Bivalve Bites: Oyster Aquaculture Research Roundup
BIVALVE BITES: EASILY DIGESTIBLE OYSTER AQUACULTURE NEWS
Researchers at VIMS are helping the industry establish oyster benchmarks.
Farmers are the foundation of the aquaculture industry, but there’s another group also driving its growth: applied researchers. At universities around the country, scientists are asking and attempting to answer questions. They’re studying, experimenting and monitoring a variety of factors in an effort to improve oyster farming — for farmers, for oyster eaters and for the environment.
We asked oyster aquaculture researchers at several Southern universities what’s currently under their metaphorical microscope (and why) and what they’re learning. Here’s what’s happening in the research realm in our region. And this is just the first batch: We’ll share our chats with a few more folks in December.
Assistant Extension Professor Andrea Tarnecki and her team are working to understand and thus, better control, oysters’ reproductive cycles.
In Alabama
Assistant Extension Professor Andrea Tarnecki, PhD speaks about some of the current activity at Auburn University Shellfish Lab on Dauphin Island.
Describe a current oyster aquaculture research project.
Oysters gather energy reserves during the cold winter months (fattening) and those reserves are used to generate gametes when the waters start warming (conditioning or ripening). Ripened oysters in the Gulf of Mexico spawn during the late spring through early fall. At the Auburn University Shellfish Lab, researchers are manipulating environmental conditions (temperature, salinity, feed, etc.) to optimize laboratory conditioning protocols for the Eastern oyster.
What are you and your team trying to learn with this research?
We are identifying optimal environmental conditions we can use at our facility to control the oyster reproductive cycle. We will learn the best way to condition oysters in the lab and the impacts of those methods on larval rearing success.
Why is it important to oyster aquaculture?
Current spawning efforts involve naturally conditioned oysters, which results in a lot of individual variability in terms of ripeness and limits the reproductive season to that of the wild. The ability to control the reproductive cycle will increase spawning consistency and allow for extension of the hatchery season.
What are its potential impacts and benefits for oyster farmers and oyster eaters?
The oyster farmers will benefit from a more reliable, consistent supply of oyster seed. In addition, seed availability will increase as the reproductive season can be extended. For oyster eaters, this means more delicious oysters in the market!
Leslie N. Sturmer and her team are hoping to figure out what’s leading to high oyster mortality on Florida farms in spring and summer.
In Florida
Leslie N. Sturmer, Shellfish Aquaculture Extension Agent IV, shares the questions the research team at University of Florida/IFAS, Shellfish Aquaculture Extension is trying to answer.
Describe a current oyster aquaculture research project.
We’ve conducted a pilot study to addresses recent unexplained oyster mortalities experienced by growers in late spring and early summer. Discussion concerning these mortality events began at a Florida oyster growers’ meeting in 2020. Although consensus was not reached about probable causes, there was agreement that a systematic approach was needed to better understand factors. With University of Florida funding, a monitoring and assessment plan was initiated to examine relationships between production and health of cultured oysters and key environmental factors. The objectives were three-fold: monitor production at commercial farms; examine water quality and phytoplankton abundance; and assess prevalence and severity of shell parasitism and Dermo disease.
What are you and your team trying to learn with this research?
A variety of factors, including water quality, disease, toxins, or poor management practices, may account for oyster mortalities. However, diversity in location, gear, seed and operational scale make it challenging to extricate the potential causes. Through establishment of four “sentinel” farms located within lease areas in Franklin (Alligator Harbor) and Wakulla (Oyster Bay) Counties, a preliminary monitoring and assessment plan began to explore production problems. Triploid oyster seed produced from the traditional Louisiana tetraploid stocks and from the new west coast-specific Florida tetraploids along with guidance were provided to growers so experimental data could be obtained at commercial farms. Oyster growth, mortality and health, along with basic but key water quality parameters, were monitored over a production cycle. Specifics results can be found here, but here’s one thing we learned: Mortality differences between genetic stocks indicate potential to develop a triploid line with higher resistance to environmental stressors and mortality events.
In Virginia
Acuff Professor of Marine Science and Shellfish Aquaculture Program Coordinator Bill Walton reports what he and his team are up to at the Virginia Institute of Marine Science, William & Mary.
Describe a current oyster aquaculture research project.
We are building a Farmed Oyster Benchmarking (FOB) program (working with colleagues at Old Dominion University), where we are quantifying different qualities of market-ready oysters from around the US, such as size, cleanliness, shell shape, meat quality, shell breakage when shucked, etc. Growers can send their oysters and get back a report to see the numbers for their oysters as well as the benchmarking averages for other oysters (combined and anonymous).
What are you and your team trying to learn with this research?
We are trying to do two things. First, we want to give growers some hard data on some aspects of product quality that lets them see where they are in the market as well as make decisions about any changes they might want to make. Second, we are trying to get a better handle on how different cultivation methods, geographic regions, times of year, etc. affect aspects of product quality.
Why is it important to oyster aquaculture?
With the explosion of varieties of oysters being grown and the increase in supply, it may become increasingly important for oyster growers to differentiate their product and identify their target market. The first step in that is truly understanding what you are growing and where that fits in the marketplace.
What are its potential impacts and benefits for oyster farmers and oyster eaters?
Like wines or beers, there is no perfect oyster. There is, however, a perfect fit for each oyster with a certain customer. We are hoping that the benchmarking program helps growers more consistently produce the oyster that their customers want.