Most divers know of the invasive lionfish problem facing the Tropical Western Atlantic and of the role REEF has played in addressing education, outreach, research, and control. REEF has been a leader in addressing the invasion across the region and across many different platforms from government control plans to on the ground derbies and market development. REEF members have been a big part of these efforts through their participation including specially organized Lionfish Field Surveys. Beginning in 2009 in partnership with REEF Board of Trustee, Peter Hughes, annual projects around the region have gathered data on lionfish populations and removed thousands of lionfish. These projects also provide important data and research samples to universities and government agencies to help us better address the invasion.
During the week long projects, either live-aboard or land based, team members are presented with training and opportunities to remove lionfish through spearing or hand netting. All collected lionfish are measured and some dissected on site to get valuable biological and impact information and some fish are prepared for team and public tastings to help promote the market for lionfish as a food fish. Team members can get fully immersed in as much of the collecting and research activities as they would like. Divers not wanting to take part in removals, still provide valuable sighting information and conduct REEF fish surveys to augment the long term data used to look at ecological changes.
A few examples of REEF project data include the 4 year project in Belize which documented the progression of the invasion. From zero fish seen or collected during the first year of the project to over 500 fish removed in a single week during year three, divers were able to document both the incredible explosion in numbers but also in sizes (Figure 1).
More recent projects (2014-2015) in the seldom dived areas of the southern Bahamas indicated that the numbers of fish may vary depending on the location, but the size distribution in unremoved areas is almost identical (Figure 2).
Finally, land-based work in Curacao over the last three years (2013-2015) is showing the effects of removals and what happens when removals stop. With regular diver removals throughout the year, the average sizes of lionfish were reduced by more than 20% resulting in a reduction in predation impacts to native marine life of 37-55% and a reduction in reproductive output of more than 64%! Following the cessation of removals, however, sizes returned almost exactly to pre-removal levels in only a single year.
Future projects in Curacao, Utila and the Bahamas are focusing not only on how many lionfish are present, but also on the effects of removals or lack of removals are having. The 2016 Utila trip will be surveying areas of the Bay Islands that are seldom surveyed including some of the offshore seamounts and the Cayos Cochinos area which is more remote. The Curacao trip in 2016 will be our fifth year of data gathering and removals and in 2017 we will focus on both revisiting previously surveyed sites for removals as well as taking a second boat of fish surveyors to compare non-removed areas and look at the impacts of removal on the native fish communities. In 2017, we will again explore the southern Bahamas aboard the Explorer Ventures live-aboard to look at completely unexploited lionfish populations. All of the lionfish trips are co-led by Lad Akins and Peter Hughes and a great way to combine research and removals to help address a region-wide problem.