Tag Archives: shrimp

Skidaway scientist proposes forecasting tool for shrimp black gill

After more than nine years of researching black gill in Georgia shrimp, scientists at the University of Georgia Skidaway Institute of Oceanography are hopeful their work may help the state’s shrimpers deal with the condition, which many shrimpers blame for reduced harvests. They want to develop a forecasting tool that would allow shrimpers to predict what kind of season they may have and prepare accordingly.

Shrimp caught and sorted during the December cruise.

Black gill is a condition found in shrimp in the southeastern United States. The Georgia Department of Natural Resources first officially reported black gill in its survey data in 1996, however Georgia shrimpers anecdotally have reported its presence at least since the 1980s. Early on, no one knew the cause of black gill or its effect on shrimp, and the number of infected shrimp has varied widely from year to year—as has the number of shrimp for harvest.

The presence of black gill is seasonal. It visually disappears during the winter. It begins appearing as the water warms in the early summer and peaks in September and October, which is also the height of the commercial shrimping season. That seasonal variability also gave UGA Skidaway Institute researcher Marc Frischer a clue as to why black gill only started appearing in the last three decades. He found a link between warmer winters and a higher incidence of black gill in the shrimping season later that year.

“What happened is that our climate is changing, especially with warmer winters,” Frischer said. “And that’s what is driving this occurrence of the symptomatic black gill.

“The ciliate that causes it has probably been here forever. We don’t think it is an invasive species. We recognize it now as an impact of climate change.”

The link to winter temperatures gave Frischer insight into a way to help the Georgia shrimpers. Since a cure for black gill is not likely, the next best answer might be a forecast tool. Frischer hopes that by providing shrimpers with some idea of what they can expect out of their efforts, it might avoid the devastating consequences the shrimp industry experienced in 2013.

“I think what we really need is a good, accurate forecasting tool that can say how good the year is going to be,” he said. “I think that would be helpful to the industry so they can calibrate their efforts to what their catches might be, and right now, we don’t really have that.”

RV Savannah crew deploy a trawl net.

Frischer was asked to get involved in the black gill project after the Georgia shrimp industry hit a crisis in 2013. Local shrimpers thought they were poised for a great season, as a shortfall of Asian imports drove prices to record levels. When the Georgia shrimpers deployed their nets, however, they discovered there were hardly any shrimp to be caught.

“There was a lot less shrimp on the market, and the prices were triple what they’d been the years before,” Frischer said. “So, the shrimpers put a lot of effort into preparing for the season, and then they didn’t catch enough shrimp to pay for their fuel cost. A lot of shrimpers when bankrupt that year.”

Frischer and his team quickly uncovered the cause: the parasite black gill, a tiny, previously undescribed, single-cell ciliate growing on the shrimps’ gills (the blackening of the gills actually is a defense mechanism shrimp use to protect against the parasite). Subsequent research confirmed the condition affects shrimp in several ways, including reducing their endurance and making them more susceptible to predators. It also probably increased mortality rates, although determining the contribution of black gill to direct mortality rates has been difficult to quantify.

Cruise participants sort the catch.

“We’ve learned a lot about the parasite’s life history, what it does and why it causes black gill,” Frischer said. “We think that’s because it feeds off of living gill tissue on the shrimp. That causes the shrimp to respond to turn on its immune system, which is what results in the symptoms of black gill.”

Although the parasite is harmful to shrimp, Frischer stressed that it is not harmful to humans. “If you’ve eaten local shrimp anytime since the 1990s, you’ve eaten shrimp with black gill. I’ve never heard of any health issues for people associated with eating shrimp affected by black gill, and they still taste delicious.”

In December, Frischer hosted the sixth “black gill cruise” on board the Research Vessel Savannah, bringing together a wide-ranging group of stakeholders including, scientists, shrimpers, managers, policy makers, educators and the press to compare notes and establish connections.

“The point of this year’s cruise was to look back and see where we’ve come and chart a path forward, what we’ve learned and what we still have to learn,” he said. “We discussed challenges currently facing the fishery, and what are perhaps new opportunities.
“It’s not wiping out shrimping. But it’s not helping either. And so, the shrimpers are being compelled to learn to live with it.”

Fall black gill cruise rolls out new smartphone app for better data collection

The University of Georgia Skidaway Institute of Oceanography entered the fourth year of its black gill research program with a daylong cruise on board the Research Vessel Savannah and the introduction of a new smartphone app that will allow shrimpers to help scientists collect data on the problem.

Led by UGA scientists Marc Frischer, Richard Lee, Kyle Johnsen and Jeb Byers, the black gill study is being conducted in partnership with UGA Marine Extension and Georgia Sea Grant, and is funded by Georgia Sea Grant.

Black gill is a condition Georgia shrimpers first noticed in the mid-1990s. Many shrimpers have blamed black gill for poor shrimp harvests in recent years, but until Frischer began his study, almost nothing was known about the condition. Now the researchers know black gill is caused by a parasite—a single-cell animal called a ciliate—although the exact type of ciliate is still a mystery.

The October cruise had three goals. The first was simply to collect data and live shrimp for additional experiments.

“We were able to collect enough live shrimp in good shape to set up our next experiment,” Frischer said. “We are planning on running another direct mortality study to investigate the relationship between temperature and black gill mortality. This time, instead of comparing ambient temperature to cooler temperatures as we did last spring and summer, we will investigate the effects of warming.”

Researchers Marc Frischer (UGA Skidaway Institute), Brian Fluech and Lisa Gentit (both UGA Marine Extension and Georgia Sea Grant) examine shrimp for signs of black gill.

Researchers Marc Frischer (UGA Skidaway Institute), Brian Fluech and Lisa Gentit (both UGA Marine Extension and Georgia Sea Grant) examine shrimp for signs of black gill.

If his hypothesis is correct, Frischer believes researchers would expect that raising fall water temperatures to warmer summer levels in a laboratory setting will induce black gill associated mortality in the shrimp caught in the fall.

Those studies will be compared to those that are being conducted in South Carolina in a slightly different manner. Frischer expects the results should be similar.

“However, as it goes with research, we are expecting surprises,” Frischer continued. “We also collected a good set of samples that will contribute to our understanding of the distribution and impact of black gill.”

A second goal was to introduce and begin field testing a new smartphone application developed by Johnsen. The app is intended to be a tool that will allow shrimp boat captains and recreational shrimpers to assist the researchers by filling some of the holes in the data by documenting the extent of black gill throughout the shrimp season. The Georgia Department of Natural Resources conducts surveys of the shrimp population up and down the coast throughout the year. However, those surveys do not provide the researchers with the rich data set they need to really get an accurate assessment of the black gill problem.

A screenshot of the smartphone app for tracking black gill.

A screenshot of the smartphone app for tracking black gill.

“Instead of having just one boat surveying the prevalence of black gill, imagine if we had a dozen, or 50 or a hundred boats all working with us,” Frischer said. “That’s the idea behind this app.”

The fishermen will use the app to document their trawls and report their data to a central database. Using GPS and the camera on their smartphone, they will record the location and images of the shrimp catch, allowing the researchers to see what the shrimpers see. If repeated by many shrimpers throughout the shrimping season, the information would give scientists a much more detailed picture of the prevalence and distribution of black gill.

“The app is complete and available on the app store, but we are still in the testing stages,” Johnsen said. “We want to make sure that it will be robust and as easy to use on a ship as possible before widely deploying it.”

Recruiting, training and coordinating the shrimpers will be the responsibility of UGA Marine Extension and Georgia Sea Grant.

“I think it should be entirely possible to at least have a small group of captains comfortable and ready to start using it when the 2017 season begins,” Frischer said.

Johnsen is excited about the app for what it can provide to the shrimping and research community, but also the implications it has for using apps to involve communities in general.

“There is still work to be done to improve the usability of these systems,” he said. “But I’m confident that we are going to see an increasing number of these ‘citizen science’ applications going forward.”

The final aim of the cruise was to bring together diverse stakeholders, including fishery managers, shrimpers and scientists, to spend the day together and share ideas.

“This was a good venue for promoting cross-talk among the stakeholder groups,” Frischer said. “I had many good conversations and appreciated the opportunity to provide a few more research updates.”

Frischer says he thinks the communication and cooperation among the various stakeholder groups has improved dramatically since the beginning of the study. He recalled that when the study began in 2013, tensions were high. Shrimpers were angry and demanded that something be done to address the problem of black gill. Meanwhile, fishery managers were unclear if black gill was even causing a problem and frustrated that no one could provide them any reliable scientific advice. The research community had not been engaged and given the resources to pursue valid investigations.

“In 2016, we still have black gill. The fishery is still in trouble, but it does feel like we are at least understanding a bit more about the issue,” Frischer said. “Most importantly, it is clear that all of us are now working together.

“My feeling is that the opportunity for us to spend a day like that together helps promote understanding, communication and trust among the shrimpers, managers and researchers.”

Black gill stakeholders meeting set for June 22

As the 2016 Georgia shrimping season gets underway, the University of Georgia Marine Extension and Georgia Sea Grant, and the UGA Skidaway Institute of Oceanography will host a meeting to present the latest research and other information on black gill in Georgia and South Carolina shrimp. The meeting will be held at the UGA Marine Extension Aquarium at the north end of Skidaway Island in Savannah, Ga. on Wednesday, June 22, from 1-4 p.m.

Black gill is a condition affecting the coastal shrimp population. It is caused by a microscopic parasite. Many shrimpers believe black gill may be largely responsible for reduced shrimp harvests in recent years. UGA Skidaway Institute scientist Marc Frischer is leading a research project, now in its third year, into the causes and effects of black gill on the Georgia and South Carolina shrimp population.

A shrimp with the Black Gill condition clearly evident.

A shrimp with the Black Gill condition clearly evident.

The purpose of the meeting is to provide stakeholders, such as shrimpers, fish house owners, wholesalers or anyone else interested in black gill, with an update on black gill research efforts.  Frischer and South Carolina Department of Natural Resources scientist Amy Fowler and will present their latest research findings. UGA Marine Extension and the Georgia Department of Natural Resources will also provide updates. The meeting will be open to the public.

The meeting is for information purposes only. No management decisions will be made.

For additional information, contact Bryan Fluech, UGA Marine Extension, at (912) 264-7269.

What: Black Gill Stakeholders Meeting

When: Wednesday, June 22, 1-4: p.m.

Where: UGA  Aquarium, 30 Ocean Science Circle, Savannah, Ga., 31411

Directions: http://marex.uga.edu/visit_aquarium/

UGA Skidaway Institute produces informational video on black gill in Georgia shrimp

The UGA Skidaway Institute of Oceanography has produced an informational video to educate the public about black gill, a condition affecting Georgia shrimp, and the institute’s research into the problem.

Black gill is a mysterious condition affecting shrimp from Florida to North Carolina. A number of shrimpers have blamed black gill for their reduced harvests.

Almost nothing was known of the condition until the UGA Skidaway Institute began looking into the issue in early 2014. Since then, researchers have learned much about the condition, but much is still unknown. This video provides background on the condition and the results of the investigation thus far.

The video can be viewed below or accessed through the UGA Skidaway Institute Web site at http://www.skio.uga.edu.

The black gill research is funded by Georgia Sea Grant. The video was produced in cooperation with UGA Marine Extension, the university’s Office of Public Service and Outreach, Georgia Sea Grant and the Georgia Department of Natural Resources.

Shrimpers, others join UGA Skidaway Institute Black Gill research cruise

UGA Skidaway Institute of Oceanography scientists are studying a condition in shrimp found along the Southeast Coast known as Black Gill. As part of this effort, a group that included UGA Skidaway Institute scientists and representatives from Georgia Sea Grant, UGA Marine Extension, Georgia DNR, the shrimping industry and researchers from North and South Carolina joined a one-day research cruise on board the R/V Savannah on October 9. The focus of the cruise was to collect shrimp for the Black Gill research project, and also to give the various groups the opportunity to exchange ideas. This account of the project comes from UGA Skidaway Institute scientist and cruise-organizer Marc Frischer.

We had 20 people on board (not including the ship’s crew), representing three states (Ga. S.C. and N.C.) and interests from the industry, management, research, and education/outreach communities. Although sometimes the conversations were outside of my comfort zone, I found the discussions and interactions that I had interesting, significant and useful. I found particularly interesting the perspectives from some of the professional shrimpers who were onboard made it clear to me that a research priority should be investigating the relationship between shrimp mortality in the field and the incidence of Black Gill. Discussions with the management community also provided me new insights into the difficulties we are facing with management and regulation. Conversations with those charged with communicating with the broader public remind me to choose words carefully to avoid misunderstanding.

A shrimp with the Black Gill condition clearly evident.

A shrimp with the Black Gill condition clearly evident.

In terms of the science, the day was largely successful despite the very low shrimp catches. Our priority was to collect enough live shrimp to conduct experiments to investigate black gill transmission and to explore the effect of ciliate infection on molting frequency. Although there were not many shrimp caught, we caught enough to conduct our planned experiments, and we were able to bring live shrimp into our facilities with almost no mortality. Utilizing the relatively large R/V Savannah and being able to dock within feet of our labs made this possible.

Skidaway Institute professor Marc Frischer examining a shrimp.

Skidaway Institute professor Marc Frischer examining a shrimp.

Thanks goes to the director of the Skidaway Institute of Oceanography (Jim Sanders) for making the vessel available to us. Cost for the ship is not covered by funding provided by Georgia Sea Grant and was provided as matching funds by the Institute.

Experiments got underway immediately upon our return and will continue for the next several weeks. If anyone is interested and wants to visit the lab for an update you are welcome to do so.

DNR's Pat Geer and Sea Grant's Jill Gambill sort through the marine life caught in a trawl.

DNR’s Pat Geer and Sea Grant’s Jill Gambill sort through the marine life caught in a trawl.

In addition to collecting live specimens, we were able to collect and preserve samples for a large variety of other analyses that will contribute to our identification of the Black Gill agent and to understanding its impact on shrimp. Several of the samples we collected are now on their way to various labs around the world where researchers with expertise beyond ours will study them.

Also, for the first time, we, collected water and sediments to be examined using our novel molecular-based diagnostic tools that are just now coming online. These studies will form the basis of a student project and thus generate both new information and new talent.

The team from the October Black Gill cruise.

The team from the October Black Gill cruise.

Unfortunately, because we were not able to catch more shrimp, we were not able to quantify the prevalence of Black Gill along the transect we sampled (offshore Wassaw Island, Wassaw Sound, and the Wilmington and Skidaway Rivers). However, this is a task valiantly undertaken by the GA DNR who had just visited the area in September and will be at it again. However, in addition to observing that catches were low everywhere, we were able to estimate a prevalence in the neighborhood of 50 percent. Except for offshore where we only caught one shrimp and it had black gill (so 100 percent). Two insights from this experience — first, our observations agree very well with DNR’s estimates and it is clear that we are probably not sampling sufficiently. Second — engaging the fishing community in this effort, if we can do so in a scientifically sound manner, will be truly helpful.

Evening @ Skidaway examines black gill in shrimp

Digital StillCameraUGA Skidaway Institute of Oceanography professor Marc Frischer will discuss his ongoing research into black gill in shrimp in an Evening @ Skidaway program on March 12th. The program will be in the McGowan Library at the UGA Skidaway Institute, beginning with a reception at 6:30 p.m. to be followed by the lecture program at 7:15 p.m.

In recent years, Georgia shrimpers have been very concerned about black gill, a mysterious condition affecting the coastal shrimp population. While the condition does not affect the edibility of the shrimp, many shrimpers believe that black gill may be largely responsible for reduced shrimp harvests. Frischer is leading a research project involving scientists, regulators and shrimpers from three states in an effort to determine the cause, effects and possible solutions to the black gill problem.

An “Evening @ Skidaway” is sponsored by the UGA Skidaway Institute of Oceanography and the Associates of Skidaway Institute.

The free program is open to the public.

For additional information, call 912-598-2325.