Predator prey relationship7/6/2023 ![]() To explain this in a much simpler way, let’s look at it this way. Large predatory fish such as sharks and groupers are vitally important in marine food webs as they keep numbers of their prey in check by directly limiting the populations. Removal of high-level predators’ results in a degraded marine ecosystem. ![]() Why should we care about the disappearance of large predatory fish? Fishing activities have reduced fish populations in studied reefs causing a severe decline in the species richness of the fished lagoons. In Kenya, one of the major changes in the state of the coral reefs is the dramatic decline in the number and individual size of finfish and very rare shark sightings. A case in point, are the reefs in East Africa, sharks have become extremely rare in these reefs! A study by Coastal Oceans Research and Development- Indian Ocean- (CORDIO) East Africa underwater surveys on reefs in Tanzania, Comoros, Madagascar and Mozambique to assess population densities of large reef associated fish recorded no sharks except for one site in Cabo Delgado, northern Mozambique. ![]() More and more smaller fish are being captured instead and a typical overfished ecosystem will lack apex predators. With the disappearance of large predatory fish, they are now nothing but just old tales. Perhaps if you have lived in a coastal community, some of the tales you heard in the company of old fishermen is big fish stories. Overfishing particularly of predatory species, exacerbated by destructive fishing practices, such as the use of longlines and gillnets, complicated by pollution and global climate has led to changes in structure and function of marine food webs over time. This brings us to the conclusion that overfishing is the most likely reason for the disappearance of large predatory fish. Given that about half the world’s populations live near coastlines, and that the world population is still on the increase, demands for ocean-derived protein continues to increase. Fishermen will automatically go after the biggest fish first but shift to smaller individuals once the bigger ones become depleted. The higher the demand, the higher the fishing effort. The demand for seafood will increase with an increase in human population. Reports have shown that the more people there are in a nation, the fewer large fish exist along their reefs. However, high-level predators such as sharks and groupers are being depleted in the oceans worldwide. Extermination of a species in a naturally balanced ecosystem would not occur as a result of predator-prey interactions. ![]() Predators and prey use a wide spectrum of adaptive strategies to cope with their interactions, such as morphological and behavioral adaptations. When I think about predator-prey relationships I often think of the natural balance that exists in any given ecosystem. UNDERSTANDING THE DELICATE BALANCE OF PREDATOR-PREY RELATIONSHIPS WHEN CONFRONTED WITH OVERFISHING ![]()
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