The importance of marine fish - World Ocean Review

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The importance of marine fish - World Ocean Review

The importance of marine fish Sardines arealso threatened bypredators from theair. Cape gannetsoff South Africa canplunge up to 8 metresbelow the surface tograb their prey.crustaceans or fish larvae, referred to as zooplankton. Zooplankton,in turn, is food for small fish and other organisms.The amount of fish that can exist in a given region isprimarily determined by the activity and amount of primaryproducers; greater primary production can supportlarger fish stocks. The simple model of a food web inwhich smaller organisms are eaten by larger ones, however,is not sufficient for explaining the relationships inthe ocean. What the larger animals do has an impact onthe entire habitat. Many other interactions are also takingplace.Network thinkingThe knowledge that the web of relationships among marineorganisms is complex is not new. Similar connectionsare also known for many habitats on land. But for a longtime in the fisheries there was a tendency to focus onindividual commercially important species such as cod,herring or sardines. Only in the past ten years has theimportance of looking at entire ecosystems becomeaccepted for the long-term preservation of fish stocks andeffective management of fisheries. The reason: numerousstocks have been overfished in many ocean regions in thepast. In some cases this has resulted in serious changes tothe habitats. It is gradually being recognized that the complexityof the marine system has to be considered in fisherymanagement. Marine habitats are by no means influencedonly by primary production at the base, but also byfactors at the higher trophic levels, from the top down.An example can be seen in the eastern Atlantic watersof the Benguela Current off Angola, Namibia and SouthAfrica. Persistent winds in this region push the surfacewaters out to sea. This is replaced by nutrient-rich water


14> Chapter 011.3 > Specimensof the jellyfishNemopilema nomuraican reach a size of2 metres and weighup to 200 kilograms.A few years agohundreds of theseanimals drifted intoJapanese waters,seriously interferingwith fisheries.rising from below near the coast. These upwelling regionsare enormously productive and rich in fish. Over manyyears mostly foreign fleets have fished intensively for sardineshere. At the beginning of this century the stock collapsed.Since then the jellyfish population in this regionhas greatly increased. Experts believe that the decline ofsardines represented the loss of an important food competitorbecause both sardines and jellyfish feed primarilyon zooplankton. In addition, young jellyfish are eaten primarilyby fish. The jellyfish scourge was unexpected. Itwas assumed that with the decline of the sardines theabundance of anchovies, another small fish species nativeto this region, would increase. The anchovy has a diet similarto that of the sardine and should have kept the jellyfishin check. But the anchovy does not appear to be a truecompetitor of the jellyfish, because so far the anchovy populationhas remained smaller than that of the sardines.Perhaps the very dynamic upwelling area is a less suitablehabitat for anchovies.There is a similar situation off the coast of Japan. Thepopulation of the jellyfish Nemopilema nomurai greatlyincreased there after the intensive fishing of sardines.Individuals of Nemopilema can reach a size of up to twometres. The fishery is now seriously impaired by thejellyfish because they clog up or even tear the nets. Butjellyfish do not always proliferate to create this kind ofdisaster. In the 1970s, off Peru, the large stocks of SouthAmerican anchovies collapsed. As a result, sardines flourishedand a jellyfish plague was avoided. In other words,it is almost impossible to predict today what effects theoverfishing of a population will have.When the big ones land in the net,the small ones benefitOverfishing has also altered the habitat in the waters offNova Scotia on the east coast of Canada. For years cod andother bottom-living (demersal) predators such as coalfish


16> Chapter 01interim increase in sprat fishing led to a moderate recoveryof the cod stocks.There is evidence that not only the planktivorous fish,but also algae benefit from the disappearance of large fish.Planktivorous fish feed on zooplankton, which, in turn,feed on the small free-floating algae, the phytoplankton.Increased numbers of planktivorous fish produce a drop inthe amount of zooplankton, and phytoplankton can flourish.This can cause a problem, especially in the nutrientrichcoastal waters where phytoplankton can grow practicallyunchecked. The result is known as an algal bloom.When the algae die they sink to the bottom. There they arebroken down by bacteria, which consume oxygen.The formation of algal blooms is complex. It seemsthat a number of favourable conditions must be present atonce. In addition to a sufficient supply of nutrients, moderatewater temperatures are necessary. By adding the factorof overfishing of large predators, the problem is apparentlyexacerbated.Greater amounts of algae sinking to greater depthsresults in increased bacterial activity there, and ultimatelyleads to a shortage of oxygen. Thus, oxygen-deficient deadzones develop in the ocean where neither fish, crustaceans,nor mussels can survive. Many scientists are thereforenow urging fishery management to expand theirfocus from only the species being fished to considerationof the entire habitat. By recognizing the interdependenciesamong different species and the trophic levels, thisecosystem-based management should prevent the continueddamage or drastic alteration of entire ocean regionscaused by intensive fishing and consideration or monitoringof single species.1.5 > Copepods areusually only a fewhundred micrometresto a few millimetresin size. They are animportant food staplefor fish and for othercrustaceans, andmake up the largestshare of the marinezooplankton.


The importance of marine fish


The importance of marine fish Clupeids frequently form dense shoals, such as here off the Moluccas. They are animportant food source for many marine organisms and very important for the ecosystem.only about the status of individual species, but also abouthow the stocks of certain fish species can be best estimated.In any case, obtaining additional data would help agreat deal.In this regard, it would also be important to gatherdata on the primary producers, the algae and other singlecelledorganisms, whose quantities and composition substantiallycontribute to the biomass in the marine region.Such a multiple indicator approach, which considers all ofthese parameters, could be very important in establishingfuture catch limits. This kind of comprehensive data set ispresently only available for a few fish species, becauseobtaining the data for all of these parameters is extremelyexpensive. Furthermore, it requires an intensive exchangeof information among scientists of various disciplines,including fishery biologists, oceanographers, and planktonspecialists, which has so far only been accomplished fora few stocks such as the Baltic Sea cod and the West Atlanticcod.


20> Chapter 01What does overfishing mean?Fish cannot be counted like elephants in a national park. Fisherybiologists therefore have to calculate the size of a stock based onspecific parameters. The size of the annual catch is important. Ifthis declines it could be a sign that the stock size is shrinking. Thequantity of sexually mature adult fish, the spawners, is also importantbecause they determine how many offspring are produced.After all, a stock can only sustain itself if the new offspring cancompensate for the number of fish that are caught or die ofnatural causes. Fishery biologists commonly assign stocks to oneof several categories: moderately exploited, fully exploited, overexploited,depleted, or recovering.The transitions between these status classes, however, are notsharp, for example, the boundary between a fully exploited andoverexploited stock. One reason for this is that different fish speciesreact very differently to fishing pressure. Species that multiplyin large numbers and reach sexual maturity early can react betterto high catch volumes than species that produce fewer offspringand require several years before they can spawn.But basically a stock is considered to be fully exploited when itis fished to the maximum and an increase in the catch is not possible.If the fishing is intensified at this point, the stock is thenpushed into the overexploited status. This stock then continues todecline because there are not enough offspring being produced.The stock is considered to be depleted when the catch is significantlybelow the historically expected amounts. Many researchersdefine this situation as the point when only 10 per cent of thehighest historical catch is achieved. When a stock is depleted thecatch cannot be increased even with intensified fishing, which isreferred to as an increase in fishing effort.A stock is considered to be recovering when the catch beginsto rise again after depletion. An example of this is the North Atlanticcod, whose stocks collapsed in the 1960s and recovered againafter a fishing ban. The Food and Agriculture Organization of theUnited Nations (FAO) presently uses three categories to describethe status of the stocks: non-fully exploited, fully exploited, andover exploited.1.8 > The example of theNorth Atlantic cod showsthat a fish stock collapseswhen not enough maturefish (spawners) are presentto produce offspring.Spawner biomass (in 1,000 tonnes)Catch (in 1,000 tonnes)2,0001,8001,6001,4001,2001,000800600400fully exploitedoverexploitedfully exploitedoverexploitedfully exploited20001950 19601970 1980 1990 2000 2010


The importance of marine fish The objectiveof the Large MarineEcosystem conceptis sustainablemanagement of theoceans. Under thisapproach the statusof marine regions ischaracterized in fivedifferent modules.Large Marine EcosystemsMost marine regions and habitats are so large that theyextend across the coastal waters of multiple countries.Comprehensive conservation in these areas is only possibleif the countries cooperate, for example, with regard topollution of the ocean. Even larger fish stocks can only besustained when the countries agree to joint policies of protectivefishery management. For a long time, these kindsof international agreements regarding coastal regions hadbeen lacking. For this reason the National Oceanic andAtmospheric Administration of the USA (NOAA) developedthe concept of Large Marine Ecosystems (LMEs) inthe 1990s. This divided the coastal marine regions of theEarth into 64 LMEs. Each LME is characterized by a typicalflora and fauna. The LMEs extend along the coasts outto the continental slope, where the continental shelf endsand starts its downward incline towards the deep sea.The characterization of certain marine regions by largecurrents is also considered. For example, the upwellingregions off South America and Southwest Africa are eachdefined as an LME.The LMEs comprise all of the coastal regions of theEarth. They are especially productive because they arewell provided with nutrients from rivers or upwelling currents.The LMEs produce 95 per cent of the global fishbiomass. These areas are also immensely important forhumans. Hundreds of millions of people worldwide livenear the coasts. Their existence depends more or lessdirectly on fishing. Thus, in addition to the biological factors,the Large Marine Ecosystem concept also deals withsocioeconomic aspects.With the support of the World Bank and the UnitedNations Environment Programme (UNEP), an effort isbeing made to improve international cooperation towardsprotecting the joint ocean regions, particularly in thedeveloping and newly industrialized countries. Researchersand politicians of the neighbouring countries meet atworkshops and conferences. The major challenge is toachieve better protection of the marine environment inspite of differences in interests.Economic aspects such as offshore oil productionoften have priority over protection of the environment.The concept of the LMEs should provide a counterbalance


22> Chapter 01641054 5553 1 2364 511 12186397 8171959216022242527282023622633583257 563435525351504847 493637163138Catch levels(2000–2004average)very highhighmoderatelowvery low1314156129 30454443423940414601. East Bering Sea02. Gulf of Alaska03. California Current04. Gulf of California05. Gulf of Mexico06. Southeast U.S.ContinentalShelf07. Northeast U.S.ContinentalShelf08. Scotian Shelf09. Newfoundland-LabradorShelf10. Insular Pacific-Hawaiian11. Pacific Central-AmericanCoastal12. Caribbean Sea13. Humboldt Current14. Patagonian Shelf15. South Brazil Shelf16. East Brazil Shelf17. North Brazil Shelf18. West Greenland Shelf19. East Greenland Shelf20. Barents Sea21. Norwegian Shelf22. North Sea23. Baltic Sea24. Celtic-Biscay Shelf25. Iberian Coastal26. Mediterranean Sea27. Canary Current28. Guinea Current29. Benguela Current30. Agulhas Current31. Somali Coastal Current32. Arabian Sea33. Red Sea34. Bay of Bengal35. Gulf of Thailand36. South China Sea37. Sulu-Celebes Sea38. Indonesian Sea39. North Australian Shelf40. Northeast AustralianShelf-Great Barrier Reef41. East-Central AustralianShelf42. Southeast Australian Shelf43. Southwest AustralianShelf44. West-Central AustralianShelf45. Northwest AustralianShelf46. New Zealand Shelf47. East China Sea48. Yellow Sea49. Kuroshio Current50. Sea of Japan51. Oyashio Current52. Okhotsk Sea53. West Bering Sea54. Chukchi Sea55. Beaufort Sea56. East Siberian Sea57. Laptev Sea58. Kara Sea59. Iceland Shelf60. Faroe Plateau61. Antarctic62. Black Sea63. Hudson Bay64. Arctic Ocean1.10 > Near-coastal ocean regions have been divided into 64 Large Marine Ecosystemsthat cross geopolitical borders. This concept is expected to improve cooperationof countries with regard to international marine conservation. The individualLMEs are coloured to indicate the intensity of fishing from 2000 to 2004. Inmany marine regions the fishing pressure has not dropped since then.


The importance of marine fish


24> Chapter 01Diversity at risk> Many stocks have been so strongly decimated by fisheries that it is nolonger commercially profitable to fish for some species. Still, most species will survive thanks totheir enormous reproductive capacity. But there are exceptions. Some species could actually be wipedout by humans. It is also alarming that the fisheries appear to influence evolution. Smaller fish oftenprevail while the larger ones become scarcer.1.11 > Animalconservationistshave been tryingfor several years toreintroduce thesturgeon to Germanwaters. A number ofthe animals releasedhave yellow markerson their backs.Fishermen who catchone of these arerequested to reportthe number onthe marker to theconservation groupand return the fishto the water.Are fish species facing extinction?Although many stocks have been overfished by industrialfisheries, as a rule this does not result in the extinction offish species. The classical notion of a species being wipedout by human activity, like the case of the dodo, a flightlessbird on the island of Mauritius, cannot be directlyapplied to fisheries. There is an economic reason for this:long before the last fish is caught it would become unprofitableto fish for it, so it would no longer be pursued bythe fishery in the affected region. Specialists refer to thiskind of situation as commercial depletion.Some fish stocks have been reduced by 50 to 80 percent in the past. This would spell extinction for many terrestrialanimals, especially for species that produce smallnumbers of offspring. The death of even low numbers ofyoung animals by disease or predation could then completelywipe out such a species. This is not the case withfish. As a rule, the stocks recover. One important reasonfor the resilience of fish stocks is their high reproductivecapacity. Cod can produce up to 10 million eggs each year.An additional factor is that a fish species is usually representedby multiple stocks.There is no question that intensive fishing has severelyreduced the amount of fish, the fish biomass, in manymarine regions. The higher trophic levels are especiallyaffected. The large fish have been and still are the first tobe depleted. But even these are usually not in danger ofbiological extinction. In order to draw conclusions aboutthe status of a fish species, all of its stocks have to beassessed. For several years there has been some controversyabout the best mathematical and statistical modelsto use for this.The Food and Agriculture Organization of the UnitedNations (FAO) has established a general classification system.It classifies fish stocks as overexploited, fully exploitedand non-fully exploited. According to the FAO, almost30 per cent of all fish stocks are considered to be overexploited.As a rule, however, the species will be preserved.Regrettable exceptionsThere are, however, exceptions. Some species of tuna fishbring such high prices on the market that catching them isprofitable even when their numbers are very limited. Onefish can weigh up to 500 kilograms. Certain species, suchas the bluefin tuna (Thunnus thynnus), which lives in theAtlantic, can bring a price of 100 dollars per kilogram. InJapan, hundreds of thousands of Euros may be paid for thefirst or best tuna of the season. Expensive fish is a mark ofprestige there. Furthermore, the first tuna of the seasonare considered to be bringers of good luck, for which somecustomers will pay a lot of money. For practical purposes,fishing for such valuable specimens can be compared with


26> Chapter 011.14 > This bluefintuna, weighing 268kilograms, fetcheda price of 566,000Euros at a fish auctionin Tokyo in January2012. It was boughtby Kiyoshi Kimura(left), president ofa sushi gastronomychain. In early 2013,Kimura even paid afull 1.3 million Eurosfor a tuna. Thattranslates into a priceper kilogram of morethan 6000 Euros.Other marine animals are also affectedNot only do fisheries alter the natural species structure ofthe fish that are being fished for; they also have an impacton the stocks of animals that are taken as bycatch.U. S. researchers have calculated that at least 200,000 loggerheadsea turtles and 50,000 leatherback turtles worldwidewere caught incidentally in the year 2000 by tunaand swordfish fishers. The turtles are caught on the hooksof “longlines”. These are usually several kilometres longand can be fitted with thousands of baited hooks. If theturtles snap at these they will be hooked. Some are able tofree themselves and others are thrown live back into theocean by the fishermen. But thousands die an agonizingdeath. Tests are now being carried out to shape the hooksso that the turtles will no longer be caught by them.The longlines can also be fatal for albatrosses becausethey do not sink to the working depth immediately afterbeing let out, rather they float for a while at the surfaceand attract the birds. Environmental organizations estimatethat hundreds of thousands of sea birds are unintentionallykilled annually worldwide by longline fishing.New methods are therefore also being tested by whichlonglines are deployed through tubes that extend up to10 metres below the surface, so that albatrosses cannotsee or reach the bait. In the Baltic Sea, the harbour porpoiseis also endangered as bycatch. There are only an estimated500 to 600 individuals remaining in the easternBaltic Sea. The harbour porpoise was hunted here fordecades. Severe icy winters are also a strain on them.Today, every unintentionally caught animal brings thestock closer to extermination. It is a near tragedy that theeastern Baltic Sea harbour seals very rarely mate withtheir relatives in the North Sea and western Baltic Sea.The North Sea stock is comparatively large. Researchersestimate it to be around 250,000 animals. Because theeastern animals do not mate with their western relatives,it is feared that the species could die out in the Baltic Sea.This would mean a loss of species diversity in the region.The fisheries influence evolutionIntensive fishing, however, also changes the biologicaldiversity in another way. Scientists are now discussingthe phenomenon of fisheries-induced evolution. When thefisheries primarily catch large and older individuals, then,over time, smaller fish that produce offspring at an earlierage become more successful. The fisheries thus criticallyupset the natural situation. In natural habitats that are notaffected by fisheries, larger fish that reach sexual maturityat a greater age are more dominant. Their eggs have lowermortality rates. The eggs and larvae can better survivephases of hunger in the beginning because they possessmore reserve substance, more yolk, than the eggs and larvaeof parents that reproduce at a younger age. The entirestock benefits from this because many offspring are regularlyproduced, which preserves the stock.Under heavy fishing pressure, on the other hand, theanimals that primarily reproduce are those that are sexuallymature at a smaller size. But they produce fewer eggs,and their eggs have higher mortality rates. Through computermodels and analyses of real catch data, and using theexample of the northeast Arctic cod, researchers havebeen able to show that this fish stock has actually undergonegenetic alteration through time. Fish with the genotypictrait of becoming sexually mature at a young age andsmall body size have become more successful. This is truefor both males and females. To illustrate this, the researchershave employed catch data in their model that extend


The importance of marine fish Over decades of fishery, plaice in the North Sea thatachieve sexual maturity with a smaller body size have graduallybecome predominant. This relationship can be clearlydepicted by using different probabilities (p) in mathematicalmodels. The body length (L) of 4-year-old plaice that will becomesexually mature in the coming season with a 90 per centprobability (p90) is illustrated. As the graph shows, this bodylength (Lp90) has decreased significantly over recent years.back to 1930 and document the gradual changes withrespect to age, size, and reproductive capacity. The studywas based on especially detailed data sets of the catchesin Norwegian waters. Originally the northeast Arctic codbecame sexually mature at an age of 9 to 10 years. In thenortheast Atlantic today, the cod is sexually mature at 6 to7 years old. It is notable that this fisheries-induced evolutionhas occurred over a period of just a few decades.Experts feel that one reason for this is that the fisheriesexert a much greater pressure than natural selection factorssuch as predators or extreme environmental conditions,such as heat or cold. The computer models also indicatethat it would take centuries for the effects of thefisheries-induced evolution to turn around – even if thefisheries were completely stopped. In actual practice, theeffects may even be irreversible. Within the past 10 yearsfisheries-induced evolution has been verified for a numberof species, including the North Sea plaice.The effect of fisheries is thus exactly the opposite of whatan animal breeder usually aims for. The animal breeder,as a rule, selects the largest and most productive animals inorder to continue breeding with them. As a result of thefisheries, by contrast, precisely those older and largeranimals with the highest reproductive capacity are killed.Genetic impoverishment in fish?In proportion to their body size, large and mature fishinvest relatively more energy into the production of eggsthan small, young animals that have considerably lessbody mass and volume. Older fish thus provide a kind ofreproductive insurance. As long as enough older fish arepresent, sufficient offspring will be produced. But instocks that consist of few age groups, and primarily ofyounger age groups, the danger of offspring deficiencyincreases when the reproductive conditions intermittentlyworsen, such as times of food scarcity. Stocks in whicholder fish predominate can more efficiently withstand thesekinds of fluctuations, because the mature ones will reliablyproduce offspring in the following season. StocksGenotypeGenotype refers to thetotal genetic informationof an organismthat is stored in thecell nucleus of eachbody cell. Among individualsof a speciesmost of the genes areidentical. But theircombination is uniquefor every individualPhenotypeThe phenotype isexpressed in theappearance of an individual:the observablecharacteristics of theindividual genotype.Phenotypic attributesinclude eye colour,psychological traits,or genetically causedillnesses.


28> Chapter 01comprising different age groups also exhibit greater resiliencebecause the spawning season of the fish varies withtheir age. There are thus a sufficient number of spawninganimals at any given time in a mixed stock. Periods ofunfavourable environmental conditions therefore have aless severe impact.Warnings are now being raised that fisheries can alsocause genetic impoverishment, or “genetic erosion” in thespecies being fished. This phenomenon is also recognizedin land animals. With the destruction of habitats like rainforests, the distribution areas of species become criticallylimited. Many individuals die before they can mate. Inaddition to the species-specific genetic material, everyorganism possesses a small share of individual geneticattributes. If the animal dies without producing offspring,these individual attributes are lost and the population isgenetically impoverished. Extreme genetic erosion isreferred to as a genetic bottleneck. In this case, a speciesis reduced to a small number of individuals. This couldoccur as the result of a natural catastrophe such as a volcaniceruption or flooding. Intensive hunting of geographicallyrestricted populations like the Siberian tiger can also1.16 > A fish stockbefore fishing, afterlead to a genetic bottleneck. In extreme cases this leads tofishing, and afterreproduction. The inbreeding. The animals produce offspring with geneticchanges in body sizedefects or that are susceptible to disease. Some scientistsare a result ofare concerned that genetic erosion leading to genetic bottlenecksoccurs not only in land animals, but also in somefisheries-inducedevolution.before fishing after fishing after reproductionfish species through overfishing. So far, however, thisassumption is hypothetical and it is presumably not valid.For most of the commercially depleted fish stocks neithergenetic erosion nor genetic bottlenecks can be statisticallyverified. Specialists believe that even fish stocks that havebeen commercially depleted still possess thousands ofindividuals capable of reproduction. The genetic variabilitythus probably remains great enough to preclude theerosion effects.Slowing down fisheries-induced evolutionExperts recommend giving more attention to the ecogeneticaspects of fishery management in the future. There isalready a general consensus that fishery managementshould not consider a fish species independently of itshabitat. Beyond this, however, ecogenetic models arenecessary. These can be used to estimate which changesare caused by fisheries and to what degree genetic changesinfluence a stock, but also how these ultimately affect thefuture fishery harvests. Through responsible fishing, thereis hope that fisheries-induced evolution can be reversed,or at least slowed down. It can probably not be completelystopped. Researchers also need to employ complex evolutionmodels. Up to now, often only the age classes of a fishstock have been considered in detail for calculations ofstock development. Fish sizes are entered into the calculationsimply as the mean of an age class. This mean, in turn,has been calculated from long years of body-lengthmeasurements. An age class for a fish stock, therefore,always has a fixed, assigned average size. In fact, however,the mean size of an age class changes from year to year,depending mainly on the food supply. In years of scarcefood supply immature animals grow more slowly. Thisvariability has to be given greater consideration in thefuture. And, of course, there are always larger and smallerindividuals within an age class. These fluctuations alsohave to be addressed. The mean value is not sufficient foran evolutionary model. Researchers therefore call formore intensive cooperation between fishery authorities,who have access to detailed data, and mathematicians andstatisticians, who can develop powerful computer models.


The importance of marine fish


AppendixBibliographyBaum, J. & B. Worm, 2009. Cascading top-down effects ofchanging oceanic predator abundances. Journal of AnimalEcology 78: 699–714.Dieckmann, U., M. Heino & A.D. Rijnsdorp, 2009. The dawn ofDarwinian fishery management. ICES Insight 46: 34–43.Dunlop, E.S., M. Heino & U. Dieckmann, 2009. Eco-geneticmodeling of contemporary life-history evolution. EcologicalApplications 19: 1815–1834.Enberg, K., E.S. Dunlop, C. Jørgensen, M. Heino & U. Dieckmann,2009. Implications of fisheries-induced evolution for stockrebuilding and recovery. Evolutionary Applications 2: 394–414.Fock, H.O., 2011: Natura 2000 and the European CommonFisheries Policy. Marine Policy 35: 181–188.Frank, K.T., B. Petrie, J.A.D. Fisher & W.C. Leggett, 2011.Transient dynamics of an altered large marine ecosystem.Nature 477: 86–88.Frank, K.T., B. Petrie & N.L. Shackell, 2007. The ups and downsof trophic control in continental shelf ecosystems. Trends inEcology and Evolution 22, 5: 236–242.Geßner, J., M. Tautenhahn, H. von Nordheim & T. Borchers,2010. Nationaler Aktionsplan zum Schutz und zur Erhaltungdes Europäischen Störs (Acipenser sturio). Bundesministeriumfür Umwelt, Naturschutz und Reaktorsicherheit (BMU),Bundesamt für Naturschutz (BfN).Heino, M., U. Dieckmann & O.R. Godø, 2002. Reaction normanalysis of fisheries-induced adaptive change and the case of theNortheast Arctic cod. ICES CM 2002/Y: 14.Jørgensen, C., K. Enberg, E.S. Dunlop, R. Arlinghaus, D.S. Boukal,K. Brander, B. Ernande, A. Gårdmark, F. Johnston, S. Matsumura,H. Pardoe, K. Raab, A. Silva, A. Vainikka, U. Dieckmann,M. Heino & A.D. Rijnsdorp, 2007. Managing evolving fish stocks.Science 318: 1247–1248.Richardson, A.J., A. Bakun, G.C. Hays, M.J. Gibbons, 2009. Thejellyfish joyride: causes, consequences and management actions.Trends in Ecology and Evolution 24: 312–222.Sherman, K. & A.M. Duda, 1999. An ecosystem approach toglobal assessment and management of coastal waters. MarineEcology Progress Series 190: 271–287.www.lme.noaa.gov/


Bibliography and Table of Figure


Publication detailsProject manager: Jan LehmkösterEditing and text: Tim SchröderCopy editing: Dimitri LadischenskyCoordinator at the Cluster of Excellence: Dr. Jörn SchmidtEditorial team at the Cluster of Excellence: Dr. Jörn Schmidt, Dr. Rüdiger Voss, Dr. Kirsten SchäferDesign and typesetting: Simone HoschackPhoto-editing: Petra Kossmann, Peggy WellerdtGraphics: Walther-Maria ScheidPrinting: DBM Druckhaus Berlin-Mitte GmbHPaper: Recysatin, FSC-certifiedISBN 978-3-86648-201-2Published by: maribus gGmbH, Pickhuben 2, 20457 Hamburgwww.maribus.comclimate-neutral

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