Sediment toxicity on the survival of Capitella capitata (Fabricius, 1780) and early life stages of Echnometra mathaei (Blainville, 1825) in Dar es Salaam coastal marine waters, Western Indian Ocean
Journal Title: Journal of Aquatic Research and Sustainability - Year 2025, Vol 2, Issue 1
Abstract
Coastal marine pollution is a growing problem worldwide and ascertaining its impacts to aquatic biota is a growing concern. This study investigated the toxicity effects of sediments from Dar es Salaam harbor on the survival of Capitella capitata (Fabricius, 1780), fertilization and embryo development of Echinometra mathaei (Blainville, 1825) benthic biota along Dar es salaam harbor. Dar es salaam harbor is the main effluent receiving area along Tanzanian coastal marine waters associated with port operations. Sediment samples were collected at 35 sampling stations, C. capitata were collected at Msasani bay, 40 km from the harbor and E. mathaei were collected at Oysterbay rock shore about 10 km from the harbor. Sediments were collected along Dar es Salaam harbor using 50 cm long light piston corer and analyzed for heavy metals and total petroleum hydrocarbon levels and were used for toxicity testing. Higher concentrations of Cu, Cd, Pb, Zn, Cr, As, Ni, Fe, Ba, Mn were observed in the southern and central part of the harbor as compared to the northern par. However, Pb, Cr, Cd and Zn had the highest concentrations at the center of the harbor. Hydrocarbons included tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane and total petroleum hydrocarbons (TPH), their levels were low though was higher in the southern part of the harbor than in the central and northern part. Survival toxicity bioassay of C. capitata was conducted in sediments and seawater made from 1:4 sediments: seawater and 1:20 ratio, in a static and 48 hours’ replaceable seawater, similarly fertilization and embryo development bioassay of E. mathaei were conducted in elutriates made from similar sediment – seawater ratios in a static and 24 hours’ replaceable seawater. Higher mortality of C. capitata, lower fertilization and embryo development of E. mathaei were observed in sediments from the central part of the harbor and in the southern part, corresponding with the observed higher heavy metals and hydrocarbons levels. Revealing that higher heavy metal and hydrocarbons levels were the cause of the observed toxic effects. Comparison of the observed toxic effects showed that fertilization bioassay is the most sensitive test, thus making it suitable as bioindicator for the tropical costal marine pollution monitoring.
Authors and Affiliations
Benard Mwakisunga, Pratap Harishchandra Bhagwanj
Keywords
Related Articles
- EP ID EP762841
- DOI https://doi.org/10.69517/jars.2025.02.01.0004
- Views 20
- Downloads 0
Unlocking the potential of the Blue Economy in Bangladesh
The Blue Economy offers Bangladesh a transformative pathway for sustainable development by leveraging its extensive 710-kilometer coastline and 118,813 square kilometers of Exclusive Economic Zone (EEZ) in the Bay of Ben...
A bibliometric analysis of climate change mitigation through agricultural soil carbon sequestration
A global network analysis on agricultural soil carbon sequestration to mitigate climate change is required for funders, researchers, journal editors, decision-makers and conference managers. Therefore, this study assesse...
Feather meal as a sustainable protein source for aquaculture in Bangladesh: Economic implications
The aquaculture industry is primarily burdened by the costs associated with feed. It is fundamentally dependent on fish meal derived from wild-caught sources as the primary source of protein. With the widespread adoption...
Evaluation of the yield performance of freshwater prawns (Macrobrachium rosenbergii) cultured in a biofloc system at various densities
Biofloc technology is beneficial for prawn farming because it saves resources, protects the environment, and uses less energy. This study was conducted to evaluate the yield performance of freshwater prawns (Macrobrachiu...
Modified culture media development using locally available fertilizers and vitamin supplements for continuous mass culture of Chaetoceros gracilis
Microalgae culture is a vital nutritional resource for hatchery development in aquaculture and has gained significant interest as a sustainable food ingredient, versatile feedstock for biofuels, with broad industrial app...