Assessment of Polycyclic Aromatic Hydrocarbons Concentration in Surface Water, Sediment and Blue Crab, Callinectes Amnicola (De Rochebrune, 1883) from Buguma Creek, Rivers State, Nigeria (Published)
Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic contaminants that pose ecological and human health risks. This study assessed PAH levels in surface water, sediment, and Callinectes amnicola from Buguma Creek, Rivers State, Nigeria. Surface water, sediment and C. Amnicola samples were collected bimonthly from three stations between May and September 2022 for PAHs analysis by gas chromatography. Physico-chemical parameters such as temperature (°C), salinity (‰), pH, dissolved oxygen (DO, mg/L), and biological oxygen demand (BOD, mg/L) were measured in surface water. Data were statistically analysed by Analysis of Variance (ANOVA). Results showed significant no spatial but temporal variations in DO, BOD, and salinity, with the highest values recorded for DO (5.3±0.4 mg/L) and BOD (5.9±0.3 mg/L) in July, while salinity peaked in May (19.0±0.0 ‰). Of the 17 PAHs listed by the agency of toxic substances and disease registry, 12 (including Naphthalene which was not listed in ATSDR) were detected, excluding benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, dibenzo(a,h)anthracene, and benzo(g,h,i)perylene. PAHs concentration followed the trend: sediment > water > C. amnicola, with the highest levels recorded in July. PAH sources were both petrogenic and pyrogenic, with petrogenic inputs dominating surface water, pyrogenic sources in C. amnicola, and both contributing equally to sediment contamination. Biota-water accumulation factor (BWAF) and biota-sediment accumulation factor (BSAF) indicated C. amnicola primarily accumulated PAHs from water rather than sediment. PAHs concentrations in all matrices exceeded by several magnitude the US Environmental Protection Agency’s limits (<1000 ng/g for sediment, <1000 ng/L for water). The presence of carcinogenic PAHs, including benzo(a)anthracene, benzo[b]fluoranthene, and benzo(a)pyrene in water and sediment, and chrysene and benzo[b]fluoranthene in C. amnicola, raises concerns over bioaccumulation and trophic transfer. In conclusion, Buguma Creek is polluted with PAHs from both pyrogenic and petrogenic sources. Given the potential ecological and human health risks associated with PAHs, regular monitoring and pollution prevention measures are essential for mitigating anthropogenic impacts and ensuring sustainable ecosystem.
Keywords: Contaminants, PAH, Shellfish, Water Quality, brackish water creek
Water Quality and Phytoplankton as Indicators of Pollution in Ibuya River (Published)
Ibuya River runs across the Old Oyo National Park and there is paucity of information on the limnology of the river. In order to assess the status of the river, phytoplankton and water quality were examined during the study period of September 2012 to February 2014 at four sampling stations. A total of 45 species of phytoplankton belonging to four families were identified. The most representative family in terms of species richness was Bacillariophyceae (25 species), followed by Chlorophyceae (9 species) and Euglenophyceae (8 species) and the least dominant is Cyanophyceae with 3 species. Water temperature was 24.73 ± 0.21°C, pH was 7.57 ± 0.04 and dissolved oxygen (DO) was 4.43 ± 0.15 mg/L, conductivity was 140.83 ± 5.60 µS/cm, TDS was 98.11 ± 3.80 m/L. Cadmium (Cd), Lead (Pb) and Phosphate (PO₄3˗) exceeded the permissible limits for surface water (0.003, 0.01 and 3.5 mg/L) respectively. The water quality and phytoplankton species composition of the river showed that allochthonous input from activities within and outside the park has subjected the ecosystem to pollution pressure.
Keywords: Anthropogenic Activities, Ibuya River, Phytoplankton, Water Quality, pollution indicators
Study on the Chemical and Biological Status of Malwatu Oya Basin, Anuradhapura in Sri Lanka. (Published)
Water pollution is a serious problem to the entire world. It threatens the health and wellbeing of humans, plants, and animals. With the advancement of communications and trade due to industrialization, accidental and purposive waste dumping, and uncontrolled use of water sources have contributed to the problem of water pollution in both surface water and the ground water. This study was mainly concerned with the evaluation of water quality of Malwathu Oya and its four basin tanks in the dry zone of Sri Lanka namely Nuwara wewa, Tissa wewa, Nachchaduwa wewa and Mahakanadarawe wewa in the Anuradhapura district using some selected water quality parameters. Malwathu Oya has been using as a source of drinking water for Anuradhapura. Eutrophication through the process of nutrient enrichment of stagnant waters due to urbanization & chemical added agricultural practices has been considered as the significant cause for water pollution in these areas. They cause algal blooms and release of toxic substances from species like cyanobacteria. Low Secchi Depth value and high chlorophyll a concentration indicate eutrophic nature of the Nuwarawewa and Tissawewa Lakes in dry periods. Malwathu oya too showed reasonably high Chlorophyll content during the same period. High nutrient loading was observed through the growth of phytoplankton species. Cylindrospermopsis raciborskii was the most dominant species recorded in the present study and Microcystis aeruginosa, Microcystis incerta, Pediastrum duplex. Merismo pediatenuissima, Melosira granulate and Diatomaelongata were also recorded from Nuwarawewa and Tissawewa during the study period. With respect to Physical and chemical parameters, very high turbidity, high nitrogen compounds ( Ammoinia, Nitrate, Nitrite), phosphate, total suspended solids, dissolved oxygen, chemical oxygen demand, biological oxygen demand were recorded in Nuwarawewa and Tissawewa due to the influence of human activities such as recreational , dumping wastes and agricultural practices. However data indicate that Nachchaduwa and Mahakandarawa lakes are well protected from above threats. At the same time Malwathuoya stream also showed the same kind of pollution pattern causing more critical situations for water treatment and water quality aspects. Therefore, an effective Lake Management and Lake monitoring programmes with integrated catchment management have to be adopted and it is a prior necessity in planning of the management practices of the catchments to get first hand information through this kind of research on these lakes.
Keywords: Coliforms, Eutrophication, Malwathuoya River Basin, Phytoplankton, Urbanization, Water Quality