Discards and by-catch in Spanish fleet targeting Greenland halibut (Reinhardtius hippoglossoides) in NAFO Divisions 3LMNO: 2008 and 2009

This study analyses the discard and by-catch composition of the Spanish fleet targeting Greenland halibut (Reinhardtius hippoglossoides) in NAFO divisions 3LMNO. During 2008 and 2009 the sampling coverage of the fishing effort was 20.6% and 16.5%, respectively. Data showed a reduced (4.3 % in weight) but highly variable discard rate. The main discarded species were the macrourids Macrourus berglax, Coryphaenoides rupestris and Nezumia bairdi, together with other 2 fish species: Antimora rostrata and Amblyraja radiata. The target species (Greenland halibut) was intermittently discarded. The discard rate showed no pattern no trend. No significant catches of benthic invertebrate taxa indicators of vulnerable marine ecosystems (VMEs) were recorded

Non-traditional resources: skate fishery and survey results in Division 3NO

Since 1993 a significant increase in the skate catches from the Spanish trawlers have been reported (Duran et al. 1996; Junquera et al. 1997). It was interpreted as a shift in the fishing strategy towards the exploitation of non-regulated species. Important skate by-catches are often taken in the Greenland halibut fishery, but at present a directed, though temporary, fishery has also been established. In this paper a review of the available information on this subject is presented

La platija en el Mar de Barents y Svalbard: un nuevo recurso

Versión del editor0,000

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

Testing Non-parametric Methods to Estimate Cod (Gadus morhua) Recruitment in NAFO Divisions 3NO

Recognizing that non-parametric methods to estimate fish stock recruitment are generally simple and they do not need to be based on ecological hypotheses, four non-parametric methods; the probability transition matrix and three algorithms to estimate recruitment probability density functions were tested on cod (Gadus morhua) data from NAFO Div. 3NO. The transition matrix method was inadequate because the cod stock failed to meet the primary Markovian assumption: the transition probability must be constant and depend only on the previous state. Of the three algorithm methods, the fixed-interval, the New England and the Cauchy, only the New England was appropriate for calculating recruitment with these stock data. A regression coefficient of r = 0.556 (d.f. = 23, P = 0.003) was obtained when the observed data were compared with the estimated. The validity of estimates of future recruitment using the New England algorithm depends on biotic and abiotic environmental conditions being similar in both the pre-recruit and the observation periods

Length/Weight relationships for Greenland halibut, Reinhardtius hippoglossoides, from Northwest Atlantic (NAFO Regulatory Area: Divisions 3L, 3M and 3NO)

Sampling length and weight data collected during Flemish Cap survey (1995 and 1996) and fishing activity monitoring (1993 and 1994) were used to produce relationships and plots for length-weight and gutted weight/total weight for Greenland halibut in the NAFO Regulatory Area (Divisions 3L, 3M and 3N0). The parameter values were obtained by sex, division and by semester

Grenadiers in the Spanish Fishery of Greenland Halibut, NAFO Divisions 3LM and 3N, 1991-1993

In the Spanish Greenland halibut fishery, grenadier are an important component in the by-catch. Their catch, catch-rate and size distribution were analyzed during the period 1991 to 1993.The importance of these species in relation to the targetted species increased in the period studied and the proportion between the two in by-catch was approximately 50%. Yields were greater during the first half year period, and increased with depth. Sizes of roundnoes were smaller to the south (3N) whereas roughead sizes were larger in this same division

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)