Josephus Mamie

Stock Assessment of Shrimp, Pandalus Borealis: in Skajalfandi Bay Iceland Josephus Mamie

The shrimp (Pandalus borealis) stock in Skjálfandi-bay northern Iceland is assessed. Management and assessment method of shrimp in Iceland is reviewed and suggestions for improvement are given for Sierra Leone. The analyses are based on time-series data of annual autumn surveys between 1991 and 2007 by the Marine Research Institute in Iceland. Length frequency analysis was done. Five age classes were identified and their proportion calculated using cohort slicing. Mean length corresponding to relative ages were estimated. Growth of P. borealis is modelled using non linear minimisation to find the best fit according to the von Bertalanffy growth curve. Growth parameters estimated were L? =24.28 mm (carapace length), growth k = 0.46 and t0= -0.42. Dynamic production model from the commercial catches and autumn surveys from1988 to 1999 gave an average biomass of 2047 tonnes. Maximum Sustainable Yield per recruit was 1.42 g which corrresponds to Fmax = 1.97 . Maximum Sustainable Yield = 566 tons and F0.1 = 0.72. Dynamic production model has advantage over surplus production models generally used in Sierra Leone.