Two studies published in the journal Ecology say that fish provide more nutrients to marine ecosystems than any other source, according to a news report at AthensPatch. Primary food sources such as sea grass and algae can't thrive without phosphorous and nitrogen, which fish excrement provides.
Study teams compared sites where the number of fish differed. They built small and large artificial reefs in several areas and monitored them for two years.
Sea grass around the larger sites, which attracted more fish, grew much faster and the surrounding zone contained more nutrients, “nearly a four-fold difference,” the article stated.
Scientists say they plan to look next at whether increasing the number of reefs increases productivity commensurately at the larger ecosystem level.