Multi-stressor Fisheries

The classic fisheries model of a single population and an omniscient harvester belies the complexity inherent in couple ecological-economic systems. Harvest is typically only one stressor among a suite of other ecological interactions. I am interested in understanding how ecological processes can alter harvester behavior and ultimately population outcomes.

Multi-species interactions: Modeling multi-species systems is difficult, because we need to specify a large number of interactions among all the species. Adding additional complexity, like space and harvest, can make such models relatively intractable. My co-authors and I employed a different approach and combined a patch occupancy model and relatively constrained ecological interactions with a bioeconomic model for harvest. This allowed us to look at the trade-offs between diversity and profit, as well as the cost-effectiveness of using marine reserves as a management strategy in a relatively simple model. This work is published here.

In my postdoctoral work, I am continuing this theme by investigating how a “new” species entering an area (perhaps due to changing climatic conditions) should be managed in the context of the existing fish species and its associated fishery. I presented this work at BIOECON in Tilburg in 2017. More results coming soon!

Evolutionary interactions: ‘Fisheries induced evolution’ captures the face that the act of fishing can exert selective pressure on populations. I worked with several co-authors to investigate the fishery-induced evolution of dispersal in a spatially explicit model; we showed that this evolutionary feedback caused marine reserves to cease being economically optimal (Moberg, Shyu, et al., 2015).

Climate change: I became interested in the ecological response to climate change by working with Andy Solow (WHOI) on a project using stochastic dominance as a definition of an unambiguous shift of a population’s distribution over time. We are continuing to develop this work.

I then chose to include climate change as a major component of my thesis. I am interested in the change over time that warming temperatures (for example) induce in a population and how a harvester might respond. I modeled a population with a continuously degrading vital rate (e.g., mortality) and characterized the optimal harvest strategy for this population, including the time at which the harvester should “fish out” the stock and cease harvesting. This work is in review.

I also extended this work to include uncertainty about how the population responds to the changing conditions and used adaptive management methods to characterize the optimal harvest strategy that includes learning about how the population responds while managing.

In the future, I plan to extend these works by including factors such as uncertainty about the size of the stock, more interspecies interaction, and harvester behavior.

Phytoplankton Ecology

My initial foray into ecology was in the Sosik lab at Woods Hole Oceanographic Institution as an undergraduate fellow.

My project involved using the high-resolution image data from phytoplankton at the Martha’s Vineyard Coastal Observatory to see how the phytoplankton community carbon to chlorophyll ratio varied as a function of the environment. As part of this, I developed an algorithm to automatically calculate the biovolume of complex cell shapes. This work was published in Limnology and Oceanography Methods and can be found here.

Later in my graduate career, I worked on a review paper with classmates from a phytoplankton ecology class. We reviewed how Sverdrup’s critical depth hypothesis was used over time and the characterized how our understanding of phytoplankton blooms has evolved since that time. Our work is published in Oceanography.

Drivers of Human Consumption

For the last several years, I have been interested in why we eat the species we eat. Why don’t we (usually) eat invasive species? Why do we tend to eat species of a higher trophic level from marine environments than terrestrial? I have started preliminary work investigating these questions for marine species, using meta-analytic techniques. I plan to extend this work collaboratively in the future to include experimental studies.

Decision Analysis

Decision Analysis

During my undergraduate studies, I worked with Dr. Linkov at the Army Corps of Engineers and later on a textbook on the application of multi-criteria decision analysis (MCDA) to environmental problems. MCDA allows decision makers to incorporate various unrelated metrics (like human health, ecological health, and cost) to assess which of multiple alternative management strategies is best. Our book uses  concrete case studies to illustrate these methodologies. We are currently developing the second edition of this work.