Piatkowski, Uwe

Wood, James B.

OceanRep

ACP-EU Fisheries Research Report (8) – Page 39Cephalopods: What makes them an idealgroup for an Internet databaseabyUwe Piatkowskib & James B. Wood cAbstractLiving cephalopods include cuttlefishes, squids, octopuses and the chambered nautilus. There are703 species described today, but the status of their systematics worldwide is decades behind that of other major marine taxa. They are quite distinct from fish not only in their morphology but also intheir life history. Cephalopods have short life spans, fast growth rates (exponential when young),and they tend towards semelparity Cephalopod research is of interest and importance firstly because of the intrinsic value in understanding the complex biol ogy and peculiar life cycles of these animals. While world-wide traditional fish stocks are decreasing the total world landings of all cephalopods have nearly doubled over the last decade (to 3.3 million tonnes in 1997). Cephalopods have gained an excellent market price and have become subject of global trade including developing countries. With an average value of US$ 2,100 per metric tonne, they gained a total market value of more than US$ 5.3 billion in 1989, which ranked them third after shrimp and tuna. Despite the increasingfishing pressure on cephalopods, basic knowledge of their biology and of management strategies of fished stocks lags behind that of most fish species. Hence, a widely accessible Internet databasewould certainly become a valuable t ool to collect and provide comprehensive information to better understand and document major aspects of cephalopod biology and fishery.a) Presented by the first author at the INCO -DEV International Workshop on Information Systems for Policy and Technical Support of Fisheries and Aquaculture, Los Baños, Philippines, 5-7 June 2000; b) Institut für Meereskunde, Universität Kiel, Düsternbrooker Weg 20, D -24105 Kiel, Germany. E-mail:upiatkowski@ifm.uni-kiel.dec) National Resource Center for Cephalopods, Uni versity of Texas Medical Branch, Galveston, TX 77555 -1163, USA. E-mail: ceph@is.dal.caACP-EU Fisheries Research Report (8) – Page 40Relatively few species, but unsolved systematicsLiving cephalopods include cuttlefishes, squids, octopuses, the chambered nautilus, and a uniquespecies found only in the deep sea called the vampire squid ( Vampyroteuthis infernalis). They are by far the most advanced group within the phylum of mollusks, which also includes snails, slugs,clams, scallops, oysters and mussels. All cephalopods are entirely marine and distr ibutedthroughout the seas of the world. There are more than 700 species described today (Sweeney &Roper, 1998), and that number increases every year as scientists discover new species, particularly in tropical and polar seas. However, the status of cepha lopod systematics worldwide is decadesbehind that of other major marine taxa. The group is very attractive to taxonomists, but difficulties in obtaining adequate funding and material have resulted in a low level of understanding(Roeleveld, 1998). There a re very few fossils of them since modern cephalopods do not have hard external shells like other mollusks. Consequently, the lack of a fossil record of coleiod cephalopods makes systematics much harder. In comparison with other marine groups, such as crust aceans,fishes or sea mammals, sound ecological studies on cephalopod ecology are sparse. This is not inconcordance with the important position that cephalopods have in major marine ecosystems(Clarke, 1996). Two obvious shortcomings are responsible for t his: (1) cephalopods are difficult to catch and mostly taken as by-catch in surveys targeting other taxa; (2) they have complicated lifecycles and distribution patterns which are only roughly understood for a few species.Physiology studies dominate ecological researchCephalopod research is of interest and importance firstly because of the intrinsic value inunderstanding the complex biology and peculiar life cycles of these animals. Cephalopods arefamous for outstanding physiological performance, which makes them the most highly evolvedmarine invertebrates. This is documented in their elaborate sense organs, large brains, activelifestyle and complex behaviour (Hanlon & Messenger, 1996). Modern research encompassesdetailed studies on genetics, symbiotic bacteria and biomedical research that makes them veryattractive for a variety of research fields and new biochemical technologies. The wealth ofinformation on cephalopod physiology is in great contrast to our poor knowledge of their ecology. Nevertheless, physiological studies are important prerequisites to understanding their ecology in the field.Cephalopod age and growth – still a mystery?There is general agreement in cephalopod research about their exceptionally high metabolism, butstill much speculation about their growth pattern and age. It is well accepted that the giantoctopuses can live up to five years, and nautilus can attain ten years. But most squid and manyoctopuses are short -lived annual species, thus being the marine equivalent of wee ds without a"robust age structure" (O'Dor, 1998). Ageing of cephalopods has always been a severe obstacle in modeling growth patterns. Reading of periodic increments within the squid statolith microstructure has developed into a routine technique to obtai n individual age estimates which form the basis for most growth models that are essential in studying cephalopod population dynamics (Pauly, 1985).Validation and culture studies, although another main problem for most short -lived species, haveshown that statolith increments (similar to increments in larval fish otoliths) are produced daily in a number of squid species. Statolith age analysis has revealed that temperate squids can completetheir life cycle in less than two years while tropical species live for less than eight months; bothfollowing linear or exponential growth models (see review of Jackson, 1994). In contrast, growthACP-EU Fisheries Research Report (8) – Page 41curves generated from analysis of length frequency data suggested an asymptotic growth curve and ages in excess of three year s for some tropical squid. Such analyses, therefore, appear to beinappropriate (Jackson & Choat, 1992), and point out the complete failure of state -of-the-art fishmodeling software to produce realistic life spans of cephalopods. Cephalopod growth remains  abiological mystery and is still a matter of some debate (e.g., Jackson & Choat, 1994; Pauly, 1998). It is curious though, that we know nothing about age and growth of the giant squid, the largestinvertebrate in the world, which can attain total lengths exceeding 20 metres. Furthermore, noreliable method to age octopuses has yet been developed. Trophic relationshipsThe overall role of cephalopods in the marine environment, their significance as food resources for higher trophic levels such as mammals and birds and their impact as predatory consumers of fishand other invertebrates, is only beginning to be studied (Clarke, 1996). It is a great challenge tointensify field and laboratory studies on trophic interrelationships where cephalopods are involve d,because they will elucidate cephalopod ecology and form the basis for further ecosystem modeling. Cephalopod fisheries and marketsWorldwide traditional fish stocks are decreasing due to over fishing and/or environmental changes. In response to this ce phalopods have gained an immense importance in substituting the traditionalmarine harvest and will gain a much larger importance in the future to supply mankind with marine living resources (Caddy, 1994; Caddy & Rodhouse, 1998). Million tonnes0,20,81,42,02,63,23,81949 1954 1959 1964 1969 1974 1979 1984 1989 1994 1999Cephalopod World CatchFig. 1. Cephalopod world catch (from FAO, 2000).As well as comprising commercially important fishery resources, selected species also show somepotential for aquaculture (Nabhitabhata, 1995). Many cephalopods are very efficient in convertingfood to biomass, particularly protein (O’Dor & Wells, 1987) Hence, the rapid growth rate and high ACP-EU Fisheries Research Report (8) – Page 42food conversion rates of cephalopods are both advantageous traits for aquaculture. Cephalopodlandings have steadily increased worldwide since the 1950s, peaking in 1997 at more than 3.3miollion tonnes (FAO 2000; Fig. 1). Although increased cephalopod landings may partly reflectincreased market demand, particularly in the Far East nations, over fishing finfish stocks haspositively affected cephalopod populations. Da ta from fifteen key FAO areas reveal that, with theexception of the north -east Atlantic, cephalopod landings have increased significantly over last 25years while groundfish have risen more slowly, remained stable, or declined (Caddy & Rodhouse,1998).Table 1. Estimated total value of marine catches in 1989 (after FAO, 1993).Species group Marine catch[million tonnes]Average unit value[US$ per tonne]Total value[billion US$]Shrimp 1.841 4000 7.370Tuna 3.985 1700 6.775Cephalopods 2.545 2100 5.344Flatfish 1.193 2900 3.459Salmon and salmonids 0.936 3500 3.278Lobster 0.202 11270 2.275Alaska pollack 6.259 331 2.072Atlantic cod 1.783 1068 1.904Herring, sardine 8.630 200 1.726Blue whiting 0.663 66 0.044Cephalopods have an excellent ma rket price and are the subject of global trade. This can easily be seen in a recent FAO study which compares total catch or production, respectively, average unitvalue and total value of major aquatic species groups (FAO, 1993; Table 1). With an average u nitvalue of 2100 US$ per metric tonne, cephalopods gained a total market value of more than 5.3billion US$ in 1989, which ranked them third after shrimp and tuna demonstrating their important economic value.Their increased economic importance may reflec t a change in their ecological importance, e.g.species replacement has been suggested as an underlying factor in changing fishery patterns in theSaharan Bank fishery (Balguerías, 2000). There is a need for development of models and forecastfishery trends in cephalopods. Ideally such models should be able to integrate environmental,biological, fishery and economic information. The accumulation of such information clearlywarrants a database on cephalopods. It would form a necessary prerequisite not only for providing and intensifying biological and ecological information on as many cephalopod species as possible,but also for modeling and forecasting fluctuations of cephalopod stocks. Management strategies for cephalopod fisheries present similar challen ges to those encountered in fisheries for finfish. However, despite the increasing fishing pressure on cephalopods, basicACP-EU Fisheries Research Report (8) – Page 43knowledge of their biology lags behind that of most fish species. Therefore, it is critical thatfisheries workers not base cephalopod  policies on what works for fish. A comprehensive database would certainly be a valuable tool to develop management strategies that adapt to cephalopodfisheries.ReferencesBalguerías, E., M.E. Quintero, & C.L. Hernández -González, 2000. The origin of the Saharan Bankcephalopod fishery. ICES J.Mar.Sci., 57:15-23.Caddy, J.F., 1994. Cephalopod and demersal finfish stocks: some statistical trends and biologicalinteractions. Squid 94 Venice. The 3rd International Cephalopod Trade Conference. Agra Europe.Caddy, J.F. & P.G. Rodhouse, 1998. Cephalopod and groundfish landings: evidence for ecological change in global fisheries? Rev. Fish Biol. Fisheries, 8:431-444.Clarke, M.R. (ed), 1996. The role of cephalopods in the world's oceans. Phil.Trans.R.Soc.Lond. B, 351:979-1112.FAO, 1993. Marine fisheries and the Law of the Sea: a decade of change. FAO Fish.Circ., 853.FAO, 2000. Total production 1950 -1998. FAO homepage http://www.fao.org/  (former FAO Yearbook offisheries statistics "Catches and landings".Hanlon, R.T. & J.T. Messenger, 1996. Cephalopod behaviour. Cambridge University Press, 232 p.Jackson, G.D., 1994. Application and future potential of statolith increment analysis in squids and sepioids.Can.J.Fish.Aquat.Sci., 51:2612-2625.Jackson, G.D. & J.H. Choat, 1992. Growth in tropical cephalopods: An analysis based on statolithmicrostructure. Can.J.Fish.Aquat.Sci., 49:218-228.Nabhitabhata, J., 1995. Mass culture of cephalopods in Thailand. World Aquaculture, 26:25-29.O'Dor, R.K. & M.J. Wells, 1987. Energy and nutrient flow. pp. 109 -133 IN Boyle, P.R. (ed.). Cephalopodlife cycles. Vol. II. Comparative reviews. Academic Press, London.O’Dor, R.K., 1998. Can understanding squid life-history strategies and recruitment impro ve management?S.Afr.J.Mar.Sci., 20:193-206.Pauly, D., 1985. Population dynamics of short -lived species, with emphasis on squids. NAFO Sci.Coun.Stud.,9:143-154.Pauly, D., 1998. Why squid, though not fish, may be better understood by pretending they are.S.Afr.J.Mar.Sci., 20:47-58.Roeleveld, M.A.C., 1998. The status and importance of cephalopod systematics in southern Africa.S.Afr.J.Mar.Sci., 20:1-16.Sweeney, M.J. & C.F.E. Roper, 1998. Classification, type localities, and type repositories of recentCephalopoda. Smithson.Contr.Zool., 586:561-599.ACP – EU Fisheries Research Report Number 8ACP-EU Fisheries Research InitiativeProceedings of the INCO-DEV International Workshop on Information Systems for Policy and Technical Support in Fisheries and AquacultureLos Baños, Philippines, 5-7 June 2000Edited byEnrico FeoliUniversity of Trieste, ItalyandCornelia E. NauenDirectorate General for Research, European Commission, Brussels, BelgiumBrusselsJune 2001ACP-EU Fisheries Research Report (8) – Page iiThe designations employed and the presentation of material in this publication do not imply the expressionof any opinion whatsoever on the part of the European Commission concerning the legal status of anycountry, territory, city or area or of its authorities, or concerning the delimitation of frontiers or boundaries.Copyright belongs to the European Commission. Nevertheless, permission is hereby granted for reproduction in whole or part for educational, scientific or development related purposes, except those involvingcommercial sale on any medium whatsoever, provided that (1) full citation of the source is given and (2)notification is given in writing to the European Commission, Directorate General for Research, InternationalRelations, 8 Square de Meeûs, B-1049 Brussels, Belgium.Copies are available free of charge upon request from the Information Desk of the Directorate General forResearch, International Relations, 8 Square de Meeûs, B-1049 Brussels, Belgium. ACP-EU Fisheries Research Report SeriesThe ACP-EU Fisheries Research Reports are a series of publications that aim to share information about the development of the ACP-EU Fisheries Research Initiative and wider findings generated in order to maximise the impact of its activities. It includes proceedings of workshops and meetings, statements on policy andresearch activities under the Initiative. An increasing number of these, in fact, transcends the strictframework of ACP-EU bi-regional S&T cooperation, in line with the global nature of the issues at hand.ACP-EU Fisheries Research Report (8) – Page iiiAbstractThe present report contains the proceedings of the INCO-DEV International Workshop onInformation Systems for Policy and Technical Support in Fisheries and Aquaculture, convened inLos Baños, Philippines, 5 -7 June 2000. It was convened to address issues associated with thedifficult transition from abundance to scarcity in aquatic resources. Reliable information will spread the right perception of the productive capacity and result in more realistic assessment of decreasing benefits and rising costs. Conservation of aquatic biodiversity, ecosystem approaches to fisheriesand aquaculture production and food quality and safety along the entire chain from production tothe consumer are key concepts that will govern approaches to aquatic living resources in the future. International trade is a major driving force in bringing many of these problems to a head, while also offering opportunities for socio-economic development. To this effect, scientists and other knowledgeable persons active in relation to these key aspectscontribute a panorama of existing information resources, experience with their development, butalso difficulties encountered. The papers point out avenues how global public goods necessary for the transition towards sustainability can be either created or more effectively shared. Internationalcooperation based on mutual respect and interest, mobilising the best of science across continents to ensure trustworthy information and knowledge, is confirmed as a most useful approach to support societal demands for sustainable fisheries and aquaculture. For bibliographic purposes this report should be cited as follows:Feoli, E. & C.E. Nauen (eds.), 2001. Proceedings of the INCO-DEVInternational Workshop on Information Systems for Policy andTechnical Support in Fisheries and Aquaculture. Los Baños,Philippines, 5-7 June 2000. Brussels, ACP-EU Fish.Res.Rep.,(8):132 p.ISSN 1025-3971

Cephalopods: What makes them an ideal group for an Internet database

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