Coral reefs are one of the most beautiful things in nature, a natural wonder actually. They are all shapes, sizes, and colors; they are the home of many fish species, and they are harmless. The sad part of the story is that they and the marine ecosystem are endangered by man’s reckless actions, such as overfishing.
Fish are depending on coral reefs to survive: they camouflage in order to be safe from predators, as well as to lie at the lurch. On the other hand, coral reefs are also depending on their inhabitants. New research shows that fish provide coral reefs with nutrients that help them grow and develop. How? By urinating and thus releasing phosphorus in the water.
A new study was led by expert Jacob Allgeier (the University of Washington’s School of Aquatic and Fishery Sciences). He and his team found that places where people tend to overfish lack healthy coral reefs. Big fish release the proper amount of nutrients (phosphorus and nitrogen) so that the colorful coral can grow strong. As fish are taken out of the water, coral reefs are left without their nutrient provider. A weak coral reef means smaller changes of survival for fish population. It is a circle that man shouldn’t break.
43 Caribbean coral reefs and 143 fish species were analyzed in order to make the research. Scientists found that overfishing affects 50% of the healthy way in which marine ecosystems work. Sites with larger predator fish had more nutrients than those with small fish.
Lead author Jacob Allgeier talks about this strong dependency:
“Fish hold a large proportion, if not most of the nutrients in a coral reef in their tissue, and they’re also in charge of recycling them. If you take the big fish out, you’re removing all of those nutrients from the ecosystem.”
Fishermen especially seek large fish, so the most exposed species are grouper, snapper, and barracuda, which, of course, lack the most in reefs.
Previous studies showed that a large population of fish helps coral reefs grow even two times faster than a reef which lacks its’ most important, vital inhabitants.
The study was published yesterday in Nature Communications. The aim of the researchers who started the investigation was to draw people’s attention to the effects of overfishing. This action backfires, as there is still man the one that loses most since his actions reduce the fish population and their capacity of reproducing.
Image courtesy of: Wikipedia