Fall 2017 – GoMRI Researcher Interview with Dr. Steve Saul

Photo Credit: Steve Saul.

Photo Credit: Steve Saul.

(From Fall 2017 Newsletter) Dr. Steve Saul from Arizona State University answered a few questions about his RFP-V project, Avoiding Surprises: Understanding the impact of the Deepwater Horizon oil spill on the decision making behaviors of fishers and how this affects the assessment and management of commercially important fish species in the Gulf of Mexico using an agent-based model.

1. Thank you for talking with us! Tell us about your research. What are the goals of your RFP-V project?

The Deepwater Horizon oil spill disrupted the livelihoods of many individuals living along the coast of the Gulf of Mexico, ranging from those in the tourism industry to those who fish the Gulf’s waters for a living. Many of those in the fishing industry, and the sectors that depend on it (fuel, restaurants, tourism, etc.), had to suspend their operations in the months after the spill due to spatial closures restricting access to potentially polluted waters. In the short run, for those fishers who lived adjacent to the closed areas and worked in areas that were closed, this affected their ability to work, their catch, and subsequently their family income. Others may have been able to continue fishing but may have had to reduce their time at sea or alter their fishing locations to work around the spatial closures.

The need to adjust behaviors in 2010 may have permanently altered the way some individuals fish and the locations where they conduct fishing operations. Such short-term and longer-term effects of the oil spill closures have not yet been evaluated in terms of how they may have socioeconomically affected the fishing community or biologically affected fish populations.

The National Marine Fisheries Service relies heavily on information compulsorily provided by the fishing industry to the government when assessing the status of fish populations in the Gulf of Mexico. If the distribution of data collected from the fishing industry has somehow changed due to changes in how people are fishing, not understanding or accounting for this change could affect the assessment and management of the Gulf’s fish resources. In order to study the magnitude and direction of these effects from the spill, we are developing a spatially explicit, agent-based bio- economic model to represent important commercial fishery species and the fleets that harvest them in the Gulf of Mexico. The model will be used to understand fishing fleet dynamics, fish population dynamics, and the interaction of these in response to spatial closures and oil pollution. Alternative responses to the  spill will also be evaluated to understand the scope of   the possible effects of oil spills on fish populations in the Gulf, how they recover, and to explore different management strategies that can be used during such events.

2. What is your background and how did you get involved with this kind of work?

I received my Ph.D. in marine biology and fisheries and a master’s degree in marine affairs and policy from the University of Miami’s Rosenstiel School for Marine and Atmospheric Science. After graduate school, I worked as a Research Fisheries Assessment Biologist for the National Marine Fisheries Service in Miami, where     I conducted stock assessments on commercially important reef fish in the Gulf of Mexico and provided management advice to regional management bodies. I then worked as a Senior Research Scientist for Nova Southeastern University, where I was a Khalid bin Sultan Living Oceans Foundation Fellow. During this time, I contributed to the Global Reef Expedition by using remotely sensed and ground-truthed data  to develop depth elevation and habitat maps  of  coral reefs for resource managers in Small Island Developing States. I am now an Assistant Professor at Arizona State University. My research interests include using quantitative tools, simulation modeling, remote sensing,  and  a  systems-based  approach  to support natural resource management both domestically and internationally.

3. What are some of the most significant or exciting findings so far from your RFP-V project?

This project is an expansion of the work I did as part of my dissertation. The first version of the model represented the reef fish fishery on the west Florida shelf and was developed to help resource managers understand how the behaviors of fishers affect their catch, where they fish, how long they fish, and what type of gear they use. We are currently in the process of developing a version of the model, which spatially encompasses the northern Gulf of Mexico, the portion located within the United States Exclusive Economic Zone. The analysis of approximately 15 data sources is currently underway in order to expand the spatial extent of the model and update biological and human behavior parameters using the most up-to-date data sources. As part of this process, the number    of fish species in the model will also be augmented  to include most of the commercially important reef fish species targeted by the fishery. An exciting component we are working on, as part of the data analysis and parameterization component, are novel ways to statistically compute the spatial distribution  of fish in the Gulf of Mexico. The ability to better understand how commercially important fish are spatially distributed across the Gulf of Mexico can help resource managers better manage fish populations.

4. Which fish species in particular are you incorporating into the model?

We selected fish species to include in the model from the snapper-grouper management complex  based  on their financial importance to the commercial and recreational fisheries that operate in the Gulf of Mexico. These species include red grouper, gag grouper, red snapper, vermilion snapper, mutton snapper, gray triggerfish, golden tilefish, and yellowedge grouper. The primary reason for selecting these species is because the spatial and temporal distribution of these fish stocks drive fisher behavior and decision-making of the commercial and recreational demersal fleets. In addition, these species are distributed in different ways across the Gulf of Mexico, both in the north- to-south and east-to-west directions and in terms of depth strata. For example, yellowedge grouper and golden tilefish live at deeper depths than the other species; mutton snapper are primarily concentrated off the coast of southwest Florida, while red snapper are primarily concentrated west of the Mississippi River delta. Incorporating multiple species across different habitats provides a diversity of options to the simulated fishing vessels with respect to site selection, fishing gear, and targeting choice, commensurate with the actual set of choices fishers select from in the real world.

5. Can you talk more about how you are evaluating the behaviors of the fishers, to understand what changes they may have made in response to the oil spill?

We are evaluating the behaviors of fishers in two ways: through conducting quantitative questionnaires that ask vessel captains about their decision-making process and by developing discrete choice models  by converting the logbook data that fishers report to the government into a panel dataset. Fisher logbook information contains records of vessel captain decisions, such as when they started a fishing trip, where they fished, and when they returned to port. This information is then merged together by date, with other information containing daily observations of processes that could affect a vessel captain’s decisions. This information can include, but is not limited to wind speed, fuel price, fish price, fishing regulations, socioeconomic status, or quota allocation (i.e. how many pounds of each species each fishing boat is allowed to catch). Discrete choice models will be fit to data prior to and after the oil spill occurred in order to see if behavioral changes can be detected in the decision-making process. Discrete choice model parameter estimates, together with questionnaire results, will be used by the simulated fishing vessels to drive their behavior and decision-making.

6. If funding were not an issue, what would you add to your project?

In the absence of funding limitations, I would most like to develop the model for the entire Gulf of Mexico large marine ecosystem and include the reef fish populations and fishing fleets that operate in the waters governed by Mexico and Cuba.

[Back to the Fall 2017 Newsletter]