Introduction
Overfishing occurs when marine species are harvestable at a faster rate than they can reproduce. It is the harvesting of fish below an acceptable level. This occurs in all water bodies such as ponds, lakes, and seas. Overfishing leads to depletion of resources, reduced biological growth rates, and low biomass levels. Sharks are the common type of fish that are over-harvested. Overfishing of sharks results in a disturbance of the marine ecosystem. Overfishing in oceanic waters is now recognized as extremely widespread and the causative factors, especially the economic factors, are well known. For a useful analysis of overfishing, data on the productivity and identity of fish stocks is essential. For, most countries, neither is generally available, and there is an urgent need to gather these basic data. The conditions of the ecosystem determine the ability of fisheries to recuperate after overfishing takes place. Freshwater ecosystems include lakes and ponds (standing-water ecosystems), rivers and streams (flowing-water ecosystems), and marshes and swamps (freshwater wetlands).
However, freshwater ecosystems occupy only about 2 percent of Earth’s surface, and all the marine species fight for their survival in these ecosystems (Clover, 2008). Overfishing is a common practice that has been taking place in many parts of the world for a long period. This paper will look at the fish demand and consumption trend, types of fishing, and acceptable levels. It will also look into the ways that can be employed to conserve and alleviate the problem of overfishing.
Fish Consumption and Demand
More than 200 million people depend on fishing for their livelihood in most developing countries. One out of every five people depends on fish as the primary source of protein. According to the UN, fish farming has been growing rapidly than all the other animal food-producing sectors. However, statistics show that fish are being over-harvested and are also affected by environmental degradation. This will soon lead to the depletion of fisheries causing threats to the food supply of millions of people who depend on fishing (Clover, 2008). The UN agencies led by secretary-general Johannesburg launched a plan in 2002 to help in the protection of the fisheries. The plan was aimed at the establishment of Marine Protected Areas (MPAs). MPAs hold the answer to the conservation and boosting of fish stocks. For a long time, the problem of overfishing has been ignored and focused directed to other biodiversity dilemmas such as deforestation, energy resource exploitation, and desertification (Clover, 2008). Fish demand has been increasing at a high rate than its supply leading to increased prices and overfishing. The prices of fish have gone higher than the prices of other animal products such as beef. Fish farming has become one of the attractive investments to both the government and entrepreneurs to the disadvantage of fishing communities and small-scale fishers. As a result, most of the fish species have been depleted or are yet to be depleted.
Types of Over Fishing
Three types of overfishing have been recognized, these are, recruit overfishing, growth overfishing, and ecosystem overfishing. Recruit overfishing is the depletion of the mature adult population to an extent of denying it the reproductive capacity. The number of mature adults left is not enough to produce offspring. This type of overfishing can be prevented by increasing the spawning stock biomass to a target level. This can be achieved by the introduction of suspensions, quotas, and minimum limits on the fish population (Ebbin, Hoel, & Sydnes, 2005).
Growth overfishing is a situation where fish that are smaller than the average size are harvested. This kind of harvesting does not yield much as would have been expected if the fish were allowed to grow to a certain size. Growth overfishing can be controlled by reducing fishing transience to significantly low levels and increasing the size of harvested fish to gain the maximum yield per recruit. Ecosystem overfishing is a situation where the ecosystem balance is changed as a result of overfishing.
Acceptable Levels
Some biological terms have been used to define what is meant by acceptable levels of fishing. Biological overfishing occurs when fish are harvested from the water at a very high rate than the time allowed for stock replenishment. The reproduction process declines and the total population decreases. Another biological term used to define acceptable levels is bioeconomic overfishing. This is a situation whereby the cost of fishing is determined by the acceptable catches. Fisheries are considered to have been overfished when the maximum economic yield is lower than the catches using the maximum resource rent. In simple terms, it means that fish are being harvested quickly than they are profitable (Ebbin, Hoel, & Sydnes, 2005).
Management and Conservation
Many fish stocks are at or near a state of decline throughout the world due to overfishing. It is, therefore, necessary for regional fisheries management organizations to take conservation and management measures, including non-discriminatory trade-restrictive measures. Conservation and management measures should be aimed at preventing overfishing while achieving, continuingly, the optimum yield from each fishery. They should be based upon the best scientific information to ensure efficiency. Individual fish farms should be managed as a different unit from other fish farmers such as the government and entrepreneurs. These measures should not be discriminative in any way and every fish farmer should be allowed to maintain stocks about his farming abilities (Munro, et al., 2004).
Management and conservation measures are aimed at establishing ways of preventing the current fisheries as well as investing in others. The community should be provided with an awareness of the need to conserve and prevent their fish farms from exploitation. If the present fisheries are exploited, tomorrow’s species will be engendered which may even become extinct. It is up to the government to employ measures aimed at controlling fish harvesting in freshwater bodies. If fish farming is well managed, it can be a profitable business especially now that demand for fish is high.
Mitigation Against Over Fishing
With the growing world population and the dependency on fish farming, it is almost impossible to solve the problem of overfishing. However, some mitigation measures have been put in place to save some of the depleted fisheries and prevent the collapse of others. These mitigation measures include the Harvest Control Rule (HCR) which has been introduced in the major fisheries all over the world. This rule has some management principles that have to be adhered to when harvesting fish. It puts restrictions on the size of fish that should be harvested and the acceptable levels in each fishery.
Another mitigation measure is the use of fishing quotas. Fishermen are allowed to take only a specified amount of fish from each fishery. Some areas are declared as no-go zones making fishing illegal to give the fish ample time to recover and reproduce. Control of consumer demand and consumption behavior can work as a mitigation measure this is because fish has become a major source of food to many people. To control fish consumption, consumers have to be enlightened on the availability of other sources of animal food and on the importance of conserving fisheries (Netherlands Institute for the Law of the Sea, 1994).
Overfishing is often related to a change in lifestyle. Some groups of people have developed regulatory strategies which seem to avoid over-fishing, but communities with excess resources or which have not experienced resource scarcity may not have developed management measures. Where resources are limited, problems may occur where different communities exploiting the same resource come into contact. Mitigation is theoretically possible against most negative impacts of development projects which influence freshwater biodiversity.
Conclusion
Overfishing is a problem that is affecting many parts of the world. It is the depletion of marine species to an extent of denying them their capacity to reproduce. For many years people have been depending on fish farming for their livelihood and food security. More than 200 million people consume fish as the main source of food. This increased demand and consumption patterns have led to the over-harvesting of fish. There are three types of overfishing: recruit overfishing, growth overfishing, and ecosystem overfishing. To recover the depleted fisheries and prevent others from being depleted, the government has to establish conservation and management measures.
Reference List
Clover, C. (2008). The End of the Line: How Overfishing Is Changing the World and What We Eat. California: University of California Press
Ebbin, S. A., Hoel, A. H., & Sydnes, A. K. (2005). A sea change: the exclusive economic zone and governance institutions for living marine resources. New York: Springer
Munro, G. R, et al (2004). The conservation and management of shared fish stocks: legal and economic aspects Volume 465 of FAO fisheries technical paper. Food & Agriculture Org.
Netherlands Institute for the Law of the Sea (1994). International organizations and the law of the sea: documentary yearbook, Volume 10 Graham & Trotman/Martinus Nijhoff