Loss of picky fish threatens coral reefs’ food webs – Eurasia Review


Coral reefs around the world, already threatened by rising temperatures due to climate change, are also facing serious challenges from the possible extinction of fish species. According to a newspaper published today in the Proceedings of the National Academy of Sciences, the networks of predatory fish and their prey on coral reefs around the world are remarkably similar, and these predatory fish are more picky than previously thought. These fragile ecosystems become even more fragile when these specialized hunters become extinct.

Coral reefs are among the most diverse ecosystems on earth and provide vital habitats for thousands of species that support the economy and ensure the food and livelihood of millions of people. In the largest and most comprehensive study of its kind, researchers from France and the University of Texas at Austin concluded that food webs in coral reefs are more sensitive than previously thought. The researchers concluded after synthesizing the stomach contents of most species of fish found on six coral reef systems around the world.

The team found that the vast majority of reef fish species are very picky about what to eat rather than opportunistically feeding on whatever they can find. Although reefs are likely to withstand the loss of multiple species of prey, the loss of a single larger species of fish can endanger the ecosystem.

“It is remarkable that we are seeing similar patterns in coral reef systems around the world. Extinctions, especially of larger fish species, can have a significant impact on coral reef systems, ”said Jordan Casey, assistant professor of marine science at UT Austin’s Marine Science Institute (UTMSI) and author of the article.

Many conditions can cause the local loss of fish species, such as: B. Climate change, commercial fishing and pollution. Such a decline in fish can result in increasing numbers of prey remaining uneaten, leading to imbalances in the food web.

“Reefs depend on the efficient use of all living things,” says Simon Brandl, also an author and assistant professor at UTMSI. “If a fish specializes in eating a particular species of snail and that fish disappears, the snail may not be eaten and live happily ever after. This creates a dead end for the food it could provide to other coral reef creatures. Good news for the snail. Bad news for everyone else who lives there. “

The study looked at the feeding habits of more than 600 species found on six different coral reefs near Okinawa, Hawaii, the West Indies, New Caledonia, Madagascar, and the Marshall Islands. Despite regional differences, the food webs showed a strikingly similar structure: 67% of the species were specialized eaters with strong preferences for certain prey, despite the enormous variety of food available on coral reefs.

“Coral reefs are important to humans for a number of reasons,” said Casey. “They are an important source of food for many people. They are also popular travel destinations and economic engines for a number of countries. However, coral reefs can only provide these important ecosystem services if the food webs remain intact. “

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