Witch flounder (Glyptocephalus cynoglossus) in the Spanish Fishery in NAFO Regulatory Area (Divisions 3LM and 3NO) 1991-94

The by-catch of witch flounder in the. Greenland halibut Spanish fishery in the NAFO Regulatory Area was analyzed during the period 1991 to 1994. A total of 32483 hauls were sampled. Data from 3N0 Spanish bottom trawl survey were also included in this analysis. Total catch was estimated for this period, showing high variability both by division and by year. The maximum was reached in 1994 in NAFO Div. 3NO.The yield shows seasonality. It was greater in March-April. In the period 1992-96, the annual yield shows a increasing. The length distribution and the length/weight relationshps was obtained in a deep range of 1500m. The length range was 24-58 in males and 26-62 in females. The mean length decreased througth the period analysed, and it was higer in the large vessel catches. The individuals were also larger in 3M division. The sex ratio showed seasonal variation in the large vessels catches, while any clear trend appears in the small ones. In addition to Greenland halibut, which was the target species, the main accompaining species of the witch flounder catches were: redfish, grenadiers, skate and occasionaly American plaice

Witch Flounder (Gyptocephalus cynoglossus) in the Spanish Deep-sea Fishery (NAFO Divisions 3LMNO), 1991–94

The by-catch of witch flounder (Glyptocephalus cynoglossus) was studied in the Spanish deep-sea fishery for Greenland halibut, which developed in the NAFO Regulatory Area in Div. 3LMNO over the period 1991–94. A total of 32 483 hauls were sampled. Some data from the Div. 3NO Spanish bottom trawl survey in 1995 and 1996 were also included in this study. Witch flounder yield was estimated for this period. The yield showed an annual seasonality where yield was greater in spring. Through the period 1992–96, the overall annual yield showed a general increase. The length frequency and the length/weight relationship were obtained from samplings performed at depths ranging from 800 m to 1500 m. The length range of the individuals was 26–60 cm in males and 22–72 cm in females. The mean length decreased throughout the period analyzed, and was higher in the large vessel catches. The individuals were also larger in Div. 3M. The sex ratio showed seasonal variation in the large vessel catches, while no clear trend appeared in the small vessels. In addition to Greenland halibut, which was the target species, the main fish species accompanying the witch flounder catches were redfish, grenadiers, skate and American plaice as incidental catch

Results from the 99 Spanish Bottom Trawl Survey in the Regulatory Area for Divisions 3NO

As the previous years a stratified-random bottom trawl survey was performed in NAFO Regulatory Area (Divisions 3NO) during 7 th to 28 th May. The survey, witch covered offshore areas on the Grand Bank, was conducted following the same procedures and the same vessel and gear of the 1995-98 surveys (Paz, et al, 1995; 1996, 1997, Durán et al, 1998). The area and strata to be covered by the survey were based on the stratification charts and tables in Bishop (1994)

The Spanish Multi-species Deep-sea Fishery on Hatton Bank (North East Atlantic): 1996-2000

This document describes the Spanish deep-sea fishery performed in international waters on the Hatton Bank and proximities (NE Atlantic) during the period 1996-2000. This is a multi-species fishery, carried out by stern bottom trawlers, mainly between June and September, in depths mainly between 800 m to 1600 m. The importance of the fishing activity in this area is increasing notably. This fishery has been monitored since the beginning in 1996, with the collaboration of the fishing industry, by means of a scientific observer programme. The observers on board provide data on catches, discards, location and depth, haul by haul. Length samples of the main species and biological material are also collected. The species composition of the catches is presented. In terms of weight, the roundnose grenadier (Coryphaenoides rupestris) and the bairdii smoothhead (Alepocephalus bairdii) are the most important species in the catches. Other less important species are the Portuguese dogfish (Centroscymnus coelolepis) and the blue ling (Molva dypterygia). In addition to the total catch, the composition of the retained catch and the discard are studied. For the main retained species, the dressing types are described and the conversion coefficients are presented. The length distribution of the catches and the discards, length-weight relationships and other biological aspects of some of the main species are analysed

Economía azul, investigación marina, impactos y ética en las turbulentas aguas de la NAFO

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Deep-sea: Vulnerable Marine Ecosystems in the North Atlantic Ocean: NEREIDA & ECOVUL/ARPA projects

Charla presentada en la DG Mare. European Commission. Directorate General for Maritime Affairs and Fisherie

A Preliminary Investigation of the Efficiency of Canadian and Spanish Survey Bottom Trawls on the Southern Grand Bank

Preliminary analysis of the capture efficiency of the bottom trawls used by Canada and Spain in surveys of the Grand Bank was conducted using a variant of the logistic model to analyse a series of comparative fishing data. Within the Canadian comparative data of the old and new survey trawls, the new survey trawl was less efficient for larger cod and yellowtail flounder but not so for American plaice. However, there is some uncertainty in capture probability for larger fish because of a sparse catches in the data. The Spanish survey trawl is more efficient than the new Canadian survey trawl because of the use of longer sweep lines, which increase catchability in plaice and yellowtail flounder. The logistic model did not fit the data well, in particular for yellowtail flounder. Further analysis is suggested which may offer more insight into modelling and interpretation of the capture efficiency of these survey trawls

New preliminary data on VME encounters in NAFO Regulatory Area (Div. 3M) from EU-Spain and Portugal Groundfish Surveys (2020) and Canadian surveys

During the 13th NAFO Working Group on Ecosystem Science and Assessment (WGESA) virtual meeting new preliminary data on deep-water corals and sponges were presented from the 2020 EU-Spain and Portugal and Canadian bottom trawl groundfish surveys. The data was made available to the NAFO WGESA to improve mapping of Vulnerable Marine Ecosystem (VME) species in the NAFO Regulatory Area (Divs. 3LMNO). During the 6th meeting of the NAFO Scientific Council WGESA, new quantitative spatial analyses were applied for corals and sponges for all the available data within the NAFO Regulatory Area (NAFO SCS, 2013). Outcomes from those analyses produced the following thresholds for VME species groups: 75 kg per tow for sponges, 0.6 kg per tow for large gorgonians, 0.15 kg per tow for small gorgonians, and 1.4 kg per tow for sea pens. Based on these thresholds deep-water coral and sponge data were identified and mapped, overlaid with the current closed areas, polygons for kernel density of sea pens and modified kernel density polygons for sponge grounds and large gorgonian VMEs. New thresholds and VME polygons were presented at the 12th WGESA meeting using additional data since 2013. These are: 100 kg per tow for sponges, 0.6 kg per tow for large gorgonians, 0.2 kg per tow for small gorgonians, 1.3 kg per tow for sea pens, and 0.35 for Boltenia sea squirts. Therefore, polygons illustrated on the figures below are the modified ones, accepted by SC.Versión del editor