Scientists found that coral ecosystems would not be as healthy as they are if it weren’t for their fish. According to recent findings, the nutrients such as phosphorus found in fish pee help coral reefs thrive.
Study authors found that a mix of phosphorus and ammonium, which is also released by the fish but through their gills, is essential for corals’ survival and week-being. The latest study also revealed that in waters where industrial fishing occurs the levels of these key nutrients are reduced to almost half.
At first researchers were puzzled with the findings but they realized that fewer fish that urinated meant a less nutritious environment for corals.
Jacob Allgeier, lead researcher involved in the study and marine biologist at University of Washington, noted that fish are important for corals because ethey move nutrients around.
Allgeier explained that the marine animals carry a large proportion of nutrients in their tissue and they are also recycling that material. As a result, if fish is gone so are the nutrients from a coral ecosystem.
In the study, researchers analyzed 142 separate fish species in more than one hundred sites across nearly four dozen Caribbean reefs. The study showed that where predator fish were more abundant the smiths of nutrients were optimal.
Across coral reefs where fishing was excessive, nutrient levels were nearly 50 percent lower. Study authors noted that the newly found mechanism highlights the indirect impact of industrial fishing on coral reefs.
The research also revealed that in waters with lower levels of nutrients from fish pee small fish were not fewer. Researchers concluded that the drastic reduction in fish pee was tied to the disappearance of large-bodied fish.
The findings are in line with a study from the 1980s which showed a link between higher growth rates in corals and abundance of fish in the ecosystem. But until now researchers weren’t able to say how exactly fish helped corals develop faster.
Study authors explained that coral reefs are very fragile ecosystems as they run on a “tight” nutrient cycle, thus having nothing to waste. And the cycle largely depends on fish which store nutrients in their tissue and excrete it back in the environamnet.
Image Source: Wikimedia