Marine ecology and conservation

In addition to tackling questions related to achieving biodiversity outcomes, we also investigate critical questions to inform effective marine conservation.  See below for a sampling of recent research projects.

Connectivity and marine spatial planning

Recent theoretical and empirical evidence suggest that changes in ocean temperature and pH may profoundly impact larval dispersal and population connectivity, yet implications of ocean change for marine reserve planning remain largely unexplored outside of coral reefs. We have developed a conceptual framework for considering the impacts of temperature and ocean acidification on spatially explicit marine conservation activities. Currently, we are studying the relative and interactive effects of warming and acidification on the probability of dispersal in marine systems. This work is critical to developing effective conservation strategies in a changing world.

Adaptive management and ecosystem services in marine reserves

The success of conservation reserves depends on establishing evidence that they are useful policy strategies in the long term. Our work on adaptive management of reserves spans from local to global scales. First, we have embraced the policy implications of marine reserves in developing strategies at international scale (e.g., International Whaling Commission Sanctuaries). While most reserves have focused on near shore and benthic fish and invertebrates, our work has advanced the idea that reserves may benefit wide-ranging species. Second, we are developing predictive capabilities for the management of marine reserve networks. We are currently working with Communidad y Biodiversidad to design and implement integrated conservation and management strategies for marine areas in the Gulf of California. One theme of this work is the development of novel ecological and socioeconomic models to determine the efficacy of marine reserves and the policy changes needed to achieve these goals. Using ecosystem services for evaluating the establishment of a marine reserve network means comparing the value of services with and without the reserves—including the value of the resources in the proposed reserves.

Marine megavertebrates and marine food

Little is known about the ecological role of marine megavertebrates. Our work on marine food webs seeks to elucidate interactions among different trophic levels including top predators, as well as wildlife-fishery interactions, with the purpose to better inform ecosystem-based management efforts that can be applied by local managers. We engage local communities in the study of ecosystem ecology and the implementation of sustainable fishing practices. For example, to understand the impact of whales on commercial fisheries, we develop food web models to examine the potential impact of a reduction in the abundance of great whales on fishery yield. Our approach has been embraced in discussions about establishing appropriate policies for conserving marine megafauna and sustaining fisheries around the globe.

Individual variability and demography

We are interested in identifying mechanistic relationships between animal behavior and demography. Our previous work on sea lions in the Gulf of California allowed us to integrate empirically-based estimates of mating behavior into demographic population models that are used in extinction risk analyses. More recently, we began developing a quantitative index of sociality, an innovative method of estimating phylogenetically-corrected demographic and life history parameters and species-specific demographic rate estimates essential for conservation and management. We are also developing a database of social, behavioral, ecological, and demographic data for marine mammals to examine the relationship between population dynamics and sociality.

Management models for marine mammals

Marine mammals are increasingly threatened by interactions with fishing gear, ocean noise, pollution, direct harvest, ship traffic, competition for food with fisheries, and coastal development. Managers must set limits to these sources of human-caused mortality and disturbance to marine mammals without compromising human welfare. Currently, the U.S. Marine Mammal Protection Act limits the allowable number of deaths caused by fisheries with a simple model called Potential Biological Removal. Although these two approaches are a vast improvement to the status quo, they do not consider the cumulative impacts of all threats and they assume largely unrealistic population dynamics. We are developing a new framework for setting removal limits that incorporates cumulative impacts and also allows for more realistic population dynamics, especially with respect to social complexity in marine mammals.