I focus on four interconnected research areas: the use of sensory cues in settlement site selection; connectivity of the marine environment; behavioral interactions between species; and the effect of anthropogenic changes, such as ocean acidification and terrestrial runoff, on the behavior of marine organisms. These efforts are linked by a common theme: understanding how marine animals sense their environment, how they are able to use this information to make decisions on optimal habitat choice and consequences these behavioral choices have on marine conservation and management in a changing environment.
The roles of biodiversity, benthic community composition, and chemical cues in corals and coral reef fishes' habitat identification.
Our lab's current largest research project focuses on the ability of coral fish larvae to chemically identify and select potential habitat. Up until the late 1990s, most researchers assumed larval recruitment and habitat selection mostly relied on ocean movements rather than larvae actively seeking their habitat (Roberts 1997). Recent research has found that pelagic reef larvae, which go out to sea and then return to the reef, actually rely on a complicated set of sensory cues in active habitat selection (Williams et al. 1984, Leis et al 2011).. Indeed, recent evidence suggests that coral and fish larvae rely on chemical cues emanating from potential habitats. Yet, the exact chemical cues that these larvae use in habitat selection remains largely unknown. In a world where habitat degradation is ever more prevalent, understanding these chemical cues is imperative.
Recent studies suggest that coral larvae are able to distinguish between healthy and degraded habitat and choose to settle on healthy habitat (Dixson et al. 2014). Other studies also suggest that juvenile and larval fish can distinguish between healthy and degraded reefs, with an innate preference for healthy habitats (Dixson et al. 2014).
We are working to expand on these previous studies to gain a better understanding of what chemical cues are used in habitat site selection. In particular, we are working on understanding the role biodiversity and community composition play in influencing larval recruitment. We are looking to test how larval corals and fish at different levels of development respond to combinations of corals and seaweeds and how varying levels of habitat degradation alter this habitat preference. We do this using a variety of techniques both in the lab and at field sites across geographic ranges. Once we understand larval chemical preferences, we then plan to test whether adding them to degraded habitat would cause larvae to choose to settle there. This research has important implications and will allow to better understand how habitat degradation alters marine biodiversity as well as better ways to restore degraded habitats.
The effects of ocean acidification on fish behavior
Our lab is also continuing to study the effect of other anthropogenic influences, particularly ocean acidification, on coral reef fish behavior. As the climate continues to change due to increased carbon dioxide levels in the atmosphere, ocean acidification becomes a more prominent concern. Coral reef environments are considered to be particularly vulnerable. In previous work, Collaborators and I have found that, at near future carbon dioxide levels, fish behavior is dramatically altered. Lab studies have demonstrated that increased carbon dioxide concentrations impair olfactory and neurological capabilities in a variety of coral reef fishes (Munday et al. 2012, Nillson et al. 2012). These increased levels alter learning and behavior to the point that young fish become attracted to the smell of their predators (Ferrari et al. 2012,. These laboratory findings have been further supported using field tests done at carbon dioxide seeps (Munday et al. 2014). More recently, we have begun to focus on the effects of ocean acidification on shark species. Our lab continues to evaluate the effects of ocean acidification on marine organisms.