Research

We research global coastal change within three major realms:

Harmful algal blooms:cover-imagev2

Our group is interested in understanding the functioning of aquatic ecosystems and how that functioning can be effected by man or can affect man. We focus much of our efforts investigating the organisms at the base of aquatic food webs, phytoplankton, and have been particularly focused on harmful algae. We investigate harmful algal blooms (HABs) caused by multiple classes of phytoplankton (cyanophyceae, dinophyceae, bacillariophyceae, pelagophyceae, ulvophyceae) in diverse ecosystems (e.g. estuaries, lakes, coastal ocean) using multiple approaches (field studies, laboratory experimental, field experiments, molecular investigations, modeling). Collectively, these studies have identified how nutrients, CO2 levels, zooplankton grazing, viral lysis, allelopathy and grazing by bivalves influence the dynamics of HABs caused by genera such as Alexandrium, Anabaena, Aureococcus, Aureoumbra, Cochlodinium, Dinophysis, Microcystis, Pseuodonitzschia, and Ulva.

Interactions between climate change and eutrophication:oa-clams

The second major research focus within our laboratory is understanding how climate change and coastal ocean acidification affects marine organisms and ecosystems. The combustion of fossil fuels has enriched levels of CO2 in the world’s oceans and decreased ocean pH. The degradation of anthropogenically-enriched organic matter in coastal ecosystems seasonally has a similar effect on ocean chemistry today, while concurrently depressing dissolved oxygen levels. The continuation of these processes can alter the growth, survival, and diversity of marine organisms. Within this realm, we have been engaged in studies investigating how future and current coastal ocean acidification effects the survival and performance of algae and larvae from bivalves and fish indigenous to North America. We further strive to understand how co-occurring stressors related to both climate change and shallow coastal ecosystems (hypoxia, thermal stress, algal blooms) may act and interact to affect the performance of marine animals.

Phase shifts in coastal ecosystems:img_3894

A third area of interest of my lab group is the understanding the ecological functioning and trophic status of shallow marine ecosystems. We investigate how anthropogenic activities such as eutrophication and the depletion of fisheries may alter the natural ecological and/or biogeochemical functioning of coastal ecosystems. In many cases, we have explored the quantitative importance and impacts of various nitrogen loading pathways on primary producers or the interactions and feedbacks among nutrient delivery pathways, pelagic phytoplankton communities, benthic filter feeders, and benthic autotrophs such as seagrass. All of these studies have important societal impacts and relevance for the management of shallow, coastal ecosystems.