Assessment of the effect of climate parameters in commercial shrimp fishing using Principal Components Analysis (PCA) (Hormozgan province)

Shrimp is one of the most important food items in the southern parts of the country, especially Hormozgan province. Therefore, harvest management of shrimp stocks was an issue that has always been taken into consideration for sustainable catches. In this study, the relationship between meteorological factors (wind speed average, temperature and rainfall) was evaluated with catch rate at shrimp catch season (7 Oct. - 6 Dec.) in the period of 1985-2015. The Principal Components Analysis (PCA) was used in order to investigate the selected climatic parameters with shrimp catching. The results of the KMO index in this test were 0.71 and Bartlett's test was significant. The results of special values, variances and cumulative variables and factor loads related to the components showed that the first component((Shrimp catch(0.03), wind speed average(0.06), temperature(0.82) and rainfall(0.33)) with 33.58% and the second component(( Shrimp catch(0.76), wind speed average(-0.84), temperature(0.28) and rainfall(0.79))with 28.67% of the total variances (62.25%), can be used to verify the identification the most important parameters affecting on shrimp changes in the province during the last thirty years .In addition, evaluation of factors related to factor loading obtained from PCA showed that rainfall (0.79) and wind speed average(-0.84), in the second component, had the most positive and negative effect on shrimp catching changes (0.76) respectively. The effect of wind on the reduction of commercial shrimp catch may be related to the lower efficiency of trawl gear due to not placing the otter board trawl on the sea bed. It is probable that the annual rainfall will not be effect on the catch in catching area, and their effect may be on the stock of young shrimp in nursery grounds last year.