There’s a new kid in town: lionfish invasion of the plankton

Abstract

Invasion of the western Atlantic Ocean, Caribbean Sea, and Gulf of Mexico by the Indo-Pacific lionfish, Pterois volitans/miles (Scopaenidae), has caused well-documented critical changes to coral reef ecosystems throughout the region. Most efforts to quantify these changes have focused on the charismatic adult stage; much less is known about the pelagic larval stage. While dispersal by the larval stage has likely been the main contributor to the rapid population expansion throughout the region, there are very few documented cases of larvae being collected anywhere in the invaded region where adult lionfish are abundant. We compared ichthyoplankton collected using identical sampling gear from the Straits of Florida in 2007–2008 (pre-lionfish population expansion to the Florida Keys) to those collected in 2014–2015 (during the ongoing expansion), providing the opportunity to test for a temporal change in the ichthyoplankton. Despite a substantially greater sampling effort in 2007–2008 [total of 938,126 m3 of water sampled compared to approximately 144,013 m3 (~ 15%) sampled in 2014–2015], we collected no lionfish larvae in 2007–2008, whereas in 2014–2015, 76 larvae were collected. The overall mean density in 2014–2015 of 0.4–0.7 lionfish larvae 1000 m−3 is comparable to a number of common reef fish families and is likely beginning to have an ecological impact on plankton constituents. As the invasion continues, additional studies of the ecological role of lionfish larvae in the plankton are warranted.