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What are Local Fish Eating?

By: Sammie Alexander

As a member of the ecology team for the Potomac Environmental Research and Education Center’s (PEREC) summer OSCAR team project, my research goal is to investigate the predator-prey dynamics between fish and macroinvertebrates in two freshwater tidal Potomac River tributaries, Gunston Cove and Hunting Creek. This means, I examine the stomach content of 15 fish species known to inhabit both embayments in order to construct a food web for each location.
Due to variations in aquatic habitat types within the embayments (i.e., vegetated and non-vegetated), I use three different methods to collect my fish samples: fyke nets, seine nets, and otter trawls.

A fyke net is a passive collection technique in which fish are guided into a funnel shaped net by three leads, or guide nets. Once fish enter the funnel through narrow openings, they are unable to return to the outside of the net. The funnels on the fyke net are comprised of subsequently narrower openings that make exiting the net difficult for many fish. This method is implemented in heavily vegetated habitats where the submerged aquatic vegetation is so dense it is impossible to actively pull other types of net through.

The second method, seine nets, are an active collection technique in which two people extend a long net perpendicular to the shore and then drag it parallel to the shore for approximately 100 feet. This targets fish along the shoreline and can be used in vegetated and non-vegetated habitat. However, seine nets become very difficult or even impossible to use effectively once the vegetation reaches a certain density.

The third method, otter trawls, are another active collection technique in which a weighted net is dropped off the back of the boat and dragged at a constant speed for 5 minutes. Like the seine net, this method can be used in vegetated habitats to an extent. If there is too much vegetation, the trawl will become clogged or too heavy and will have to be reset, so it is best used in open water.

Once my fish samples are collected, I take them back to the lab to remove their stomachs for examination. I then sort the contents of their stomach into groups based on the lowest possible taxonomic level, which can be challenging if the organisms in the stomach have already begun to digest.

While there are published studies focused on the diet of many of the fish species I am studying this summer, none of the studies focus on populations in these specific tributaries of the Potomac River. The species found in these systems are unique, in a way, due to their close relationship with wastewater treatment plants upstream. These treatment plants feed nutrient rich effluent (i.e., discharge water) into the streams that then flow into these embayments. Adding additional nutrients to an aquatic system has the potential to influence the type of organisms that can live there.

I will use the organisms I identify in the fish stomachs to construct a food web, which will allow me to compare the diets of fish communities that reside in non-vegetated habitats, such as shorelines and open water, to the fish communities that reside in vegetated habitats, such as the submerged aquatic vegetation (SAV) beds.

Pursuing this question is interesting because in the 1980’s Gunston Cove was a hypereutrophic (i.e., very nutrient rich) system, due to the nutrient rich effluent released from the Noman M. Cole, Jr. Pollution Control Plant (NCPCP), which provided ample nutrient resources for phytoplankton algae to grow. Eventually, the algae became so abundant that it formed a thick green layer over much of Gunston Cove, which blocked the sunlight from reaching the streambed, preventing the growth of SAV. However, in an effort to reduce the occurrence of these harmful algal blooms, NCPCP reduced the amount of nutrients released in their effluent and after many years SAV beds began to reestablish (like they were prior to the 1980’s).

Now that nutrients, such as phosphorus (the first nutrient that was reduced in the wastewater effluent) and nitrogen, are better regulated, light is able to penetrate the surface and in turn SAV is able to grow. The food webs I construct will compare the potential impacts shifting from the historically non-vegetated habitat to the emerging vegetated habitat may have on the diets of fish in Gunston Cove and Hunting Creek.

As an Environmental Science student, I am very interested in the interactions that take place between organisms within an ecosystem. One day I hope to incorporate ecosystem modeling and spatial analysis into my own research, to investigate the potential impact factors such as climate change or invasive species can have on populations of aquatic species.

When I saw that Dr. de Mutsert was looking for a student to help construct a food web, I thought that this was a great place to start. Before I can create models to predict how stressors such as climate change or invasive species will impact an ecosystem, I must first understand how the species currently interact with their environment and surrounding community.

Now, I begin week seven of attempting to answer an unanswered question with high hopes and a long to-do list. I have spent many hours this summer on a boat collecting fish for my project, and macroinvertebrates for my partner’s, trolling the internet and library for resources on how to conduct a diet study and information on the history of the fish community in the Potomac River. More recently I have begun processing my 196 fish samples to try to understand what exactly is going on in the Potomac River (i.e., who is eating whom). The past six weeks have been spent collecting my fish samples and preparing the content in their stomachs to be examined.

With only two weeks left until our results are due to our advisors, it is now time I use our data to begin connecting the dots between the inhabitants of each embayment. The only thing standing between the coveted answer and myself are approximately 190 fish stomachs, but have no fear – I’ve come prepared with my microscope, tweezers, and coffee. Stay tuned to find out what happens next.

Modeling a Coastal Environment with Human Elements

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Kim de Mutsert was one of the Keynote Speakers at the CSDMS (Community Surface Dynamics Modeling System) annual meeting “Modeling Coupled Earth and Human Systems – The Dynamic Duo.” That took place in Boulder, Colorado from May 23-25, 2017. See the presentation below entitled: “Modeling a Coastal Environment with Human Elements.”

Keynote Abstract:

If one system comes to mind where the human element is intertwined with the environment, it is the Louisiana coastal area in the Southern United States. Often referred to as the working coast, coastal Louisiana supports large industries with its ports, navigation channels, oil, and productive fisheries. In addition to that, Louisianians have a significant cultural connection to the coastal wetlands and their natural resources. Unfortunately, the land is disappearing into the sea with coastal erosion rates higher than anywhere else in the US. Due to these high rates of land loss, this system needs rigorous protection and restoration. While the restoration plans are mostly focused on building land, the effects on, for example, fisheries of proposed strategies should be estimated as well before decisions can be made on how to move forward. Through several projects I have been involved in, from small modeling projects to bold coastal design programs, I present how coupled models play a key role in science-based coastal management that considers the natural processes as well as the human element.

PEREC Represents GMU at Occoquan River Fest

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Damselfly Larvae captured from a NOVA stream

PEREC Faculty and George Mason Students spent a wonderful Saturday at the Occoquan River Fest. The festival was a great place for NOVA residents to learn about the history and environment of the Occoquan River.

PEREC’s booth was dedicated to the health and ecosystem of local Virginia streams. Students and Faculty provided some great hands on activities, by fishing out live organisms for visitors to see up close. Crayfish, amphipods, and cranefly larvae were caught from the river that day and temporarily held in a glass aquarium. Children were able to get up close and personal, using magnifying glasses to get a detailed look at the organisms from their backyard.

“It’s great seeing the excitement in young kids when they examine small critters like crayfish and cranefly larvae up close,” says Kim De Mutsert.

Crayfish

George Mason graduate and undergraduate students were able to practice their science communication skills, with children and adults alike. The students explained that the number and types of organisms found in a river help scientists determine how “healthy” (i.e. unpolluted) the waterway is.

But it wasn’t just GMU students doing to the teaching.

“It was so interesting to see how much the parents would learn from their kids,” Grad student, Jessica Melton says. “The kids would tell their parents that what we caught was only 100 meters away. They’d explain to them what a cranefly was (Parents often thought it was a nuisance or large mosquito) as it’s very common in the area. The parents realized that it’s actually a beneficial species to keep around.”

That kind of experience is what made the day a success.

An annual event, PEREC looks forward to next year’s Occoquan River River Fest!

Original post: https://cos.gmu.edu/perec/perec-represents-at-occoquan-river-fest/#

OSCAR Paid Summer Internships 2017

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PEREC faculty Amy Fowler and Kim de Mutsert are currently looking for dedicated undergraduates to participate in a one of a kind research experience. The paid, 10-week summer program will give students the unique experience of collaborating with experienced faculty in research and scientific communication.

What kind of research will students be doing?

Students will assess biological and chemical aspects of two Potomac locations, Hunting Creek and Gunston Cove. PEREC faculty has sampled both of these regions, but the OSCAR research study will be the first of its kind.

While each student will focus on one specific area of research, together each project will look at the effects of micropollutants, such as mercury, in the food web. Students will collect data on the population of invertebrates, fishes, and zooplankton in the river. This is considered a good indicator of overall ecosystem health, as “sensitive” organisms are less likely to be found when there are pollutants present. A high diversity of organisms is also indicative of a healthy ecosystem.

Students will also test the river bottom to see if there are any micropollutants present, and if so, how deep in the sediment? When compared to the biological data, students will be able to determine if there is a correlation between less pollution and more organism diversity.

Not only will students get to help design and implement a research project, they will also get to participate in community outreach. Students will get to hone their oral communication skills through two oral presentations, and will also get experience writing a scientific report.

Why is this research important?

Studies have demonstrated that micropollutants (substances which are toxic in small doses) can build up in the environment, whether that be the sediment, or through the food chain. Bioaccumulation is when animals higher up in the food change have higher amounts of micropollutants, due to the fact that they consume many small organisms (such as zooplankton) that have consumed pollutants.

While few people swim in the Potomac River or eat the fish from there, the Potomac is a Chesapeake Bay watershed. There is a strong change that micropollutants found in the Potomac can make their way to the Bay, where many people spend their summers fishing and swimming.

How is it funded?

Dr. Fowler and Dr. De Mutsert have both successfully teamed up to earn two grants to fund student research.

From the Virginia Sea Grant, $5,000 were awarded to support student summer research. Dr. Fowler and Dr. De Mutsert have also won an impressive $38,000 from the OSCAR Summer Team Project Grant.

Dr. Fowler is especially excited for the summer, because she is a new faculty member, and can’t wait to meet new undergrads, who she hopes to mentor “as early as possible” in their academic career.

“Mentoring makes me a better teacher and a better scientist… I really enjoy helping students become better researcher, even if that’s not what they end up doing, you can always look at the world through the lens of a scientist, you can always question the world.”

Dr. De Mutsert is excited that the Potomac Science Center will immediately be used to its full potential:

“A summer research experience in aquatic science ideally takes place in an off-campus research facility right on the water. I am really excited we are able to offer that. We have an interdisciplinary team of scientists including geologists, chemists, ecologists, and science communication experts together in the same building that are involved in this project, and are mentoring the students. We can be on the water when we want to, and plan to be on a boat with the students at least once a week.”

Both agree that this summer experience will prepare students for a future as a scientist, as it will strengthen their communication skills in a way class labs are not able to. Scientists are always writing proposals, grants, and preparing lectures. This summer research experience will give them the skills and confidence to do these effectively.

What is the future of this program?

This pilot program will hopefully open the door for further research experience for undergraduates. While the 2017 summer program is currently only open to George Mason students, PEREC hopes to open up it up to undergraduates nation wide.

If this initial program is successful, it may open the door for funding from the National Science Foundation’s Research Experience for Undergraduates (https://www.nsf.gov/crssprgm/reu/). This will allow PEREC to accept undergraduates from all over the country for their research program. As the Potomac Science Center is the only center located on a Freshwater Tidal river, it would be a unique, and invaluable opportunity for any young scientist.

Interested students can apply here.

Just Keep Swimming: Staying Afloat While Exploring Undergraduate Fish Research

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By: Tanya Traeger

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The author (Tanya Traeger) processing samples for DNA barcoding at SERC. Image courtesy of Tanya Traeger.

The holidays have arrived, signaling an end to my last full-time semester at GMU!

To provide some background, I am studying to be a veterinarian and wanted to gain experience in research. The biology department at GMU offers a research semester every fall for students such as myself looking to explore their future. This is how I happened upon Kim and the rest of her fish heads!

For those of you who may not know, GMU has been actively working with Fairfax County for 30 years in efforts to improve water quality of Gunston Cove, a tributary to the Potomac River. Dramatic decreases in both nitrogen and phosphorus have led to increased water clarity. This change has caused a transition from a phytoplankton dominated habitat to that of submerged aquatic vegetation (SAV).

Each summer, fish are collected, measured, and sorted by habitat to note any changes in the community structure. This year specifically, Casey Pehrson, one of Kim’s graduate students, was working on diet study of the fish at Gunston Cove. Kim partnered me with her over the summer. We took a total of three days out on the water collecting fish and recording them as has been done over the years. We kept any fish over 50 mm and euthanized them for further analysis of their stomach content.

Back at the lab, stomachs were removed and dissected. Prey items were sorted and classified to the lowest taxonomic level. Each prey item was then frozen in sterile wells for further analysis using DNA barcoding – which I will discuss in further detail.

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Image of a snail shell taken with the microscope camera. Image courtesy of Tanya Traeger.

Because the amplification of the DNA and barcoding process is a time-consuming process, data analysis was conducted on the taxonomic data. Using Primer-E, software specifically designed for ecologist, the prey items were analyzed by fish species and habitat type. Two species were used in this part of the analysis: the pumpkinseed fish and the bluegill fish. Submerged aquatic vegetation (SAV), open water, and the littoral zone were the assessed habitat types. The results found that while there was both a significant difference in prey items between the species, there was an even greater difference between habitat.

Additionally, fish community data from 1999 was pulled from the Potomac Environmental Research and Education Center (PEREC). Comparing this data to the community data from 2016, a significant shift was observed in the community structure. Because diet data was not available from the 1999 fish community, the open water habitat was used as a proxy to represent the fish diet for that year while the SAV habitat was used to represent the fish diet for 2016. Given that significant differences were found between habitats, it can be concluded that the fish who use the SAV habitat for prey items will likely continue to thrive, while those fish who prefer the open water may decrease in number. A great example of this can be found with the decrease in the Golden Shiner. Its numbers decreased by more than 50% between 1999 and 2016. This can likely be attributed to the fact that plankton is one of the Golden Shiner’s top prey items. While there is still plankton in the cove, the number has dramatically decreased since the shift to SAV dominance.

As mentioned before, prey items were frozen for further analysis using DNA barcoding. This method involves amplifying DNA from each prey item and, through a series of many steps, producing a genomic sequence for each item. The results for these fish are still pending, but this will provide a more complete picture of the fish diets as many items will be able to be classified to the species level. This is being accomplished through collaboration with the Smithsonian Environmental Research Center (SERC) in Edgewater, MD. I have spent a handful of days out their working with a few of their scientists. It involves a lot of patience and pipetting! I must say that my thumbs are feeling very strong!

All in all, I would have to say that this has been a fun experience for me – especially the days out on the boat! Of course, the field work is the most fun, but I have also been introduced to a side of ecology that I did not know much about. It was also great to get a good understanding for the amount of time and thought that goes into research. It is a field that requires patience and attention to detail. Lots of planning goes into the way that methods are to be carried out prior to jumping into things. Possibly the most important lesson of all that I learned from this experience is that often your research will depend on what data you can collect. For instance, with this project we were originally hoping to compare the fish diet of the native catfish to the non-native, invasive blue catfish. However, after three days on the boat we were unable to collect any native catfish and only collected a small number of blue catfish. Therefore, our research direction had to shift. At least in similar studies, you will always be at the mercy of the organism you are collecting!

I would specifically like to thank Kim for this great opportunity and providing lots of direction as this was my first experience working with fish and I frequently felt a little lost!  Also, a huge thank you to Casey for assisting with the dissections, field work, accompanying me to SERC, and pretty much everything else!

Announcement: Post-doctoral research fellow in fish ecology and ecosystem modeling

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Post-doctoral research fellow in fish ecology and ecosystem modeling

George Mason University
Fairfax, Virginia, US

The George Mason University Department of Environmental Science and Policy is looking for an enthusiastic and energetic person for a post-doctoral research position in fish ecology and ecosystem modeling. The candidate will collaborate on ongoing projects in Dr. de Mutsert’s fish ecology lab (www.demutsertlab.com).

Responsibilities:
The primary responsibility is ecosystem modeling to assess effects of hypoxia on fish and fisheries in the Gulf of Mexico. The candidate will help improve an Ecospace model developed in Ecopath with Ecosim software, run model simulations, and help develop decision support tools for managers. Tasks include model development, preparation of results and model output for presentations, reports and publications, and help with organizing workshops. Additional responsibilities include fish and shellfish modeling to support Louisiana’s Coastal Master Plan, and field oriented fish ecology projects in Virginia. The field-focused projects may include laboratory work such as sample preparation for stable isotope analysis and caloric content analysis, and fish identification in the field and the lab. The candidate is expected to attend meetings and conferences, and prepare scientific publications.

Qualifications:
A PhD is required in fisheries science, oceanography, aquatic ecology, marine sciences or related fields. Experience working with ArcGIS and EwE software is desired, and knowledge of programming in R, SAS, Fortran, Python, or VB.NET is preferred.

Application Instructions:
For full consideration, applicants must apply for position number F103AZ at http://jobs.gmu.edu/postings/39306 by December 21, 2016; complete and submit the online application, and upload a cover letter, CV, research statement, and contact information of three references. Three letters of recommendation should be emailed directly by your references to the head of the search committee, Kim de Mutsert: kdemutse@gmu.edu.

Additional information:
This is a 1-year contract with the option to extend.

Science Diplomacy at its finest: the creation of the world’s largest MPA in international waters

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By:  Adrian Dahood

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Adelie penguins coming ashore in the Ross Sea

A VERY BIG thing has just happened. A new, and enormous Marine Protected Area (MPA) was just established. On October 27th 2016 headlines from media outlets across the globe erupted with the unbelievably good news that a sizable MPA had been declared in Antarctica’s Ross Sea. This is only the second Antarctic MPA.

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A sampling of world press headlines announcing the Ross Sea MPA.

I do not use the word “unbelievably” lightly. Every October since 2011, there have been headlines about the Ross Sea and MPA efforts there. Until this year, those headlines have largely reflected a lack of diplomatic progress to establish the MPA.

The Ross Sea is the most southern sea in the world. It is not governed by any one nation. Rather, the Ross Sea exists in international waters and is governed collectively by all Nations Party to the Antarctic Treaty and the Conservation of Antarctic Marine Living Resources (CAMLR) Convention. The Commissioners of the CAMLR Convention make decisions by consensus. This is a very powerful way to come to decisions because no action is taken until all Parties agree. Decisions made by consensus tend to be harder to reach, but are long lasting. In order for the Ross Sea Marine Protected Area to be adopted, representatives from 24 nations and the European Union had to support the proposal and give their consent. Collectively these representatives are known as the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

CCAMLR Nations have vastly different ideologies related to conservation. Nations like the United States, the United Kingdom, Australia, and the European Union have historically pushed forcefully for conservation efforts. Nations such as Russia, China, Japan, and Korea have advocated strongly to maintain fishing access. ALL of 24 member Nations and the European Union reached an agreement to set aside 1.55 million km² area of the Ross Sea as an MPA. The Ross Sea MPA is approximately twice the size of Texas and is the largest protected area in the world.

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The newly adopted Ross Sea MPA. Map drawn by The Pew Charitable Trusts and made available here (PDF).

The path to reach agreement on the Ross Sea MPA has been long and hard fought. The idea for the MPA came from the scientific community, specifically Dr. David Ainley who has been conducting research on Ross Sea marine ecosystems for decades. In 2002 Dr. Ainley submitted to CCAMLR the first paper describing the conservation significance of the Ross Sea. It is one of the last places on earth where ecosystem have not been significantly altered by human activities. In 2009 the First International Marine Conservation Congress (IMCC) was held right here at George Mason University. Dr. Ainley and interested scientists and conservationist organized a workshop on the Ross Sea to push for development of an MPA proposal. That same year the first, and until now, only Antarctic MPA was designated near the South Orkney Islands. The first Ross Sea MPA Scenario (a type of preliminary proposal) was submitted two years later by the United States Delegation the 2011 CCAMLR Scientific Committee meeting. The United States, and eventual co-proponent New Zealand, have been submitting a revised, or clarified, proposal to CCAMLR every year since. Nations that conduct the most fishing in the Antarctic had the greatest reservations about creating an MPA in the Ross Sea. It took a lot of work convince them of the merits of the Ross Sea MPA and to revise the proposal so that it was acceptable to all Parties. Adoption of the MPA this year recognizes the many years of scientific work, diplomatic compromise, and even educational efforts put in by the small army of people who have been advocating for the Ross Sea MPA. This army includes scientists from academia, government scientists and policy makers, NGO scientists and policy advocates, and even the general public.

We scientists played what may seem to you as unlikely roles in this particular MPA process. I include myself here, because I have been involved, at least peripherally, in the Ross Sea MPA since 2010. The Antarctic Treaty (1959) sets Antarctica aside for peaceful purposes and specifically calls for freedom of scientific investigation and cooperation. The Antarctic Treaty therefore establishes scientists as key stakeholders in Antarctic conservation efforts, and not merely conveyors of impartial information to aid the decision making process.

The Ross Sea research community embraced this role of stakeholder, advocating for their study areas, their study organisms, and their very ability to continue doing research in a pristine area in the face of a small fishery seeking to expand. University researchers spoke to their classes, to their departments, and to their funding agencies to raise awareness and earn more funding. Scientists and policy specialists at NGOs, such as The Pew Charitable Trusts, used their organizations resources to fund more research and push public awareness campaigns. Scientists working for the US Government conducted scientific diplomacy. We went to stake holder meetings (so many meetings!) and did our best to represent United States stake holder views to our agencies and internationally to CCAMLR Delegates. NOAA’s Antarctic Ecosystem Research Division invested significant time and effort into developing proposals for the the Ross Sea MPA, even though the majority of their own scientific investigations do not occur in the Ross Sea region. Scientists employed by NOAA and the NSF worked with NZ scientists and conducted outreach to the broader scientific community, to ensure that the best available science was used to develop and improve each iteration of the MPA proposal. And then, with proposal in hand, they conducted diplomatic missions with representatives from the Department of State, to convince CCAMLR Delegations from around the world to support the proposal for a Ross Sea MPA. There were countless meetings that lasted into the wee hours of the morning, many of which did not end with meaningful compromise or progress. Some countries were easy to bring on board. Others needed multiple meetings outside of the CCAMLR setting and changes in larger geopolitics to bring them on board. I would like to think that the little bit of support work I did, including GIS, endless editing of early stage documents, and some talking points I wrote for Secretary of State Kerry aided the process.

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A now protected sea ice pressure ridge in the Ross Sea. These areas are important habitat for the Weddell seals, and other species.

The final Ross Sea MPA design reflects the years of hard work and compromise that went into creating it. The amount of area protected is makes it the largest protected, either terrestrial or marine, in the world. A significant portion of the MPA has been designated as no-take, where no fishing is allowed. Other zones have been designated solely for research fishing or have reduced levels of fishing. These are huge accomplishments for conservationists. However, those successes came at a cost. Fishing nations imposed a 35 year “sunset clause” which requires MPA proponents to re-argue for protecting the region in 35 years. Failure to reach consensus to extend the duration of the MPA at that time would end protection. Additionally, some of the areas most important to foraging animals were excluded from the MPA, because they are of great interest to the fishery. In the best compromises everybody sacrifices. Though the final Ross Sea MPA is not what Dr. Ainley and his group of scientists envisioned when they started fourteen years ago, it a tremendous achievement. It cannot be understated how exciting it is that in this day and age of escalating geopolitics, rival Nations came together, made many compromises, and established long-term protection for the Ross Sea.

The success of the Ross Sea MPA proposal bodes well for the establishment of more Antarctic MPAs. I am now tucking into my Ecopath with Ecosim model of the Antarctic Peninsula region with renewed vigor. My model is designed to aid in the MPA designation process for the Antarctic Peninsula region. After six years of limited progress on Antarctic MPAs, it seems that CCAMLR has finally found some momentum and more MPAs will be designated.

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It’s the dawn of a new day for Antarctic MPAs. Will the Antarctic Peninsula region be the next place an MPA is established?