Life on the edge: Environmental determinants of tilefish (Lopholatilus chamaeleonticeps) abundance since its virtual extinction in 1882

Abstract

Unlike many temperate marine species that alter spatial or depth distributions in response to environmental change, tilefish (Lopholatilus chamaeleonticeps) has such specific habitat requirements that off the coast of New England, USA, it is restricted to the normally warm-water, upper continental shelf slope, where it excavates and occupies burrows. In 1882, tens of millions of adult tilefish died suddenly following the intrusion of lethally cold Subarctic water into the tilefish habitat. Here we show that the same climate driver implicated in the 1882 event (the North Atlantic Oscillation: NAO) has also affected commercial tilefish landings throughout most of the 20th century by altering slope water temperatures and likely the tilefish's reproductive success. We also show that this temperature-landings relationship broke down in the 1970s coincident with dramatically increased exploitation. Reconstructions of decadal to millennial scale variations in slope water temperatures explain why no mass mortality occurred following the 2010 negative NAO anomaly, despite being similar in magnitude to the NAO anomaly that preceded the 1882 event.