Study Project 99/016 “Data collection for stock assessment of two hakes (Merluccius hubbsi and M. australis) in international and Falkland waters of the SW Atlantic” ran from January 2000 to December 2001. The main objective of the project was the collection and collation of already existing and newly
acquired fishery and biological data needed for preliminary assessment of two hake species occurring in the study area. In addition to this basic remit, additional objectives included the creation of a common
database, study of spawning seasons and areas, discard pattern and length-frequency composition of target and non-target species, estimation of annual by-catch rates, analysis of trophic relationships, marine mammals by-catch and sightings, morphometric analysis for stock differentiation, and developing GIS
applications for analysis of the data collected.
Historical fishery and biological data series available from IEO and FIGFD (since 1988 and 1987 respectively) were provided to the project. New fishery and biological data were collected by scientific observers provided by IEO, ANAMER and FIGFD, and placed on board Spanish fishing vessels operating
in the study area during the project period. Data on fishing activity included effort, catches and discards of target and non-target species on a haul-by-haul basis. Biological information (size, sex, maturity stage, etc)
of target and non-target species was recorded on a daily basis. Data on landings and effort were provided by ANAMER to its subcontractor (MG OTERO) for processing and estimation of total catch and effort
of the whole Spanish fishing fleet in the area; MG OTERO was also responsible for organisation of observers in collaboration with ANAMER staff in Vigo and Port Stanley. Ancillary data on location, time of fishing, depth, SST, SBT, sea roughness, wind, etc, was recorded on a haul-by-haul basis. This type of information was essential for development of GIS at AU to relate the species distribution to physical and
environmental factors. Other information collected was about by-catches and sightings of small cetaceans and seabirds, and biological samples such as otoliths, stomachs and whole specimens of hakes for
subsequent studies on growth (IEO, FIGFD), diet and morphometrics (AU).
All the historical and new data collected during the project were collated and integrated into a common database designed by all participants and built at IEO. The information was used for preliminary assessment of two hake populations co-ordinated by RRAG during a workshop held in London in July
2001. All these data will be analysed and written up for future publications. Discard rates of target species were generally low in all areas and seasons with the highest discard rate for Notothen sp. (around 100% of
the catch). Illex squid was found to be the major by-catch for hake fishery in the 46 S area.
IEO observers reported data on incidental catches of marine mammals and sea birds since 1993 and the analysis of this information was made by AU. The observed mortality in the fishing gears comprised small
numbers of black-browed albatross, gentoo penguin and the hourglass dolphin. The species most frequently sighted was the Peale’s dolphin, although this species did not appear in by-catches, followed by the hourglass dolphin.
The project provided an opportunity to collect and integrate for the first time at European level the necessary fishery and biological data for the development of partial stock assessment for the future rational management of the fisheries in the area. Such management is needed for the sustainability of
the commercial fisheries, the conservation of the onshore and offshore jobs and the supply of fish to the most important markets worldwide.EUROPEAN COMMISSION
DIRECTORATE GENERAL FISHERIES – DG XI
