EUROPEAN INLAND FISHERIES ADVISORY COMMISSION
Budapest, Hungary, 1-7 June 2000
PROGRESS REPORT, SUB-COMMISSION III
PROTECTION OF THE AQUATIC RESOURCE
EIFAC Expert Consultation on Accumulated Toxicants in Fish
In the course of 1998 the Department of Aquatic Toxicology of the RIFCH SB Vodnany continued sampling fish and other components of aquatic ecosystems for the determination of pollutants. The results of the analyses are put into the database of both the RIFCH and the Ministry of Agriculture of the Czech Republic.
The results of monitoring the pollutant content in fish and other components of aquatic ecosystems were presented at two international conferences.
At the EUROTOX meeting in Lyon in July 1998, a paper on pesticides and fish was presented. Results of monitoring of residues of DDT and of its metabolites (HCB, HCH isomers and triazines - mainly of atrazine) in fish were included in this paper.
Results of fish analyses from the Elbe River Project II (1996 - 1997) were presented at the Eighth International Magdeburger Seminar in Karlsbad in October 1998.
The Elbe River Project III was initiated in 1999 in cooperation with the International Commission for Elbe River Protection. Apart from the chemical monitoring, methods of biological monitoring are being applied in this project.
In the course of 1998, the highest attention was paid to the status of contamination of the aquatic environment of the Czech Republic by Polycyclic Aromatic Hydrocarbons (PAHs). Results were presented at the conference of the European Association of Fish Pathologists in Greece in 1999. It was found that large parts of PAHs (about 70%) in aquatic systems are located in bottom sediments where they are biologically unavailable. In fish, PAH metabolites (e.g. 1-hydroxypyrene) are primarily found in the liver and the bile, making these organs useful monitoring targets. The PAH contamination of several localities of the Vltava, Tichá Orlice and Elbe Rivers was assessed by determining 1-hydroxypyrenes in fish bile, and by measuring PAHs in bottom sediments.
Increased concentrations of 1-hydroxypyrene in the bile of bream, perch and rainbow trout, relating to relatively high PAH concentrations in bottom sediments, were found primarily at localities downstream of industrial sites.
In view of the fact that this Expert Consultation has no clear terms of reference nor time-limit, and because it has focused on problems pertaining primarily to the Czech Republic, the relevance of this activity for other EIFAC member states and, thus, its future involvement with EIFAC have to be reviewed during the Twenty-first Session.
Working Party on Effects of Physical Modifications of the Aquatic Habitat on Fish Populations
After the ad hoc meeting of the Working Party during the Symposium on River Fisheries (Hull, 1998), there had been no activity in the intersessional period, due to the heavy workload of the convenor. Because of this unsatisfactory situation, and in order to give way towards reactivating the Working Party, the convenor of the Working Party, J. Coeck (Belgium), will resign from his function as convenor, while still remaining a member of the Working Party. A new convenor will therefore have to be nominated, and the further lines of activity will have to be decided upon by the Session.
Ad hoc Working Party on Methodologies for Rehabilitation of Lakes and Reservoirs
This activity was upgraded to an ad hoc Working Party during the Twentieth Session of EIFAC in 1998, with H. Lehtonen (Finland) as the convenor. The main purpose of this activity is to prepare a manual on rehabilitation of lakes and reservoirs as a companion to the one for rivers. A tentative contents list was agreed for the manual and a number of participants volunteered to prepare individual chapters. Chapter outlines were originally due by October 1998, and the draft chapters were to be submitted by the end of May 1999.
So far, outlines for most of the 13 chapters have been received. However, until now, only six chapters have been completed, including the introduction. Because the elaboration of several chapters still to be written has to be coordinated with some of the completed chapters, it is recommended to review the structure and contents of the manual based on work done so far, and to re-examine the list of contributors and the time schedule for individual contributions. This procedure will allow better integration of the missing chapters by avoiding redundancy, and focus on the specific subjects of these chapters. Ian Cowx has kindly agreed to edit the manuscripts in order to standardize the format and achieve a well-written, complete manual.
Working Party on the Prevention and Control of Bird Predation
The convenor, E. Staub (Switzerland), reports that there has been little activity of the Working Party. It is not clear whether there are any specific questions that would have to be addressed within this Working Party. Also, no activity has been noted the European cormorant management plan level during the last years. Unfortunately, the countries holding the most important breeding areas, such as the Netherlands and Denmark, are not willing to take any action against the rising numbers of cormorants or to permit actions for lowering cormorant numbers. However, with the elimination of the cormorant from the EU list of highly protected birds, EU member states may take action against the cormorant in well-founded cases. Some countries have indeed made use of this possibility in recent years.
In order to promote the basic ideas of the Cormorant Management plan established under the Convention on Migratory Species (CMS), a research project "Reducing the conflicts between cormorants and fisheries on a pan-European scale" (REDCOFE) was elaborated by various institutions and submitted to the European Commission in October 1999 for funding. The project was approved in April 2000 and will last two years. It aims at reducing conflicts between birds and fish/fisheries at a pan-European scale.
The convenor has conducted a European-wide literature survey on fish-relevant publications on cormorants and other fish-eating birds published during the intersessional period 1998-2000 (see attached Annex). Conclusions and recommendations for future work of the Working Party will be formulated during an ad hoc meeting at the beginning of the Twenty-first Session of EIFAC.
Working Party on the Influence of Management Practices on the Environment
The convenor, M. Aprahamian (UK), reports that there has been little progress, in spite of his continued effort to get the Working Party started. A request for nominating working group members issued after the Twentieth Session of EIFAC in Portugal showed no results. A follow up e-mail from P. Hickley (UK) to other Correspondents has generated some positive responses. The convenor is pleased to report that three people have meanwhile agreed to join the Working Party: U. Grosch (Germany), B. Kronvang (Denmark) and D. Mires (Israel). The main reason why it was so difficult to get work started was that in the first instance the group would have needed to meet in person and agree on terms of reference. This will hopefully take place during the EIFAC Session in Budapest, thus allowing to finally make some substantial progress. According to the convenor, the plan is to put together a framework which the Working Party will discuss and change accordingly. Once the framework has been agreed, the aim would be for each member of the group to develop a particular work area which the convenor would then bring together in a final report.
GESAMP/EIFAC Working Group on Endocrine Disruptors in the Aquatic Environment
It was the intention of the coordinator of this activity, P.-D. Hansen (Germany), to initiate work at a joint GESAMP/EIFAC meeting organized by the International Maritime Organisation (IMO). Unfortunately, IMO did not get any funding for such a meeting. Therefore, the meeting did not take place, and no progress was made in this Working Group.
EIFAC Working Party on Bird Predation
Status report for the intersessional period 1998-2000
A meeting is planned at the beginning of the Twenty-first Session of EIFAC.
2. Fish-relevant publications on cormorants and other fish-eating birds during the intersessional period 1998-2000
The following summary, arranged by country, provides an overview of fish-relevant publications on cormorants and other fish-eating birds. Papers before 1998 have not been considered. The list includes primary journals and grey literature.
Uiblein et al. (2000) give information on the situation of grayling in three rivers located in Oberösterreich. They conclude that all measures to improve the situation of grayling should take into account predation by fish-eating birds (especially cormorant, grey heron and goosander). In the region of Steiermark (Zauner 1999) a loss of 98% of grayling biomass is reported and attributed to cormorant predation. In the region of Kärnten, a comparison of the fish stocks at the beginning and the end of wintertime showed losses of 67-99% (AKL 1999). Perger (1998) completed these studies with an analysis of cormorant diet (n = 59 pellets containing 75% cyprinids). In the booklet of Rutschke (1998) there is a chapter on cormorants and fisheries presenting an ornithological point of view.
AKL (Amt der Kärntner Landesregierung) (1999). Kärntner Umweltbericht 1999. Natürlich Kärnten, Umweltschutz Land Kärnten, p. 184-186.
Perger N. (1998). Fisch als Nahrung des Kormorans in alpinen Gewässern. Diplomarbeit, Inst. für Zoologie, Universität Graz, Graz, 81 pp.
Rutschke E. (1998). Der Kormoran – Biologie, Ökologie, Schadabwehr. Parey, Berlin, 161 pp.
Uiblein F, Jagsch A., Könner G., Weiss St., Gollmann P. & Kainz E. (2000). Untersuchungen zu lokaler Anpassung, Gefährdung und Schutz der Äschen (Thymallus thymallus) in drei Gewässern in Oberösterreich. Österreichs Fischerei 53: 89-165.
Zauner G. (1999) Einfluss des Kormorans auf die fischökologischen Verhältnisse der steirischen Enns zwischen Liezen und Johnsbach. Universität für Bodenkultur, Wien, 58 pp.
Cormorants are reported to regularly cause great damage to fish stocks in ponds.
Musil P., Cepák J. & Marincová M. (1999). Great Cormorant in the Czech Republic: Populations status and action plan. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Bildsoe et al. (1998) studied technical measures to reduce cormorant predation in pond nets.
Bildsoe M., Jensen I.B. & Verstergaard K.S. (1998). Foraging behaviour of cormorants Palacrocorax carbo in pound nets in Denmark: the use of barrel nets to reduce predation. Wildlife Biology 4: 129-136.
Recent data on the number of wintering cormorants in France (and other countries) are given in Troillet (1999). Frederiksen et al. (1999), using a population model, tried to assess whether culling of wintering cormorants in France has the potential to affect population density. In Lake Geneva, cyprinids are the main prey (amounting to 75% of the diet) whereas perch is the dominating species (70%) in the diet of cormorants feeding in Lake Annecy (Mathieu & Gerdeaux 1999). It seems that cormorants are partly responsible for the decreasing roach yield in Lake Geneva. Cormorant stomachs (n = 141 from 3 sites) from the River Moselle contained those fish species (33% roach, 18% perch, 11% bream) that are also highly abundant in the fish population of the river (Collas 1999). Roach was also dominating (32%) in cormorant stomachs (n = 52) from the Rivers Marne and Saulx (Collas 1998). The number of shot cormorants is strongly limited by the government.
Collas M. (1998). Approche du regime alimentaire du Grand Cormoran (Palacrocorax carbo); rivières Marne, Saulx et Moselle, hiver 1997/98. Conseil supérieur de la pêche, Délégation régionale No. 3, Montigny-lès-Metz, 24 pp. et annexes.
Collas M. (1999). Comportement alimentaire du Grand Cormoran sur la rivière Moselle. Conseil supérieur de la pêche, Délégation régionale No. 3, Montigny-lès-Metz, 37 pp.
Frederiksen M., Lebreton J-D. & Bregnballe T. (1999). A population model for European Great Cormorants: preliminary results and applications to management. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Mathieu L. & Gerdeaux D. (1999). The predation of Great Cormorant in Lakes Geneva, Annecy and Bourget. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Trolliet B. (1999). Répartition et effectifs du grand cormoran (Palacrocorax carbo) en Europe. Gibier Faune Sauvage - Game and Wildlife 16: 177-223.
In the Bavarian area there exists a severe cormorant reduction program: the number or cormorants shot was 657, 6'259, 3'285 and 3'577 in winters 1995/96 through 1998/99, respectively (Keller 1999). Proposals to overcome the deadlock situation are expected on an European scale: more and realistic activity is needed from the CMS-Convention and the EU (Lukowicz 1998). A special issue of the journal "Vogel und Umwelt" with eight papers (see Richarz & Werner 1998) describes the situation in the regions of Hessen and Rheinland-Pfalz. An annex lists the cormorant reduction measures in all German Bundesländer. The chapter on cormorant and fisheries (Werner & Richarz 1998), texted by two ornithologists, concludes that there is no scientifically proven reduction of fish stocks or yield in open waters. For aquaculture units, however, a negative effect of cormorant predation is agreed. In the area of Baden-Württemberg, angling clubs started to collect relevant data and produce reports on cormorant effects; these are annually issued (e.g. Landesfischereiverband Baden 1998, 1999). There is extensive information on cormorant damage (Jäger 1999; Proske 1999; Wissmath et al. 1998; Wissmath et al. 2000) and protection measures (Leppelsack 1999; Schmidt 1998; Schreckenbach et al. 1998). Both issues provoke technical and political discussions (Zobel 1998). Fiedler (1999) presents a ringing recovery analysis of the years 1986-99 giving information on the flypaths from breeding to wintering areas. Keller & Visser (1999) analysed the daily consumption rate, based on the doubly labelled water technique: in captivity it was 1325 kJ day-1 corresponding to 341 g fish day-1, and in the wild 2094 kJ day-1 corresponding to 539 g fish day-1.
Fiedler W. (1999). Kormorane Phalacrocorax carbo als Durchzügler und Wintergäste in Suddeutschland und Österreich – eine Ringfundanalyse. Der Ornithologische Beobachter 96: 183-192.
Jäger S. (1999). Ergebnisse der Kormoranzählung im Bereich der Ruhrfischereigenossenschaft und in Schwerte-Geisecke 1996-98. Fischer & Teichwirt 50: 49-50.
Keller T. & Visser H. (1999). Daily energy expenditure of Great Cormorans Phalacrocorax carbo sinisis wintering at Lake Chiemsee, Southern Germany. Ardea 87: 61-69.
Keller T.M. (1999). Cormorant management in Bavaria, southern Germany – shooting as a proper management tool? Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Landesfischereiverband Baden (1998). Kormoran und Fischerei. Landesfischereiverband Baden, Arbeitskreis IX, Freiburg.
Landesfischereiverband Baden (1999). Kormoran und Fischerei. Landesfischereiverband Baden, Arbeitskreis IX, Freiburg.
Leppelsack H-J. (1999). Versuche zur Vergrämung von Kormoranen durch Unterwasserschall. Fischer & Teichwirt 50: 49-50.
Lukowicz M. (1998). Possibilities of solving the problem of losses to the inland fisheries caused by cormorants. III. Krajowa Konferencja Rybackich Uzytkowników Jezior, Olsztyn, p. 47-70.
Proske C. (1999). Kormoran-Schäden in der Karpfenteichwirtschaft des Aischgrundes. Fischer & Teichwirt 50: 177-179.
Richarz K. & Werner M. (1998). Die Arbeitsgruppe "Kormoran" für Hessen und Rheinland-Pfalz. Vogel und Umwelt 9: 205-206.
Schmidt J.P. (1998). Kormoranabwehr durch weitmaschige Überspannung von Karfenwinterungsteichen in der Oberpfalz. Ornithol. Anzeiger 37: 1-18.
Schreckenbach K., Dersinske E. & Schulz A. (1998). Einfluss von Kormoranen auf Satzkarpfen in ungeschützten und überspannten Teichen. Fischer & Teichwirt 49: 186-192.
Werner M. & Richarz K. (1998). Kormoran und Fischerei. Vogel und Umwelt 9: 263-268.
Wissmath P., Wunner U. & Huber B. (1998). Kormoranschäden an Stellnetzen der Seenfischer- eine hinnehmbare Bagatelle oder ein handfester fischereiwirtschaftlicher Schaden? Fischer & Teichwirt 49: 486-489.
Wissmath P., Reschenauer M. & Limburg U. (2000). Kormoranschäden in der Netzfischerei am Ammersee? Fischer & Teichwirt 51: 82-84.
Zobel H. (1998). Internationales Smposium: "Der Kormoran im Spannungsfeld zwischen Naturschutz und Teichwirtschaft" in Königswartha. Fischer & Teichwirt 49: 3-8.
Great cormorant: The Waterbird Society (formerly, Colonial Waterbird Society) held its 23d Annual Meeting in Grado, Italy. There was a special session on cormorants with a good dozen of presentations concerning cormorants in Europe and the USA. In the Northern Adriatic area a lot of suitable nesting habitats exist (Volpony 1999). The cormorant breeding population (n = 400 pairs in 1999) may substantially increase in the future. This situation, together with a high number of wintering birds, is expected to promote conflicts with aquaculture producers. An extended analysis of pellets (n = 1'206) by Volponi & Privileggi (1999) showed variations in space (between colonies) and time (changing foraging grounds due to prey distribution during wintertime). The cormorant problem should be solved at an European level by reducing the reproduction intensity in the breeding areas, whereas shooting of wintering cormorants is considered a palliative measure (Cau et al. 199?).
Other waterbirds: The stomach content of 22 great crested grebes (Podiceps cristatus) was dominated by bleak (Alburnus alburnus; 83%) and roach (Rutilus rutilus; 15%) in Lago di Como.
Cau A., Bacetti N., Cataudella S., Corda G., Donati F., Mainardi D., Rossi R. & Bertelletti M. (199?). Relazione finale "Impatto degli uccelli ittiofagi sull'attivita di Acquacoltura". Commissione Scientifica Nazionale sugli uccelli ittiofagi, Ministerio delle Risorse Agricole, Alimentarie e Foresti, Roma. 98 pp.
Volponi S. & Privileggi N. P. (1999). Diet and predation of Great Cormorants wintering in two areas along the Northern Adriatic Sea coast. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Volponi S., Cherubini G. & Utmar P. (1999). Population development of wintering and breeding Great Cormorants in the Northern Adriatic, Italy. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
The file with all abstracts of the 23d Annual Meeting of ist 23d Annual Meeting of the Waterbird Society is also available via my e-mail ([email protected]).
Great cormorant: Studies on cormorants' prey selection in a water tank showed a visual detection at a distance of at least 1.4 m (Strod et al. 1999). Choice experiments showed preference for larger fish.
Other waterbirds: There are foraging studies (Nathan et al. 1999) on a second cormorant species, the globally threatened pygmy cormorant (Phalacrocorax pygmeus).
Strod T., Izhaki I., Arad Z. & Katzir G. (1999). Prey detection and prey preference in diving cormorants. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Nathan M., Izhaki I. , Zorovski Y., Arad Z. & Katzir G. (1999). Behavioral and eco-physiological aspects of the Pigmy cormorant's biology. Abact for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Breeding cormorants from 4 colonies were flying 2.9 km on average (range 1.5 – 5 km) to their feeding areas (Lorentsen & Rov). Kelp forests (Laminaria hyperborea) are shown to be an important habitat for young fish and preferred foraging area for cormorants.
Lorentsen S-H. & Rov N. (1999). Close overlap between feeding areas for Great Cormorants and Kelp forests. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
An extended analyses of pellets (n >1200) by Bzoma & Stempniewicz (1999) revealed 70-95% round goby (Neogobius melanostomus) during April through September 1998, and 90% stickleback (Gasterosteus aculeatus) during October through November 1998. Goc et al. (1999) tracked birds that were equipped with radio-transmitters, and Kopciewicz et al. (1999) studied breeding success.
Bzoma S. & Stempniewicz L. (1999). Changes in numbers and diet of cormorants Phalacrocorax carbo in the Gulf of Gdansk. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Goc M., Iliszko L. & Brylski T. (1999). Foraging flight pattern of the cormorant (Phalacrocorax carbo sinensis) studied during a breeding season by telemetry and visual counts. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Kopciewicz P., Nitecki C., Bzoma S. & Stempniewicz L. (1999). Breeding succes of cormorants Phalacrocorax carbo sinensis in the colony at Katy Rybackie (N Poland), 1995-1999. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
Gogu-Bogdan & Hanganu (1999) compared the diet of a fluvial colony with that of a fluvio-maritime one.
Gogu-Bogdan M. & Hanganu D. (1999). Comparative studies in food composition of Great Cormorant in three different colonies from the Danube delta reserve. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
The estimated fish consumption by cormorants in a highly productive lake was 15 kg ha-1 year-1 (in comparison, the yield of the fishery was 8.6 kg ha-1 year-1). Main foraging species was ruffe (Gymnocephalus cernuus) amounting to 75% of the diet. Cormorant predation probably did not lead to a decline of commercial fish species, since eel (which is most important for the fishery) was absent in the diet.
Engström H.D. (1999). Long-term effect of cormorant predation on fish communities and fishery in a freshwater lake (Ymsen) of south-central Sweden. Abstract for the 23d Annual Waterbird Society Meeting in Grado, Italy.
For several running waters there exist detailed data (AFV 1999; Renz 2000) on the presence of cormorants and common merganser (Merganser merganser), angling yield, fish stocking, estimation of fish population size and stomach content of piscivorous birds (n = 2000 cormorant stomachs for the whole of Switzerland). Most research activities are co-ordinated by a cormorant-fish working group (AG K+F 1988) with the aim to assess the effectiveness of the Swiss cormorant management plan. Additional data are available on fish loss in gillnets caused by cormorants (Egloff 1998). Cormorant control programs are limited to running waters; about 1'000 cormorants are shot each winter. Some ornithologists (e.g. Suter 1999) deny scientifically proven damage in running waters. However, fish loss from gill nets is accepted as damage.
AFV (Aargauischer Fischereiverband) (1999). Fische und Kormorane im Kanton Aargau - Ergänzungsbericht 1999. Bericht des Aargauischen Fischereiverbandes, 16 pp.
AG K+F (Arbeitsgruppe Kormoran und Fische) (1998). Arbeitsverzeichnis für die Berichterstattung der Erfolgskontrolle. Papier der AG K+F (Sitzung vom 9.6.98).
Egloff K. (1998). Kormoran und Berufsfischerei im Untersee, Winter 1997/98. Fischereiaufsicht Kt. Thurgau, 14 pp.
Renz H. (2000). Gefiederte Prädatoren plündern die Saane. Petri-Heil 51/3: 15-17.
Suter W. (1999). Kormoran – Phalacrocorax carbo. In: Heine G. et al. (1999). Die Vögel des Bodenseegebietes. Orn. Jh. Bad.-Württ. 14/15, p. 203-207.
Great Cormorant: Mous (2000) gives information on the complex situation of plankti-/benthivorous and piscivorous fish, fishermen's target species, bycatch of immature fish, fish predation by birds etc. Management options are analysed with a population model.
Other waterbirds: In addition to the predation problem, the fisheries of The Netherlands are confronted with bird protection problems because wintering waterbirds are drowned in gillnets (van Eerden et al. 1999).
Mous P.J (2000). Ineractions between fisheries and birds in Ijsselmeer, The Netherlands. Thesis, University of Wageningen, 205 pp.
Van Eerden M., Dubbledam W. & Muller J. (1999). Sterfte van watervogels door visserij met staande netten in het Ijsselmeer en Markermeer. RIZA, rapport 99.060, 42 pp.
The results of a four-year research program (MAFF 1999; ....) give recent data on the number of wintering and breeding cormorants and goosanders, and on its distribution on the coast and in inland waters. The impact of fish-eating birds is a problem for specific fisheries rather than a general problem. Some times bird predation can be high enough to cause serious problems. Factors other than predation by birds can affect fisheries and have a more significant impact than bird predation. Evidence on whether or not shooting to kill enhances the effectiveness of bird scaring was inconclusive; and apart from human presence, no other management measure were found to be consistently effective although fish refuges showed some promise.
MAFF (Minstry of Agriculture, Fisheries and Food) (1999). ...[File lost] ...
3. Activities of international bodies
Cormorant research group
The cormorant research group of Wetlands International held its last symposium in April 1997. There is no announcement for a next symposium.
The papers of the 1997 symposium are issued in Polish Journal of Ecology 45.
European Anglers Alliance (EAA)
The EAA (1998) collected the data on wintering birds and made proposals.
EAA (European Alliance of Anglers) (1998). Situation of the cormorant in Europe. EAA, Amersfoort, 48 pp.
European Management Plan of CMS
In October 1998, the Danish Ministry of Environment sent out the finalised "Action Plan for the Management of the Great Cormorant" which was elaborated under the umbrella of the Bonn Convention (or CMS, Convention on Migratory Species). Amongst other proposals the plan presents measures in order to control cormorant populations within existing breeding colonies. However, the countries with the strongholds of the European breeding population are seemingly not willing to implement such measures.
Under the lead of D. Carss, Institute of Terrestrial Ecology, UK, the research project REDCOFE (Reducing the conflicts between cormorants and fisheries on a pan-European scale) was submitted to the European Commission in October 1999 to get subsidies. The project was accepted in April 2000. It intends to push forward the basic idea of the CMS-Management plan. It will last two years; in total, four working meetings are planned (each of about 3 days).
There are two representatives of EIFAC amongst the participants in the project:
Project leader: Dave Carss; BirdLife International: Julian Hughes; Denmark: Thomas Bregenballe, Mogens Bilsoe and Christian Dieperink; EAA (European Anglers Alliance): Gilbert Marsollier; EIFAC (European Inland Fisheries Advisory Commission): Erich Staub and Heiner Klinger; Estonia: Redik Eschbaum; France: Loic Marion and Daniel Gerdeaux; Germany: Thomas Keller and Harald Kleisinger; Greece: Kazantzidis Savas; Latvia: Janis Baumanis; Israel: Ido Izhaki, Zeef Arad and Gado Katzir; Poland: Robert Gwiazda; Spain: Carlos Garcia de Leaniz, Sweden: Stellan Hamrin and Henri Engström; The Netherlands: Mennobart van Eerden and Willem Dekker; United Kingdom: Ian Winfield, Philip Scott Jones, Ian Russell.
Conclusions and Recommendations
To be discussed and drafted at the meeting planned at the beginning of the 21st EIFAC Session.
The Convenor of the Working Party:
Erich STAUB, BUWAL, Fisheries Section, Post-box, CH-3003 Bern, Switzerland
e-mail: [email protected]
SUMMARY REPORT OF SYMPOSIUM OF THE EIFAC WORKING GROUP
ON EFFECTS OF PHYSICAL MODIFICATIONS OF THE AQUATIC HABITAT ON FISH POPULATIONS, RECREATIONAL FISHERIES, RESOLUTION OF CONFLICTS WITHIN RIVER CATCHMENTS
A Symposium and Workshop on Management and Ecology of Lake and Reservoir Fisheries, convened by Ian G. Cowx, was held in the University of Hull International Fisheries Institute, Hull, from 10 to 14 April 2000. The Symposium was attended by 92 persons from 34 countries.
The main documentation consisted of 54 experience papers and 21 poster presentations. The Workshop was organized into two main Working Groups on:
- stock assessment and rehabilitation and mitigation activities;
- management issues.
At the last session of the Symposium the main conclusions and recommendations were presented. The proceedings of the Symposium will be published by Fishing News Books, Blackwell Science, Oxford, in autumn 2001.
B. Stock assessment for management purposes
It was recognized that lacustrine fisheries are formed in diverse types of habitats from small ponds to large lakes and reservoirs. Consequently, there is a need for an array of methods to provide adequate assessment of stocks in those habitats. These vary from environmental correlation methods, through sampling gears and romote methods (e.g. hydroacoustics) to catch assessment surveys (catch effort methods). It was rtecognised that there is no perfect sampling technique and a combination of methods is required to gain the desired precision instock biomass. In this respect, there is a need to define the objectives of the assessment activity to ensure the appropriate precision in information is gained. In many instances it was questioned whether stock assessment was necessary as trends in species composition, catches etc., can provide adequate information for management at minimal costs.
The major constraints on stock assessment were inadequate development in gear technology, poor data analytical methods, weak understanding of the limitation of stock assessment procedures, and lack of resources.
C. Anthropogenic activities/rehabilitation and mitigation
It was recognised issues affecting lake and resrvoir fisheries are either related to the fishery istself (e,g, overexploitation, inadequate recruitrment or maintenance of biodiversity), the ecosystem or watershed (e,g, pollution, nutrient enrichment, hypolimnetic anoxia), or the human dimension. It is possible:
to identify and prioritise problems impacting upon lake and reservoir fisheries and aquatic communities;
but it is less easy to identify and carry out appropriate technical solutions to these problems, mainly because of the scale of action required.
The mechanisms for rehabilitation or improvement of lakes and reservoir fisheries are in their infancy and often restricted to stock enhancement procedures (targeting the fishery problems), or simple regulation of pollution and land use changes.
From the human dimension, problem arise from fiser dissatisfaction, poor catch quality, excessive fishing effort, access problems and multiple resource user conflicts. Most of the factors causing problems for fish communities are outside the control of the fisheries sector. Those involved in fisheries must therefore broaden and strengthen their cause, by interacting and making alliances with other interested parties, in seeking to limit damage to aquatic ecosystems, and promote rehabilitation and enhancement activities.
D. Management Issues
Several key management issues were raised which link to other outputs of the Symposium.
Whilst stock assessment may not be required per se there is a need to improve fisheries statistical monitoring procedures to provide baseline information on exploitation levels.
There is a need to improve communication linkages between fisheries managers, scientists and those utilizing the resource. This can be the first step in management of the resources which appears to be the most desirable way to manage large-scale lacustrine fisheries.
The profile of lake fisheries needs raising in general, and particularly where there is a multiple array of resource users who are often in conflict or potential conflict. To support this action there is a growing awareness of the importance for economic and social evaluation of fisheries to ensure they are well represented in all development activities. It is recommended that priority be given to developing and promoting economic evaluation of inland fisheries.
If water and aquatic resources are to be exploited on a sustainable basis in the future, concerted effort is needed to resolve the conflicts between user groups. Where possible, this must be based on sound scientific evidence, close liaison between user groups, full cost-benefit analysis and transparency in the decision-making process. Where scientific information is not available this should not prevent decisions being made, but the precautionary approach should be adopted. If resolution of conflict is to be successful it must involve cross education of all user groups, recognition of stockholder participation and needs, and be probably implemented at the local community level.
There is also the need for robust methods for prioritizing demands for the water and aquatic resources of lake and reservoirs that balance human requirements against protection of the environment and biodiversity.