfoundland and Labrador Region Subdivision 3Ps cod

Landings (000s t) 90,000 Fixed Mobile TAC 80,000 002 00- 01- 02- 03- 04- Year1 97 98 99 (J-M) 01 023 033 043 053 70,000 TAC 10.0 20.0 30.0 6.02 20.0 15.0 15.0 15.0 15.0 60,000 50,000 Can. 7.4 16.6 20.4 3.5 20.3 13.2 12.5 12.6 7.0 40,000

4 (t) Landings French 1.6 3.1 3.2 4.7 4.7 2.3 2.3 2.4 0.9 30,000

20,000 Totals 9 19.7 23.6 8.2 25.0 15.5 14.8 15.0 7.95 10,000 1 During the moratorium (1994-1996) catches were limited to 0 by-catch and sentinel fishery and were <1,000 t and are not 1959 1963 1967 1971 1975 1979 1983 1987 1991 1995 1999 2003 shown. Year 2 During 2000 the management year was changed to begin on Fig. 2. Reported annual calendar year landings 1 April (rather than 1 January) and an interim TAC of 6,000 t (t) by gear sector. Note that TAC’s are by was allocated for the first three months (Jan.-Mar.) of 2000. management year (1 April-31 March) since 2000. 3 Provisional. 4 France (St. Pierre and Miquelon) is allocated 15.6% of the TAC but carried forward a portion the 1999 allocation to the During 2003, cod landings comprised a first three months (Jan-Mar) of 2000. 5 Approximate landings to end of September 2004. range of ages (mostly 5-7 year olds). The 1997 year class accounted for 32% of the In 2003/04, total reported landings were total catch numbers in the 2003 fishery 14,980 t, mostly (76.5%) from the fixed compared to 24% at age 5 in 2002. This gear sector. The total includes a year class was strongly represented in recreational fishery catch of 152 t, and a catches of all gear types. French catch of 2,376 t, approximately 1,642 t of which was caught by otter The catch in the first three months of 2004 trawlers and the remainder (734 t) by was taken mostly by offshore mobile gear fixed gear, particularly gillnets. and was dominated by 6-7 year olds, with 15 year olds (1989 year class) also well represented.

90,000 Canada Other TAC 80,000

70,000 Species Biology

60,000

50,000 Stock structure and migration patterns

40,000 of 3Ps cod are complex and poorly Landings (t) 30,000 understood. Migration of offshore

20,000 components of the stock to inshore areas

10,000 during spring and summer, as well as the

0 existence of inshore components that 1959 1963 1967 1971 1975 1979 1983 1987 1991 1995 1999 2003 Year remain outside the research vessel trawl survey areas throughout the year, Fig. 1. Reported calendar year landings (t) by complicate the assessment of stock country. Note that TAC’s are by management year (1 April-31 March) since 2000. status.

Tagging studies initiated in spring 1997 in were expanded in subsequent years (1998-2003) to include

3

Newfoundland and Labrador Region Subdivision 3Ps cod inner and outer and two calculation of spawner biomass. Males offshore areas (Burgeo/Hermitage generally mature about one year younger Channel and Halibut Channel). In these than females but show a similar trend seven years over 63,700 fish were tagged over time. and 11,800 reported as recaptured. Cod tagged inshore were mostly recaptured Spawning is spatially widespread in 3Ps, inshore, even 5-6 years after release. occurring close to shore as well as on Returns also indicated that some cod Burgeo Bank, St. Pierre Bank, and in tagged offshore were recaptured in the Halibut Channel. Timing of spawning is inshore fixed gear fishery on the south variable and extremely protracted, with coast during the summer and fall. spawning fish present from March until Tagging indicated some movement of August in Placentia Bay. The proportions cod between 3Ps and neighbouring stock of fish at various stages of maturation areas (3Pn4RS, 3KL, and 3NO). No during the 2004 spring research vessel tagging was conducted in the inshore of survey were similar to those observed in 3Ps during 2004. recent years.

Maturation in female cod sampled during Growth, calculated from length-at-age in research trawl surveys was estimated by research trawl survey samples, has cohort for the current assessment. The varied over time. A peak occurred in the proportion of female cod maturing at mid-1970s for young ages (3-4) and younger ages has increased (Fig. 3). progressively later to 1980 for older ages. From the mid-1980s to the present, length-at-age tended to increase at young 1.0 Age 7 ages (2-3) and to vary with no clear trend 0.8 Age 6 at older ages. Year-to-year variability at Age 5 older ages has been considerable (as 0.6 much as 20 cm at age 10) during the past 0.4 decade or so. In general, current values of length at age are not unusual in 0.2 Proportion mature comparison to past values. 0.0 1960 1965 1970 1975 1980 1985 1990 1995 2000 The condition of cod is typically Year expressed as W/L3, where W is the gutted weight or liver weight, and L is the Fig. 3. Estimated proportion mature at ages 5-7 (females). length. Comparison of post-1992 condition with that observed during 1985- For example, the proportion of 5 year old 1992 is difficult because survey timing females that are mature is now the has changed. Condition varies seasonally highest in the time series and has and tends to decline during winter and increased from about 10-20% in the early spring. In general, condition of cod in 1970s and early 1980s to 40% in the mid- the 1993-2004 surveys shows no clear 1990’s and to over 60% in the early trend and does not appear to be unusual. 2000s. The reasons for the change toward earlier age at maturity are not fully understood, but changing age at maturity has a considerable influence in the 4

Newfoundland and Labrador Region Subdivision 3Ps cod

Resource Status 2004 was 80,500 t, slightly higher than the 2003 survey estimate. Sources of information 250,000 Biomass index Stock status at the end of March 2004 200,000 was updated using age-disaggregated data from commercial landings to the 150,000 end of the 2003/04 fishery, and 100,000

abundance indices from Canadian (t) index Biomass (1972-2004) research vessel trawl 50,000 surveys, industry trawl surveys (GEAC, 0 1997-2003), and sentinel surveys (1995- 1983 1986 1989 1992 1994 1997 2000 2003 Year 2003). Age-aggregated catch rate data Fig. 4. Research vessel survey biomass index (t) from logbooks for the under 35' sector (+1 SD). There were two surveys in 1993 (1997-2003) were also examined. Annual (February and April). exploitation rates were estimated from tagging experiments conducted in 80.0 different regions of 3Ps during 1997- 70.0 w 2003. 60.0

50.0

Research vessel surveys 40.0

Canadian research vessel bottom trawl 30.0 surveys were conducted from 1972-1982 20.0 Mean no. of cod per to cod per of Mean no. by the research vessel A. T. Cameron 10.0 using a Yankee 41.5 otter trawl. Surveys 0.0 from 1983 to 1995 were conducted by the 1983 1986 1989 1992 1994 1997 2000 2003 Year Wilfred Templeman, or the sister vessel the Alfred Needler, using the Engel 145 Fig. 5. Research vessel survey abundance index Hi-Lift otter trawl. Since 1996, the surveys (mean numbers per tow) for 3Ps. There were two have been conducted by the Wilfred surveys in 1993 (February and April). Templeman and the Teleost using the Campelen 1800 shrimp trawl. Data The survey abundance index is variable, collected with the gear used between but shows a declining trend from the mid- 1983-1995 were converted to Campelen- 1980s to the early 1990s. There has been equivalent units based on comparative a slight upward trend since the early fishing experiments. 1990s, but this has reversed in the past three years. The high 1995 estimate was The survey biomass index is variable strongly influenced by a single large but declined from the mid-1980s to the catch. The 1997 survey was low and did lowest values observed during the early not encounter aggregations of fish that 1990s. Values for the post-moratorium were observed in surveys and period have been higher than those of the commercial catches in subsequent years. early 1990’s, but not as high as those of the 1980’s (Fig. 4). The biomass index in Spatial distribution: During the April 2004 survey, the distribution of cod was

5

Newfoundland and Labrador Region Subdivision 3Ps cod similar to that during the 2001-2003 results for 1997 were from a smaller surveys (Fig. 6). Cod in these recent surveyed area. In all years this survey surveys remain less widely distributed has shown aggregations of cod in the across the top of St. Pierre Bank southern Halibut Channel and on or compared to 1999 and 2000. The largest adjacent to St. Pierre Bank. catches in 2004 were localized in the southern Halibut Channel, Fortune Bay, 300,000 and in the Burgeo Bank-Hermitage Biomass Index Channel area. 250,000 200,000

150,000

100,000 Biomass index (t) index Biomass 50,000

0 1997 1998 1999 2000 2001 2002 2003 Year

Fig. 7. Biomass index (t) (+1 SD) from the industry (GEAC) trawl surveys.

The biomass index from the GEAC

surveys is variable with no clear trend Fig. 6. Spatial distribution of 2004 research over time (Fig. 7). vessel trawl survey catches. The scale is numbers of cod per tow. 60

Age composition: The age range of 50 survey catches over the post-moratorium 40 period has expanded, with the 1989 year 30 class relatively well represented in the most recent survey at age 15. The 1997 20 and 1998 year classes have been 10

strongly represented in the survey index tow per cod of no. Mean 0 for several years. The 2000 and 2001 1997 1998 1999 2000 2001 2002 2003 year classes appear particularly weak in Year the most recent surveys. The 1999 year class is also below average. Fig. 8. Abundance index (mean numbers per tow) from the industry (GEAC) trawl surveys.

The abundance index (numbers per tow) Industry (GEAC, Groundfish from the GEAC surveys has also been Enterprise Allocation Council) trawl variable with no clear trend from 1997 to survey 2003 (Fig. 8).

During fall 2003 a seventh consecutive In the 2003 survey, the 1997 and 1998 industry survey was conducted with a year-classes were well represented. standardized un-lined commercial trawl. These results are in general agreement Survey coverage has varied slightly and with those from spring research vessel 6

Newfoundland and Labrador Region Subdivision 3Ps cod trawl surveys and previous GEAC effects to produce annual indices of total surveys in 2001 and 2002. catch rate and catch rate-at-age.

The standardized total annual catch rate Sentinel survey index for gillnets shows no clear trend from 1995-1997, but was progressively Fixed gear sentinel surveys have been lower in 1998 and 1999, and remained conducted at 16 sites along the south low from 2000 to 2003 (Fig. 9, upper coast of Newfoundland (13 sites in 2003) panel). The index for line-trawls shows a from St. Brides to Burgeo from late decline from 1996 to 1997, but has February of 1995 and are continuing in subsequently been relatively stable (Fig. 2004. However, the 2004 survey is not 9, lower panel). yet complete and the analysis could not be extended to include the current year. The standardized age-disaggregated indices for gillnets and line-trawls show

50.0 similar trends with the relatively strong Gillnet 1989 and 1990 year-classes being 40.0 replaced by subsequent weaker year- 30.0 classes resulting in an overall decline in

20.0 catch rates. The incoming 1997 and 1998 year-classes appear to be slightly 10.0

Numbercod ofnet / stronger in the line-trawl index in 2001, 0.0 2002 and 2003, but are poorly 1995 1996 1997 1998 1999 2000 2001 2002 2003 represented in the gillnet index in those Year years. Catch rates for older fish (age 300.0 classes prior to 1997) have continued to Line trawl 250.0 decline in the index for gillnets but not in

200.0 the index for linetrawl.

150.0 Log-books 100.0

No. of cod/ 1000 hooks 50.0 Standardized annual catch rates from 0.0 science logbooks (<35’ sector) for vessels 1995 1996 1997 1998 1999 2000 2001 2002 2003 fishing gillnets show a declining trend Year during 1998-2000, but have subsequently Fig. 9. Standardized sentinel catch rate indices shown a slight increasing trend. A for gillnets (upper panel) and line-trawls (lower declining trend during 1997-1999 was panel). Error bars are 95% confidence intervals for the estimates. observed for line-trawls, followed by stable catch rates to 2002 and an Gillnet catch rates come mostly from sites increase in 2003. The commercial index in Placentia Bay whereas line-trawl catch is based on weight of fish caught whereas rates come mostly from sites west of the the sentinel index is based on numbers. Burin Peninsula.

The sentinel survey data were standardized to remove site and seasonal

7

Newfoundland and Labrador Region Subdivision 3Ps cod

As in the previous assessment, mean 50 Gillnet exploitation was much lower among cod 40 tagged offshore (3Psh) throughout 1998-

30 2003 in spite of substantial offshore landings. These low offshore exploitation 20 rates are consistent with a large offshore Kg cod / NetKg 10 biomass in relation to the magnitude of

0 recent offshore catches. However, the 1996 1997 1998 1999 2000 2001 2002 2003 2004 offshore estimates of exploitation are Year considered uncertain because of localized offshore tagging coverage and 400 Linetrawl localized distribution of fishing activity in 350 Plot with error bars the offshore. There is also greater 300 uncertainty in the reporting rates of tags 250 from the offshore, and in the survival of 200 fish caught for tagging offshore in deep 150 (>200 m) water. Kg cod / 1000 Hooks 1000 / cod Kg 100 1996 1997 1998 1999 2000 2001 2002 2003 2004 Tagging coverage of the offshore was Year expanded in 2003 to address some of

Fig. 10. Standardized catch rates for gillnets and these concerns, and to investigate line-trawls from science logbooks for vessels <35’. whether winter catches in the offshore Error bars are 95% confidence intervals of the portion of 3Ps include northern Gulf cod. means. A total of 1,000 cod were tagged and

released in 3Psg/h during the December Tagging 2003 GEAC survey. Results to date are preliminary, but both the numbers of Information from recaptures of cod tagged cod returned and distribution of tagged in various regions of 3Ps since recaptures (all within 3Ps) are similar to 1997 was used to estimate average those of cod tagged in the offshore of 3Ps annual exploitation (harvest) rates for during April. cod tagged in specific unit areas. During 2001 and 2002, the mean exploitation rate was relatively high for cod tagged in Industry perspective Placentia Bay (26% and 21%) compared to those tagged in Fortune Bay (11%, In the offshore fishing areas, there was a both years), Burgeo Bank/Hermitage continuing trend toward smaller Channel (7% and 5%) or Halibut Channel proportions of very large cod in the (2% and 1%), respectively. 2003/04 catch. These larger fish tend to be caught in the winter months from During 2003, mean annual exploitation January to March. The change in estimates remained high for cod tagged spawning closure from the end of March in Placentia Bay (22.4%), but remained to the end of February in 2001 may have low (2-10%) for cod tagged elsewhere in contributed to the trend toward smaller 3Ps. fish in catches. No significant changes in catch rates or distribution were noted.

8

Newfoundland and Labrador Region Subdivision 3Ps cod

Trends in population size, spawner Other considerations biomass, recruitment, and exploitation were similar among different model Temperature formulations. Results from two of the SPA formulations are given to show these Temperatures during the spring of 2004 trends and to illustrate uncertainty related warmed considerably over 2003 values to to different fishery selectivity patterns. In 1oC above normal in the surface layers and one of these formulations (Run 1), older by almost 0.5oC in the near-bottom depths ages were assumed to be not fully over St. Pierre Bank. The areal extent of selected by the fishery; in the other (Run <0oC bottom water during 2003 increased 2) it was assumed that older ages were to the highest in about 13 years but fully selected by the fishery. decreased during 2004 to <10%, the lowest since 1988. Results from the two SPA formulations indicate that there is considerable Cold water in the late 1980s and early uncertainty about the absolute size of the 1990s was associated with a cod population. The spawner stock disappearance of cod from the shallow biomass estimates for 1 January 2004 strata on top of St. Pierre Bank and a shift from these two SPA formulations ranged to deeper water at the time of year when from 88,000 to 130,000 t. the research trawl survey was conducted. Survey results from 1998-2000, when Population numbers increased from the waters were warmer, indicate some late 1970s to a peak in 1985 (Fig. 11). reappearance of cod in these shallow Numbers declined from the mid-1980s to strata; however, in 2001-2003 the numbers the early 1990s, and remained low during of cod in these shallow strata and regions the moratorium. Population numbers to the east were lower and this pattern has increased during the late 1990’s (1998- persisted into 2004 in spite of the warmer 2000), but have subsequently declined. temperatures. 250,000 Run 1 Run 2 Sequential Population Analyses 200,000

150,000 Several sequential population analysis (SPA) model formulations were applied in 100,000 the current assessment to explore the 50,000

uncertainty regarding the appropriate (000's) cod of Number model. These included some of the 0 formulations used in the 2001-2003 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 assessments, updated with one more Year year of data. In addition to the total Fig. 11. Trends in population (3+) numbers. reported commercial catch, results from DFO RV surveys, GEAC surveys and Population biomass increased during the sentinel surveys were used in the late 1970’s to a peak in 1985 then declined analysis. steadily through the late 1980’s and early 1990’s (Fig. 12). Population biomass increased during the moratorium, but 9

Newfoundland and Labrador Region Subdivision 3Ps cod leveled off or declined slightly during 1998-

2000 before increasing again during 2000- 140,000 Ages 3-6 2003. Population biomass in 2004 is similar 120,000 Ages 7-14 to or slightly less than 2003 values. 100,000

80,000 250,000 Run 1 60,000 Run 2 200,000 40,000 Spawner biomass (t)

(t) 20,000 150,000 0 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 100,000

Biomass Biomass 140,000 Ages 3-6 50,000 120,000 Ages 7-14 100,000 0 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 80,000 Year 60,000

Fig. 12. Trends in 3+ population biomass. 40,000

Spawner biomass (t) 20,000 Spawner biomass showed a similar trend 0 to that of population biomass from 1977 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 Year to 1999; thereafter the trends differ markedly, with spawner biomass Fig. 14. Trends in the age composition of the declining during 1999 to 2001, followed spawner biomass. Upper panel - Run 1, lower by a substantial increase in recent years, panel – Run 2. particularly during 2001 to 2003 (Fig. 13). Estimates from the two SPAs show that recruitment has been variable in 3Ps, with 140,000 Run 1 a long-term decline between year classes 120,000 Run 2 in the mid-1970s and the mid-1990s (Fig. 100,000 15). SPA estimates indicate a

80,000 succession of relatively weak age classes during the early to mid-1990’s. The year 60,000 classes produced in 1997 and 1998 are 40,000 estimated to be relatively strong, but Spawner biomass (t) biomass Spawner 20,000 these are followed by three weak year 0 classes (1999, 2000, and 2001). 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 Year

Fig. 13. Trends in spawner biomass.

The age composition of the spawner biomass has changed considerably in the recent period (Fig. 14). With the decline in age at maturity of two strong year classes, spawner biomass has increased dramatically during 2002-2004 The spawner biomass in 2002-2004 comprises an unusually high proportion of 5 and 6 yr olds. 10

Newfoundland and Labrador Region Subdivision 3Ps cod

Spawner biomass limit reference 100,000 points Run 1 Run 2 80,000 The precautionary approach framework under development for management of 60,000 domestic fisheries requires a spawning

40,000 stock biomass limit reference point (Blim) to be developed for each stock. The risk

Nos. at ageNos. at 3 (000's) 20,000 that the stock may fall below this limit should be assessed with respect to catch 0 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 options. In the current assessment, Year class various candidate reference points were

Fig. 15. Trends in recruitment (numbers at age reviewed. Brec (where rec=recovery) is 3). the lowest spawner biomass from which a secure recovery has occurred. Brec is Estimates from the two SPA formulations recommended as being suitable for 3Ps also show that the annual exploitation cod as this stock has undergone two rate, expressed as percentage of 3+ recovery cycles since 1977. Current numbers removed by the fishery, varied spawning stock biomass was compared over time (Fig. 16). Exploitation during in relative terms with Brec, defined as the the late 1970s to 1985 was typically spawning stock biomass at the beginning between 10 and 17%, but increased to of 1994 (i.e. 36,000 t and 13,000 t for the between 20 and 35% just prior to the two respective SPA formulations). The moratorium in 1993. With the reopening current biomass is 3.6 times larger and of the fishery in 1997, exploitation rates 6.9 times larger than Brec for the two were low relative to the pre-moratorium respective SPA formulations (see Fig. 13) period and increased to a peak in 1999, but thereafter have declined again to about 6-8%. Projections

40.0 Run 1 In the current assessment, 3-year Run 2 30.0 deterministic projections to 1 April 2007 were computed for the two SPA

20.0 formulations. In the first year the catch was assumed to be 15,000 t which is the TAC 10.0 for the 1 April 2004 – 31 March 2005 Exploitationrate (%) management year. At this catch level, the 0.0 spawner biomass is estimated to decrease 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 by approximately 7,000 t and 5,000 t for Year the respective SPA formulations. These Fig. 16. Exploitation rate (percent 3+ numbers removed by the fishery). declines are consistent with the projections from the 2003 assessment.

The projections for the management years 2005/06 and 2006/07 were for fixed annual catch options ranging from 5,000 to 20,000 t. At catch options ranging from 11

Newfoundland and Labrador Region Subdivision 3Ps cod

10,000 to 20,000 t both formulations In the previous assessment, splitting the indicated that spawner biomass will decline research vessel survey index of 3Ps was by 1 April 2007 (Table 1). At a catch option intended to reduce the possible influence of 5,000 t both formulations indicated a of northern Gulf cod on the index. small increase (1.6-3.7%) in spawner However, new information shows biomass by 1 April 2007. synchrony in recent year class strengths between eastern and western 3Ps and Under all catch options considered for the general asynchrony with the northern Gulf two SPA formulations, the projected stock. In the current assessment the spawner biomass on 1 April 2007 was research vessel survey was treated as a considerably greater than Blim. single index. Nevertheless, there will be years when mixing will occur and % change in SSB from 120,000 t (Apr.1/2004) influence survey catch rates. Year 5,000t 10,000t 15,000t 20,000t Run 1 2006 -1.4% -5.4% -9.3% -13.3% 2007 1.6% -6.2% -14.1% -21.9% As described in previous assessments, there is considerable uncertainty % change in SSB from 81, 000 t (Apr.1/2004) regarding the appropriate SPA Year 5,000t 10,000t 15,000t 20,000t formulation for this stock. Consequently, Run 2 2006 -0.9% -6.8% -12.6% -18.4% 2007 3.7% -7.8% -19.4% -30.9% different SPA formulations were again evaluated in this assessment to explore Table 1. Projected changes in spawner biomass this uncertainty. (SSB) at various fixed catch options to 1 April 2006 and 1 April 2007. To estimate population numbers using SPA, some assumptions are usually made about how commercial fishery Sources of uncertainty selectivity changes with cod size and hence age. Different assumptions can Information on fish older than age 14 is not produce estimates that differ included in the analytical assessment of substantially, although overall trends are this stock, because the available data are similar for this stock. not considered reliable. Nevertheless, the proportion of the population greater than The sentinel gillnet index is based on data age 14 is likely to have been small since primarily from Placentia Bay and shows the moratorium. trends that are inconsistent among sites. While the reasons for the inconsistencies There is considerable uncertainty are unclear, during 1997-2003 this index regarding the origins of fish found in 3Ps may have been influenced by competitive at various times of year. Tagging effects associated with high effort from experiments suggest that the amount of the reopened commercial fishery. mixing with adjacent stocks can vary from year to year. The assessment is sensitive The 3 year deterministic projections do not to mortality on 3Ps cod occurring when take any uncertainties into account. The fish are outside 3Ps and to the incursions trends in the projections depend heavily on of non-3Ps fish into the stock area at the the accuracy of estimates of recent year time of the survey and the fishery. classes, and their subsequent survival and recruitment to the fishery in 2005-2007. These projections are also sensitive to 12

Newfoundland and Labrador Region Subdivision 3Ps cod recent and substantial changes in highest in their respective time series (i.e. estimates of the proportion of females that since 1977). mature at young ages and become part of the spawning population. The age structure of the recent spawner biomass is unusual and comprises a The estimates of exploitation for fish much higher proportion of fish that are tagged offshore are considered more maturing at younger ages than in the uncertain because of localized offshore past. Younger spawners are less effective tagging coverage and localized at producing recruitment; consequently, distribution of fishing activity in the although the spawner biomass is high the offshore. There is also greater uncertainty current reproductive potential of the stock in the reporting rates of tags from the is lower than in the past. offshore and possibly in the survival of fish caught for tagging offshore in deep water. Management Considerations

There is considerable uncertainty about the There are no explicit management current productivity of this stock. The objectives for this stock. Consequently, spawner biomass is currently producing far only catch options considered to be fewer recruits than it did at the start of this informative for fisheries management period (i.e. 1977). This may be cause for were evaluated in the current concern in the application of limit reference assessment. The TAC in the four points such as Brec. Recent changes in the management years ending 31 March composition of the spawner biomass may 2005 was 15,000 t and the catch options have lowered the reproductive potential of considered were 5, 10, 15, and 20,000 t. the stock; consequently, the ability of the stock to rebuild from Brec may be lower Both SPA formulations used to illustrate than in the past, should it be reduced to stock trends indicated that spawner that level. biomass will decline in the next management year (2005/06) for all catch options from 5,000 to 20,000 t. However, Outlook the estimated spawning biomass at 1 April 2006 will be considerably greater Two strong year classes (1997-1998) are than the recommended biological limit well represented in the 2003 catch and reference point (Blim). these are likely to dominate the fishery in the coming years. However, these are At fixed annual catch options ranging from followed by weak recruitment (1999-2001 10,000 to 20,000 t for the 2005/06 and year classes), and current catch levels 2006/07 management years, both SPA are unlikely to be sustainable in the long- formulations indicated that spawner term unless recruitment improves. biomass will decline further by 1 April 2007 (see Table 1). At a catch option of 5,000 t Spawner biomass estimates for 1 both SPA formulations indicated a small January 2004 from the two SPA increase in spawner biomass by 1 April formulations ranged from 88,000 t to 2007. 130,000 t. Spawner biomass estimates from both SPA formulations are the 13

Newfoundland and Labrador Region Subdivision 3Ps cod

The incentive for under-reporting of For More Information: catches remains with the implementation of trip limits, and IQ’s. There are also Contact: John Brattey concerns about discarding of small fish in Fisheries and Oceans Canada the hook and line fishery. Increased PO Box 5667 monitoring of catches and landings would St. John’s, NL A1C 5X1 result in better estimates of deaths caused by fishing. Tel: 709-772-2001 Fax: 709-772-4501 Email: [email protected] Because of uncertainties in stock structure, excessive exploitation on sub- components of the stock should be avoided. Measures should be References implemented to further reduce the relatively high exploitation rate in Brattey, J., N. G. Cadigan, B. P. Healey, Placentia Bay (3Psc) that is evident from G. R. Lilly, E. F. Murphy, P. A. Shelton, analyses of the tagging data, sentinel and J.-C. Mahé. 2004. An assessment catch rate indices, and commercial catch of the cod (Gadus morhua) stock in rate indices for vessels <35’. NAFO Subdivision 3Ps in October 2004. DFO Can. Science Advisory Recent management measures (seasonal Secretariat Res. Doc. 2004/083. closures and switch to individual quotas, rather than a competitive fishery in Brattey, J., N. G. Cadigan, B. P. Healey, western 3Ps) reduced the reported winter G. R. Lilly, E. F. Murphy, D. E. catches from the mixing area (3Psa/d Stansbury, and J.-C. Mahé. 2003. An combined) to only 260 t during 2002/03. assessment of the Atlantic cod (Gadus However, the winter catch from this area morhua) stock in NAFO Subdivision increased to over 500 t in 2003/04. 3Ps in October 2003. DFO Can. Catches from this area in winter should Science Advisory Secretariat Res. be minimized to reduce the potential Doc. 2003/092. impact on the 3Pn4RS cod stock. Brattey, J. and B. P. Healey. 2004. A complex series of area/time closures on Exploitation of Atlantic cod (Gadus directed cod fishing in 3Ps has been morhua) in NAFO Subdiv. 3Ps: further introduced to address concerns about updates based on tag returns during stock mixing and disruption of spawning 1997-2004. DFO Can. Science activity. The consequences of area/time Advisory Secretariat. Res. Doc. closures should be carefully considered 2004/084. as these may result in higher exploitation rates on the components of the stock that Colbourne, E. B., and E. F. Murphy. remain open to fishing. 2004. Physical oceanographic conditions in NAFO Division 3P during 2004 - possible influences on the distribution and abundance of Atlantic cod (Gadus morhua). DFO Can. Sci. Advisory Secretariat. Res. Doc. 2004/086.

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Newfoundland and Labrador Region Subdivision 3Ps cod

McClintock, J. 2003. Cod catch results 2002: year six of the NAFO Subdivision 3Ps Fall GEAC Surveys. DFO Canadian Science Advisory Secretariat Res. Doc. 2003/097.

Maddock-Parsons, D., and R. Stead. 2003. Sentinel surveys 1995-2003: Catch per unit effort in NAFO Subdivision 3Ps. DFO Canadian Science Advisory Secretariat Res. Doc 2003/094.

This report is available from the:

Newfoundland and Labrador Region Science Branch Fisheries and Oceans Canada PO Box 5667 St. John's NL A1C 5X1

Telephone: (709) 772-2027/8892 Fax: (709) 772-6100 E-mail: [email protected] Internet address: www.dfo-mpo.gc.ca/csas

ISSN 1480-4913 (Printed) © Her Majesty the Queen in Right of Canada 2004

La version française est disponible à l’adresse ci-dessus.

Correct citation for this publication

DFO, 2004. Subdivision 3Ps Cod. DFO Can. Sci. Advis. Sec. Stock Status Report. 2004/039.

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