Coral crisis in the Caribbean

The introduction and interview with Michelle Paddack, Ph.D. conducted by Katherine Cure and posted on emagazine.com:

Introduction
A recent study showed declines in coral reef fish along the entire Caribbean. The study, which pooled data from over 300 reefs and 273 fish species, shows declines in both fish we catch and those we don’t. These falling species numbers are thought to be happening in response to massive declines in coral cover along the region since the 1970s. The findings, by lead researcher Michelle Paddack, were published in this year’s April edition of Current Biology. Meta-analysis—the technique used—analyzes the result of multiple studies by pooling data. The methodology is a powerful tool for summarizing research done over long periods of time by multiple researchers. Paddack’s quest, which included visits to all major marine labs in the Caribbean, looked at surveys from 48 different projects, some dating back to 1955. Most data used was unpublished, and required digging—asking hundreds of researchers for their data, and pulling in collaborators like Peter Mumby and Ross Roberston, renowned researchers in the field of coral reef fish ecology.

E Magazine: Tell me about the declining fish populations in the Caribbean, and what you have discovered.

Michelle Paddack: What we are seeing in coral reefs is a ‘fishing down of the food web,’ a term introduced by fisheries biologist Daniel Pauly some years ago, meaning that we fish first the predatory fishes and then start collecting fish from lower trophic levels. At the beginning of this dataset, heavy fishing was common in the Caribbean and mainly targeted large predators; only recently has effort shifted into herbivorous fish, so we are just seeing that decline.

But the really significant thing that I am seeing is that the decline is occurring both for fish species that we fish and those that we do not fish, and the rate of change in both is pretty similar. This suggests that it’s not just human fishing pressure causing these declines. Declines may be due to effects of declines in coral cover, which we know to be about 80% since 1970. It may be that this impact is only now starting to affect more fish species, like, for example, very small cleaner fish, which are declining very strongly.