The IUCN/SSC Shark Specialist Group
Shark News 6: March 1996
|
ICES Study Group on
Elasmobranch Fishes
Ramon Bonfil
The International Council for the Exploration of the Sea (ICES)
established a Study Group on Elasmobranch Fishes during its 1994
Statutory Meeting and Annual Science Conference. This group met at
the ICES headquarters in Copenhagen, Denmark, on 15-18 August
1995, under the Chairmanship of Dr Helder da Silva. The meeting
represented an important first step towards a more organised and
integrated approach to the study ofelasmobranchs and their fisheries
in the North Atlantic.
The Study Group's terms of reference were as follows:
a) To review the status of elasmobranch stocks within the
Northeast and Northwest Atlantic and, where possible, identify
trends in biomass and recruitment.
b) To identify the extent of the commercial and sport fisheries in
which elasmobranchs are targeted or caught as bycatch and estimate
the amount (biomass/numbers per size class) ofelasmobranchs taken
as catch and lost as discards.
c) To describe/review the ecological role of elasmobranch
species, their reproductive dynamics and predation ofelasmobranchs
by species or group of species.
d) To coordinate techniques of age determination and age
verification of elasmobranchs.
e) To coordinate methods of modelling and assessment of
elasmobranch stocks.
f) To identify the development of compensatory mechanisms as
a response to exploitation.
g) To outline an action plan for attaining the goals set above.
h) To reportto the Demersal Fish Committee in September 1995.
The major achievements of the meeting were to produce a single
report containing much of the available information on elasmobranch
fishes and their fisheries in European and eastern North American
waters, and to initiate some much needed joint work on key issues
relevant to the sustainable exploitation of elasmobranchs.
Because the terms of reference for the meeting covered such a broad
selection of topics, it is not surprising that it was not possible to provide
full answers to all questions posed at this first meeting. Nevertheless, a
preliminary account of all the topics to be addressed was provided.
Work at the meeting included discussions on the state of the
knowledge of some processes of population dynamics relevant to
fisheries assessment and management. A maior task was to prepare
synopses of the extent of commercial and sport fisheries (including
varying amounts of catch statistics) for Belgium, Canada, Denmark,
France, Germany, Iceland, Ireland, Netherlands, Norway, Portugal,
Spain, UK, and USA. Because this was an ICES meeting, these
synopses as well as many of the other issues included in the report
were centred on waters covered by the ICES and NAFO statistical
areas. In many cases it was felt that there is not enough information
available at present to draw conclusions about the status of shark
stocks in the ICES/NAFO regions.
The Study Group report to the Demersal Fish Committee included
a number of recommendations, summarised as follows:
- the identification to species level of skates and sharks, including
deep-water sharks, during all survey cruises;
- an improved level of species classification for records of skates
(including those landed as wings) and sharks in commercial catches;
- a reminder for member countries to check the conversion
factors used to raise species to live weight;
- examination of patterns of discards of elasmobranchs from
other fisheries, quantification of discards and survival studies;
- elasmobranchs to be included in the remit of the ICES Study
Group on Stock Identification;
- convening Workshops on predation (to examine availability
of data and elasmobranch stomach content samples) and aging
(methodologies, validation and verification);
- use of a case population for which there is a good data set to test
validity of methodological assessments in elasmobranch populations;
- management advice for elasmobranch exploitation, including
consideration of precautionary measures (e.g. direct catch or effort
controls, or technical conservation measures) where there is strong
evidence of decreasing abundance in an elasmobranch fishery; and
- maintaining contact between ICES and the International
Commission for the Conservation of Atlantic Tuna (ICCAT), which
sent observers to the Study Group meeting.
- The terms of reference for the Elasmobranch Study Group agreed
by ICES at its 1995 Annual Science Conference are to work by
correspondence in 1996 to:
a) advise on the preparation of identification sheets for deep-
water sharks, skates and rays, including skate wings, and identify the
most important species;
b) compile the data available on the geographical distribution of
species and identify species for which data are sufficient for analytical
assessment;
c) plan a meeting in 1997 to conduct analytical assessments and
evaluate the effects of exploitation and/or environmental changes on
the stocks considered.
In addition, there is the possibility of organising an age and
growth determination/verification workshop in the near future.
The final report of the meeting, ICES 1995, is available from the
ICES Secretariat, Palaegade 2-4, DK-1261 Copenhagen K, Denmark
(http://www.ices.inst.dk/).
Participants, 1995 Study Group on Elasmobranch Fishes
| R. Bonfil-Sanders |
Canada |
H.M. da Silva (Chairman) |
Portugal |
| M.H. DuBuit |
France |
M. Stehmann |
Germany |
| S. Mykklevoll |
Norway |
Y. Uozumi (Observer) |
ICCAT1 |
| H. Nakano (Observer) |
ICCAT1 |
P. Walker |
Netherlands |
| M.G. Pawson |
United Kingdom |
|
|
1International Commission for the Conservation of Atlantic Tuna
ICES. 1995. Report on the Study Group on Elasmobranch Fishes. ICES CM 1995/G:3.
ICES Demersal Fish Committee, Copenhagen, Denmark. 88pp.
The author greatly appreciates the partial funding provided by the IUCN Shark Specialist
Group and the Fisheries Centre, UBC, and accommodation in Copenhagen provided very kindly
by Mr Garry Hopwood.
Ramon Bonfil, Fisheries Centre, UBC, Vancouver, CANADA.
|
|
|
|
|
