Graduate_Research

My research interests span the range of marine ecology to include basic ecological questions about larval dynamics such as how larval behavior and oceanography influence dispersal, and how dispersal influences population and community structure; to questions about humans impact nature such as how global warming effects community species’ range limits. I am interested in using innovative techniques such as natural larval tags to address some of these questions. Natural tags, a multivariate measure of trace elements in calcified structures like larval shells, otoliths and statoliths, can be used to track dispersal of invertebrate larvae.

The movement of larvae among spatially separated populations, can be a driving force in the persistence of marine populations. The recent range extension of Kellet’s Whelk, Kelletia kelletii, illustrates the need to identify natal origins of larvae to understand connectivity among historic and new populations. K. kelletii ranged from Isla Asuncion, Mexico to Pt. Conception, California, but since the 1980s have been found as far north as Monterey Bay. Two possible explanations have been proposed to explain this, 1) an episodic reversal of prevailing current patterns during the spawning season, facilitating northward transport of larvae from south of Pt. Conception, or 2) warming of northern coastal waters, allowing larvae produced at northern sites to survive. The aim of this study is to use natural tags in statoliths of larval K. kelletii to determine whether northern populations are reliant on larvae from south of Pt. Conception for persistence. I will build an atlas of tags from potential source populations throughout K. kelletii range, over multiple years to determine spatial and temporal variation in tags. Then I will collect juveniles from Monterey Bay and compare the natal core of statoliths with the larval atlas to determine where juveniles were born. I predict that most larval recruitment in Monterey Bay originates from adults in the northern region with some detectable levels of larval exchange among regions. Kellet’s Whelk can act as model species for understanding population connectivity in marine reserves and detailed knowledge of larval dynamics will aid future management of fisheries and temperate reefs in California.