Effects of Water Pollution in Koluama Area, Niger Delta Area, Nigeria Fish Species Composition, Histology, Shrimp Fishery and Fishing Gear Type

Abstract

The effect of water pollution in Koluama Area in the Niger Delta region of Nigeria to determine its effects on fish species composition, histology, shrimp fishery and fishing gear type. A total of twenty (20) species belonging to eleven (11) families were recorded. <em>Strongylura senegalensis</em>, <em>Lagocephalus laevigatus</em>, <em>Tarpon atlantica</em>, <em>Pristis pristis</em>, <em>Galeoides decadatylus and Butis koilomatodon</em> were rare. <em> Ephippion guttifer </em>, <em>Chaetodipterus goreensis</em>, <em> Sardinella maderensis</em>, <em>Sardinella aurita </em>, <em>Liza falcipinnis </em>, <em>Mugil bananensis</em>, <em>Pentanemus quinquarius</em>, <em>Polydactylus quadrafilis</em> and <em> Trichuris lepturis</em> were common. <em>Ethmalosa fimbriata</em>, <em>Liza grandisquamis</em>, <em> Sphyraena guachancho</em>, <em>Mugil curema</em>, <em>Sphyraena guachancho</em> and <em> Dormitator pleurops</em> were abundant. None was dominant. The highest number of fish species (16) were recorded in fish town and none was recorded in Kuloma 1 and one (1) was recorded for Kulauma 11. Foroupa, Ekeni, Ejetu and Ikebiri fishing port 1 and 2 recorded 8, 7, 3 and 5 fish species respectively. Artisanal fishing is based on traditional methods of fishing using essentially canoe and different fishing nets which depend on the season and target fish species. Canoes may be motorized or hand-paddled. Common gear types include shrimp traps, drift gill nets, set gill nets, cast nets, seine nets, hook and lines. Lift nets may be use by women folk who target small shrimp species in the creeks and creek lets. Other fishing methods include hand-picking for periwinkles, oysters and other shellfish by women folk and children. Prominent among the fishing devices are edek, a type of fish fence used in the creeks; alot, a large trap used on sand and mud-banks in the estuaries; and otunwa, a barbed spear. Fishers using these devices either operated from their home villages, exploiting the nearby waters, or staged long distance fishing expeditions, during which they lived in distant camps or house-boats. The heavy metals concentration level values are: $Cd (0.013^a±0.001)$, $Cr (2.04^b±0.01)$, $Cu (2.16^b±0.10)$, $Pb (2.20^b±0.16)$ and $Zn (1.03^{ab}±0.03)$ for <em>Lagocephalus laevigatus</em>; $Cd (0.01^a±0.001)$, $Cr (1.60^b±0.44)$, $Cu (1.25^{ab}±0.08)$, $Pb (1.10^{ab}±0.15)$ and $Zn (0.50^b±0.04)$ for <em>Tarpon atlantica</em> and $Cd (0.02^{ab}±0.003)$, $Cr (2.35^{ab}±0.40)$, $Cu (2.60^a±0.08)$, $Pb (2.30^a±0.45)$ and $Zn (1.11^a±0.17)$ for <em>Pristis pristis</em>. The presence of heavy metals in the fish samples examined is an evidence of environmental degradation.