The lionfish, a longstanding showstopper in home aquariums, is a flourishing invasive species in U.S. Southeast and Caribbean coastal waters. One way to help. The development of lionfish-specific traps was listed as the top priority at this meeting. Ranked second was the need to better understand what type of harvesting. Lionfish have become the poster child for invasive species issues in the lionfish symposium at the meeting of the Gulf and Caribbean.
Invasive Lionfish Are Like a Living, Breathing, Devastating Oil Spill
Importantly, Green et al. While spatially restricted culling can effectively reduce lionfish density, there is a lack of key metrics, such as the relationship between effort and percent of the population removed to assess the efficiency of this approach Frazer et al.Invasive Lionfish Control
Marine resource managers in the Caribbean, working under budget limitations, would greatly benefit from these metrics as it would be possible to know the effort needed to achieve specific removal targets. A framework to determine the fishing effort required to achieve reductions in lionfish densities, consistent with threshold levels estimated by the model proposed by Green et al. Here we aim to develop such a framework to aid in the effective and efficient culling of lionfish.
Effectiveness of removals of the invasive lionfish: how many dives are needed to deplete a reef?
To estimate the effort required to reduce lionfish populations by a given percentage, as specified by the difference between the initial and target densities, we followed a three-step approach. First, we culled lionfish populations at multiple sites by conducting removal dives over consecutive days and monitored changes in catch per unit effort at each site over time.
- Effectiveness of removals of the invasive lionfish: how many dives are needed to deplete a reef?
Second, we used a depletion model and the aforementioned data to estimate initial lionfish population sizes and lionfish catchability at each site. Finally, we integrated the depletion model results from all sites into a simple exponential model to determine the percentage of the initial population removed for a given amount of effort. Our proposed framework can be easily implemented using data already collected in common culling efforts and as such could be incorporated into existing removal strategies.
Methods Study site We sampled seven sites on Turneffe atoll But in reality, nobody knows. Researchers who study lionfish genetics say that the current invaders are all very similar, genetically, which indicate that the current population came from just a few rogue individuals.
One study puts the number at about eight original females. Others say it only requires three.
Smithsonian reported on the invasion in But soon those lionfish began to breed a dynasty. They laid hundreds of gelatinous eggs that released microscopic lionfish larvae. The larvae drifted on the current.
They grew into adults, capable of reproducing every 55 days and during all seasons of the year. The fish, unknown in the Americas 30 years ago, settled on reefs, wrecks and ledges. Everywhere the lionfish arrives, it begins to slowly nibble away at the local flora and fauna. And since nothing eats it, it creeps along, much like an oil spill, until some sort of external force comes in to clean up.