RESEARCH PROJECTS


Marine Metapopulation Connectivity: Modeling, Estimation and Demographic Consequences


Collaborators
Dr. Julie Kellner, WHOI
Dr. Rubao Ji, WHOI
Dr. Simon Thorrold, WHOI
Dr. Michael Neubert, WHOI

Students and Postdocs
Ben Jones, WHOI/MIT Joint Program Graduate Student
Séverine Choukroun, WHOI Postdoctoral Investigator
Jason Sadowski, WHOI Summer Student Fellow
Xueming Zhu, WHOI Guest Investigator

Project Description
The goal of this project is to develop a tractable modeling framework for estimating marine metapopulation connectivity and its demographic consequences. This will be achieved by utilizing a highly integrated multifaceted approach which draws upon gravity, demographic, and biological- hydrodynamic coupled models. The project has specific objectives to accomplish this goal: (1) Determine reliable predictors of population connectivity from a range of habitat and oceanographic metrics that influence larval dispersal and settlement. The predictive ability of these metrics will be assessed through the development of gravity models which incorporate both natal and settlement site attributes as well as “distance” functions derived from habitat distributions and biological- hydrodynamic coupled models which describe how dispersal probability declines with travel time. (2) Evaluate the robustness of these prediction measures and different forms of the gravity model at various temporal and spatial scales to examine their potential suitability for a broad range of marine metapopulations. (3) Develop matrix metapopulation models to improve our understanding of how physical oceanographic processes and dispersal behavior influence the dynamics and spatial connectivity of marine metapopulations. Additional information on this project is available here.

This work is funded by the National Science Foundation Biological Oceanography and Physical Oceanography Programs.

Multispecies fisheries and ecosystem-based management: understanding the role of trophic connectivity


Project Description
Ecosystem-based fishery management is promoted as a means of simultaneously alleviating many of the escalating direct and indirect effects of fishing on targeted populations, trophic connectivity, essential habitats, and ecosystem functions. By utilizing a multispecies bioeconomic approach for a coral reef community, the optimal harvesting rates of multiple trophic levels can be determined. One can then ask how this comprehensive optimization, which incorporates trophic connectivity, differs from single-species management approaches when additional factors such as incidental bycatch and habitat destruction are also minimized. Lastly, this trophic analysis will be extended to ask how these predictions would change under additional ecosystem-based management objectives. In particular, I will examine two such scenarios which explicitly value different trophic levels: (1) increasing the abundance of a herbivorous prey which provides an important ecosystem function as a dominant grazer in the community and (2) promoting the recovery of coral reef habitat. By considering both ecological and economic factors important to multispecies fisheries, the results from this work will provide a greater understanding of the tradeoffs inherent to ecosystem-based fisheries management.

This project is funded by The Thomas B. Wheeler Award for Ocean Science and Society, The Penzance Endowed Fund in Support of WHOI Assistant Scientists, and The John E. and Anne W. Sawyer Endowed Fund in Special Support of WHOI Scientific Staff.

Assessing the conservation and economic compatibility of MPA networks:
a metacommunity approach to managing biodiversity and fisheries exploitation


Collaborators
Dr. Julie Kellner, WHOI
Dr. Michael Neubert, WHOI

Students
Emily Moberg - WHOI/MIT Joint Program Graduate Student

Project Description
The goal of this project is to identify characteristics of exploited marine community networks (habitat distribution, oceanographic dynamics and directionality, spatial harvesting patterns) that have the potential to yield conservation gains in terms of biodiversity while simultaneously increasing economic productivity. To do this, we will develop a metacommunity modeling framework (many species, many locales) based on a variety of marine habitats (e.g., kelp forests, rocky and coral reefs) that takes into account spatial aspects of both fish and harvesters. By assessing the gains derived from implementing MPA networks within a range of marine communities, we can identify which spatial patterns could yield the greatest conservation and/or economic gains from the implementation of no-take areas and weigh the sensitivity of these gains to dispersal pathways and existing harvesting patterns. We will analyze an array of archetypical habitat configurations and oceanographic patterns that would encompass communities protected by MPA networks (e.g., coastal California) and maps of fish distributions and essential fish habitat important for fish spawning, breeding, feeding and growth (e.g., maps of Habitat Areas of Particular Concern for West Coast Groundfish available from the National Marine Fisheries Service). By advancing the discussion of MPAs forward to thinking about communities rather than individual species, we can gain a better understanding of optimizing connectivity across MPA networks in order to achieve the most “bang for our buck” in terms of biodiversity and conservation while minimizing economic impacts.

This project is funded by The Seaver Institute, the WHOI Marine Policy Center and WHOI's Director of Research.