Growth, Mortality and Exploitation of Sardinella maderensis (Lowe, 1838) in the Liberian coastal waters

Sardinella maderensis also known as flat ‘sardinella’ forms part of the commercially important fish species of Liberia which prefers areas of lower salinities close to the mouth of river. Though S. maderensis appears throughout the year in Ivory Coast coastal waters with a strong reduction from May to July due to the transition from warm season to cold season, adults S. maderensis are more sedentary. S. maderensis fishery is of great importance to fishing households within most coastal communities in Liberia, both economically and food security wise. As a result, S. maderensis fishery like other commercially important fish species in Liberia is currently subjected to intense fishing pressure. Intensive fishing pressure on marine biodiversity by location and depth has led to decline of marine capture fisheries.

In Liberia, factors such as poor fisheries data collection, limited resources, conflicts and illegal, unregulated and unreported (IUU) do not only make it difficult to estimate the status of almost all of the marine biodiversity but also presents a great challenge to fisheries managers. However, Togba reported that Sardinella, Barracudas, Croakers, Sharks and Ilisha africana constituted 83% and 59.06% of local fish supply in 2004 and 2005 respectively; indicating that there has been a declined in fish catches.

Stock Assessment and Estimation of Optimum Yield for Tilapia Stock (Oreochromis niloticus) in Lake Hawassa, Ethiopia

The basic purpose of stock assessment is to provide decision makers with the information necessary to make rational choices on the optimum level of exploitation of aquatic living resources such as fish. Aquatic living resources are limited butrenewable, and fish stock assessment may be described as the search for the exploitation level, which in the long run gives the maximum sustainable bio-economic yield in weight from fishery.

Fish resource utilization is the primary and an important economic activity. Its purpose is to provide a flow of benefits to human society; it serves as a food because ofits rich nutritional value in provision of protein. The global capture fisheries production in 2008 was reported by FAO, Fisheries and Aquaculture Department, as 90 million tones, with an estimated first-sale value of US$93.9 billion, comprising about 80 million tons from marine waters and 10 million tons from inland waters.