Characterization of macro-benthic fauna for ecological health status of the Fosu and Benya lagoons in coastal Ghana

Abstract

This study conducted a comparative analysis of benthic macroinvertebrate communities in the Fosu and Benya lagoons in Ghana, based on the anthropogenic effect on the two lagoons. Salinity, oxygen, temperature, conductivity, turbidity and pH were measured, invertebrate richness and species densities were determined. The AZTI Marine Biotic Index (AMBI) and multivariate statistics were used to determine the different responses of fauna to pollution. The fauna were categorized into five ecological groups based on the degree of tolerance of the different species to pollution: disturbancesensitive species; disturbance-indifferent species, disturbance-tolerant species, second-order opportunistic species; and first-order opportunistic species. The Fosu Lagoon supported more pollution tolerant species, whereas the Benya Lagoon had more species that were sensitive to organic enrichment under relatively unpolluted conditions. Chironomus sp., which is adapted to virtually anoxic conditions, was the most abundant in the Fosu Lagoon whereas Nemertea sp. was the most abundant in the Benya Lagoon. The numerical and relative abundance (%) of all 7 taxa in the Fosu Lagoon was 1,359 and 92.35%, respectively. The numerical and relative abundance (%) of all 34 taxa in the Benya Lagoon was 2,459 and 87.52%, respectively. Expectedly, the level of dissolved oxygen in the less saline Fosu Lagoon was higher than that in the more saline Benya Lagoon. The reduced photoperiod and photosynthetic activities of aquatic plants might account for this trend. There is a need to implement comprehensive monitoring and management initiatives for sustaining the ecological health of coastal lagoons in Ghana in order to support the many people that depend upon these ecosystems for their livelihood.

Towards Conservation of Coastal Wetlands: An Assessment of The Ecological Health Status of A Neglected Lagoon In Ghana

“…Interestingly, the overall species diversity of the Brenu lagoon indicated a moderately balanced and stable structure. The species diversity encountered in this lagoon is higher than Fosu (Armah, Ason, Luginaah, & Essandoh, 2012) and Sakumo (Dzakpasu, 2019).…”

Benthic macroinvertebrates as indicators of water quality: A case study of estuarine ecosystems along the coast of Ghana

“…On the other hand, pollution-tolerant species, including midge larvae, oligochaeta, scuds, copepods, and snails, thrive in polluted or disturbed aquatic ecosystems [ [27] , [28] , [29] , [30] ]. While previous studies in Ghana have explored marine benthic macroinvertebrates, more data is needed to monitor coastal waters and regulate anthropogenic activities degrading surface waterbodies [ [29] , [30] , [31] , [32] , [33] , [34] , [35] ]. Table 1 lists other coastal waterbodies in the country that have previously been assessed.…”