International Council for the
Exploration of the Sea
CM 1995/K.:22 Poster
Shellfish Committee
Not to he cited without (lrior reference to the authors
Correlation analysis oe interannual variation
in cephalopod landings from European waters
I
Department of Zoology, University oe Aberdeen, TiUydrone Avenue, Aberdeen AB9 2TN, UK
21nstituto Portugues de Investig~ioMaritima, Ministeno do Mac, A venida de Drasilia, 1400 Lisboa, Portugal
3 Instituto de
Investigaciones Marinas, Consejo Superia- de Investigaciones Cientfficas, rl Eduaroo Cabello, 6, Vig~36208, EspafIa
41nstitul für Meereskunde, Universität Kiel, DOsternbrooker Weg 20, 0-24105 Kiel, Germany
S
DePartmento de Oceanografia e Pescas, Universidade dos A~es, Cals de St Cruz, PT-9900 Ilorta, Faial, A~es, Portugal
'l.a1xntoire deDiologie et Diolechnologies Marines, Universit6 de Caen, Esp1anada de la Paix, 14032 Caen Cedex, France
Abstract
The anespoodcnce oe interannual tralds in ccpbalqxxl catehes aaoos Europcan waters is analyzed. Data
00
ccphalopod landings amI, where available, flShing etToct. by Eurqx:an oountries wcre canpilcd and cntacd into a
careJatioo analysis.
Relevant fishing eITert data could be obtained ooly foc the UK and Patugal. In the UK data, CPUE was
stroogly cmelated 'hith landings, Suggesting that landings could be used as an index oe abundaIlce. Fa both SOOlland
and Patugal there wris reasonabIe carespoodcnce betwem interannual trcnds in catebes by different fishing gears.
IJoWever. it cannot be asswned that landings are always a realistic index of abundance.
In the N~east Atlantic and the Mediterranean. interannual tralds in landings oe rertain cepbal~
categaies in adjaccnt countries tcndcd 10 bc similar bolh aau;s spccies and aaoss areas. There was seme evidcnce of
correSpooding tralds ovcr looga- time periods and 00 a Jarger spatial scale, particuJarly foc 1JJligoforbesi. pointing to
the possible role ofJarge-scale cliffiatic oc occanographic factcrs in dcterinining cephalopod abundaIlce.
IntroducUon
are
CephaloPods
an increasingly important ftshery resource in European waters and a number of
species of squid. cuttlefish and oc1OpUs are landed commercially. Recent research has focused mainly on squid.
In European waters. the squid species of greatest imporiance to commercial flSheries are the so-caIIcd common
squids (Cepbalopoda: Loliginidae), 1JJligo forbesi (veined squid) and 1. vulgaris (European squid). Doth are
widely distributed in Northeast Atlantic and Mediterran6an waters. a1though 1. forbesi has a more northerly
distribution and is scacce in southem Portuguese and Mediterranean waters. while 1. vulgaris has a more
southerly distribution and is rarely found in Scottish waters. An isolated. genetically distinct. population of 1.
forbesi is fomid in the Azores (Martins 1982. Drierley et al.• 1993. 1995; Pierce et al.• 1994a) while a subspecies of 1.. vulgaris. 1. v. reynaudii. occufS on the southern arid western coasts of Mrica.
Landings oe oommon squids (Loligo spp.) in European countries vary widely from year 10 year.
apparently unrelated 10 fishing effort in those countries which record fishing effort (Pierce et aLt 1994b). Since
1
1990, annuallandings in several European countries have decreased.lIowever, this apparent trend has not been
subjeet to rigorous analysis and previous data suggest that there may be cyclie variation in abundance (Pieree et
aZ., 1994b). Tbe short (annual) life-cycle (Coelho et aZ., 1994; Guerra & Rocha, 1994; Moreno et aZ., 1994;
Pierce et aZ.• 1994c; Porteiro & Martins, 1994; Collins et aZ.• 1995) may in part aceount foe the high variability
in abundance, since the populations are not buffercd against fluetuations in recruiunent or excessive mortality
ofbreeding adults (Pierce & Guerra. 1994).
It is commonly thought that cephalopods such as lJJligo spp. may be highly sensitive to variation in
hydrographie conditions (Caddy, 1983; Forsythe. 1993). Indieect evidence that this is the case may be obtained
if eommon trends in abundanee are apparent across a wide geographical area.
Tbe present paper examines correlations between interannual trends in squid and other cephalopod
landings in different EC countries.
Materials and Methods
ICES supplied data on squid Iandings 1973-94 by Europcan eountries fishing in the Northeast Atlantie
and data on total annual cephalopod landings in EC eountries 1965-92 from the Northeast Atlantie (FAO area
27) and Mediterranean (FAO area 37) were asscmbled from FAO Ycarbooks of Fishery Statisties, Catehcs and
Landings (Food & Agrieulture Organization, Roine). Long-fmned (Ioliginid) squid landings from the NE
Atlantic were also compiled by direct access to national databases in England and Wales (1980-94), Seotland •
(1904-94), France (1960-94), Spain (1983-94), Portugal (1960-93) and the Azores (1948-93). Wbere possible
the data were subdivided by area andlor gear. Wbere effort data were available, overall CPUE was derivcd
(totallandings divided by total effort).
Similarities in inter-annual trends foe different data categories were evaluated by non-parametric
eorrelation analysis (DMDP statistical software). Due to the very large number of possible comparisons, the
analysis is restricted to answering specific qucstions. Tbc first thrce questions relate to the utility of landings
data as an abundance index:
(a) Are the same trends seen in Iandings and CPUE?
(b) Are the same trends seen for different gear types?
(e) Are the same trends seen in catehes by different countries fishing in the same area?
Two further questions relate to the trends over large areas:
(d) Are the same trends seen for different cephalopod eategories within the same area?
(e) Are the same trends seen for a particular species in different areas?
Comments on the categorization 0/ cephalopod landings in published data
Ccphalopods are cIassified into a scries of categories by FAO. the use of whieb has bccn inconsistent, . .
and not all of wbicb are mutually exclusive. Some cephalopod Iandings are recorded as "Cephalopods not •
elsewbere idcntified". Many EC countries recordCd squid landings from area 27 as "Squid (Loliginidae or
Ommastrephidae)" up to approx. 1980, after wbieb landings were categorized as "lJJligo spp.... For Scotland,
Northem Ireland, Ireland and Portugal it is reasonable to assume that, prior to 1980, the squid landed was
usuaIly lJJligo. Tbc category "Squid (Loliginidae or Ommastrephidae)" continues to appcar until 1985 in data
foe England & Wales, possibly refiecting participation in the Todarodes sagittatus fishery in the wly 1980s.
France recorded squid landings as "lJJligo spp." until 1980 and as "Squid (Loliginidae or Ommastrephidae)"
thereafter. 1I0wever, landings are probably still mainly of lJJligo /orbesi andloe 1.. lulgaris. Spain bas switehed
from a1ways recording "lJJligo spp.... "11le.x illecebrosus" and "Todarodes sagittatus" scparately to recording an
increasing proportion of Iandings as "Squid (Loliginidac or Ommastrephidae)". Decause Spain has a flShery for
ommastrcphids, this category is certain to incIude a mixtUre of species, including thc ommastrephid Todaropsis
eblanae as weIl as thc above mentioned species. Similar problems of categorization arise less frequently for
cuttlefish and octopus, but Spain and Portugal have both switehed bCtween using "Scpiidae or Sepiolidae" and
"Sepia officinalis" for all euttlefish landings. Also, Spain normaIly records octopus landings as ''Octopodidae''
but during 1973-6 recorded aII octopus landed as "Eledone". France recorded Iandings of "Octopus vulgaris" in
1975-76 but nOrmaIlY recorded "Octopodidac". Note that the Illex species Ianded by Spain is more likely to be
Illex coindetii than I. illecebrosus, since the latter is a Northwest Atlantic species.
Data foe FAO area 37 (Mediterranean) present (ewer problems, but France and Greece both switehed
(in 1981) from recording "Sepiidae or Sepiolidae" to recording "Sepia officinaZis". Spain and Greece recorded
2
landings of lllex coindetii, althougb Grcecc switebed in 1981 10 rccording "Squid (Loliginidae or
Ornmastrepbidae)". Grecce also started recording Octopus \'ulgaris in 1983, as weIl as Octopodid3.e.
Result.§
(a) Landings and CPUEfor Loligo
This analysis used data extracted dircctly from National databases. In data on Loligo landings from
ScotIand (Fig. 1) and England + Wales, landings and CPVE were significantly correlated, foe individual geartypcs and overall (fable I). For Portugal, annual Loligo landings from the trawl fishery (1988·1992) were
negatively correlated with CPVE but the trend is not statistically significant. Data foe other countries were not
available.
(b) Comparisons between gearsfor Loligo landings and CPUE
t
This analysis used data extracted directly from National databases. Landings of Loligo in ScotIand by
different gear categories wcre correlated, except foe seine nets versus hcavy lrawling gear and the same was
true of CPVE (Fig. 2, Table 2). Landings of Loligo in England by different gears Were generally not correlated,
except for heavy trawls versus seine, and this also applies for CPVE data. Landings of loliginids in Portugal
from the artisanal fishery were correlatcd with trawl and with seine landings.
(c) Comparisons between landings ofLoligo by different countries jishing in the same area
This aßaJysis used data providcd by ICES. The statisticai power of the anaiysis is restricted by
incomplete data. Possibly many missing values actually represent zero catches but it was ncccssary 10 assume
they were missing data. Interrannual trends in landings of Loligo by different countries fishing in the same
ICES fishery subdivision were weIl correlatcd in some iIIiportant squid flShcry areas, particularly the west coast
of ScotIand (VIa; Fig. 3) and the lrish Sea areas (VIIa) but not in other areas (fable 3). In the caSe of area Via.
it is possible that landings by Ireland are poorly correlated with those of other countries bec3use landings from
Vlb were included with those from Via.
(d) Different cephalopod species within lhe same area
This analysis used data published by FAO. For all countries except Spain, the different FAO categories
of squid, cuttlefish and oc1opus in area 27 were combined foe analysis, but the squid can be assumed 10 have
bcCn mostly Loligo spp.
.'.
"
For area 27 as a whole, there wcre no significant correlations between landings of the three main taxa,
but positive correlations were seen in landings, bY Spain, except foe Todarodes (Fig. 4), and France, also
bctwecn squid and cuttlefish for England and Wales (fable 4).
More categories of cephaloPods are distinguished in Mediterranean (area 37). Overall, there were
positive correlations bctween many of these categories (fable 5). For individual countries (Italy, Greece, Malta
and Cyprus), some positive correlations bctween species were seen, although lllex landings in Greece were
negatively correlated with those of other spccies. while Sepia and Todarodes landings in ltaly were negatively
correlatCd (Fig. 5). Squid and octopus landings in Spain'were also negatively correlated.
(e) Trends across /arge areas
JCES data were available foe many countries: the two examples chosen here are foe oountries fishing
across different, but overlapping, areas. lCES landings data foe England & Wales showed comparable
interannual trends in Loligo landings foe many flShery areas, with Only landings from the northem North Se:i
(IVa) being negatively correlated with landings from elsewhere (fable 6). Spain fishes squid from a wider area,
and positive correlations are seen bctwecn landings in Spain from the west
of ScotI:lrid (VI) arid Ireland
(VIIbc), the CeItic Sea (VIIg-k), the Bay of Biscay (VIII) arid west Portugal (IX) (Fig. 6, Table 6).
The FAO data show some correspondence bctWeen Iandings
Loligo from area 27 by different
countries, and this was also the case for cuttlefish (fable 7). Iri
37, landings of these cepbalopOO
categories by different countrics were as often negativcly correlatCd as pOsitively correlated (Table 8), although
landings of octopods by different countries were mostly positively correlated. A difficullY with interpreting
these trends is that the fishing areas of different countries overlap extensively.
coasts
oe
European
area
3
Comparisons betwcen landings from FAO arcas 27 and 37 are possible using area totals and foe the
two countries, France and Spain, wbicb routinely fisb for cepbalopods in both arcas. Squid landings from the
two arcas tended to bc positively corrclated, octopus landings negatively correlated. Overall cuttlefisb landings
from the two arcas werc corrclated but landings of cuttlefisb in France from the two areas wcre negatively
related (Table 9).
Longcr time series of data for long-finned squid (Loligo) landings wcre obtained directly from
National databases held in the Azores, Portugal and Scotland. Additional data series wcre obtained foe France
and Spain but covered shorter pcriods. Previous comments about the FAO data notwithstanding, it appeared
from the new Spanisb data (1983-94) that published (arca 27) totals foe FAO categories "Loligo" and "Squid
(Loliginidae or Ommastrepbidae)" sbould be added to approximate to totalloliginid landings. These new FAO
totals werc used foe pre-1983 data and combined with the new 1983-94 data to ercate a new data series. The
new Frencb data (1980-94) wcre similarly grafted onto earlier FAO data to create a new data series. Landings
by Scotland wcre correlated with those in France and the Azores, wbile landings in Spain wcre negatively
corrclated with those in the Azores (Table 10). The pattern of landings since 1980 appears strikingly similar for
Scotland. the Azores, Portugal and France (Fig. 7). 1I0wevcr, statistically, only the correlation between
Scotland and the Azores is significant over this period (Table 10).
DL'icusslon
Tbis kind of analysis will always be limited by the quality of the data available, but collection and •
reporting of data on cepbalopods, wbicb are not quota species in EC waters, is particularly poor (Anon., 1993,
1994; Donoso-Perez & Forest., 1993; Pierce & Guerra, 1994). Tbc main problems are:
(a) Umited objcctives of data collection by National Governments. Many countries record total
ccpbalopod landings but not all record associated data on location or fisbing effort.
(b) Low accuracy: there is ample scope for buman error in the way data are collected. In the UK
fisbery we are awarC of examples of large amounts of squid going unrecorded duc to categorization as "other
spccies" or being landed by smaIl boats, also of quota species being mis-reported as squid.
(c) Inconsistent categorization of ccpbalopods: continuity of data over time is compromised by
splitting and lumping of categories (see above).
(d) Incomplete rcporting to International bodies.
Additionally, interpreting trends in sucb data series is difficult. Wben a large number of variables is
being analysed. corrclation analysis will inevitably generate SOme spurious corrclations, and corrclations may
not indicate any underlying causal relationsbip. TempofaI autocorrclation may also be a problem, althougb for
sbort-lived spccies with non-overlapping generations, abundances in two adjaccnt years may probably be
regarded as independent, because the only direct link is througb recruitmenl In any case, the approach used in
the present paper represents one of the few feasible means of addressing the questions raised.
Pierce et al. (1994b) argued that, in the Scottisb fisbery, landings of Loligo werc ~ reasonable index of
abundance bccause they werc strongly correlated with CPUE. Even thougb squid may be targetted by Scottisba
fisbermen in years of high abundance, the impact of this on ovcrall CPUE (by the entire fleet) appears to bave'"
becn negligible. Tbis conclusion is supported by the present analysis far Scottisb and Englisb data but not for
Portuguese data. Tbus, for countries wbich report landings but not effort there must remain doubt as to wbether
landings are related to abundance.
Tbe UK data also show that landings and CPUE recorded for different gear-typcs da not always record
the same picture. Similarly, trends in landings by different countries fisbing in the same ICES fisbery
subdivision did not always correspond. Tbis is likely to reflcct diffcrences in fisbing effort or methods rather
than abundance, so it is generally preferable to treat data from different countries separately.
Analyses of both FAO and ICES datisets sbowed the existence of parallel trends both aeross species
and aeross areas: there are certainly more significant positive correlations tban would bave becn expected by
chance alone. At present bowever we can only provisiOnally suggest that this might. to some extent, reflcct a
common response to changing environmental conditions.
The analysis of data obtaincd by direct aCccss to National databases was particularly interesting,
reveaIing striking corrcspondence between trends in landings of Loligo in Scotland and tbe Azores over tbe last
15 years. Landings in France and Portugal sbowed somewhat similar trends. while tbe pattern of Spanish
landings was entircly different. It may be relevant that Scotland and the Azores are unique in landing only
Loligo forbesi, albcit possibly different subspccies, whereas the other countries land a mixture of Loligo forbesi
and L vulgaris. Ir tbis correspondence bctwcen trends in midAtlantic and Continentat shelf landings can bc
sbown to reflcct trends in abundance rather than a common response of flsberies to cbanging technology and
4
I.'
•
,
market forccs - and in thc casc of Scotland we believe it can • this represcnts the best evidence yet available that
squid abundance could be controllcd by large-scale climatic or oceanogrnphic factors. In a complementary
analysis, Picrce (1995) showed that squid landings in Scotland could be weU-predictcd from sca surface
tempcraturc data.
'"., '
;
,.' "
Acknowledgements
UK landings data wcre supplicd by SOAFD and MAFF. French data were supplied by the Mfaires
Maritimes. Additional infonnation on squid landings was supplicd by lCES and we would like to thank Maria
2'.arecki Coe her assistance with extrncting these data. The analysis was fundcd by agrant from the European
0573) and wc are grnteful to many colleagues working on squid and
Commission, (projcct no. AIR 1
associated with this projcct for discussions and contributions to 'these ideas.
ern
References
•
Anon., 1993. Report of the Study Group on Cephalopod Diology. Kiel, 21-22 September 1992. International Councilfor
the Exploration ofthe Sea. C.M. 19931K:66.
Anon., 1994. Report of the Study Group on The Ufe llistory and Assessment of Cephalopods. International Councilfor the
Exploration ofthe Sea. CM 19941K:7
Drierley, A.S., Thorpe. J.P., Clarke, M.R. Martins. II.R., 1993. A preliminary biochemical genetie investigation of the
population structure of Lolig%rbesi Steenstrup. 1856 from the Dritish Isles and the Azores.1n Okutani, T., ODor.
R.K. and Kubodera, T. (eds.) Recent advances in cephalopodjisheries biology. Tokai University Press, Tokyo, 6169.
Drierley, A., Thorpe. J., Pierce, GJ., Clarke, M.R., Doyle. P.R. 1995. Genetie variation in Loligo forbesi in the Northeast
. Atlantie Mar. Riol. 121, 501·508.
Caddy. J.F., 1983. The cephalopods: factors relevant to their population dynamics and to the assessment and management
of stocks. In Ad~'ances in assessment ofworld cepha/opod resources. edited by J.F. Caddy, FAO Fish. Tech. Pap.,
231: 416-449.
Coelho. M.L., J. Quintela, V. Dettencourt, G. Olavo and 11. Villa, 1994. Population structure, maturation patterns and
fecundity of the squid Loligo vulgaris from southern Portugal. Fish. Res., 21, 87-102.
Collins, M.A., Dumell, GM. & Rodhouse, P.G., '1995. Reproductive strategies of male and female Loligo forbesi
(Cephalopoda: Loliginidae). J. Mar. Riol Ass. U.K., 75, 621-634.
Oonoso-Perez, R. & Forest. A., 1993. Analyse des peeheries fran~aises de cephalopodes dans le golfe de Gascogne
(division VIII du CIEM). ICES C.M.1993/K.:51
Forsythe, J.W.• 1993. A working hypothesis of how seasonal temperature change may impact the field growth of young
cephalopods.ln: Okutani, T., O'Oor, R and Kubodera, T. (eds), Recent advances in Cephalopod Fisheries Riology,
Tokai University Press, Tokyo, pp. 133-143.
Guerra, A. and F. Rocha, 1994. The life history of Loligo vulgaris and Loligo forbesi (Cephalopoda: Loliginidae) in
Galician waters (NW Spain). Fish. Res., 21, 43-70.
Martins. II.R. 1982. Diologieal studies of the exploited stock oe Loligo forbesi (Mollusca: Cephalopoda) in the Azures. J.
Mar. Riol Ass. U.K., 62, 799-808.
Moreno. A., M.M. Cunha and J.M.F. Pereira. 1994. Population biology of veined squid (Loligo forbesi) and EurOpean
Squid (Loligo vulgaris) from the Portuguese coast. Fish. Res., 21, 87·102.
Pierce, GJ., 1995. Stock assessment with a theItllOOlCter: a:nelatioos between sea surface temperature and landings oe squid
(Loligo forbesl) in Scotland.International Council for the Exploration ofthe Sea. C.M. 19951K:21.
Pierce, GJ., Doyle, P.R., Dailey. N. & lIastie, L.C., 1994. Distribution and abundance of the fished population of Loligo
/orbesi in UK waters: analysis of research cruise data. International Council/or the Exploration o/Ihe Sea. C.M.
19941K:22
Pierce, GJ., Boyle, PR, lIastie, LC. & Key, L, 1994c. The life history of Loligo forbesi in Scottish waters. Fish. Res.•
21, 17-41
Pierce, GJ", Doyle, P.R., Ilastie, L.C. & Shanks. A., 1994b. Distribution and abundance of the fished Population of Loligo
forbesi in UK waters: analysis of fishery data. Fish. Res., 21,193-216.
Pierce, GJ. & Guerra, A., 1994. Stock assessment methods used for cephalopod fisheries. Fish. Res. 21, 255-285.
Pierce, GJ., Thorpe, RS., Ilastie, L.C., Drierley, A.S., Doyle, P.R., Guerra, A., Jamieson, R. & Avila, P., 1994a.
Geographie variation in Loligo forbesi in the Northeast Atlantie: analysis of morphometrie data and tests of causal
hypotheses. Mar. RioL, 119,541-548.
Porteiro F. and 11. R Martins. 1994. Population biologyof Lolig%rbesi Steenstrup. 1856 (Mollusca: Cephalopoda) in the
AZores: sampie composition and maturation of squid caught by jigging. Fish. Res., 21, 103·114.
5
Tahle 4
TableI
Correlations bel"'een
CorrelatioßS bt"hu"t"n Lol;go landingli and (,Pl 'E
Spt.~annan's
Spt.'armdll"S nml cllm:latinn COt.'t1idl'nl". Sil!nitkant cOfTl'latiuns are indical~d tly Ixlld
type. Data fM indi\idual goa'·typ." a,o f,om 19RO-94 (ie. 1'1=15)_ The all·goa, dala fu,
Ika... yua~l
Lighllra,,1
Pairtra",1
Sc"..inc
All
Engl(Uld &- ""tlles 1,\'=1OJ
,uid
Cllllllllf'J Is/d"dJ t.V=9J
('ulth,~'
s.~arman·s nmk c\\lTdatiI1n Ctx'ltidl'nt,\. Signitkant corrclalions are indicatl'd tay hold ty~.
Da.. fUf individual g,'ar-Iyp<' arc frum 19HI~94 (1'1=15) in Seodand and England + Wal",. and
19Rfl.93 (N=R) in Portugal. fka\oy = hc:avy oller lra,,-I. light = light oller lrawl. Pair = pair
dl'mc~ St,.'il1l's. An.. = artisanal fi.<;ht."ry.
uawl. Sc..'inc =
Ligh'
Pair
s....inc
AI'
Gear
Lighl
Pai,
Seine
AU
Landm,s:r. En~/dnd & Walt'f
Sl'ine
Ikavy \.i~hl Pair
G,,'ar
Gl'ar
Lighl
Pair
.(). I Xfi
Ligh'
Pair
-O.lH6
1l.1l14
0.271
-0.3Y3
0.554
-0.486
&'ine
All
&'ine
11.150
0.71MI
AU
t11l19
Illl'I~
('Ulll<
0.5 \11
Spdln'.\'=2tt,It, 17, ~"',I9"1
u,!; n l11f't
T("I
uid
/11" 0.44'Tod. O.IOli\to
SqUld
CUll!< 0.725' 11.5'20' 0542' 0.701'
0:1 0.413' 0.5'05' OOH~' 0.662'
het"t't"n gear.. t)ope'S ror l..oligo landin~ aod CPl'E.
wltclm,r:". Sc OIfund
PJir
St.'ine
Ika\V \.i 'ht
0.557
0.511 I 0.864
0.050 0.664 0.711
0.664 0.9K2 0.857 0.632
CPL"E. Sror/dnJ
St.·ine
Pair
Ika\V \.i.ht
0.6'16
0.579 0.782
0.025 0.564 0.611
0.725 0.989 0.775 0.557
I
AU
0.810
0.527
0.952
0.898
0.857
('utll~
0.766
-0.149
Cn'E, Eng/dM & Wal..
Pai,
St'in~
Ikavv Lioht
-'lIY6
-0.325 0.139
0.679 0.104 -0.264
-0.214 O.OJ2 0.8'16 -0.225
•
Londings. Portup,al
('Jl'ar I Trawl Arl
St.'inC'.
Art
Scine
holdl)"pt!'.
Ire/tlnd (,\'=61
. uit.f
uid
CUll!<
Gl'ar
ar~ indil'a~d ~y
-O.4HO
Table2
('or~latif)rlS
cUTldatiun'i
=
En.land
0.957
0.950
0.975
0.807
0.589
Seolland
0.946
0.9116
0.9116
0.954
0.979
(ß.'ar
«phalop'nd (al~ories: F "0 art"B 27.
cOt.'ffi\.'i~nlS. Signilkant
The analysis is tJa.'\l~d on FAO data fnT 'Jndin~ .. Irnm JreJ.. ~7. 14tl5-IW2. Only cnumrit.',\
recoTding: more man on~ catt"gllry* 01' ct.'phalupud an: indud\.'d. *Cat~gnri~s ha\~ h!.,'n
comt'lined \\-here arpropriate 1'il'C (ext). Cuul~ = "Stpia (lffic,"ah~" + -St.·piida~ or
Sepiolidae", O.:l = "Ocr()poc1.Jüf'·' or "a:ropus \uJgdri.S" or "Elt'dont' ~rp:·. Squid "LuJIl:o
spp:' or "Squid (Loliginida~ or <)mma<;,m·phidat.·..• or "//ln ,Jlf'ubm\us" ur "To(L"()Jf'~
sagittarus", Tod = "T()(larodts sagirtatus",
t~=2ll.
Scotland gtX'S "at.:k In N74
landi~~ of difft"renl
rank corrclatilm
0.647
Table 5
Table3
Corrt"lations betw"," landings 01 squid· by diß'eR'nt couotrles ft."ihing In the samr anL
Correlalions be"'~n landlngs cf differml cephalopod calegories: FAO aNa 37.
SigniflCan, com:latitms are indi<ated ~y hold IYpe. The anlysis is based on ICES data (\973·94).
·landings of "1.oligo" and "Squid ,." elscwhere included" were summed because Ihe use of these
catC'gories was amhiguous. For most enontries. the squid ean be assumed Lo be Loligo. Scot :=
Scotland, N. Ire = Northom (rcland, I. Man = Isle of Man. Engl = England & Wales. Belg =
Ilclgium. , Fran = France, Port = Portugal. IVa = Northem Nurth Sea, \Vb = centraI North Sea,
IVc = Suuthem North Sca. VIa = wes' of Scodand. Vlb = Rockall. Vlla = lrish Se•• Vllbc =
West of Ircland. Vlld = fa'lom English Channcl, Vlle = Western Englisb Channcl, VIIf = Bri..ol
Channcl. Vllg-k Collie Sc.. VIII = Bay of Biscay.1X Wes' Portugal.
Spearman's rank correlalion coeffkicnts. Signifte.n' correlalions an: indieated by hold
Iype. The analysis is based on FAD data for Iandings from area 37. 1965-1992. Only
eounbies recording more Ihan Orte category· of cephaJopod are included. ·Categories
have been combined where appropriale (see leK.I). Cuule
"Sf'pia officinalis" +
"'Sepüdae or Sepiolidae". Oel :z wOctopodida~.. or "(kretpus vulgaris" or "EJ,Jon, spp.
Squid = "I..oligo spp." or "Squid (Loliginidae or Omm&.<;;lrephidae)" or "I/I~x coindt-nr
or "Toonrodn .ogitto....... Tod. "Todor-ob. sogirra....~. O.v.1 "Oc'opus v.lga.u".
Ekd. Ek~ spp.
=
=
Iran
Set.
En I
0.2IIt
fran
0.0 IS' ~l.2.W
f ngl
fraß
Ireland
tran 0.495"
1",land -0..242" -0.219'
Set. 0.409' 0.253' 0.027'
Spain 0.571' 0.6111" .(l.214'
VI/<lIN=I<I'. 11'.12'. 16'.1".111.21'. tI'
fran
J Man 1R."land
I
Ild
Ingl
franc
I. Man
1",land
N,lre
Set.
0.21S'
0.132'
01146'
0.23S'
-{lIl9'
0020'
"'n
0.551'
0.811'
0.25S'
0.6520.131'
1116'l"
0.J51'
0.4'\5'
0.:147"
"ngl
han
h
n05:"-
nOtO"
O..5"Ht
VlIg ~ 1.'<=21'.1-1'.11',16',12')
[k"lg
f.ngl
-O,U4r
Fran
0.4#
f.ngl
O.18S
har"..
In:land
0.205"
I",tand .(lOBS' O.75<f 0.239'
Spain -O..18S' .(1.1%' .(l.OJI' -0.3'\8'
VIIbc(N.5". fI,l4"1
In I
Fran
lreland
~ran -O..IS8'
(",land 041S' o 3S9'
Spain OS92' 0.170' -O..Nt
0.38t
VII.fN=I'l'.I1'1
Bt-J
fn I
~ngl
0.tt5'
Iran 0.2J2' 0.6."lI'
I
0.205"
0 0fIJ' 0 300'
0.011' -0..316' -O.4IX/
f
0.6'11' -0..261'
Vlld (N= 21'. 16')
Ild
N. Ire
O.l~1O'
O.lUr
fran
ScoI
Spaln
-O.oor
F'iC<
(N=19)
Lol.
CUllie
C'ullie
llkx
Squid
0.05g"
CUllle -O..OIr
Oel -0.701' -0.037' -0.740' -0.381'
O. v.1
Itnly(N=28)
Tod.
Sf'nia O. vul
LoL
0.260
S.pia 0.086 -0.439
O. v.1 0.457 0.796 -0.232
EI.d. 0.334 0.397 -0.199 0.5J6
C'ulll~
CUlll~
-
1:t1
Sen,
=
Lol.
VlbIN=5".Iz'. T.~I
"ll!
Iran
Set.
VldIN=ll'.lIr. 19'. lIJ'. 11". 1.1, Ir.tt.lil
=
=
Spoin(N=2(f,ll',21!)
111..
Souid
0.477'
IVb tN= Ir. 2rtl
Bel
In I
Ingl 0.397"
Set. 0.279' o.5O't
IVa (N='h. I4h. 15rl
=
VI/f(N=III', 15'. In
Bel
Fn I
I.ngl -0..127"
fran
-0.203"
~;uid
CUllie
Squid
C'uttle
O. v.1
Oet
Tod.
1/1"
Squid
O. v"1
EI.d.
CUllie
Oe,
- .0.82.3'
0.037
I
0.753
0.769
0.672
C'yprus IN=201
O. vul
1/1" ..0,696"
0..577"
\'/IIIN=II',1', S. 15'1 .rx'(N=141
Bel
I-n t
fran
Purt*
I.ngl -O.04B'
Iran 0.5/x! -O.2tlO"
Spain -O..51x! 0.500' -O.22U'
Spain'
0.117
Oel
G,,,r. (N=20', tI', )(1)
111..
0.388
-0.060
MI/:;,t=2~ullle
Tod.
Lot.
I
Oe'. 0.869
~
0.823"
0.877'
0.891' 0.952'
0.891'
-0.60'1'
0.791'
0.829' 0.845' 0.709'
Ar.. 37 wtal. IN;.~~ 0' N=I5"1
('unkTod
1IJf''(
,uid 0. vul EI,,J.
Lol.
0.204
-O..33S' 0.205'
0.772 0.705 -0.0111'
0.199 0.827 -0.007" 0.593
0.458
·0.027 0.338 0.17\" 0.196
0.744 0.281
0.550 0.581 -0..0'16' 0.694
0.894 0.546 0.639
0.127 0.878 0.254' 0-594
•
Table8
Correlations betwee. landings by dirr.renl rounlries: FAO area 37.
Table6
Correlations bel....n landings from different lCES ..eas.
Ctlt.·ftid~nts. Signitkanl correlations are indicated by hold type. Codt"s für leES F~ri~S
Suhdi~isi\ln,,: IVa = ~tlnh~m ~(lnh S~a. IVh =: cenLraI North Sea. IVc = Southem North Sea.. VIa = \liest of Scol1and. \db =
Rodall. Vlla = lrish So•• VIIIlC = Wost 01' 1",land. Vlld = E.stern Engtish Chann.l. vne = Western English Chann.!. VIU' =
Bri<lol Ch.nno!. VlIgk Collie Soa. VIII B.y 01' Bisc.y.IX =W.st Portugal.
Spcannan's rank Cllrrelatilln
=
=
Vlh
VIa
IVh
IV.
IVa
IVh
IVc
VI.
Vfh
Vlla
VIIIlC
Vlld
Vlle
VlIf
VIIgk
VIII
Spt"annan's rank com-Iation cc.K.·nic.:i~nl'i. Signifil'ant corr~lations are indil:al~d ~y tll.lll
type. The analysis is based on FAO dala rOt landtngs rrom a",a 27. 1965·19'12. Fr.n ,
France. Gree = Greec~, hai = ltaly. Cypr = C~pru'i. n = To(ldr(Jf.Jf'f $(I.r:lIIaruf. 0\' =
Octopus \lulgaris, EI = El,don, spp.•
VlI.
VlIllC
"wligo ,pp." (,v=2S'.2Itl
Fran
Soain ltalv
Gn.'l'
Spain -0.326'
ltaly -0.320' -0 14"
Gree -Q.2.'i7" -0.134' n.n 1lJ'
Malta 0.34T -Q.322' 1l.147' -0.485'
Top riglll: Spain (N=5', 11',8',15')
VlIe
Vl!f
VII.·k VIII
IX
Vlld
~12.~7'
().:t50b
0.596'
O.l\.ltf OA6II'
.O-Itr-l 0.264'
.U.36t 0.167' O.46~'
11 147" UJMltl
·1I.~Or'
~)417' 0.448' 1).248'
.n.310' IUI~' 0.723'
O.IMI'J' 0.1\.13' O.3·ur
.0.496' 0.615' 0.76-1'
·0.691' ~).lI'J7" '(J.6.W"
O.261f
0.242"
0.71Xr
0.057'
0.4-19'" 0.216'
t
O.36R' ·053S
0.387" lun'
0.61T 0.116'
0.526' (U6!'
(1,(148-
01
0.846' .0.323 0.49r'
0.028'
0.55r 0.3W'
0.708" 0.349'
0.541- 0.396'
00559'"
O.4S1
CR
0.598'
-u.l1i 0.460' 0.681' 0.22r 0.53t O.:!'JO"
O.281f ·11.207"
Cun/,fish 1-"=/9'. 2';. 2K 1
Fran Srain
1... lv
G"'c Malta
Spain -O.lJr
11
ftaly 0.53S' -0070
Greec -0.791' -OO~5" -0.518"
Malla 0.426' -0.166' .lll~~~ -U.2.... 1"
Cypr -0.510' ~).o~f ~l.:!'lO' 0.702' -O.-l6'l"
0.590' 0.526' 0.756'
0.228' OA76' O.IXXJ'
0.284'
O.024C'
0.225' 0.185'
0.620'
0.346' 0.122' 0.274'
·0121' 0.551'
0.333'
Fnm
Spain
OvItal
EIltal
Grce
Malta
Cypr
BOI::m 1'/1: England & Wales (1'1=15',11', u,lI', 18',1(1, 211, Id', 11', 11', </, Ir, 1'1', I'r,21')
•
Gn:i' I-U6(III'"
Tlltalj -O.:!\I~' .11.74'/'
Ocropodl(W.dN=lrT. 2Ft. 21')
Soain ()l. hai Elltal Gn'\.'
0.675'
0.620' 0.536'
0.724' 0.7I/{ 0.588'
-Q.118' 0.234' 0.114' 0.214' -O.7ll9'
-Q0'I2' 0.51l3' 0.501' 0.60.1' 0.787'
-Q.053'
-Q.nr
-0.230'
Correlations betw..n 'andings from FAO are.. 27 and 37.
Correlations beI,,""," landings by different rountrif'S: FAO area 27.
Spl'arman's rank com:latinn l'fll'Uit:k'nl'i, Significant correlations are indicat.cd ~y bold type,
The analysis i,s ha"-'d on FAll data for landings from area 27. 1965·1992. Seal = Seotland. N.
Ire = Nortbern 1",land. 1",1 = '",Iand. I. Man = Lsle or Man. Engl = England & Wales. Belg
Belgium, Ch Isl = Channcllsl.nds. Fran = France. Port Portugal, Germ C..:nnany, Norw =
Norway. kel = kcland. Denm = Denmark. 11011 = lIolland. The lirst tahulalion. rar "wligo
spp," also inl,:ludc..'.'i "&,uid (Lolig;nidac or (lmma.~lrephidaerfor those counuies which eilhcr
nnrmally land only LoliRo or R.'Cord othcor ()mma.~trephids separately (see tex.t).
=
I
Todn,~,(N="',4")
I Snain Norw
Norw 1-Q·35"
l<ell -O.4Id 0.526'
</, 11'.25', Ir, Il, 8', 1It, 1'1.20)
Denm Holl
FMI
Olsl Fran
Snain
0.138'
0.829'
0.148"
0.854'
0.303' 0.661' O.Bar 0.891'
-6.722" -lI.ln' 0.728" 0.466' 0.221'
0.281' -0.3'6' 0.12T 0.241' 00558' -Q.JOJi
C.nl,fish (N=/lf,
IMI
Fllgl
Ch Isl
Fran
Spain
Port
=
"wlign .•pp. "/0' "Squid (wliginiJn, 0' OmmastrephiJa,j"/
IN=2ft, 17', 12'. 2g'. 2(1. 21.15'.111'.111. 2!1. 1<1)
o Isl Fran Snain
I Man FMl
11<'1.
N.lre 1"'1
SeOI
tl.266'
h
O.440 0.1Jl6'
tl.4.1ll' 0.857' 0.219'
0.5'" 0.767' 0.268' 0.56$'
o.J31' 0.2H' 0.453" -0.112' 0.412'
0.212' -0.147' O.o2S' -0.275" 0.394' 0.474'
0.564' -OOM" 0.197' 0.287" 0.138' 0.3n' 0.271'
-O.I~I' -0.475" ~1.37'I' -0397" -00540" -0.232" -0.430' 0.019"
0.l!'l9' 0.114' O.III'J' 0.298' 0.208' 0.066' 0.537' -0. nt -Q.255'
l/l',x(N=ft,lt)
I Soain Pon
Port 0.4116'
C..:nn I -0.796' O.lM.r
OcrnpoJiJn, (N=S',"'.
lrel
Enel
Engl -Q.210'
Fran -Q.746' 0.549'
Spain -Q.7'I~' 0085"
Port -Q,5IMt 0.5'H{
111. 15'.27")
Fran
Snain
0.3.15'
0.601' -0.3'10'
-0.573"
Table9.
Table 7
N.lre
(",I
I. Man
Fllgl
Belg
Chlsl
Fran
Spain
Port
Malta
-o.4t~.
=
Spearman's rank. correlation coefflcients. SignÜlcant correlations are indicak.'d by
bold type. Cuule = cutLleflSh. Tod TodIlrod,s sagitlarus. ·Two spC'Cics of tll,~
are recorded. bul most l/le.< landings in hoth areas are liIt.ly (0 he oe I. coinJelii.
=
I
France~1
Spain
TOTAL
.
(N=2tr'.
Irl. 15'. !/'.24'. 111. 21'1
1II".
wliPO
-
0.54r
0.069'
Tod
0.675'
0.296'
0.368'
. ~'uid
0.171'
0.643"
0.070'
Cultle
-0.538"
0.123'
O.S09'
~1.158'
-0.461'
-0.322'
Tablel0.
Correlalions _
..n 'andlngs oe tong.ßnned squld from
Ihe NE Adanlic by differenl European <ountries.
Spearman's rank correlalion coefftcients. SigniflCaOl correlations are
indicated by hold Iype. Tbc anaIysis is hased on data ohtaincd hy direcl
hy FAO data on Iandings rrom
area 27. 1948·1994 and 198().1994.
access to National datahases. supplemented
Topriglll: 1911f).1994(N=IS',I4")
SeOlland Franc.
Soain
Portu.al Azores
ScotIand l1.-.+/h~)
0.379'
-0.400'
0.284'
o.5Oll"
France
0.439' :;',:;,";,'/'
-0.579'
-0.002'
0.279'
Spain
-0.216"
OJ)90" ~;.~::~::::;.:~~~
O.l03~
-o,248~
Portugal
0.060'
0.022'
0.186' 1!t::~':':':,:i::(1 -0.231'
0.270'
-0.208'· -o.7SO'
-0.109' ;:':::',::,~'j
Azores
BotuJm "fr: 1948·1994 (N=31r. 34". 45', 2!/'. 28', 3j)
Figure 1
Figure 2
~",o ...- - - - - - - - - - - - - - - - ; - - - - - - ,
s()()
I,,'X)
600
lOi~1
400
."(10
2()()
H~avy
0-+----,---=::,---,...---,---_;
0
so
70
s~
...
••
...
""
RR
'N'
tJ!
Q4
8~
'NI
Q~
Q4
I~OO
'\I'IlIU.,--------------------__,
~7~)
otter trawl
Light oltt.'r tmwl
Ellon IIO(Mk lll' htlUr~ ti~hing)
tOllO
</l
11)
:!uun
c::
c::
5()()
c::
0
.9
17 Cin
I~"'-t----__r---__,_---.,----r_--_;
7~
>\lI
70
so
s~
o.~ ...- - - - - - - - - - - - - - - - - - - _ _ ,
o.
04
1),2
o.o-t----,-----,----r----,---_;
•
70
Year
Year
~~~~l
.~.:
6000.--------------------,
o
~
m
•
~
~
--
---6-4000
2000
</l
11)
</l
8
§
c::
c::
m
~
.5
.5
</l
75
~
---6-4000
</l
bll
c::
bll
c::
:ac::
:ac::
ro
2000
ro
....l
....l
Figure 3
Year
Figure 4
Year
W
~
85
III~•
Loligo
Loligo + und
W
•
•
300,-----------------------,
' ' 'Ij
11:':IU)
--..- Via
-0--
'li.lltlO
Lolixo
o
L,.,---..-----r---,.---,.---.-6~
70
7~
80
7~
80
Vlb
100
90
8\
""'0...-----------------------,
:!()OO
TtJc/art~lt'r
,,~
7n
90
'"C
'"C
0)
0)
C
C
Si
Si
.5
'"
Oll
:a
:ac
.::
'"Oll
c
c
§
j
-J
•
:1
I~j
o l,,----r---,-----,..----,----,-M
m
~
~
80
90
Year
Figure 6
Figure 5
Year
~I"·~~I
75
'"c
11)
c
Si
.5
'"
Oll
c
:a
§
-J
80
85
90
:Is~n
~.
95
I
,
.
6~
70
75
80
85
FIgure legends
90
95
Figure 1. Landings oe Loligo in Scotland. hours fishing and overall CPUE for Loligo. 19&094.
Flgore 2. landiogs 01 La/igo io Seodand c1assified by gear·typc. 198()·94.
Flgore 3. landings 01 squid (presumed to bc La/igo) from ICES fisbcl)/ subdivisilm Via
<oast 01 Seolland) by different Europcan <ountries. 1973·94.
IWC,<!
Flgure 4. landings 01 different eephalopods [rom FAO area 27 (NE Allanti<) by Spaio. 1%5·
92.
Figure 5. Landings of different cephalopods (rom FAO area 37 (Mediterranean) hy ltaly.
1965·92.
Flgure 6. landiogs 01 squid [rom differentICES fisbcl)l subdiv",iuns by Spain. 1973-94. Nm<
lhat., Cor several oe these years. no data wcre reportL-d lo ICES.
Flgore 7. landiogs 01 loog-fioocd squid (La/igo) from the NE Allantic by Seolland. Fral1<.-c.
Spain. Ponugal and the Aznres. 1948-94. Only the first and I.st o[ these dataselS e.",nd back
6~
m
Year
Pi"nrp 7
75
~
90
95
101948.