Many people have observed the striking increases in sharpnose pufferfish on Caribbean reefs this year. You can read accounts of the explosion here and here (hint: click “next message” to scroll through them). The sharpnose puffer is a small (3-4 cm), goofy (or cute depending on your perspective) fish that hovers around the bottom of reefs like little helicopters. My lab surveyed 20 reefs in Belize in May and we were struck by their densities. At several sites, they were literally the most common fish! Their antics kept us all entertained as we performed our surveys.
Such regional population explosions are not uncommon. I worked on a massive explosion of subtidal mussels with Jon Witman in the Gulf of Maine when I was a PhD student in the mid 1990s. We surveyed dozens of sites off Rhode Island, New Hampshire and up into Maine, many miles offshore. Everywhere we went, the coverage by tiny mussel recruits was near 100%. But within months, their predators responded and sea star populations, having gone through their own explosion, gobbled them up (Witman et al 2003).
Regarding the sharpnose pufferfish phenom, our otherside video of the month prize goes to Drew Wohl who documented the plight of the sharpnose puffer in a short film that includes dire warnings and sad music to accompany the puffer-death-spiral.
Canary in a coal mine? Caused by coastal development? Personally, I really doubt it. In Belize, the puffers where everywhere, including inside fully-protected reserves and on reefs tens of miles from shore and people. In fact the highest densities (64 individuals per 100m2) were on Glovers Reef, just east of the WCS research station in a no-take reserve.
Witman, J.D., et al. (2003) Massive prey recruitment and the control of rocky subtidal communities on large spatial scales. Ecological Monographs 73, 441-462