|Temporal and spatial distribution of fish and shrimp assemblage in the Bakkhali river estuary of Bangladesh in relation to some water quality parameters|
|Rashed-Un-Nabia, Md.; Al-Mamun, Md. A.; Ullah, Md. H.; Mustafa, M.G. (2011). Temporal and spatial distribution of fish and shrimp assemblage in the Bakkhali river estuary of Bangladesh in relation to some water quality parameters. Mar. Biol. Res. 7(5): 436-452|
|In: Marine Biology Research. Taylor & Francis: Oslo. ISSN 1745-1000, more|
Fish and shrimp species, together with water quality data, were collected from two different stations located inside the Bakkhali river estuary of Bangladesh during winter, premonsoon and monsoon periods. Significant temporal differences were observed for water temperature, salinity and dissolved oxygen. The average catch of fish and shrimps per net between stations varied between 1.89±0.36kg at station 1 and 7.54±4.39kg at station 2, while the average catch in winter, premonsoon and monsoon periods found to be 2.79±1.08kg/net, 6.31±1.03kg/net and 5.06±2.89kg/net, respectively, with a significant difference in catch per net between stations although no significant difference in catch per net was observed between seasons. A total of 18,467 individuals of fish (35 species) and shrimp (10 species) were found in the present study. Three species of shrimps were observed to be dominant (>10.0%) and these were Metapenaeus lysianassa (17.07%), Ambassis dussumieri (14.54%) and Macrobrachium villosimanus (12.13%). Clear differences in faunal abundances were observed between seasons and stations with higher mean abundances during winter (1747.83±421.99 individual/5kg) and at Station 1 (1444±866.74 individuals/5kg). Similarly, the diversity indices, both Shannon–Wiener and Margalef, showed significant differences between stations and seasons (except Shannon for stations). Analyses of similarity (ANOSIM) results confirm both spatial and temporal differences in species community structure with a highly diverse assemblage. Canonical Correspondence Analysis results indicated that salinity and transparency were the main variables influencing fish and shrimp distribution in the Bakkhali river estuary.