Ecological study on the impact of mariculture fish cage site on the physico-chemical characteristics of Lagos Lagoon, South Western Nigeria

Abstract

A six months investigation on the environmental impact of fish cage culture on surface water and sediment of the Lagos lagoon were studied monthly from February 2011 to July 2011. Samples were collected from three stations, 1 (upstream of cage culture site), 2 (cage culture site) and 3 (downstream of cage culture site) between 07:00 and 11:00 h. During this period, the surface water ranged between 23.34 ± 3.39-23.79 ± 1.52°C, depth ranged between 0.91-0.99 m. The lowest DO value and highest biological oxygen demand (BOD) (mean = 4.43 and 6.00 mg/L) was recorded at station 2, respectively. These values may be due to the required oxygen used to break down fish wastes and excess feed pellets from the fish cage at this station. The analysis of variance test on parameters of water samples collected showed no significant difference (p>0.05) among the three study stations while the analysis of variance test on the sediment samples collected showed significance difference (p<0.05) in ammonium and total organic carbon among the study stations. There is a need for future development initiatives to focus on best management practices (BMPs) for low impact, ecologically sound and sustainable aquaculture.

Morphodynamics in a Tropical Shallow Lagoon: Observation and Inferences of Change

“…Lagos' population is currently about 17 million, up from 2 to 3 million in the 1970s. Despite this pressure, research to date on the lagoon only identifies ecological studies [17][18][19], lagoon sensitivity and pollution studies [17,20,21], fishery and plankton sustainability [22,23] and partial pressures on the lagoon ecosystem habitat. All these, although, are part of the outcome of the impact created by the growing population (about 17 million) of the city of Lagos Nigeria around the Lagos Lagoon.…”

Impacts des exploitations piscicoles en cages flottantes sur la structure des macroinvertébrés benthiques de la lagune Ebrié (Côte d’Ivoire)

“…Ces dernières restent les systèmes d'élevage qui suscitent le plus de préoccupation au niveau environnemental. Ces fermes, exploitées pour la production intensive de poissons en pleine eau, ont l'inconvénient d'enrichir les sédiments situés en dessous des cages en matières organiques (Olapoju et al, 2014). Ces matières organiques, constituées essentiellement de débris d'aliments non ingérés et de composés issus du métabolisme des poissons élevés (Gorlach-Lira et al, 2013), peuvent affecter la qualité des eaux et perturber la structure de la communauté benthique.…”