We have a number of projects going on at the moment. One project is looking at urchins and how they are affected by predators. It is not only academically interesting to understand urchin predator-prey dynamics. Urchins play an important "role" in kelp forests as they are voracious grazers. Unchecked by predation, urchins may be capable of consuming so much kelp that they completely transform the ecosystem from complex three-dimensional structure to much simpler "urchin barrens." If the habitat is changed, this will have consequences for other species by altering food availability, shelter, and so forth. Some urchin species are also commercially important, or provide food for fished species. Predators of urchins include spiny lobsters, sheephead, and other large fishes.
Other ongoing work involves the California spiny lobster, Panulirus interruptus. Spiny lobsters tend to live in a limited geographical area, but it is unclear how big their "home range" is exactly. Lobsters typically shelter during the day and travel after sunset in seatch of food, mates, or shelter. One study underway is looking at the distance and patterns of these movements. Spiny lobsters represent one of the larger fisheries in Southern California. In an effort to protect biodiversity, conserve habitat, and sustain fisheries, "no-take" marine reserves are being established up and down the California coast (CA MLPA). If spiny lobsters move around a lot (or have big home ranges), marine reserves may have to be larger to protect the species. Other work in our lab on spinies includes a collaborative project with the California Department of Fish and Game, investigating lobster populations in the San Diego Bay.Still other research is looking at food web interactions in kelp forests up and down the California coastline. There is contention over what factors are most important in controlling the structure of ecological communities in these rocky-bottom ecosystems. These factors are generally split into "bottom-up," which includes things that affect plant/algae growth, and "top-down," the processes of predation and herbivory. Obviously both of these broad processes are important, but their relative contributions are unclear.
Another project is examining abalone populations, seeking to understand how connected different populations are (in other words, how "open" or "closed" the populations are). Most marine species have a planktonic life stage in which they are more-or-less subject to the currents. Eventually they settle out and either live at the ocean floor or swim about water column. For many species, including abalone, it isn't perfectly clear how much the populations disperse and how genetically distinct sub-populations are.
Kelp forests aren't the only place we play - we also do research in seagrass beds, which are mainly in shallow soft-sediment areas, such as bays and estuaries. Current seagrass studies in our lab focus mainly on predator-prey dynamics. Seagrasses are touted as classic "nursery habitat," meaning simply that juveniles of lots of species live there because of the high levels of primary productivity. Many species that are found as adults in other environments may spend the early portion of their life amongst seagrasses. Lots of fish species here eat small crustaceans which in turn nibble on algae. This algae competes with seagrass for light and space. So, understanding how predation works under different conditions is important for the health of the entire ecosystem, as well as neighboring ecosystems.This brings me to my research interests! I'm planning on looking at how different factors affect the "health" of seagrasses and their animal communities. Soft-sediment ecosystems have the ability to transition from dominance by algae/plankton to seagrass and vice versa, representing "degraded" and "pristine" ecosystems respectively. In short, I'd like to examine whether these transitions are gradual or abrupt. If they are abrupt, what is the breaking point? How hard is it to transition from one to the other? Perhaps more importantly, can the species living within seagrass beds mediate transitions between seagrass-dominance and algal-dominance? The evolution of my research ideas is ongoing, but this is the general direction that I would like to take my work.
