Estimation of Maximum Sustainable Yield and Maximum Economic Rent from the Ph,Lippine Small Pelagic Fisheries
Bureau of Fisheries and Aquatic Resources ISSN 0115.3684
Vol. X, No.3 May 1987
Estimation of Maximum Sustainable Yield and Maximum Economic Rent from the Ph,lippine Small Pelagic Fisheries
P. Dalzell P. Corpuz R. Ganaden and D. Pauly
Bureau of Fisheries and Aquatic Resources Small Pelagics International Center for Living Aquatic Resources Management Arcadia Bldg.. 860 Quezon Avenue Management Project Quezon City 3rd Floor, Bloomingdale Bldg. Philippines Salcedo St., Legaspi Village Makati, Metro Manila Philippines
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Estimation of Maximum Sustainabre Yield and Maximum Economic Rent from the Philippine Small Pelagic Fisheries
P. DALZELL1 P. CORPUZ1 R. GANADEN2 and D. PAUL Y1
Bureau of Fisheries and Aquatic Resources Technical Paper Series Vol. X NO.3 May 1987
1 ICLARM 2 BFAR MC P.O. Box 1501 Division of Fisheries Research Makati, Metro Manila Ben-Lor Bldg., Quezon Avenue Philippines Quezon City Estimation of Maximum Sustainable Yield and Maximum Economic Rent from the Philippine Small Pelagic Fisheries
P. DALZELL P. CORPUZ R. GANADEN D. PAULY
1987
Published jointly by the Bureau of Fisheries and Aquatic Resources, Arcadia Bldg., 860 Quezon Avenue, Quezon City, Phili~pines and International Center for Living Aquatic Resources Management, MC P.O. Box 1501, Makati, Metro Manila, Philippines
Printed in Manila, Philippines
Dalzell, P., P. Corpuz, R. Ganaden and D. Pauly. 1987. Estimation of maximum sustainable yield and maximum economic rent from the Philippine small pelagic fisheries. BFAR Technical Paper Series. Vol. X, NO.3. 23 p. Bureau of Fisheries and Aquatic Resources, Quezon City, Philippines and International Center for Living Aquatic Resources Management, Manila, Philippines.
ISSN 0115-3684
ICLARM Contribution No. 413 Contribution NO.5 of the Small Pelagics Management Program
------Contents
Acknowledgements iv Abstract 1 Introduction 1 Catch Data 2 Available records of catch and landings data 2 Nominal commercial catch and under-reporting 2 Nominal municipal catch 3 Municipal small pelagic catch, 1948-1975 4 Fishing Effort 4 Choice of an index of fishing effort 4 Commercial fleet horsepower and gross tonnage 4 Commercial fleet gross tonnage, 1948-1961 6 Standardization of commercial fleet horsepower 7 Adjustment of commercial catch, 1948-1964 11 Carrier fleet horsepower 11 Municipal fleet horsepower 13 Municipal fishermen horsepower equivalent 15 Proportion of municipal fleet horsepower applied to small pelagics 17 Adjustment of municipal fleet horsepower to commercial equivalent 17 Surplus Production and Economic Models 19 Yield curve for Philippine small pelagics 19 Cost of fishing and economic rent 20 Discussion 21 References 22
III Acknowledgements
We thank our colleagues in BFAR, ICLARMand other institutionsfor their helpfuldiscussions concerning sources of data. We thank in particular Ms.Josefina Perez and Ms. Lourdes Bautista for their help in rationalizing the methods used to collect census data during 1970,1977 and 1980. Special thanks are also due to Ms. Norma (Omar) Parial who typed the manuscript and coped stoicallywiththe numerous revisions of the many tables.
IV
--- Estimation of Maximum Sustainable Yield and Maximum Economic Rent from the Philippine Small Pelagic Fisheries
P. DALZELL P. CORPUZ International Center for Living Aquatic Resources Management MC P.O. Box 1501 Makati, Metro Manila . Philippines R. GANADEN Bureau of Fisheries and Aquatic Resources Arcadia Building Quezon Avenue, Quezon City
D. PAULY International Center for Living Aquatic Resources Management MC P.O. Box 1501 Makati, Metro Manila Philippines
Abstract
A method is presented whereby the fishing power of commercial fishin;} fleets and municipal fishing vessels can be standardized with respect to landed catches of small pelagic fishes in the Philippines. Fishing power was expressed as adjusted fleet horsepower (hp) and averaged over two years to account for the average life span of small pelagic fishes. The corresponding plot of landed catch vs fishing power was used to obtain a countrywide estimate of annual maximum sustainable yield for Philippine small pelagic fishes of 544,000 tonnes at an optimal fishing pressure of 256,000 hp. The yield curve indicates that presently, the Philippine smail pelagic fisheries are heavily overfished and that since 1973, small pelagic landings have shown a declining trend. The maximum annual yield above costs was estimatedto be about 500,000 t at a fishing effort of 155,000 hp or 35% of the present effort level. At current fish values. the maximum economic rent from the Philippine small pelagic fisheries would be about US$250 million.
Introduction
The catch of small pelagic fishes from Philippine waters is currently estimated to be about 500,000 tonnes/year (Dalzell and Ganaden 1987a). This catch is composed principally of roundscads (Decapterus spp.), sardines (Sardinella spp.), anchovies (Stolephorus and Engraulis spp.) and mackerels (Rastrelligerspp.) with thoebalance made up by big-eye scads
ICLARM Contribution No. 413
1 2
(Selarspp.), round herrings (Dussummieria spp.) and fusiliers (Caesio and Pterocaesio spp.). The landings of small pelagic fishes have remained at about 500,000 tonnes/year from 1970 onwards whilst nominal fishing effort in terms of numbers of commercial and municipalfishing vessels has increased. These observations suggest that the Philippinesmall pelagic fish stocks are currently overfished. More precise indications of overfishingare provided by the relation$hipbetween catch and fishing effort. Conventional theory rests on the fact that catch per unit of effort declines as fishing effort increases; the rate of increase of catch with increasing effortdeclines and the relationship between the two can be described by a parabolic function as was demonstrated by Schaefer (1954).Alater modificationofthe modelby Fox(1970)suggestedthatan asymmetricalcurve may give a better fitto catch and effortdata. The original Schaefer model was conceivedforsingle-speciesstocks butvariationsofthe model have also been used for multispecies stocks (Brownet al. 1974; Gulland 1976; Marten and Polovina 1982; Ralston and Polovina 1982; Munro 1983; Dalzell 1984: Munroand Williams 1985).The rationalebehindthis has beenthata multispeciesassemblageshowedvariationin fishing pressure in a mqnner similar to a single-species stock. Inthe Philippines, stock production models were fitted to catch and nominal fishing effortdata for demersal and pelagic fishes in different areas of the country (SCSP 1976r 1977, 1978). No attempt was made, however, to account for the differences in fishing power of different fishingvessels. Inthis paper, we describe methods bywhicha timeseries of catchand fishingeffortdata between 1948 and 1985 was reconstructed from existing records. The results are discussed with respect to management and the economics of the fisheries.
Catch Data
Available records of catch and landings data
A considerable number of steps were required to reconstruct the time series of both catch and effort data for Philipppine small pelagic fisheries between 1948-1985. As an aid to understanding the steps involved, a flow chart of the various data sources and adjustments is given in Fig. 1. Records of landed catches in the Philippines have been collected and published by the Bureau of Fisheries and Aquatic Resources (BFAR) and its predecessors from 1948 onwards. Recording of catch data is termed the National Catch Enumeration Scheme (NCES). The methods and extent of the data collection between 1948 and 1985 have been summarized by Ramos (1987). The terms "catches" and "landings" are used here synonymously since most marine fish caught in the Philippines are landed for sale at recognized landing centers throughout the country. A small fraction of the catch goes to the fishermen themselves for food. The reporting of catch data by the NCES is made on the basis of vessel gross tonnage. Catches landed from vessels of three gross tons or greater are termed "commercial catches" whilst those from vessels less than 3 GT are termed "municipal". Municipal catch, as far as small pelagics are concerned, refers essentially to small-scale artisanal fishing and passive gears .There is, however, much overlap in terms of species caught.
Nominalcommercial catch and under-reporting
The composition of the small pelagic fish landings by family group is given in Table 1. Statistics on commercial fish landings in the Philippines extend from 1948 to the present. According to Ramos (1987) the data collection for commercial landings was improved substantially between 1961 and 1965. The commercia/landings prior to 1965 were under- reported and this is discussed and adjustments are made further below.
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3
Commercial Municipal l-. l-. I' I' Annu" c.ch by Annuai fin'! ho~~ {h.pJ Annual flHi number h..p.n. g.t. ~ 86 'ereton.. 0' smallpetegicl in Census d... 'rom 1968. commen:;,a! vesseb W'S,..)tInu" lleet gross tOnnage .so fleet g.t.. '964- arti., vessels_1980. municip81catch 1976-1979 1970.1977 and 1980 of sm~1 pel.agia. tg.rJ. 1978~198S for five , 985 for Ii" principal 19&4 used to t'stima-t8.nn~ $In"1 useld to estima.e annual 1964.1985 commercial smal' pelagic commercill small pelagic petag~ Ulcn 1968.1975 n"unicip81 rltet numtH!-r. fishing vesseh "eet h.p. .I'd number I of munic,pll fish...men ';"';nl """1 ~ ! I I ! EStimate of M'nual tiNt h.p. Estimate of annual fleet Estimate of carrier nett I ..p, ~,""'I of different cilttogories '964.'985 1.1. 1948-1963 h 1964-1985 I of fishermen .stl~ted /" I ~ , Estim.. of .annual"Nt h..p. ~ V..see Md fishermen h~. for small pet~ic fishingyeuel'. Oivi$ion 0' carr fIeft 8dded 1000thH 1948-1965 h. p. b~tw"n other species I I and small pell9;c fishin9 I Municip,alh.p.~jU1ted on b~, ! ~ of per Cf'nt conttibul:on !)y "".sl Annu.1 carcn/II.p. for ra..,. t pelagic1: 10 mW1ic~I:.1 tOI311 catch prineip.1 commercia. small Division 01 small pell9tc carrier tI~M h.p. on b.si, pelagic fishinO \leipls I of catch contribution, ~ from pune sei"efs. rit't9 ; Enim.tion of !nnu.( ::nd'tlh.p. Adjustment of .nnwl fleet h.D. of "lII'tte,. at\d trawlffs ~ by mun'eipal fiShery different veuels to purse S8j",. I equivalent. Figu,es for 1948-1961 based on adjustment ';)ClOt calculated betw"n 1962-1966 I
I ~ ~ , Plot of ca1:Ch/h.p. n. mean annual Adjustment of trawler and Adjustment of ",nu" rnun'cipal h.p. avt"a;ed betWeen rwo years_ ri"9 nett~r carritt fleet small petagicJ h.p. to commercial Curve fitted todallbetween .h.Q. fractions to purse purw se;n., eouw.lent 1965.1985. Und~rrepor1in9 of carch se,,,er eQuiYlle"t betwHn 1948-1964 adiusted for
I L-.. Fishtn9 fI.eetand cat,ier tli!'et h.p. .:KIded together
I
I
! Annual adjusted mun;cjpal and commerc,.. flMt h o. added together. Annual municipal ..lid commercial c,"cnes addlKllogether
~ Annualtot~ small pelagic catch ...s. mean annu.al tOtal adjusted flHt h.p, .v.raged O~r rwo yean
~ Estimation at MSY and'MSY
+ Fishery assumed to b. in economic equilibrium. 1981.1985. Estimation 01 MEY and 'MEV
~ Time se,ies of catch. effort and catch per effort
Rg. 1. Flowchart of steps required to construct yield curve lor Philippine small pelagic fishery.
Nominal municipal catch
Collection of statistical data on a wide scale for municipal fisheries commenced only in 1976. Earlier. this was done through extrapolation from a survey of five fish landing sites performed during the mid-1950s (Ramos 1987). 4
Table 1. The composilion of Philippine small pelagic fisheries and Ihe conlribulion 10 marine and 10tal landings.
Common Family Mean Annual Percenlaae of Name Name Calcha Marine Clch
Roundscads Carangidae 162,013 13.2 Sardines Clupeidae 123,104 10.1 Anchoviesb Engraulidae 76,038 . 6.2 Mackerelsc Scombridae 55,398 4.5 Big-eye scads Carangidae 39,985 3.3 Round herrings.- Clupeidae 33,757 2.8 F'Jsiliers Caesionidae 17,316 1.4
aBased on 1976-1984 landings. bMosllyStolephorus anchovies, may contain some £ngraulisjaponicus. cRastrelligerspp. only.
Municipal small pelagic catch, 1948-1975
The proportion of small pelagic fish in the municipal catch between 1976 and 1980 was 28.5-39.2%, with an average of 34.6% (Table 2). As there was an overall decline of the small pelagic fish component of the municipal catch, particularly after 1979, the mean of 38% for the 1976-1979 municipal catch data was assumed to be also representative of municipal catches prior to 1976 and was used to compute the municipal small pelagic catch from 1948-1975.
Table 2. Contribution 10 lolal municipal catch of small pelagics, 1977-1985.
Year (A) Municipal (8) Municipal calch (I) small pel. catch 8. 100/A
1977 710,840 275,252 39 1978 686,890 259,732 38 1979 635,538 224,208 35 1980 647.284 211,948 37 1981 709,989 237,422 33 1982 708,016 232,179 33 1983 770,988 257,207 33 1984 789,975 242,878 31 1985 785,132 223,559 28
Fishing Effort
Choice of an index of fishing effort
Dalzell and Ganaden (1987) have shown that five gears, purse seines, basnigs, ring nets, trawlers and muro-ami, account for 98% of the Philippine commercial small pelagic catch. Data on the number of each type of fishing vessel extend from 1948 to 1985, on fleet gross tonnage from 1962 to 1985 and on fleet horsepower from 1978 to 1985. Fleet horsepower was chosen as the best index of fishing effort. Beverton and Holt (1957) showed that there is a direct relationship between fishing power and engine power for North Sea trawlers while Levi and Grannetti (1973) showed that gasoline consumption, which is itself related to engine power, might be used as an index of fishing effort.
Commercial fleet horsepower and gross tonnage
To estimate fleet horsepower prior to 1978, it was necessary to establish the relationship between fleet horsepower and fleet gross tonnage for the five principal small pelagic fishing
- -- 5 vessels. The relationship between fleet gross tonnage and fleet horsepower for the different fishing vessels is shown in Fig. 2 based on the data in Tables 3-7. Except for the trawlers, the various scatter plots can be fitted with a simple linear function~However, since the 95% confidence limits of the equation lie on either side of the origin in each instance, a line passing through the origin and the mean provides a good a fit to the points. This is simply the ratio of horsepower to gross tonnage from which the trawl fleet hor.sepowersfor years prior to 1978 may also be estimated. Further, use of the horsepower-gross tonnage ratio ensures that at low fleet gross tonnages unrealistically high or negative horsepowers are not estimated.
\20
.... ., ~ 100 :;; 50 o ~ '"a. o VI a. .... 80 ~ 40 o .... -'='" o -'= o 60 '030 4;.,x OJ - ., - 40 ~ x 20 880 A. Ring -nellers o \0 ~ c c .... .,.... ., ~ ~ o o a. a. ., ., VI I VI I <:; o ; -'=r<> I -'=", o I o - 100:- ., -., . ~x ~x I o 2 4 6 8 10 12 10 20 30 Annual fleet gross Annual fleet gross tonnage X 103 tonnage X 103 83 28 8/ 12 Q Ir 79. :;r 0 '"a. 10 r 88~ 'f) I 84 .... ;: 0 8' .c'" r 0 0J 881 -'"., x 4 "0 C. Muro -ami c c 2 0 2 4 6 8 10 12 Annual fleet gross Vessel gross tonnage tonnage X 103 X 102 Fig. 2. A-E: Annual fleet horsepower versus annual fleet gross tonnage for commercial fishing vessels catching small pelagic fish, 1978-1985. F: Horsepower versus gross tonnage 86 commercial fish carrier vessels, 1980-1985. Dotted lines fitted by linear regression, solid lines forced through mean and origin. 6 Table 3. Fleet gross tonnage and horsepower for commercial purse seiners, 1978-1985. Year Gross tonnage Horsepower 1978 26,720 62,754 1979 25,198 80,564 1980 26,954 35,844 1981 40,850 98,587 1982 43,030 105,602 1983 41,203 / 95,186 1984 35,787 81,530 1985 32,002 80,202 Mean 34,039 80,033 Table 4. Fleet gross tonnage and horsepower for commercial Table 5. Fleet gross tonnage and horsepower for commercial basnigs, 1978-1985. ring netters, 1978-1985. Year Gross tonnage Horsepower Year Gross tonnage Horsepower 1978 11,537 96,920 1978 2,187 12,855 1979 11,320 100,154 1979 2,496 20,223 1980 9,588 62,179 1980 2,450 16,810 1981 8,497 81,536 1981 3,973 28,951 1982 10,025 84,469 1982 4,934 28,729 1983 8,243 80,397 1983 5,765 29,498 1984 9,878 90,186 1984 8,395 45,857 1985 10,069 90,325 1985 8,103 48,944 Mean 9,895 85,771 Mean 4.799 28,983 Table 6. Fleet gross tonnage and horsepower for commercial Table 7. Fleet gross tonage and horsepower for commercial otter trawlers, 1978-1985. muro-ami vessels, 1978-1985. Year Gross tonnage Horsepower Year Gross tonnage Horsepower 1978 24,318 156,035 1978 500 974 1979 25,198 188,977 197:9 9,756 11,736 1980 28,911 150,633 1980 1,074 636 1981 25,630 162,119 1981 10,937 5,705 1982 27,785 174,682 1982 11,164 11,437 1983 27,050 199,949 1983 11,932 11,985 1984 26,508 159,854 1984 9,379 8,732 1985 24,395 162,472 1985 10,800 10,098 Mean 26,224 169,340 Mean 8,193 7,663 Commercial fleet gross tonnage, 1948-1961 The fleet gross tonnages prior to 1962 were estimated from the relationship between fleet gross tonnage and number of vessels between 1962 to 1985 (Fig. 3). For the basnigs and purse seines the scatter of points suggested a curvilinear relationship that was fitted by a power curve. The data for trawlers could be fitted by a linear function with 95% confidence limits which included the origin. A line through the origin and the mean was therefore used. A similar line was also used for the muro-amidata which were very widely scattered. Catches of small pelagics by muro-ami, however, account for only 3% of the total commercial production (Dalzell and Ganaden 1987) and errors involved here should have a negligible effect on overall yield curve estimates. - - --- 7 Purse seiners 50r : .. 30 r- Basnigs ,.I . I I ,30 I 20 "/1 .,',, , -' X 40[20 / .,., . ... ,.... ,, 10 Q.) 10 ...s ....·..44 01 .... ,-r .... .," 0 .... -...... c 0 - 0 c 200 400 600 100 300 500 700 0 900 1,100 - Annual number Annual number (/) of bo a ts (/) of boats '-0 -01 Q.) Muro -ami -Q.) ., - .8 Trawlers 40r . ': ( 0 I - .. , - :J I /' . c 20 4 c - . ... Fig. 3. Annual fleet gross tonnage versus annual fleet numl::er for purse seines. basnigs. tra'Hlers and muro-ami, 1962-1985. Standardization of commercial fleet horsepower The annual fleet gross tonnage and horsepower of the five principle small pelagic fishing vessel types are given in Tables 8 and 9. At present, the purse seiners catch the bulk of the small pelagic fish caught in the Philippines (44%) by commercial vessels. Thus, all vessel horsepowers were adjusted to purse seiner equivalents. The fleet catch by each gear type, recorded by BFAR from 1962 to 1985, is summarized in Table 10. Prior to 1962, the catch composition by different fishing vessels was not so recorded. The catch per unit of horsepower was calculated and is given in Table 11. The efficiency of each gear relative to purse seiners was then estimated (Table 12) and horsepower of the other vessel types adjusted accordingly. The horsepowers prior to 1962 were adjusted by the mean efficiencies from 1962 to 1965. The adjusted horsepowers of the individual fleets and the total fleet are given in Table 13, and the total horsepower and commercial small pelagic catch are summarized in Table 14. 8 Table 8. ESlimated 9ross tonnage of commercial fishing a vessels, 1948-1985. Source: BFARSlatistics. Year Ba9 Nel Muro-ami Purse Seine Rin9 Net Trawl 1948 1,389 1,350 1 603 1949 2,487 300 1 2,330 1950 4,140 300 5 5,162 1951 7,972 300 19 7,632 1952 11,982 ISO 44 9.399 1953 44,835 7SO 26 9,118 1954 12,130 4SO 112 - 12,412 1955 42,636 1,500 55 12,091 1956 9,873 3,151 376 12,673 1957 8,957 3,301 244 11,368 1958 14,588 4,651 170 14:019 1959 14,083 4,951 390 16.691 1960 12,729 7,051 418 17,875 196' 12,927 7,201 362 18,558 19,j2 15,732 3,780 331 360 20,542 1!!63 19,397 3,019 396 606 20,512 1964 18,872 2,797 2,897 136 20,292 1965 22,652 4,904 3.458 201 23,194 1966 23,254 2.870 6.840 172 22.060 1967 24.904 2,528 7,461 125 27,097 1968 19.593 2,067 8,877 37 33,301 1969 18,015 3,160 9,808 369 35.251 1970 18,227 2,570 9,763 36!! 35.126 1971 15,625 1,128 11,096 358 33.6S6 1972 14,852 5,992 20,369 448 36,076 1973 17,327 6,754 42,994 562 39.365 1974 13,269 7,170 18,249 704 34,384 1975 14,932 7,875 18,569 905 2!!.223 1976 14,868 8,530 20.428 1,184 28,482 1977 9,505 8,327 18,414 S'-01 24,448 1978 11,537 500 26.720 2,187 2.31S 1979 11,320 9,756 25.198 2.496 25,19!: 1960 9,588 1,074 26.594 2540 2E,9i j 1961 8,497 10,937 40,850 3.973 25.63C 1982 10,025 11,14 43.030 4.934 27.765 1983 8,243 11,932 41,203 5.765 27.050 198: 9,878 9,379 35,787 8,395 265CB 1985 10,069 10,080 32,602 8,103 ._-24.395 aGross tonnages between 194e 196 estimated tror:1rcrationships berNeen gross tonr.age and nU:i,t;: cl VCSSCIS from 1962-1955. Table 9. Unadjusted horsepwer 01 sma1 pelagic fIshing vessels. 1948-:965. ___0- Year Bag Net lAuro-ami Purse Seine Ring t\et Irawi -.. - .------1945 12.459 1,262 2 4.016 1949 22,308 261 3 j5.5a 1950 37,135 281 13 34.512 1951 71,S08 281 47 50,829 1952 107,478 140 108 62,597 1953 106,159 701 64 60.726 1954 108,806 421 276 82,6<34 1955 113,362 1,403 135 80.526 1956 88,560 2,946 925 83,735 1957 60,344 3,086 600 75,711 1958 130,854 4,349 418 93.367 1959 126,324 4,629 95!! 111,162 1960 114,179 6,593 1,028 119,048 1961 115,955 6,733 891 123,596 1962 141,116 3,534 814 2,344 13'0.810 1963 173,991 2,823 974 3.660 136,610 1964 169,281 2,615 7,127 821 135,-'45 1965 203,188 4,585 8,507 1,214 154,194 1966 208,588 2,683 16,826 1,039 146,920 1967 223,388 2,364 18.254 755 IS0,466 1968 175,749 1,933 21,837 223 221,785 1969 161,594 2,955 24,128 2,229 234,772 1970 163,496 2,403 2",017 2,229 233.939 1971 140,156 1,055 27,2!!6 2,162 224.349 1972 133,222 5,603 50,108 2,706 240,266 1973 155,423 6,315 105,765 3,394 263,S03 1974 119,023 6,704 44,893 4,252 228.997 1975 133,940 7,363 45,680 5,466 194,625 1976 133,366 7,976 50,253 7,151 189,690 1977 85,260 7,786 45,298 5,357 162,824 1978 96,920 974 62,754 12,855 156.035 1979 100,154 11,736 80,564 20,223 188,977 1980 62,179 636 35,844 16,810 150,633 1981 81,356 5,705 98,587 28,951 162,119 1982 84,469 11,437 105,602 28,72!! 174,682 1983 80,397 11,985 95,186 29,498 199,949 1984 90,186 8,732 81,530 45,857 159,854 1985 90,325 10,098 80,202 48,944 162,472 -- 9 Table 10. Catch (t) of small pelagic fishes by commercial fish vessels from 1962-1985. Source: BFAR Statistics. Year Bag Net Muro-am; P. Seine Ring Net Trawl 1962 52,267 .18,512 1,490 5,176 1963 80,293 6,374 2,869 7,584 1964 80,979 7,263 8,400 11,917 1965 109,220 8,756 29,965 39,235 1966 109,220 6,682 22,268 29,458 1967 82,265 4,619 29,584 45,168 1968 107,239 5,448 42,188 31,322 1969 98,451 8,571 68,626 26,547 1970 116,800 8,126 78,148 32,904 1971 81,006 9,295 112,041 40,968 1972 85,080 9,221 137,554 21,504 1973 27,695 18,593 207,101 27,904 1974 27,688 15,037 173,804 34,809 1975 32,551 15,517 153,933 5,372 36.411 1976 30,173 13,799 190,363 8,280 37,977 1977 48,749 8,801 144,644 12,057 53,737 1978 90,630 4,682 100,576 16,360 49,714 1979 74,107 7,087 108,567 13,890 33,232 1980 68,822 7,947 101,308 13,818 63,169 1981 72,340 8,010 103,182 14,813 41,608 1982 92,812 8,398 116.458 16,236 49,342 1983 64,702 7,053 136,197 14,419 50,106 1984 68,181 7,263 114,721 17,945 40,273 1985 67,310 7,044 97,928 23,803 35,364 Table 11. Catch (t) per horsepower of small pelagic fishing gears in the Philippines from 1962-1985.a Year P. Seine Basnig Trawl Ring Net Muro-ami 1962 1.83 0.37 0.04 5.24 1963 2.95 0.46 0.06 2.26 1964 1.18 0.48 0.09 2.78 1965 3.52 0.54 0.25 1.91 1966 1.32 0.50 0.20 2.49 1967 1.61 0.37 0.25 1.95 1968 1.93 0.61 0.14 2.82 1969 2.84 0.61 0.11 2.90 1970 3.25 0.71 0.14 3.38 1971 4.10 0.58 0.18 8.81 1972 2.75 0.64 0.09 1.65 1973 1.96 0.18 0.11 2.94 1974 3.87 0.23 0.15 2.24 1975 3.37 0.24 0.19 0.18 2.11 1976 3.74 0.57 0.20 1.16 1.73 1977 3.19 0.57 0.33 2.25 1.13 1978 1.60 0.94 0.32 1.27 0.8? 1979 1.35 0.74 0.18 0.69 C.60 1980 2.83 1.11 0.24 0.82 1.00 1981 1.47 0.89 0.26 0.51 1.40 1982 1.10 1.10 0.28 0.57 0.73 1983 1.43 0.80 0.25 0.49 0.59 1984 1.41 0.76 0.25 0.39 0.83 1985 1.22 0.75 0.22 0.49 0.70 aTotal catch of species groupings by vessellype were not reported prior to 1962. 10 Table 12. Annual efficiency of small pelagic fishing gears in the Philippines from 1962- 1985. Purse seine catch per effort taken as yearly standard (i.e., 1). Year Basnig Trawl Ring Net Muro-ami 1962 0.20 O.O:? 2.86 1963 0.16 0.02 0.77 1964 0.41 0.08 2.36 1965 0.15 0.07 0.54 1966 0.38 0.15 1.89 1967 0.23 0.16 1.21 1968 0.32 0.07 1.46 1969 0.21 0.04 1.02 1970 0.22 0.04 1.04 1971 0.14 0.04 2.15 1972 0.23 0.03 0.60 1973 0.09 0.06 1.50 1974 0.06 0.04 0.58 1975 0.07 0-06 0.29 0.63 1976 0.15 0.05 0.31 0.46 1977 0.18 0.10 0.71 0.35 1978 0.59 0.20 0.79 0.54 1979 0.55 0.13 0.51 0.44 1980 0.39 0.08 0.29 0.35 1981 0.61 0.18 0.29 0.95 1982 1.00 0.25 0.35 0.66 1983 0.56 0.17 0.52 0.41 1984 0.54 0.18 0.28 0.59 1985 0.61 0.18 0.40 0.57 Table 13. Horspower of small pelagic fishing vessels adjusted to purse seine equivalent. Estimates for years prior to 1962.based on average efficiencies between 1962-1966. Year P. Seine Basnig Trawl Ring Net Muro-ami Total 1948 2 3,239 281 2,120 5,642 1949 3 5,800 1,086 472 7,361 1950 13 9,655 2,416 472 12.556 1951 47 18,529 3.558 472 22,606 1952 108 27,944 4.382 235 32.669 1953 64 27,601 4,251 1.178 33,094 1954 276 28.289 5,786 707 35,058 1955 135 29,474 5,637 2,357 37,603 1956 925 23,025 5,862 4,949 34,761 1957 600 20,889 5.300 5,784 32,573 1958 418 34,022 6.536 7,306 48.282 1959 959 32,844 7,781 7,777 49,361 1960 1,028 29,687 8,333 11,076 50,124 1961 891 30,148 8,652 11,311 51,002 1962 814 28,223 2,736 10,107 41.880 1963 974 27,839 2.732 2,174 33,719 1964 8,127 69,405 10,812 6,171 94.515 1965 8,507 30,478 10,794 2,476 52,255 1966 16,826 79,263 2,O38 5,071 123,198 1967 18,354 51,379 28,875 2,860 101,468 1968 21,837 56.240 15,525 2,822 96,424 1969 24,128 33.935 9,391 3.014 70;468 1970 24,017 35,969 9,358 2,499 71,843 1971 27,296 19,622 8,974 2,268 58,160 1972 50,108 30,641 7,208 3,362 91,319 1973 105,765 13.988 15,810 9,473 145.036 1974 44.893 7,141 9,160 3.888 65,082 1975 45,680 9,376 11,678 1,585 4.369 72,688 1976 50,253 20,005 9,485 2,217 3,669 85,629 1977 45,298 15,347 16.282 3,803 2,725 83,455 1978 62,754 57,183 31,207 10,155 526 161,825 1979 80,564 55,085 24,567 10,314 5,164 175,694 1980 66,307 24,250 12,051 4,875 223 107,706 1981 98,587 49,627 29,181 10,133 5,420 192,948 1982 105,602 84,469 43,671 14,939 7,548 256,229 1983 95,186 45,022 33,991 10,029 4,914 189,142 1984 81,530 48,700 28,774 12,840 5,152 176,996 1985 80,202 55,098 29,245 19,578 5,756 189,879 ------ 11 Table 14. Catchand effort data for Philippine small pelagic fishes caught by commercial fishing vessels. Year Vessel 2-year Catcha Catch/effort horsepower average (t) (tIhp) 1948 5,642 5,642 59,638 . "10.57 1949 7,361 6,502 . 66,960 10.30 1950 12,556 9,959 69,5C6 6.98 1951 22,606 17,581 113,059 6.33 1952 32,669 27,638 126,416 4.57 1953 33,094 32,882 116,423 3.54 1954 35,058 34,076 160,995 4.72 1955 37,603 36,331 172,556 4.75 1956 34,761 36,182 145,020 4.01 1957 31,973 3:1,367 141,251 4.27 1958 48,282 40,128 175,021 4.38 1959 49,361 48,822 170,696 3.47 1960 50,124 49,743 172,680 3.46 1961 51,002 50,563 181,112 3.55 1962 41,880 46,441 200,830 4.35 1963 33,719 37,800 232,042 6.11 1964 94,757 64,117 219,985 3.42 1965 52,255 73,385 176,278 2.41 1966 123,198 87,727 174,650 2.00 1967 101,468 112,333 178,738 1.59 1968 96,424 98,946 196,178 1.98 1969 70,468 83,468 209,162 2.52 1970 71,843 71,156 240,883 3.38 1971 58,160 65,002 250,313 3.85 1972 91,319 74,740 258,388 3.49 1973 145,036 118,178 283,173 2.42 1974 65,082 105,059 259,907 2.47 1975 72,688 68,885 251,531 3.64 1976 85,629 79,159 283,567 3.58 1977 83,455 84,542 270,736 3.18 1978 161,825 122,640 267,523 2.19 1979 175,694 168,760 241,638 1.43 1980 107,706 141,700 233,734 1.65 1981 192,948 150,327 249,045 1.66 1982 256,229 224,589 281,962 1.25 1983 189,142 222,686 274,422 1.23 1984 176,996 183,069 251,658 1.37 1985 189,879 183,438 244,933 1.33 aCatches from 1948-1965 adjusted upwards to account for for under-reporting (see text). Adjustment of commercial catch, 1948-1964 A plot of the unadjusted catch per effortagainst effort (tonneslhp versus hp) for commercial fish catches is shown in Fig. 4. FollowingGulland (1983) the mean effort between two years was used to account for the effect of a previous years' fishing on the stocks during the following year. The average lifespan of the various small pelagic fishes is about two years (Dalzell and Ganaden 1987). The data for 1965 to 1985 show clearly the decline in catch (C) per effort (C/f) with increasing effort (f)and can be well described by plot of 10geC/fon f. There is, however, a similar relationship for the data prior to the 1960s and the difference is presumably due to under- reporting of catches between 1948-1964. To account for this under-reporting, the mean catch and effort from 1948 to 1960 were estimated and the difference between the observed and predicted values gave the raising factor for correcting the data. The improvements in catch reportingfrom1961 to 1965are reflectedinthe declineofthe raisingfactorillustratedin Fig. 5. CarrIer fleet horsepower An important aspect of commercial fishing in the Philippines is the large fleet of carrier vessels that service the fishing boats. Basnigs are essentially day boats whilst muro-ami 12 ..c -u 0 U . 1965 - 1985 "- . o /948 - 1964 Q) -:: u 4.0 r - 3.0 I- 0 Q) 0 (/) Q) 0 Cl. . .L:- 0 . . L- 0 2.0 lOo Q) E I Cl. (/) . ..c u - 0 _ 0 0 o -- 00 Cb:> U 8 0 Q) 1.0 I 0 0 0 E ::J E c 0 c Fig. 4. Annual catch per horsepower of small pelagic fish versus mean annual adjusted commercial fishing fleet horsepower, 1948-1965. 4.0 ..c o -o o .... 3.0 +-o -0 o Q) o +-.... o c> g- 2.0 c ... If) o .... 0:::: -0Q) § 1.0 .... o ...... 1948 50 55 60 65 70 75 80 1985 Year Fig. 5. Annual variation in the raising factor for underreporting of commercial small pelagic catch, 1948-1985. ---- 13 transport their own catch. Purse seiners, ring netters and trawlers, however, frequently unload catches to carrier vessels to maximize fishing time. Further, carrier boat numbers have increased steadily since 1964 and risen dramatically from 270 vessels in 1978 to 650 by 1985. The horsepower of the carrier vessels must by necessity be accounted for when calculating annual fleet fishing power because their presence allows greater fishing time by fishing vessels. The fleet horsepower of carrier vessels has not been reported by the NCES statistics, only numbers and gross tonnage. Information on individual vessel gross tonnage and horsepower is collected by the BFAR licensing Division when issuing licenses. The relationship between gross tonnage and horsepower for 86 carrier vessels from records between 1980-1985 is included in Fig. 2. As with the fishing vessels, the confidence limits of the regression included the origin thus the horsepower-gross tonnage ratio was used to estimate carrier vessel fleet hors.epower from 1964-1985. Prior to 1964, no information was recorded on carrier vessel gross tonnage by BFAR. However, the number of carrier vessels prior to 1964 was very low and their effect on overall fleet fishing power was negligible. The carrier vessels transport not only small pelagic fishes but also demersal species and large pelagic fisheries such as tunas and spanish mackerels. This was adjusted for by multiplying the carrier vessel horsepower by the percentage of small pelagic fish in the total catch (Table 15). The relative contribution to the catch by purse seiners, ring netters and trawlers (Table 16) was then used to allocate the carrier fleet horsepower amongst the three fishing gears (Table 17). The efficiencies of the trawlers and ring netters for each year were then used to adjust the respective fleet horsepower fraction to the purse seine equivalent (Table 18). This was then added to the original commercial fleet horsepower (Table 19). Municipal fleet horsepower Data on municipal fisheries in the Philippines are much less complete than for commercial fishing. Some data do exist, however, from post-war census surveys of municipal fishing in 1948,1970,1977 and 1980 (Bureau of Census and Statistics 1953; NEDA 1971,1977,1981). From these census data, it was possible to extract the numbers of powered and nonpowered vessels, the fleet horsepower of powered vessels and number of full-time, part-time and Table 15. Adjustment of carrier fleet horsepower to account for transport of demersal fishes. Oemersals Percentage Commercial and other Total afsmall Carrier Adjusted Year small coastal (tannes) pelagics fleet carrier pelagics pelagics in total hp fleethp 1964 219,985 96,389 316,374 69.5 6,005 4,173 1965 170,278 100,934 277,212 63.6 11,167 7,102 1966 174,650 105,316 279,966 62.4 16,325 10,131 1967 178,738 108,330 287,068 62.3 52,516 32,717 1968 196,178 124,822 321,000 61.1 24,771 15,135 1969 209,162 111,725 320,887 65.2 28,165 18,364 1970 240,883 111,275 352,158 68.4 32,383 22,150 1971 250,313 116,580 366,893 68.2 51,546 35-,206 1972 258,388 123,374 381,762 67.7 92,523 62,638 1973 283.173 131,230 414.403 68.3 28,261 19,302 1974 259,907 158,735 418,642 62.1 128,955 80,081 1975 251,531 204,244 455,775 55.2 116,990 64,578 1976 283,567 187,136 470,703 60.2 119,111 71,705 1977 270,736 174,572 445,308 60.8 116,291 70,705 1978 267,523 174,980 442,503 60.5 84,133 50,900 1979 241,638 182,399 424,037 57.0 101,485 57,846 1980 233,734 183,273 417,007 56.1 153,200 85,945 1981 249,045 161,827 410,872 60.6 199,571 120,940 1982 281,962 146.232 428,194 65.8 214,337 141,034 1983 274.422 137,108 411,530 66.7 241,717 161,225 1984 251,658 162,015 413,673 60.8 221,504 134,674 1985 244,933 172,296 417,229 58.7 242,062 142.090 14 Table 16. Percentage contribution by commercial fishing to the smaD pelagic fish catch in !he Phippines from 1964 to 1985. Year Bag Net Muro-ami P. Seine Ring Net Trawl 1964 74.6 6.7 7.7 11.0 1965 58.4 4.7 16.0 21.0 1966 64.1 4.1 13.7 18.7 1967 SO.9 2.9 18.3 27.9 1968 57.6 2.9 22.7 .16.8 1969 48.7 3.4 33.9 13.1 1970 49.5 3.4 33.1 13.9 1971 33.3 3.8 46.0 16.8 372 33.6 3.6 54.3 8.5 1973 9.8 6.6 73.6 9.9 1974 11.0 6.0 69.? 13.8 1975 13.3 6.2 62.0 3.9 14.6 1976 10.8 4.9 67.8 3.0 13.5 1977 17.9 3.2 54.6 4.4 19.8 1978 34.6 1.8 38.4 6.2 19.0 1979 31.3 3.0 45.8 5.9 14.0 1980 30.2 3.5 44.4 6.1 15.9 1981 30.1 3.3 43.0 6.2 17.3 1982 32.8 3.0 41.1 5.7 17.4 1983 23.7 2.6 SO.O 5.3 18.4 1984 27.5 2.9 46.2 7.2 16.2 1985 29.1 3.0 42.3 10.3 15.3 Table 17. Unadjusted horsepower of carrier vessels. Vessel horsepower. divided into relative contribution to catch by purse seines, ring neners and trawlers. Year P. Seine Ring Net Trawl 1964 1,718 2,455 1965 3,071 4,031 1966 4,284 5,847 1967 12,959 19,758 1968 8,698 6,437 1969 13,246 5,118 1970 15,599 6,551 1971 25,788 9,418 1972 54,160 8,478 1973 17,013 2,289 1974 65,801 13,315 1975 49,737 3,129 11,712 1976 57,670 2,552 11.483 1977 48,991 3,948 17,766 1978 30,732 4,962 15,206 1978 40,325 5,195 12,326 1980 57,469 7,896 20,580 1981 78,202 11.276 31,463 1982 90,288 12,522 38,224 1983 10,979 11,594 40,252 1984 89,396 13,932 31,347 1985 88,519 21,554 32,017 Table'18. Horsepower of carrier vessels adjusted to purse seine equivalent from annual relative efficiency of fishing gears. Year P. Seine Ring Net Traw! Total 1964 1,718 49 1,767 1965 3,071 81 3,152 1966 4,284 468 4,752 1967 12,959 2,964 15,923 1968 8,698 1,030 9,728 1969 13.246 358 13,604 1970 15,599 262 15,861 1971 25,788 377 26,165 1972 54,160 254 54.414 1973 17,013 137 17,1SO 1974 65,801 525 66,326 1975 49.737 907 703 51,347 1976 57,670 791 574 59,035 1977 48,991 2,803 1,777 53,571 1978 30,732 3,920 3,041 37,693 1979 40,235 2,649 1,602 44,485 1980 57,469 2,290 1,646 61,405 1981 78,202 3,270 5,663 87,135 1982 90,288 4,383 9,556 104,227 1983 109,379 6,029 6.843 122,251 1984 89,396 3,901 5,642 98,939 1985 88,519 8,622 5.763 102,904 --- 15 Table 19. Total commercial fleet horsepower (fishing and carrier vessels) and Philippine commercial small pelagic catch, 1948-1985. Year Comm. fleet Carrier fleet Total commercial 2-year Catch Catch/effort horsepower horsepower fleet horsepower average (m.t) (m.tJhp) 1948 5,642 5,642 5,642 59,638 10.57 1949 7,361 7,361 6,501 66,960 10.30 1950 12,556 12,556 9,959 69,506 6.98 1951 22,606 22,606 17,581 113,059 6.33 1952 32,669 32,669 27,638 126,416 4.57 1953 33,094 33,094 32,882 116,423 3.54 1954 35,058 35,058 34,066 160,995 4.72 1955 37,603 37,603 36,321 172,556 4.75 1956 34,671 34,671 36,137 145,020 4.01 1957 31,973 31,973 33,322 141,251 4.27 1958 48,282 48,282 40,128 175,031 4.47 1959 49,361 49,361 48,822 170,696 3.47 1960 50,124 50,1?4 49,743 172,680 3.46 1961 51,002 51,002 50,563 181,112 3.55 1962 41,880 41,880 46,441 200,830 4.35 1963 33.719 33,719 75,599 232,042 6.11 1964 94.757 1,767 96,524 65,122 219,985 3.38 1965 52,555 3,152 55,707 76,116 176,278 2.32 1966 123,198 4.752 127,950 91,829 174,650 1.90 1967 101,468 15,923 117,391 122,671 178,378 1.45 1968 96,424 9,.728 106,152 111,772 196,178 1.75 1969 70.468 13,604 84,072 95,112 209,162 2.20 1970 71,843 15,861 87,704 85,888 240,883 2.80 1971 58,160 26,165 84,325 86,015 250,313 2.91 1972 91,319 54,414 145,733 115,029 258,388 1.37 1973 145,036 17,150 162,186 153,960 286,1 73 l.a7 1974 65,C82 66,326 131,408 146,797 259,907 1.76 1975 72,6.:9 51,347 124,035 127,722 251,531 196 1976 85,629 59,035 144,664 134,350 283,567 2.14 1977 a3,455 53,571 137,026 140,845 270,736 1.92 1978 151,825 37,693 199,518 168,272 267,523 1.60 1979 175,69& 44,456 220,150 209,849 241,638 1.15 1980 107,7C6 61,405 169,111 197,646 233,734 1.20 1981 192,948 87,135 280,083 224,597 249,045 1.11 1982 256,229 104,227 360,456 320,270 281,962 0.88 1983 189,142 122,251 311,393 335,925 274,422 0.82 1984 176,995 98,939 275,935 293,664 251658 0.86 19a5 169,879 102,904 292,783 284,359 244,933 0.86 occasional fishermen. These data are summarized in Table 20 and shown in Fig. 6. Each of the different scatters could be fitted with an exponential curve from which the figures for the missing years could be estimated. The annual municipalfleet horsepower for each year is given in Table 24. Municipal fishermen horsepower equivalent The average ratio of nonpowered to powered vessels in the municipal fishery is 3:1. These nonpowered vessels are propelled either by wind or muscle power. Further, muscle power is Table 20. Summary of availabledata 9n the numbers ofmunicipalfishingvessels and municipalfisherr.1en. Year Nonoowered Powered hp of powered I full-timea part-timeb Occasionalc Total vessels vessels vessels I fishermen fishermen fishermen I fishermen 1948 16,618 3,384 43,377d 31,821e 22,911f 8,2739 63,005 1971 129,793 59,875 758,801 166,922 120,183 43,400 330,505 1977 144,742 80,774 924,994 197,310 109,616 58,462 365,388 1980 291,175 110,652 1,537,462 369,126 . 284,574 + 143,671h = 797,371 a 150-365 days/yr b50-149 dayslyr cl-49 dayslyr destimated from relationship between hp and numberotvessels for 1971,1977 and 1980. e,f,gcafculated from proportions of fishing activity during 1971. hadjusted to account for indusion of males 10-14 years old in 1980 census. 16 ... -'" Q) '" A 0 0 o 1,500 E- ~ 300 0. u Q) 'c x ;:) o Non powered ox 200 . Powered , 1,000 E - ,, . - , c -- 0 4; ='- 0 c 0,," E t; 100 ", u 500 ...... Q) ,.. '0 0> .c 0> -- C c E .S ---- =' ;:).&:. 0 c :c 0 Z . 1950 '60 '70 1980 c (/) 1950 '60 '70 1980 - Fig. 6. Annual variation of municipal fishing vessels (A), municipal powered vessels fleet horsepower (B) and numbers of municipal fishermen (C), 1948-1985. Fitted curves take the form. required in much of the artisanal fisheries to set and haul various fishing gears. Consequently, the horsepower equivalent of the fishermen's energy output needs to be accounted for when estimating municipal small pelagic fishing effort.The number of fishermen engaged in full-time, part-time and occasional fishing for each year determined from interpolation of census data (Table 20) is given in Table 21. An estimate of average daily energy output by Southeast Asian Table 21. Annual nlJiTt~c:s01'full-tme', 'part.nme"andoccasion a! hshe~en in lI1ePhilippines. 19<8-198S. Year Full.time Pa:,.time 1948 31.821 22,911 8.273 1949 33,S62 24,514 8.3~2 1950 36.461 25.265 9.Q36 1951 39.143 28, ,.1 9.769 1952 42.024 3:).152 10.6:)4 1953 45.116 32.306 11,4:7 1954 48.436 34,614 12."4 1955 52.000 37.055 13.~a1 195'3 55.826 39.735 14.6::3 1957 59.934 42,574 15.620 1958 64.34'1 45,615 17.137 1959 69,078 48.874 18.564 1950 74.161 52,635 20,111 1961 79,618 56,106 21.705 1962 85,476 50.114 23.S;)() 1963 91.766 64,408 25.566 1964 98.519 69,010 27.895 1965 105,768 73,939 3:).001 1960 113.550 79.221 32.500 1967 121.905 84.881 35.207 1958 130,875 90.944 38.139 1969 140,505 97,441 41.316 1970 166.922 120,183 43.400 1971 161,943 111.860 48,465 1972 173.859 119,850 52.523 1973 186.652 128.412 56.897 1974 200.386 137.585 61.636 1975 215.130 147,414 66.789 1976 230.960 157,945 72,333 1977 197.310 109,616 58.462 1978 266,199 181,317 84.8S1 1979 285.786 194,269 91.950 1980 369,126 284,574 143,671 1981 329.391 223.016 107.~ 1982 353.628 236.948 116.89\ 1983 379,648 256.017 126.627 1984 407.583 274.306 137,173 1985 437,192 293,902 148,598 17 males at work has been given by Karim (1985) as 11,572 kilojoulesper day.This maybe translated into horsepower as 0.18 hp (1 hp = 746 joules/second). The daily energy expenditure of municipal fishermen in the three occupational categories was converted to horsepower assuming an average six hours actually fishing during a fishing trip (BFAR unpublished data) (Table 22). The h.orsepowerequivalent of part-time and occasional fishermen was adjusted downwards based on the mean percentages of days actual fishing with respect to full-time fishing. . Table 22. Horsepower equivalentof Philippinemunicipalfishermen, 1948-1985. Year Full-time Part-time Occasional Total 1948 1,428 412 41 1,881 1949 1,524 441 42 2,007 1950 1,637 473 45 2,155 1951 1,757 507 49 2,313 1952 1,886 543 53 2,482 1953 2,025 582 57 2,664 1954 2,174 623 62 2,859 1955 2,334 668 67 3,069 1956 2,506 715 73 3,294 1957 2.690 766 79 3,535 1958 2,888 821 86 3,795 1959 3,101 880 93 4,074 1960 3,329 947 101 4.377 1961 3,574 1.010 109 4,693 1962 3,837 1,082 118 5,037 1963 4,119 1.159 128 5,406 1964 4,422 1,242 138 5,802 1965 4.747 1,331 150 6,228 1966 5,097 1,426 163 6,686 1967 5.472 1,528 176 7,176 1968 5,874 1,637 191 7,702 1969 6.306 1.754 207 8,267 1970 7,492 2,163 217 9,872 1971 7.269 2,013 242 9,524 1972 7,804 2,157 263 10,22/, 1973 8.378 2,311 284 10,973 1974 8,994 2,477 308 11,779 1975 9,656 2.653 334 12,643 1976 10,367 2,843 362 13,572 1977 8.856 1,973 292 11,121 1978 11,948 3,264 424 15,636 1979 12,827 3,497 460 16,874 1980 16,568 5,122 718 22,408 1981 14,785 4,014 540 19,339 1982 15,872 4,301 584 20,757 1983 17,040 4,608 633 22,281 1984 18,294 4,938 686 23,918 1985 19,623 5,290 743 25,656 ProportIon of munIcipal fleet horsepower applied to small pelaglcs The fishermen's horsepower equivalent was added to the municipal vessel horsepower, then adjusted for each year to account for the proportion of the total municipal effort directed towards small pelagic fishes (Table 23). The total adjusted municipal fleet horsepower is included in Table 24 together with the municipal fleet horsepower and small pelagic catch. Adjustment of municipal fleet horsepower to commercial equivalent To construct a yield curve for the total small pelagic fish catch, it was necessary to adjust the municipal fleet and fishermen horsepower equivalent to the purse seine equivalent, in the same manner as the commercial fishing fleet and carrier vessel horsepower. The adjusted municipal horsepower, commercial and carrier vessel horsepower and total small pelagic catch are given in Table 25. 18 Table 23. Total municipalfteel and fishermen horsepower, 1948,1985 and adjustmenllO horsepower direcl8d 10sma. pelagia. Year Municipal Fishermen TOIaI Adjusteda Vessels (hpl (hpl 1948 43,377 1,881 45,258 17,198 1949 52,892 2,007 54,899 20,862 1950 59,042 2,155 61,197 23,255 1951 65,907 2,313 68,220 25,924 1952 73,571 2,482 76,053 28,900 1953 82,125 2,664 84,789 32,220 1954 91,675 2,859 94,534 35,923 1955 102,334 3,069 105,403 40,053 1956 114,234 3,294 117,528 44,661 1957 127,516 3,535 131,051 49,799 1958 142,344 3,795 146,139 55,533 1959 158,895 4,074 162,969 61,926 1960 177,371 4,377 181,748 69,064 1961 197,996 4,693 202,689 77,022 1962 221,018 5,037 226,055 85,901 1963 246,718 5,406 252,124 95,807 1964 275,406 5,802 281.208 106,859 1965 307,429 6,228 313,657 119,190 1966 343,176 6,686 349,862 133,097 1967 383,080 7,176 390,256 148,297 1968 427,624 7,702 435,326 165,424 1969 477,347 8,267 485,614 184,533 1970 758,801 9,872 768,673 292,096 1971 594,812 9,524 604,336 229,648 1972 663,975 10,224 674,199 256,165 1973 741,181 10,973 752,154 285,819 . 1974 827,364 11,779 839,143 318,874 1975 923,568 12,643 936,211 355,760 1976 1,030,959 13,572 1,044,531 407,367 1977 924,994 11,121 936,115 365,085 1978 1,284,654 15,363 1,300,017 494,110 1979 1,434,031 16,874 1,450,905 507,817 1980 1,537,462 22,408 1,559,870 577,152 1981 1,786,913 19,339 1,806.252 596,063 1982 1,994,692 20,757 2,015,449 665,098 1983 2,226,630 22,281 2,248,911 742,141 1984 2,485,539 23,918 2,509,457 777,932 1985 2,774,552 25,656 2,800,208 784,058 aPercenlage of small pelagics in municipaf catch used !:I adjusl lolaf municipal horsepower. For 1948-1975data, a mean value of38% was used. Table 24. Catch and eHortdala for small pelagic fishes caught by municipalfisheries, 1948- 1985. Municipal 2-year Municipaf Catch per eHort Year horsepower average catch (II (lIhpl 1948 17,198 17,198 49,420 2.87 1949 20,862 19,030 60,294 3.17 1950 23.255 22,058 55,781 2.53 1951 25,924 24,589 75,009 3.05 1952 28,220 27,412 79,308 2.89 1953 32,200 30,560 75,721 2.48 1954 35,923 34.071 78,041 2.29 1955 40,053 37,988 83,214 2.19 1956 44,661 42,657 94,433 2.21 1957 49,799 47,230 96,409 2.04 1958 55,533 52,666 97:,723 1.86 1959 61.926 58.729 99,018 1.69 1960 69.064 65,495 100,503 1.53 1961 77,022 73,042 102,010 1.40 1962 85.901 C:,461 103,541 1.27 1963 95.807 90.854 105,094 1.16 1964 106,859 101,333 107,436 1.06 1965 119,190 113,024 115,493 1.02 1966 133,097 126,143 124,156 0.98 1967 148,297 140,697 133,467 0.95 1968 165,424 156,860 168,788 1.08 1969 184,533 174,978 181,447 1.04 1970 292,096 238,314 194,007 0.81 1971 229,648 261,148 206,304 0.79 1972 286,165 242,665 227,519 0.94 1973 285,819 270,992 243,122 0.90 1974 318,874 302,343 260,104 0.86 1975 355,760 337.317 278,056 0.82 1976 407,367 381,563 242,907 0.64 1977 365,085 386,226 275,252 0.71 1978 494.110 429,598 259,732 0.60 1979 507,817 500,963 224,2CB 0.45 1980 577,152 342.484 241.948 0.71 1981 596,063 586,607 237,422 0.40 1982 665,098 630,580 232,179 0.37 1983 742,141 703,620 257,207 0.36 1984 777,932 760,036 242,878 0.32 1985 784.058 780,GG5 223,559 0.29 ------ 19 Table 25. Tolal annual small pelagiccalch and ICtalfteelhoBepower, 1948-1985. Year Municipal CommereiaJ Tolal 2.yoar Catch Card1letfon horsepower horsepower horsepower average (m.l) (m.lIhp) 1948 4.634 5.642 10.276 10,276 109.058 10.61 1949 5,899 7.361 13,260 11.768 133.254 11.32 19SO 7.941 12.556 20,491 16.878 125,287 7.42 1951 11,803 22.606 34,409 27.453 188,068 6.85 1952 17.270 32.669 49,939 42,174 205,724 4.68 1953 21,392 33.094 56,486 53,212 192.144 4.45 1954 16.695 35.038 51,733 54,110 239,036 4.42 1955 17.474 37.603 55.076 53.405 255:770 4.82 1956 20,432 34.671 55.103 55,090 239.463 4.35 1957 22,670 31.973 54.643 54,873 237.660 4.33 1958 22,120 48.292 70,402 62.523 272.744 4.36 1959 28,777 / 49.361 78,138 74,270 269,714 3.63 1960 28.818 SO,124 78.942 78,540 273,163 3.40 1961 28.486 51,002 79.488 79.215 263,122 3.57 1962 23.624 41.800 65.504 72,496 304.371 4.20 1963 17.262 33,719 SO.981 58.243 336,136 5.77 1964 31.413 96,524 127,937 89.459 327,421 3.66 1965 49,731 55.707 105,438 116,688 291,771 2.SO 1966 65,594 127,9SO 1!1.s.::44 149,491 298.886 2.00 1967 92.860 117.391 210.251 201,898 3\2.205 1.55 1968 97.253 106.152 203.405 206.828 364.966 1.76 1969 82.240 84.072 166.312 \84.859 390,609 2.11 1970 69.11\ 87.704 156.815 161.564 434.890 2.69 197\ 70,510 84.325 154,835 155,825 456.617 2.93 1972 167.439 145,733 313.172 234.004 485.907 2.08 1973 130.076 162,1:5 292.262 302.717 526.295 1.74 1974 148,148 131.408 279,555 285,909 520.016 1.92 1975 14\,673 124.035 265.708 272.632 529,587 1.94 1975 \14.469 144,664 259.133 252.42\ 526,554 2.01 1977 142.904 137,026 279.930 269.532 545,988 2.03 1978 163.247 199.518 362.765 321.348 527,255 1.64 1979 195.376 220,180 415,556 389.161 465.846 1.20 1980 202,066 169.111 37\.177 393.367 475.682 1.2\ 1981 211.179 280.083 491.262 431.220 486.467 1.13 1982 264.844 360.456 625.290 558,276 514.141 0.92 1983 309.593 311.393 620.986 623.138 531.629 0.85 1984 281.213 275.935 557.148 589.067 494.535 0.84 1985 265.538 292.733 558.321 557,735 468.494 0.54 Surplus Production and Economic Models YieldcurveforPhilippinesmallpelagics A plot of total small pelagic catch versus mean annual adjusted fleet ho'sepower is shown in Fig. 7. The estimated yield curve gave a maximum sustainable yield(MSY)of 544,000 tonnes r<> 600r ,9.6 ,510 o x 500 MEY-- . · 8.0 425 ....0 E ~ /, , ~ ~ ~ ~70 " en § '0 400 0 340 ~ (J I: . ',6.4, 200~ j 3.2 5: 170 ~ ~ 2 ~ : ~ I o I ::: o~ 100 l:f48 J 1.6 j 85 ~ o -o f- 0 100 200 300 400 500 600 700 Mean annual total adjusted fleet horsepower (X 103) Fig. 7. Total annual small pelagic catch versus mean annual adjusted fleet horsepower. Curve A is the Fox model fitted by conventional means; curve B represents another interpretation of the data (see text). The fMEYand MEYare based an the assumption that the fishery achieved equilibriumbetween 1981-1985. Equation of the line: y =x.e 1.751.e-3.893.1 0-6x. 20 for an optimum effort of 256,000 horsepower. The relationship between catch per effort and effort for the Philippine small pelagic fishery is shown in Fig. 8. The time series of catch, adjusted horsepower and catch per effort for the total small pelagic catch is shown in Fig. 9. a. .J:: I 2 .J:: "- "0o ,.. o 10 .J:: +-'- II) 0 - 8 I .. :::L..l)(I) 0._ 6 '+- 0'1 '- 0 Q) (I) 4 a. a. .J:: 2 +-0 0 . . 0 E U 0 II) 100 200 300 400 500 600 700 Mean annual total adjusted fleet horsepower (X 103) Fig. 8. Catch per effort for the total small pelagic fish catch versus mean annual total adjusted fleet horsepower. The limitations of a simple surplus production model for describing Philippine small pelagic fisheries are apparent at the highest levels of fishing effort. Both the Schaefer and Fox models require that little or no change of fishing effort has occurred from year to year for estimation of surplus production. In theory the catches predicted by the yield curve can be sustained at a given level of effort. Where fishing effort increases rapidly this not only takes surplus production but actually depletes the biomass itself. Catches, will therefore, be higher than the equilibrium yield. Conversely, if effort levels decline very rapidly catches will be lower than predicted whilst the depleted stock adjusts to a lower fishing regime. The problems of investigating the relationship between catch and fishing effort in nonequilibrium situations has been discussed in detail by Caddy (1983). During the early 1980s, fishing effort for small pelagics (and probably other stocks) increased markedly in the Philippines. The catches during this period were higher than predicted by the yield curve as a result of the effects discussed previously. An alternative trajectory for the yield curve that accounts for this effect is shown fitted by eye in Fig. 8. Pella and Tomlinson's (1969) generalized stock production model can account for the skew resulting from rapid change of effort in a fishery. This model involves a more complex analysis than a simple regression of catch per unit effort against effort and its application to Philippine small pelagic catches will be reported elsewhere. Cost of fishing and economic rent The yield curve shown in Fig. 7 can also be used to investigate aspects of the economics of small pelagic fisheries in the Philippines. The annual catches can be expressed as monetary units by multiplying with the 1985 average wholesale price per tonne for small pelagics. This was obtained from unpublished data on file at the Bureau of Agricultural Economics (BAEcon) and was expressed as both Peso and US dollar values (Fig.7). It was assumed that the fishery reached equilibrium after 1981 and from this a linear cost function could be derived. The pure profit or resource rent from the fishery is represented by the difference between the yield curve and the cost function. The resource rent is maximized when the slope of yield curve is equal to that of the cost function. The maximum economic yield (MEY) of 500,000 tonnes occurs at an effort of almost 155,000 hp or 60% of the MSY fishing effort generating MSY and 35% of the present effort level. The economic rent of the small pelagic fisheries is equivalent to 366,000 tonnes worth a 21 600 Catch =..:; r Ou 500 ECi IJ) UIt) 400 _ 0 0":; - X 300 c 200 ..!2 o Q) 100 r-a. 0 1948 '50 '55 '60 '65 '70 '75 '80 1985 700 r Effort It) Q 600 X ".::!. 500 o .... 400 0 0 :J a. C Q) 300 C IJ) o .... _ 200 0 100 .... 0 1948 '50 '55 '60 '65 '70 '75 '80 1985 a. . 12.... Catch per effort ..:; '- ..:; ...... = u 10 oCi - E U 8 0....If) __- ..:;IJ) Fig. 9. Time series of total small pelagic catch, fishing effort and catch per effort. 1948-1985. total of US$ 250 million dollars. The yield at MEY is slightly higher than the production at present-day levels of fishing effort. Thus, reduction of effort by about 70% would not lead to a reduction in catch in the long run. Rather, the catch per effort and profitability of those fishermen left in the fishery would increase appreciably. Discussion The gross overfishing of Philippine small pelagic fish stocks is a post-World War II phenomenon. Spoehr (1984) reported that large-scale industrial fisheries in the Philippines were preceeded during the antebellum years by Japanese commercial fishing using sail- and motor-power~d sampans with beam trawls. The number of people involved in fishing at the turn of the century, based on census data was about 103,000 (Bureau of Census 1905) and rose by 1939 to 264,000 people (Bureau of Census and Statistics 1953). Between 1939-1948 this number dropped to 141,500 people (Bureau of Census 1953) due, no doubt, to the effects of the -- -- -.-. 22 war. This suggests a marked decrease in fishing pressure, particularly on Philippine inshore stocks as a whole, similar to the decline in the fishing of Australian and North Sea fish stocks over the same period because of wartime disruption (Fairbridge 1948; Beverton and Holt 1957). The post-war history and expansion of the Philippine small pelagic fisheries is that of an open access fishery. From Fig. 9 the general decline in catch per effort from year to year is evident as effort increases. Fishing effort increased markedly in the 1970s; catches have shown a declining trend from 1973 to 1985. It is clear from these analyses alone that Philippine small pelagic fish stocks overall are severely overfished. Other lines of evidence also indicate the overfishing of Philippine small pelagic fish stocks. Calvelo and Dalzell (1987) examined the relationship between catch and nominal fishing effort for roundscads between 1975 and 1985 and showed that catch per effort declined with increasing fishing effort. They also showed that fishing mortalities for roundscads stocks were very high and above conventionally accepted levels thought to maximize production. A similar conclusion was also reached by Dalzell and Ganaden (1987b) for other small pelagic stocks such as anchovies, sardines and mackerels. Thus, one should be able to conclude, at this stage, that a wholesale reduction of effort, down to MEY level (45% of present effort level, see Fig. 7), or at least to MSY level should be implemented. Such reduction would not only stabilize the catch (Beddington and May 1977) but indeed increase it slightly, while considerably reducing harvesting costs (see Fig. 7). We realize, given the current politico-economic climate in the Philippines, and the high ratp of (fishermen) population growth, that a massive reduction of fishing effort would be difficult to implement across the board. However, as is also the case for the demersal fisheries of the Philippines - which are also severely overfished (Silvestre and Pauly 1986) - fishing effort is not evenly distributed among fishermen. Thus a small reduction of the purse seine and basnig fleets, for example, while detrimental for a few large-scale owners/operators would benefit a large number of small-scale fishermen. Moreover, a large economic rent, now dissipated by the Philippine small-scale pelagic (and demersal) fisheries, would be generated by a massive reduction of effort, and part of this rent appropriately concentrated e.g., in the form of taxes - could be used to create opportunities for alternative incomes in fisherfolk communities (Smith 1981). We hope that resource economists will start to consider fisheries management schemes structured around these or very similar elements, which probably include the only way the Philippine marine fisheries could be rehabilitated. References Beddington, J.R. and R.M. May. 1977. Harvesting natural population in a randomly fluctuating environment. Science (Washington, D.C.). 1977: 463-465. Beverton, R.J.H. and S.J. Holt. 1957. On the dynamics of exploited fish populations. Fish. Invest. Ser. 11, Vol. 19. 533 p. Brown, B.E., J.A. Brenan, M.D. Grosslein, E.G. Heyerdahl and R.C. Hennemuth. 1976. The effect of fishing on the marine finfish biomass in the Northwest Atlantic from the Gulf of Maine to Cape Hatteras. Int. Comm. Northwest AU.Fish. Res. Bull. 12: 49-68. Bureau of Census. 1905. Census of the Philippine Islands: 1903. Vol. IV, Agricultural, Social and Industrial Statistics. Washington. Bureau of Census and Statistics. 1953. Census of the Philippines: 1948. Vol. IV, Economic Census Report. Caddy, J.F. 1983. An alternative to equilibrium theory for management of Expert Consultation on the Regulation of Fishing Effort. Expert Consultation on the Regulation of Fishing Effort (Fishing Mortality), 17-26 January 1983, Rome, Italy. FAO WCFMD/Prep. 1 sers/2IPaneI22-38 p. Calvelo, R. and P. Dalzell. 1987. A review of the recent status of stocks of roundscads in the Philippines. IPFC/87/Symp/IV.lnf. 9. Paper presented at the Indo-Pacific Fishery Commission Symposium on the exploitation and management of marine fishery resources in Southeast Asia, 16-19th February, 1987, Darwin, Australia (in press). Dalzell, P. 1984. The population biology and management of bait-fish in Papua New Guinea waters. Report 84-05: 59 p. Fisheries Research and Surveys Branch, Dept. of Primary Industry, Port Moresby. ----- ... ..-.-.... ------ 23 Dalzell, P. and R. Ganaden. 1987a. A review ofthe fisheries for small pelagic fishes in Philippinewaters. Bureau of Fisheries and Aquatic Resources, Tech. Pap. Ser. Vol.X No.1: 58 p. Dalzell, P. and R. Ganaden. 1987b. The overfishingof small pelagic fish stocks in the Philippines. IPFC/87/Symp/IV/Int.8. Paper presented at the Indo-PacificFishery Commission Symposium on the exploitation and management of marine fishery resources in Southeast Asia, 16-19th February, Darwin,.Australia(in press). . Fairbridge, W.S. 1948. The effect of the war on the East Australiantrawlfishery. J. Counc. Sci. Indust. Res. 21(2): 75-98. Fox, W.W. 1970. An exponential yield model foroptimizingexploited fish populations. Trans. Am. Fish. Soc. 99: 80-88. Gulland, J.A. 1979. Report of the FAa/laD workshop on the fishery resources of the western Indian Ocean south of the equator. MaM, Seychelles, 23 October-4 November, 1978. IOFC/Dec/79/45. FAa, Rome. 102 p. Kartm,M.N.A.1985. Energy expenditure of a group of students at UniversitiPertanian Malaysia. Pertanika 8(1): 155-157. Levi, D. and G. Giannetti. 1973. Fuel consumption as an index of fishingeffort. Stud. Rev. Gen. Fish. Counc. Medit.53: 1-17. Manacop, P.A. and S.V. Laron. 1952. Two outstanding craft and fishinggear of the Philippines. Bull.Fish. Res. Soc. Philipp.3, 4: 73-84. Marten, G.G. and J.J. Polovina. 1982. A comparative study of fish yields from various ecosystem, p. 255- 289. In Pauly, D. and G.!.Murphy (eds.) Theory and management of tropical fisheries. ICLARM Conference Proceedings 9, 360 p. InternationalCenter for LivingAquatic Resources Management, Manila, Philippines, and Divisionof Fisheries Research, Commonwealth Scientific and Industrial Research Organisation, Cronulla, Australia. Munro,J.L., editor. 1983. Caribbean coral reef fishery resources. ICLARMStudies and Reviews 7, 276 p. International Center for LivingAquatic Resources Management, Manila, Philippines. Munro,'J.L. and D.M.Williams.1985. Assessment and management of coral reef fisheries: biological, environmental and socio-economic aspects. Proc. FifthInt.Coral Reef Congr., Tahiti, 1985, Vol. 4: 545-581. NEDA.1971. Census of fisheries. National Economic and Development and Authority,National Census and Statistics Office,Manila. NEDA.1977. Inventoryof fishery units. National Economic and DevelopmentAuthority, National Census and Statistics Office,Manila. NEDA.1981. 1980 Census of fisheries, national summary. National Economic and [tevelopment Authority,National Census and Statistics Office,Manila. Ralston, S. and J.J. Polovina. 1982. A multispecies analysis of the commercial deep-sea hand-line fishery in Hawaii. Fish. Bull.80(3): 435-448. Ramos, C.M. 1987. Fisheries statistics system in the Philippines. Paper presented at the National Conference on Fisheries Planning and Policy,16-20th March, 1987, Baguio, Philippines, mimeo. Schaefer, M.B.1954. Some aspects of the dynamics of population importantto the management of the commercial marine fisheries. Inter. Am.Trop. Tuna Com. Bull.2: 247-268. SCSP. 1976. Report of the BFAR/SCSP Workshop on the fishery resources of the Visayan and Sibuyan Sea areas. SCS/Gen/76/7, South China Seas Fisheries Development and Coordinating Programme, Manila,26 p. SCSP. 1977. Report of the BFAR/SCSP Workshop on the fishery resources of the Sulu Sea, Bohol Sea and Moro Gulf areas. SCS/GEN/77/11. South China Seas Fisheries Development Coordinating Programme, Manila:35 p. SCSP. 1978. Report of the BFAR/SCSP Workshop on the fishery resources of the Pacific Coast of the Philippines. SCS/GerV78/19, South China Seas Fisheries Development Programme, Manila:49 p. Silvestre, G. and D. Pauly. 1986. Estimates of potential and economic rent from Philippinedemersal stocks, 1946-1984. Proceedings of the WESTPACSymposium on Marine Science in the Western Pacific, Townsville,Australia, 1-6 December 1986. (In press) Smith, I.A.1981. Improvingfishing incomes when resources are overfished. Mar. Pol. 5: 17-22. OTHER REPORTS IN THIS SERIES Bautista, A.O. and AH. Rubio. 1982. Survey of Manila Bay fisheries. A preliminary report. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. V(1):10 p. Ganaden, A.A, N.C. Barut and S.M. Ali, Jr. 1982. Catch, species and size composition of tunas caught by different gear in Mindanao. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. V(2):25 p. Technical Paper VI(1) not issued Rosales, S.V.D. and M.E. Cowan. 1983. The invertebrate fauna of Apo Reef. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. VI(2):8 p. Sy, J.C., F.S. Herrera and J.W. McManus. 1983. Coral community structure of a fringing reef at Mactan Island, Cebu, Philippines. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. VI(3):7 p. Estudillo, RA 1984. Dinoflagellate blooms (red tide) in Maqueda Bay of Western Samar. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. VII(1):8 p. Ganaden, RA, R. Deanon and M. Llorca. 1984. The bangus fry industry in the Philippines. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. VII(2):11 p. Ronquillo, I.A and M.E.G. Llana. 1985. A bibliography of BFAR's researches and popular writings (1947- "1984).Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. VIII(1):104 p. Estudillo, RA et al. 1985. Oceanographic investigation of Lingayen Gulf. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. VIII(2):37 p. Signey, L. 1986. An analysis of income distribution of fishing manpower in commercial fisheries. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. IX(1):13 p. Dalzell, P. and RA Ganaden. 1987. A review of the fisheries for small pelagic fishes in Philippine waters. Bureau of Fisheries and Aquatic Resources Tech. Pap. Ser. X(1):58 p. ------ERRATA SHEET Page4 Paragraph 2. Dalzell and Ganaden (1987a) Page 16 Fig. 6. Second sentence of caption should read: Fitted curves take the form: y = ea . eb . x