Monthly Archives: July 2018

What Happens in Marine Protected Areas

By: Erika Nava

I am currently a graduate student working in Dr. Mark Steele’s Fish Ecology Lab at California State University, Northridge. My research is on unintended effects of Marine Protected Areas (MPAs), comparing fish foraging behavior within and outside MPAs in Southern California.

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MPAs are usually established to allow organisms and habitats to recover from anthropogenic impacts such as overfishing. As populations rebuild within marine protected areas, the higher population densities may result in resource limitation. Such competition for resources may cause increased mortality, reduced growth rates, or reduced reproduction. While establishment of MPAs has clearly been shown to benefit targeted species in terms of their size and population biomass, it is not well known how these changes affect diet and feeding behavior, as would be expected if food resources become limited in MPAs. I am evaluating whether California sheephead, which is known to have higher biomass in MPAs, is prey limited within them and is shifting its foraging behavior as a result.

I am currently starting my second field season at Wrigley Institute with the support of their Wrigley Summer Fellowship. This summer I will focus on deploying a baited remote underwater video (BRUV) device at six MPAs and their paired non-MPA sites along the Southern California Bight. The BRUVs will allow me to observe fish foraging behavior, without the influence of divers. Since it can be difficult to observe diet with natural observations and impossible to control for prey availability, I use BRUVs to introduce a standardized prey item and observe sheephead’s attraction towards this bait. Since fish densities have increased within MPAs, competition for food might increase therefore I expect fish inside the MPAs to demonstrate higher attraction towards the BRUV.

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Most studies on MPAs have focused on evaluating their performance in terms of recovery of targeted species, but few have evaluated how this protection can affect trophic interactions. Fish diet and behavior, for example, might change, and documenting such changes could improve our understanding of how MPAs affect protected species. My research intends to evaluate whether California sheephead is food limited within MPAs in southern California.

Kelp Power

By: Tristan Jordan-Huffman

Greetings from the USC Wrigley Institute for Environmental Studies! I am incredibly grateful to be able to spend this summer on Catalina Island, which wouldn’t be possible without funding from the National Science Foundation for this REU program.

Our first few weeks have been quite eventful, and filled with both work and play. The experience has exceeded all expectations thus far! Throughout the past few weeks, I have been working on one of the components of the ‘USC Experimental Depth Cycling of Kelp for Affordable Biomass Feedstock’ project which is funded by the Department of Energy’s ARPA-E program. The goal is to explore kelp’s potential as a source of sustainable biodiesel.

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My project is focused on discovering the optimal point at which to out-plant the juvenile kelp onto kelp elevators that raise and lower the kelp, which will be installed in the following months. After spending the first week at Wrigley searching for juvenile kelp patches, I was able to find two distinct patches at the Intakes dive site for my research project, which is slightly north of Big Fisherman’s Cove. Upon finding the patches, we marked them with cement cinder blocks attached to buoys, which will be removed at the end of the project. On each dive, I have been assisted by USC’s diver intern, Rilee Sanders, as well as my fellow REUs, Declan Farr and Hunter Ramo.

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After our patches were properly marked, we began to look for individual Macrocystis pyrifera, specifically looking for individuals under 1 meter in height, which is how we are able to define them as a juvenile. We began the project hoping to find a minimum of 40 individuals, however, we discovered that our sites had an abundance of individuals within our desired size classes, so we have now expanded our sample size to 100. Unfortunately, it is quite difficult to identify individuals less than 5cm in the wild, so we decided to out-plant a structure from the kelp lab which houses our smallest class of individuals. In addition to the size of the individuals, we will also be looking at the number of pneumatocysts, blades, and individual growth rates, in order to obtain a comprehensive profile of each individual.

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In terms of a daily schedule, I have been diving several times per week in order to collect data, and my fellow researchers have been more than helpful by assisting me with my data collection throughout the project. When I’m not working in the water, I can be found in the kelp lab with my REU research partner, Connie Machuca, who is working on another aspect of the kelp project. I am very fortunate to have the opportunity to be assigned a partner for this project, because it has made the entire experience much easier!

In addition to our work, we have spent lots of time on the volleyball court, as well as playing music at various places throughout campus. Life on Catalina is certainly different from Los Angeles, but I am enjoying every second of it!