Essential fish habitats (EFH) of small pelagic fishes in the north of the Persian Gulf and Oman Sea, Iran

Abstract

Small pelagic fishes particularly anchovy (Encrasicholina punctifer) and sardine (Sardinella sindensis) have an important role to support the Iranian fisheries, and are distributed along the entire length of the Persian Gulf and Oman Sea coastal waters. Using small pelagic fisheries logbook, a GIS-based environmental modelling approach was applied to investigate the presence and abundance of anchovy and sardine in relation to environmental variables. Sea Surface Temperature(SST), Sea surface chlorophyll-a concentration (Chlo-a), Sea Surface Salinity (SSS), Photosynthetically Active Radiation(PAR), Wind Speed (WS), Wind direction (WD), Bathymetry (depth), Distance from the nearest coast and Sea ground slope were collected from internet-based sources and scientific documents monthly from October 2014 to March 2015. Redundancy analysis (RDA) was applied to provide preliminary view of relationships between fish presence/absence and environmental variables, followed by application of Generalized Additive Models (GAMs). GAMs indicated the presence/absence of fish was related to distance from nearest coast, depth, sea surface Chlorophyll-a and SST. Essential fish habitat (EFH) maps were generated for anchovy and sardine, based on the predicted probability of presence of each spices. Results of the EFH showed that sardine to be concentrated in specific areas of more favorable conditions, such as north of the Persian Gulf zone and all areas of north west of Oman Sea zone. However, EFH of anchovy showed a more widespread distribution, occupying most of the north west of Oman Sea coastal waters , south of Qeshm Island in Strait of Hormoz zone as well as Parsian district in north of the Persian Gulf zone. In this study it seems that the anchovy have probability presence whispered to the areas with more distance from the coastal waters. However, the EFH probability presences of sardine were predicted for near coastal water and obviously, shallower waters. Due to small pelagic fisheries development, it is highly recommended to investigate anchovy and sardine fishing possibility in areas with high EFH prediction probability. However, in order to increase the accuracy and scope of essential fish habitat prediction probability for small pelagic fishes, implementation of a comprehensive acoustic survey in small pelagic fishing season and fishing grounds were highly recommended for all Iranian coastal wateres.