Background
The red lionfish (Pterois volitans) is a common predatory fish on Indo-Pacific reefs. However, in the late 1980’s, a population was established in the Western Atlantic due to aquarium fish being released. Many efforts have been made to mitigate their presence, but one of the greatest problems faced by biologists is the sheer area that these fish now occupy. Research about the preferred habitat of P. volitans could aid in fine-tuning deterrence approaches.
hypotheses
I hope to determine what factors in an ecosystem are most conducive to sustaining lionfish. Currently, I have two hypotheses as to what drives their presence on reefs:
- Lionfish presence on reefs is affected by octocoral abundance.
- Lionfish presence on reefs is affected by rugosity.
Predictions
- I expect lionfish to be more likely to be found on reefs with high octocoral abundance. This effect would likely be due to their cryptic coloration allowing them hide amongst sea fans, thereby making it easier for them to ambush prey
- I believe lionfish are more prevalent on reefs with high rugosity. The relief and ledges on these types of reefs provides them a place to corner prey and hide from predators.
Methods
- A great deal of data already exists about the octocoral abundance and rugosity of the reefs we research. However, it is important to make sure this information is up-to-date after Hurricane Irma, so more data will be gathered.
- Percent cover of octocorals will be measured via CPCe (Coral Point Count with Excel extensions) analysis of substrate pictures.
- Rugosity will be measured using the chain and tape method.
- Lionfish counts will be gathered by following a 50m transect tape across each reef, looking 10m out to either side of it for fish.
Analysis
- Using the data on percent cover of octocorals and rugosity, I will determine the preferred values of each for lionfish.
- Once these values are determined, if the octocoral cover and rugosity are known on any reef in the Florida Keys, I will be able to make a rough estimation of the likelihood that lionfish will be present without having to run fish count surveys on that reef.
References
1. Green, S.J., Tamburello, N., Miller, S.E. et al. Coral Reefs (2013) 32: 413. https://doi.org/10.1007/s00338-012-0987-8
Credits:
Created with images by G1les - "red sea lionfish scuba" • dimitrisvetsikas1969 - "cyprus ayia napa lover's bridge"