Environmental Determinants InfluencingFish Community Structure and Diversity in Two DistinctSeasons among Wetlands of Northern Region (Ghana)

摘要

Fish community structure was assessed in six wetlands using cast nets, to correlate with environmental variables with diversity and distribution patterns, from 2010 to 2012. A total of 2,239 individuals belonging to 44 species and 1,938 individuals belonging to 40 species were sampled in the dry and wet seasons. Mochokid and Mormyrid families dominated fish community and constituted 14.8%, respectively, followed by Alestids (12.9%) and Chlariids (11.1%). Rarer taxons were centropomids, channids, malapteruds, and oesteoglossids and represented 1.9%, respectively. Overall, CPUE per net did not vary significantly (Tukey HSD test, p = 0.27) in the dry and wet seasons. Wuntori marsh consistently showed dominance in mean monthly CPUE per net (dry = 115 ±4.5; wet = 107 ± 7.7 seasons), while Bunglung constructed wetland was the least recorded (dry = 56.5 ± 6.2; wet = 58.3 ±4.1 seasons). Fish diversity and richness differed significantly (F = 0.11, p = 0.03) among seasons. Environmental disturbances were season-specific and did not differ significantly (F = 0.16, df = 14, p = 0.97) among sites. A DCA ordination explained 69% variability in fish distribution patterns, while PCA showed that 81.8% of nitrate-nitrogen, phosphate, and grazing intensity onaxis 1 and conductivity, temperature, and turbidity on axis 2 influenced fish community structure. Wetland conservation must be promoted to sustain fish abundance and overall ecosystem stability.