Study of Fish Exploitation Pattern of Lake Gerio, Yola, Adamawa State, Nigeria Ekundayo, T
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Journal of Survey in Fisheries Sciences 1(3)9-20 2014 Study of fish exploitation pattern of lake Gerio, Yola, Adamawa State, Nigeria Ekundayo, T. M1*; Sogbesan, O. A2; Haruna, A. B.3 Received: December 2013- Accepted: April 2014 Abstract Lack of exploratory data for effective stock management, negligence on the part of the regulatory bodies with regards to data collection have made clear impossible to know precisely how much fish is taken from lake Geriyo daily, monthly, or annually and this has led to decline in the fisheries yield and reduction in the livelihood of the fishermen in this community. An investigation was carried out on Lake Geriyo between the months of April and July 2010 to know the pattern of fish exploitation. A total of fourteen (14) species of thirteen (13) families were identified during the period. The family Claridae is the only family with two species while the other families had only one specie. Mormyrus species were found to have the highest percentage (27.7%) by number while Clarias species had the lowest of 7.54%. The total numbers of species were 1140 species and the corresponding total weights were 198 kg. In the course of the study, fishermen used unregulated mesh sized less than 2 inches. And most of the fish caught were undersized ranging from 0.06 kg to 0.78 kg. The mean catch per unit effort is 3.67. The correlation coefficient, r=0.734 which shows that there is a high correlation between the effort and the yield. The Yield (y)=11.143+3.560 effort which is an evidence of overfishing. Keywords: Fish, Exploitation, Pattern, Overfishing, Lake Geriyo Downloaded from sifisheriessciences.com at 13:43 +0330 on Wednesday October 6th 2021 [ DOI: 10.18331/SFS2014.1.1.2 ] 1,2,3-Modibbo Adama University of Technology, Yola, Adamawa State, Nigeria *Corresponding author's email: [email protected] 10 Ekundayo et al., Study of fish exploitation pattern of... Introduction Tropical artisanal fisheries supply a fisheries. However, the increase has not been considerable amount of animal protein to able to bridge the demand-supply gap (FAO, people living in developing countries (Bayley 2000). Aquaculture has witnessed some & Petrere, 1989). These fisheries are usually developments over the years with the hundreds less impacting on fish communities than large and thousands of commercial farms and commercial and industrial fisheries, which homestead fish ponds. employ a greater fishing effort (Welcomme, Nigerians consume some 1.3 million 1985). Similarly, South America presents a metric tons of fish a year including up to great diversity of freshwater fishes that forms a 700,000 metric tons of imported frozen fish huge available fishing stock (Böhlke et al, (Miller, 2004). According to aquaculture and 1978; Lowe-McConnell, 1984). inland fisheries project newsletter, April 2004, Fisheries and associated activities have Nigeria has 14 million hectares of inland water been a major way of life in coastal much of which lack proper management. communities in Nigeria. Of an estimated 120 Nigeria could be self sufficient in fish million people in Nigeria, about 1% engages in production and be a major exporter of fish if fisheries and over 24 million Nigerians depend the over 14 million hectares of Nigeria’s inland on fisheries for their livelihood (Moses, 2000). water bodies are developed and properly Fisheries contributed about 4.5% & 0.5% managed (Abiodun et al, 2005). respectively to the national GDP and export Rivers are rich aquatic ecosystems that earnings (Moses, 2000). Total export earnings are coming under an increasing amount of from fish was USD 50 million while the strains from human exploitation. Humans have import value was USD 375.03 million in 2001 developed a general attitude that most water (Federal Department of Fisheries. FDF, exist to provide us with something. Rivers are pers.com). Fish provide cheap and quality no exception to this and are suffering directly proteins to Nigerians. However, according to and indirectly from the increasing pressure of Amao et al, 2006, fish contribute only 36.6 gm man’s resource exploitation. Unfortunately, per day in the net protein utilization in strategies for managing the exploitation of Nigerian homes, a level still below the fisheries resources have too often been aimed recommended requirement by the World at short term gain, ignoring the long term Health Organization. This consumption consequences of human activities in order to represents only 20%-30% of the total annual maintain a sustainable usable yield from the Downloaded from sifisheriessciences.com at 13:43 +0330 on Wednesday October 6th 2021 [ DOI: 10.18331/SFS2014.1.1.2 ] protein consumed in inland states and over water and associated ecosystems. It is 80% in coastal communities (FAO, 2000a). important to realize that fish are not infinite The demand for fish outstrips the local resource. They require good long term production. Available statistics shows that the management and protection from over growth in fish production is due to the exploitation. increased activities in aquaculture and artisanal Journal of Survey in Fisheries Sciences1(1) 2014 11 Most artisanal Fishermen in Nigerian including rivers, which are major fishery rivers exploit a large number of fish species resources. Some of the concerns are: using a range of fishing gear (consisting of The increased capacity to exploit fish lines, nets and traps), each adapted to stocks due to increased demand and effort particular species life stages and habitats. Use (time at river, number of boats) and of the gear varies from season to season in improvement in fishing technology. such a way that nearly all life stages of species Significant decline in fish stocks seen are vulnerable to capture. This type of multi globally and in Nigeria. species, multi gear fishery is especially The destruction or alteration of spawning difficult to survey and does not yield readily to and nursery grounds through fishing practices standard mesh dependent methods of control. or coastal development. The growing population density put The lack of field monitoring for some pressure on inland fish resources and has fisheries and lack of information on the many tended to increase over the whole continent species fished. over the last 20 years (Welcomme, 2003). As The death of many non commercial fishing effort increases, fishing impacts, fish species or by-catch in some fishing fleets such assemblages by successively eliminating the as turtles. Changes in the structure of fish large individuals and without good populations by reduction in the numbers of management, leading to a decline in fish grazing fish or predator species may adversely production in the subsequent fishery affect the ecology of freshwater habitats and exploitation. Unfortunately, the history of there is a need for some knowledge in this management of inland fisheries worldwide area. shows generally low success rate in containing Unsound fishing methods-trawling is the growing pressure on fish stocks. This was regarded as one of the most environmentally mainly because of the centralized nature of the dubious fishing methods. traditional managements whereby all the It is estimated that 70% of the water natural waters were regulated by the central resources is trawled at least once a year, governments with little attention to the impacting in the bottom living (benthic) differing biological and ecological needs of the communities. Compared to other fishing fish stocks and the social and economic nations, Nigeria appear to be lagging in conditions of the fisheries. development of selective fishing gear. Fishing is one of the most important and Lack of exploratory data for effective Downloaded from sifisheriessciences.com at 13:43 +0330 on Wednesday October 6th 2021 [ DOI: 10.18331/SFS2014.1.1.2 ] valuable marine industries. However, there are stock management, negligence on the part of a number of growing concerns about problems the regulatory bodies with regards to data with the management of fisheries resources collection have made clear impossible to know and fishing methods which are placing precisely how much fish is taken from lake excessive strain on the water ecosystems, Geriyo daily, monthly, or annually. Therefore, lack of substantial data implies poor 12 Ekundayo et al., Study of fish exploitation pattern of... management. And the trend of fish catches is water ecosystem. Similarly, discard is also a on the decline due to over harvesting among problem because the by-catch are released or other factors. According to Millennium returned to the river either dead or alive. The Ecosystem Assessment (2006), capture live ones released are somehow stressed. These fisheries nationwide is undergoing stock problems make the conservation and depletion. management of the fisheries resources Illegal, unreported and unregulated impossible. (IUU) fishing is an economic problem that The need to study the exploitation pattern takes place in lake Geriyo. It occurs in at the lake Geriyo is highly imperative. It has virtually all fisheries given that some been estimated that most of the world’s major fishermen don’t report their catches, their level inland fisheries are now at their maximum of fishery is hard to quantify. However catches level of exploitation (FAO, 1995). of some species are thought to be many times Furthermore, Welcomme and Bartley (1997) more than the permitted level due to IUU have indicated that catches from inland fishing. IUU fishing includes: fisheries are in decline due to the deteriorating -Fishing in contravention of laws and quality of the aquatic environment and poor regulations of a community, state, country or management. an international agreement. The information on the exploitation -Misreporting catches to the relevant authority. pattern at the lake Geriyo reveals the need for -Fishing in a way that undermines the conservation of the fisheries resources management effects to conserve species and available for a long term sustainable ecosystems.