An interesting fish story brought to us by the good folks at Science Daily. It's the tale of red grouper (Epinephelus morio) in the Gulf of Mexico off Florida. They're apparently in the construction business, and have a lot to say about what shares the community with them. Researchers at Florida State University, reporting in the online Open Fish Science Journal, tell us that the fish dig out and maintain complicated three-dimensional structures that are significant not only to the grouper themselves, but to a wide range of marine life. They show this behavior throughout their lives, with juvenile grouper excavating in inshore habitats and larger individuals working at greater depths.

Young red grouper in Florida Bay were observed removing sediment that had accumulated in solution holes, craters in the substrate that were formed during times of lower sea level as fresh water dissolved away the limestone. The result is to transform what would be a flat, structure-free habitat into one that is complex and three-dimensional. This pockmarked substrate is attractive to a variety of marine life, including spiny lobsters looking for a place to hide. In other words, the red grouper is functioning as something of a keystone species in much the same fashion as gopher tortoises in pine communities.

There is concern that increased fishing pressure on the red grouper could have a cascading effect on the other species that are dependent on it.