Research

Current Research

Ichthyoplankton metrics as indicators of ecosystem change

Indices of climate change that rely on communities of organisms are a necessary next-step in predicting the impacts of climate change on ecosystems. The objectives of this study are to 1) synthesize available ichthyoplankton data for the Gulf of Mexico and coastal southeast U.S., 2) identify patterns of change in composition and abundance of key fish taxa, 3) examine the relationship between patterns in fish abundance data and environmental variables, and 4) develop and test an index of climate change based on patterns in key fish taxa.

Ecosystem monitoring to determine impacts of hypoxia in Chandeleur Sound

Episodic hypoxia has been documented in in Chandeleur Sound since 2008. Hypoxic water in the Sound is an extension of the larger hypoxic region that occurs in the northern Gulf of Mexico each summer. Recent efforts have been made to characterize the scale of hypoxia, but little is known regarding the impacts of the hypoxic zone on the Chandeleur Sound ecosystem and recreational fishing in the region. The objectives of this study are to develop a long-term monitoring program in Chandeleur Sound focusing on benthic invertebrates and juvenile fish. This monitoring program will be used to identify patterns of change in composition and abundance of recreational fisheries species and their prey resources, and to examine the relationship between aforementioned patterns and hypoxia intensity/duration.

Decision support tools for adaptive management of invasive lionfish

Indo-pacific lionfish Pterois volitans are among the most successful invasive species in human history. An adaptive management plan that considers local and regional action, as well as the impacts of management actions on socio-economic concerns, is necessary to address this complex issue and to ensure the latest science is incorporated into management. Along with collaborative partners from regional wildlife managers, NOAA, and the tourism industry, we are developing a decision support tool that incorporates information from field and laboratory experiments, bioenergetics models, and data sources that can be accessed and used by fisheries managers (survey, buoy, and satellite data).

Benthic production in the Northern Gulf of Mexico

Ecosystem-based management of marine and coastal resources in the Gulf of Mexico requires an understanding of the flow of energy through the food web, yet benthic production is rarely incorporated into ecosystem models. This project will develop a benthic production model for the northern Gulf of Mexico under various scenarios of hypoxia duration and severity. Field and laboratory experiments on key benthic species support the modeling effort.

Past Research

Incorporating habitat quality and climate into albacore tuna production estimates

There is some evidence that patterns of climate variability have impacts on habitat availability for albacore tuna. However, the impact of changing climate and current structure on habitat for albacore tuna is not fully understood because habitat quality for albacore tuna has yet to be quantitatively and mechanistically defined. We used a spatially explicit, bioenergetics-based modeling approach to quantify the quality of pelagic habitat for albacore tuna in the northern portion of the California Current, a highly variable region characterized by large scale climatic oscillations.

User-driven tools to predict and assess effects of reduced nutrients and hypoxia on living resources in the Gulf of Mexico

The northern Gulf of Mexico (NGOMEX) experiences an annually recurrent region of summer hypoxia. Links between seasonal hypoxia in the NGOMEX and fish production are unclear, but managers and stakeholders alike need readily available and quantitative tools to predict the effects of planned nutrient reduction strategies aimed to minimize the hypoxic zone.  This research examined the impact of hypoxia on trophic interactions between pelagic fish in the NGOMEX.

Marine benthic predator-prey interactions and global change

An understanding of the mechanisms by which habitat loss and storms impact predator-prey interactions may elucidate the fate of individual species in the face of global change. Field survey data, field caging experiments, laboratory mesocosm experiments, time-series analysis, and mathematical models were used to assess the role of habitat, major storm events, and predators on bivalve distribution in the lower Chesapeake Bay.

Ocean acidification and predator-prey interactions

 

Ocean acidification reduces the integrity of marine mollusk shells and interferes with predator-prey interactions. The effect of ocean acidification on predator-prey interactions was examined through two separate experiments: 1) using mud crabs and oysters acidified in situ in acid sulfate soil estuaries in New South Wales, Australia, and 2) using blue crabs and softshell clams acidified in the lab with CO2.