This Paper Not to Be to the Author International Council for The
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• This paper not to be to the author International Council for the CH 1973/K:22 Exploration of the Sea Shellfish and Benthos Committee A review of the lobster fishcry of England and 1-Tales by E. Edwards . " Ministry of A;riculture, Fisheries and Food, Fisheries Laboratory, Burr~am-6n-Crouch, Essex. Introduction The European lobster (Homarus.Kammarus) is the most valuable species of shellfish landed in, England and Vales. The recorded catch in 1972 totalled .: 8 437 cwt (4'30 tonnes), valued at 1:639 283, representing a quarter of the value of.,all shellfish landed th8t yenr, ~ .' Staff fron the Pinistry'o Fisheries Laboratories at Conwy end Burnham- on-Crouch have studied this species since the early 1950s, with the investiga- ";" . tions beine concentrated off Yo~~shire and Cornwall (Hepper 1959, 1967, 1971) und Uales (Simpson 1958 1 1961). Folloifing 'representutions from various sections of the fishing industry that lobster catches in many parts of the country ,fere decl~ing, thc 11inistry's lobster programnc was expanded in 1972 to cover all the important fishing arens in England and 1-1ales. The main aim of this investigation, w'hich began in April 1'372, is to e:~amine the present state of the fishery and to consider whether additional conservation measures are required to ensure 0. sustaincd yield. This preliminary programme t-1ill continue for a further year, to be followed by more detailed population studies on the various stocks• .' ~, . • '. I ", • ,. The proportion of th~'total lleight of lobsters taken inthree iniportant coastal areas is shovITl in ~~gure 2. Based on an average for,the last 10 years (1962-71),47 per cent of the country's catch has been landed at ports on the east coast between Berwick and HaTItich. During the same period, the south " coast (Newhaven-Falmouth) landed 23 per cent of the catch, and west eoast and Welsh ports 30.. per cent. Landings on the east coast have declined since 1962; in eontrast, landings have increased at south eoast ports since 1969 following the discovery of new grounds in the Enelish Channel. During this period there has also been a steady increase in the yield from the Welsh coast lobster fishery. Fishing season " The main lobster seoson in Enp:land and "ales is between May 'and September, when 80 per cent of the annual catch is taken. In general, peak landiTIgs oceur , '" d~ringAugust and September: after October, landings in most' areas decline e ," ,:'(Fi~~e 3). ' TABLE 1 RECORDED LOBSTER lAllDINGS liND THEIR VALUE m ENGL.\ND .!\.ND UALES 1962/71 YEAR HEIGHT VALUE AVERAGE VALUE -- (cwt) -(~) (iL per ewt) 1962 '9 225 279 489 30.3 1963 ":':9438 287 232~ 30.4 1964 ' 9400 353 851 37.6 1965 7 824 331 679 42.4 ' 1966 8 240 379 197 46~O 1967 7 611 355585 46.7' 1968 7 302 383 288 52~5 •• 1969 7 547 446 816 .:.59.2 1970 ' " . 9 660 609 595 ;' 63.1 1971 8 871 600 219" , 67.7 Note 1 ewt = 50.8 kg. Landings and vnlue of the f,i_s]1er;y: . ' The recorded total DnrlURl lobster landings ~nd their v::},ue during the 10-yerr period 1962-71 ere sho't'Tn in T-::ble 1 ~nd Figure 4. ,Fluctuations in l~ndings occurred during this Deriod, p~rticulcrly behreen 19?5 nn~ 1969, when they fell to belo'Vl-cvernge levels. Hore rec~ntlyin1970., nnd 1971, lo.ndings were o.bove average und nearly equ21 t6 the high catches made in th~ early 1960s. 2 These rccent inere~ses in the tot~l e~teh nre the result of the exploitntion of previously lnrgely unfished lobster stocks ~long tho south eonst nnd in the western English Chor~el. Houever, they m~sk the general deeline in entehes nnd enteh per unit of effort vlhieh h~s tnken plnee in thc trnditional lobster fishing arens - pnrtieulnrly on the enst eonst (see Inter seetion ). eateh in relation to effort Reeords of l~~dings aleno,nlthougl1 vnluablo, do not givo n true guide to the state of' a fishcry. The uso of enteh per'unit of effort datn is.more informntive, sinee they uill not be nffeetcd by chnngos in the leyel' of fishing ··~ffört•.. For the period 1961-1972, collcetors of statisties employed by tho Ministry on apart-time bnsis hnve rccorded enteh end effort dntti from many of 'the mnin shellfish ports in England. These dntu ineludo detnils of the number cf trnps hnulcd weekly by c~ch rcgistcred bont nnd the weekly weight of lobsters • lnnded, together with the weight of crabs nnd ernwfish (which ure not eonsidered here ). It is not aluays possiblc to rceord ·these dutn for every,boat.in euch port, but usuall;r the mujority of the fleet -is included. There are, 'howevcr, eertain gn~s in the data pnrtieularlyintho south and west, where it has been diffieult to organize the eollcction of thc rcquircd informntion.' A system involvine theissue of loe-books to solected fishermen l1ho reeord their'own eatch und the numbor of deys fished h~s rcecntly been introdueed in these arens. The fluctuations observed in the lobster enteh per unit of effort duta eollected sinee 1962 nre dineusscd bclow. East eoust The Dost importnnt lobster fishillG nreas are in the eounties of Northumbcrland and Yorkshirc (Figura 1). In reeent yenrs lobster.landings in boththese eonstal regions hnve deelined (Figura 5). Reeorded Inndings at ports ~ . in Yorkshire huve fallen from 2 392 cut in 1965 to 1 212 cwt in 1971, a drop of . 50 per cent. However, dntn eolleeted during this period showed that the effort hnd deelined from 1 869 775 traps hnuled in the 1965 senson to 1 506 504 in . 1971, a fall of 19 per cent. This reduction in the effort in the Yorkshire trnp fishery, vlhieh applies to both lobsters und crubs, is mainly the result of this type of fishing beeoming less profitable for the largervessel: of 15 metres und over. Thc changeover to more profitable types of fishing has also been aecelernted by the development of rrn important trawl fishery in·the area, und :~anyof the larger vensels in this fishery have now·been oquipped with the more p~~crful engines and uinches neeessnry fortrawling. The bulk of the lobster nnd crabcateh in Yorkshire is nml landcd by small open boats bebleen 5 and 10 metres in lcngth, ercued by 2 mcn, 1<1hich are cconomical to rune These facts dembnstrate how the cconomics of fiohing cnn nlter thc level of exploitation on a population and hou importunt it is for the 'invcstigutor to huve'detailed 3 knowledge of ench fishing aren• . Although thc reduction in annunl Inndings of lobsters off,Yorlcshire enn be pnrtly explnined by the substantinl rcduction in effort, ,it does not en,t~rely ,nccount for thc eontinuing declinc, in cntehes (Figure 5) nnd in the cntch per unit cf effort (Figurc 6). In most finhcries n reduction in fishing on n stock lends to an incrense in the cateh "per unit of cffort. However, this may ~,~.~~ , fully apply to a passive' trap fishery, wherc shellfish arc nttraeted into the traps by bait. On first consideration it would appear that fewer traps in an area might reduec the effectiveness of a fishery because pnrts of a stock might remain unexploited. Howcver, lobnter fishermen usually site traps on the most produetive arcns, movinl; them around as grounds become dcpleted" und this \'lOuld help to maintain a fairly stable eateh per unit of effort. Since ,1970 lobster catches 'in,some urens of Yorkshiro havo improved nnd thc numbcr of traps fished has'remnined fairly constantj astate of equilibrium uay therefore have been reaehed. Our continuing programme of investigations into the Yorkshire lobster und erab stoeksis designed to ndd,further to our knowledge of the effeets of • 'exploitation onthis population~ Simiiliarly, in Northumberland thera has been a steady decline in both total lundings (Figure 5) and the eateh per 1.U1it of effort (Figure 6). It is likely that the variouG factorG llhich havo been diGeussed in relation to Yorkshire also apply to this fishery. However, since 1970 thero has boen a slight improvement in landings and catch per unit of effort und this could be tho rCGult of a lower level of fiGhing effort, duo in part to tho purehase by fishermen of larger vesGels for trm'l'ling.' Sotith ~nd west co~stn In contrast to Northumoerland and Yorkshire, landings on the south COGst ,(hctw8en Ncwhaven andF~lmouth) have increased in recent years (Figure 5) follo'dng tho exploitation of several largely unfished lobstor stocks • in the Eriglish ehannel. Hm-Tever. on tho tradit ional inshore grounds thore are signs that heavy fiGhing is rcdueing the fishable Gtock to a level v1hich i8 causing concern. Lobster landings in varioun partn of the WOGt coaGt have also increased; this applies particularly to ~ales, \lhere there has been an increase in fishing effort in the last few years, rcsulting in a substantial inerease in landings (Figure 5). Unfortunately, datn on cnteh perunit of effortare not 'available from 1-Tales; log books \vcro issued to selected fishermen in 1972 and it is hoped to continuG this on an annual basis. Lobster eatehes off Cornwall have fallen in recent yearn und until 1969 there .ras a steady fall in thc cntch per unit of üffort, but this has stabilized in recent years (Figure 6). Discussions Thc rosulto available indicate eonsiderable variation be~ieen the yields from the different lobster fishing arens in England and WaleG. In some arens 4 -- ----------------------- there is evidence to ohow that catches have declined rapidly in recent years • .