Impacts of petroleum hydrocarbons on fish communities of river Areba, Niger Delta, Southern Nigeria
The effects of petroleum activities on the fish community of River Areba, a small rainforest river, in Niger Delta, Southern Nigeria were studied for one year, January to December, 2002. Two stations within the river stretch were studied; one close to the area of petroleum activities was marked as station 1 while the other 5.30 kilometers downstream was marked as station 2. A total of 41 fish species accounting for 856 individuals representing 32 genera and 19 families were captured. Forty one (41) species representing 648 individuals, 32 genera and 19 families were caught in station 2 while twenty six (26) species representing 208 individuals, 21 genera (18) and families were captured in station 1. Twenty six (26) species were ubiquitous among the two stations while 15 species were restricted to station 2. The monthly variations of Total Petroleum Hydrocarbons (TPH) fluctuated between 0.13mg/l in March to 45.11mg/l in September in station 1 with a mean of 12.15mg/l while station 2 values ranged from below detection in March and April to 12.68mg/l in September with a mean of 3.72mg/l. The values of Total Petroleum Hydrocarbons in sediments in station I ranged from 34.70mg/kg in April to 256.10mg/kg in March with a mean of 91.05mg/kg while in station 2 values fluctuated between 16.80mg/kg in March to 93.80mg/kg in April with a mean of 33.94mg/kg. Out of sixteen aromatic components recorded, station 1 accounted for 0.09423mg/l while station 2 accounted for 0.00796mg/l.
Key words: Petroleum hydrocarbons, impacts, fish species, rainforest river, Niger Delta, Nigeria.