Genetics Helps Unravel Invasive Lionfish Introduction Scenarios

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A new USGS study finds a lack of evidence to support the widely accepted introduction scenario in which the invasive lionfish originated solely from Florida and identifies alternative introduction pathways. 

Florida has long been considered the primary point of lionfish introduction, but a new U.S. Geological Survey study suggests that the invasive species may have been introduced solely in the Bahamas or North Carolina, or in multiple locations, including the Bahamas, North Carolina, and/or Florida.  

The lionfish is native to the Indo-Pacific region, but were first reported off the Florida coast in 1985. These initial recorded sightings led many scientists and environmental managers to believe that Florida was the invasive fish’s only introduction point before it rapidly spread into the western North Atlantic, Caribbean and Gulf of Mexico.

Scientists at the USGS Wetland and Aquatic Research Center and partners investigated the genetic differences in almost 1,800 lionfish collected throughout the invaded range. Their findings indicate a lack of evidence that Florida was the primary point of invasion, and instead point to three possible alternative introduction scenarios. 

One scenario is that lionfish may have been introduced in the Bahamas, before traveling north via the Gulf Stream to North Carolina and then dispersing south to Florida. Alternatively, lionfish may have been introduced in the waters off North Carolina, subsequently travelling to the Bahamas, Florida, and the Caribbean. The third scenario supports lionfish being introduced at multiple locations, including the Bahamas, North Carolina, and/or Florida.  

Lionfish have disrupted marine food webs and negatively impacted native marine ecosystems. Understanding where lionfish and other invasive species are introduced may shed light on how the species spread. It also helps natural resource managers design and implement effective strategies that can be used to control the invasive species locally or limit it from spreading even further. These findings highlight the complexity of invasive fish introduction and distribution scenarios and how genetic approaches can help guide the response to future non-native marine fish introductions.  

For more information on USGS lionfish research, please visit: https://www.usgs.gov/centers/wetland-and-aquatic-research-center-warc/science-topics/lionfish