Featured Research

from universities, journals, and other organizations

Turning Freshwater Farm Ponds Into Crab Farms

Date:
October 15, 2008
Source:
North Carolina State University
Summary:
Biologist are working to grow and harvest blue crabs from freshwater ponds, instead of from the sea.

Blue crab. A new kind of crab harvest is on the way – blue crabs grown and harvested from freshwater ponds, instead of from the sea.
Credit: iStockphoto/John M. Chase

Work by researchers at North Carolina State University is leading to a new kind of crab harvest – blue crabs grown and harvested from freshwater ponds, instead of from the sea.

Crab lovers shouldn't worry, researchers say, because the pond-raised crabs look and taste just like their ocean-raised brethren.

North Carolina's native blue crab population has been at historic lows since 2000. Dr. Dave Eggleston, director of NC State's Center for Marine Sciences and Technology (CMAST) and professor of marine, earth and atmospheric sciences, looked at various methods for helping the population recover. He hit upon a solution which not only reduces pressure on existing crab populations, but also benefits farmers looking to diversify their crops: using irrigation ponds on farms to grow blue crabs.

"We started out by catching small crabs in the wild and stocking them into farm ponds loaded with bass and bluegill predators, and were still able to get 12 percent survival," Eggleston says.

"So we teamed with the University of Maryland's Center of Marine Biotechnology who had the expertise to growth hatchery-reared blue crabs, and stocked these blue crabs in freshwater experimental aquaculture ponds at NC State's Vernon James Research and Extension Center in Plymouth, N.C., where the crabs exhibited some of the highest growth rates on record."

Eggleston then noticed that a lot of farmers in Eastern N.C. were trying to diversify their crop offerings in response to the decline in tobacco demand.

"A lot of these farms have irrigation ponds, and we thought if crabs can live in fresh water, this would take some pressure off the coastal crab population and give farmers another crop, by letting their ponds work for them," he says.

Eggleston and his fellow researchers discovered that crabs can tolerate a salinity level of only .3 parts per thousand, which is about the same level found in coastal tap water. They did further work to determine the best set of circumstances for raising crab: population density, food rations, and habitat structure in ponds.

This past July, Eggleston and Ray Harris, NC State director of cooperative extension for Carteret County, had the opportunity for a large-scale test when they stocked a 10-acre lake with 40,000 hatchery-raised crabs, and a smaller pond with 4,000 crabs. The crabs will take approximately 105 days to reach maturity, and so far the endeavor looks successful.

With the rapid rate of growth for pond-raised crabs, Eggleston expects that in a given year, a farm could produce two to three harvests, as crabs don't do well in freshwater during the winter months.

"If you look at a 2 1/2 -acre pond, you could stock it with 50,000 hatchery-raised crabs and expect to harvest around 20 percent, or 10,000 fully grown crabs. At $3 per crab, that's $30,000 – and multiply that times three. It definitely adds up."

Funding for this research was provided by the N.C. Blue Crab Research Program that was established by the N.C. General Assembly and is administered by North Carolina Sea Grant.


Story Source:

The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.


Cite This Page:

North Carolina State University. "Turning Freshwater Farm Ponds Into Crab Farms." ScienceDaily. ScienceDaily, 15 October 2008. <www.sciencedaily.com/releases/2008/10/081003191417.htm>.
North Carolina State University. (2008, October 15). Turning Freshwater Farm Ponds Into Crab Farms. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2008/10/081003191417.htm
North Carolina State University. "Turning Freshwater Farm Ponds Into Crab Farms." ScienceDaily. www.sciencedaily.com/releases/2008/10/081003191417.htm (accessed October 23, 2014).

Share This



More Plants & Animals News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
Goofy Dinosaur Blends Barney and Jar Jar Binks

Goofy Dinosaur Blends Barney and Jar Jar Binks

AP (Oct. 22, 2014) A collection of dinosaur bones reveal a creature that is far more weird and goofy-looking than scientists originally thought when they found just the arm bones nearly 50 years ago, according to a new report in the journal Nature. (Oct. 22) Video provided by AP
Powered by NewsLook.com
San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Bear Cub Strolls Through Oregon Drug Store

Raw: Bear Cub Strolls Through Oregon Drug Store

AP (Oct. 22, 2014) Shoppers at an Oregon drug store were surprised by a bear cub scurrying down the aisles this past weekend. (Oct. 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins