Regional differences in an established population of invasive Indo-Pacific lionfish (Pterois volitans and P.miles) in south Florida.

David R Bryan,Ashley Siana,Jeremiah Blondeau,Jerald S Ault

doi:10.7717/peerj.5700

Abstract

About nine years ago (circa 2009), Indo-Pacific lionfishes (Pterois volitans and P. miles) invaded the south Florida coral reef ecosystem. During the intervening period of time, there has been substantial research on their biology, life history, demography, and habitat preferences; however, little is known concerning their regional population status and trends in the region. Here, we use a large-scale fisheries independent reef fish visual survey to investigate lionfish population status among three south Florida regions: Dry Tortugas, Florida Keys, and southeast Florida. Density estimates (ind ha−1) have been relatively stable since 2012, and are lower than other areas reported in the western Atlantic and Caribbean Sea. Low, stable population densities in south Florida suggest there may be a natural mechanism for lionfish population control. In the Dry Tortugas, lionfish density in 2016 was significantly lower (0.6 ind ha−1 ± 0.15 SE) than the two other south Florida regions. The Dry Tortugas region has the highest percentage of marine protected areas, the lowest level of exploitation, and thus the highest densities of potential lionfish predators and competitors. In the Florida Keys and southeast Florida in 2016, lionfish densities were greater (5.4 ind ha−1 ± 1.0 SE and 9.0 ± 2.7 SE, respectively) than the Dry Tortugas. Fishing pressure on lionfish was higher in these two regions, but densities of several potential predators and competitors were substantially lower. Despite relatively low regional lionfish densities that can be attributed to some combination of fishing mortality and natural biocontrol, lionfish are still well established in the south Florida coral reef ecosystem, warranting continued concern.

Highlights

Indo-Pacific lionfishes (Pterois volitans and P. miles) are the first non-native marine fish species to become established in the central western Atlantic (Whitfield et al, 2002; Schofield, 2009)
Lionfish density in the Dry Tortugas was significantly greater in 2012 (2.2 ind ha−1 ± 0.5 standard error (SE)) and 2014 (2.6 ind ha−1 ± 0.6 SE) than in 2010 (0.4 ind ha−1 ± 0.3 SE), but in 2016 it declined to 0.6 ind ha−1 (±0.15 SE) (Fig. 2)
In the Florida Keys, density initially increased following the invasion to 6.5 ind ha−1 (±1.2 SE) in 2011, declined significantly during 2012 and 2014, and increased slightly to 5.3 ind ha−1 (±1.0 SE) in 2016

Summary

Introduction

Indo-Pacific lionfishes (Pterois volitans and P. miles) are the first non-native marine fish species to become established in the central western Atlantic (Whitfield et al, 2002; Schofield, 2009). How to cite this article Bryan et al (2018), Regional differences in an established population of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) in south Florida. After the arrival of larval recruits, lionfish became established in south Florida through local reproduction coupled with continued larval recruitment from the eastern Gulf of Mexico, Meso-American, and Cuban reefs (Schofield, 2009; Johnston & Purkis, 2015). Following their arrival in south Florida, lionfish occurrence and relative abundance increased dramatically (Ruttenberg et al, 2012). There is significant concern that lionfish predation on native reef fishes may threaten coral reef ecosystems throughout its introduced range (Albins & Hixon, 2008; Albins & Hixon, 2013)

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Discussion

Conclusion