Nature has provided us with an incredible resource in the diverse assemblage of molluscan shellfish that inhabit our coastal bays and estuaries. One bivalve species in particular provides many human benefits. The eastern oyster (Crassostrea virginica) has not only proven to be a preferred food species for people but also derives many vital ecosystem services through its existence in our near-shore estuaries. Oysters are born as planktonic larvae that drift in the water for about 2 weeks. They are called a spat when they settle out of the water column and glue themselves to a suitable hard surface, such as another oyster shell, and begin to grow their own shell. Oysters feed on particulates in the water throughout their life and when mature can filter as much as 50 gallons per day. Because of this life style they provide some degree of water purification and improvement in water clarity. The structure of an oyster reef is also a valuable habitat component which provides shelter for a plethora of small creatures that support a vast food web in the estuary ecosystem.
Oystermen participate in shelling program for Apalachicola Bay
Barges will also be used to relay shells for replenishing oyster habitat.
Although we have several native species of oysters in the Gulf of Mexico the eastern oyster is the only species that supports a commercial industry. in Florida, the bulk of that industry has traditionally been centered around Apalachicola Bay in the mid-Panhandle region of the state. This one estuary system typically produces 90 percent of the state’s oyster crop and 10-13 percent of the nation’s harvest. Some good harvest years have yielded 4-6 million pounds of oyster meat (shells excluded) from this single bay. In recent years however there has been a dramatic decline in oyster abundance. The industry, along with concerned natural resource managers, is seeking to rebuild numbers to a sustainable harvest level. The reasons for this precipitous drop in numbers is the subject of much debate but savvy natural resource professionals believe a combination of factors have been involved over several years to cause the current situation.
Fossil oyster shell being relayed to bay bottom.
So, how do you bring back a thriving oyster industry from the brink of collapse? Several factors need to be considered and addressed as part of a holistic management approach. At the present time there are two primary mechanisms being employed to support increased oyster recruitment to Apalachicola Bay. The first involves “planting” a suitable material on the bay bottom for oyster spat attachment and growth. In the past this has primarily consisted of oyster shells from the shucking plants. More recently the industry has been employing the use of fossil shell material from a local mine. Oystermen are being employed to transfer the shell from land-based loading areas to the designated deposition sites in the bay. Funding is also forthcoming to allow shelling by barges to cover more area. The other strategy to assist with recovery has involved the use of regulatory authority in consultation with local experts and oystermen with decades of experience on the bay. This approach can reduce the harvest pressure on oysters and support a more rapid recovery, given proper conditions in the estuary. Bag limits have been reduced, enforcement has been stepped up to ensure compliance with the rules, and harvest areas have been adjusted.
Oystermen line up early to receive shell for relay project.
There are, of course, other important aspects to the solution for bringing back the thriving industry of the past and many of them relate to natural cycles of drought and flooding. Increasing human demands for water from the river system that feeds the bay tend to magnify the effects of natural drought cycles. If salinity remains high for longer periods there is an increased pressure from oyster predators that typically are limited by lower salinity. Factors related to oyster diseases and parasites are also in the mix. To say that it is a complicated situation would be an understatement. Researchers who have studied the system for their entire careers find it difficult to quantify the problems and solutions for this large, complex natural ecosystem that has been an important cultural and economic component of Florida’s makeup since early humans roasted or cracked open the first oyster. Hopefully, with enough concerned partners working towards effective management strategies we can once again enjoy in abundance the wholesome, delicate morsels that have been called the food of the gods.
Oysters on the half shell ready to eat! Photo Courtesy of Florida Sea Grant
Making oysters a healthy and sustainable seafood choice is the goal of oystermen and seafood dealers across the nation and the state of Florida. New education programs for the oyster industry went into effect January 1, 2014 and were implemented by the Florida Department of Agriculture and Consumer Services (FDACS) this past spring. FDACS oversees oyster resources and seafood dealer certification.More information about FDACS division Aquaculture can be found at http://www.freshfromflorida.com/Divisions-Offices/Aquaculture .
As our fall harvest areas reopen, many local oystermen are now viewing a new 25 minute video which is now required along with a Commercial Saltwater Products License to harvest oysters commercially. Florida Fish and Wildlife Commission (FWC) issues licenses for both commercial and recreational oyster harvesters and enforces laws related to harvesting. More information regarding proper licensing can be found online at http://myfwc.com/license .
All harvesters can do their part to insure seafood safety by following important harvesting guidelines. These include time and temperature protocols in the collections and transportation of shellfish to the dealer or home. Also important, are harvest boat safety, condition, and sanitation practices. Protection of oyster resources through proper culling and following the 3” inch size limit is important to creating sustainable oyster resources. The new video provides this education and an Oyster Harvester Training Certificate for commercial harvesters is available to those who watch the video at the following FDACS and UF/IFAS Extension Offices by appointment:
FDACS Field Offices:
Melbourne Office: 321-984-4890
Port Charlotte Office: 941-613-0954
Cedar Key Office: 352-543-1084
Tallahassee Office: 850-617-7600
Apalachicola Shellfish Center: 850-653-8317
UF/IFAS Locations:
Bay County: 850-784-6105
Franklin County: 850-653-9337
Santa Rosa County: 850-623-3868
This harvesting and training information is also appropriate for recreational harvesters even though it is not required.
Seafood safety is of interest to everyone,including harvesters, seafood dealers, and consumers. Each year there are a relatively small number of serious cases of foodborne illness as result of shellfish consumption. Often illness is a result of poor choices made by consumers. Consumption of raw oysters or other shellfish is not recommended for individuals with compromised immune systems. Poor immune systems are often the result of liver-disease or when chemotherapy treatment is used. Patient diagnosed with diabetes, iron overload disease, and HIV/AIDS are also advised not to consume raw shellfish.
New research also suggests another risk group are patients with acid reflux and digestive issues. Some over the counter and prescription medications, including antacids and proton pump inhibitors, increase stomach pH which allows more potentially harmful bacteria to survive ingestion, leaving patients at a higher risk for a variety of foodborne illnesses. The best advice is to consult your doctor if you have questions about whether consuming raw shellfish is appropriate for your health concern. Cooking is also a tasty way to safely prepare and enjoy shellfish. For additional guidance please visit http://safeoysters.org .
This catchy phrase coined by Robert Turpin (Escambia County Marine Resources Division) describes the new invader to our marine waters. Many coastal residents are aware of the invasive lionfish that has invaded our local reefs but few have probably heard of the Asian Tiger Shrimp. This member of the penaid shrimp family, the same family are ediblewhite, brown, and pink shrimp come from, was brought to the United States in the 1960’s and 70’s as an aquaculture project. Over the years farmers have moved from Tiger Shrimp to the Pacific White Shrimp and the last known active farm was in 2004.
The Asian Tiger Shrimp can reach lengths of 12″
In 1988 2000 of these shrimp were lost from a farm in South Carolina during a flood event. 10% of those were recaptured and some were collected as far away as Cape Canaveral. No more was heard from this release until 2006 when 6 were captured; one of those in Mississippi Sound near Dauphin Island. Each year since the number of reported captures has increased suggesting they are breeding.
2006 – 6 captured
2007 – 4 captured
2008 – 21 captured
2009 – 47 captured
2010 – 32 captured
2011 – 591 captured
One individual was caught in 2011 near Panama City and 5 were collected in 2012 in Pensacola Bay. In recent weeks the Sea Grant Agent in Escambia County has received reports of numerous Tiger Shrimp being collected from Escambia Bay. There is currently no scientific evidence of negative impacts of this shrimp in our area. They are aggressive predators of benthic invertebrates and may out compete our native penaid shrimps and could possibly feed directly on the juveniles.
Five tiger shrimp captured by shrimpers in Pensacola Bay.
NOAA scientists are interested in obtaining samples of this shrimp for DNA studies. It differs from other local penaid shrimp in that it is larger (8-12” long), dark in color (dark green to black) and has light stripes (white to cream colored). The larva and juveniles live in the bay. Sub adults will migrate offshore for breeding. They are a tropical species that have a low tolerance for cold temperatures, showing no growth below 20°C, but have a high tolerance for changes in salinity. If you thing you may have one of these shrimp and are interested in donating one, please contact Sea Grant Agent Rick O’Connor at (850) 475-5230 or roc1@ufl.edu.
The commercial and recreation stone crab season has opened! Now is the time to enjoy local stone crab claws. Whether you catch them yourself or buy from a local seafood market, the delicious meat is worth the effort and cost.
There are 2 species of stone crab found along the Gulf Coast. The Florida Stone Crab is found in the southern part of the state, while the Gulf stone crab is found from the Western Panhandle to Mexico.
Stone crabs can be found in holes along oyster reefs, rock jetties and shorelines lined with riprap. Adult stone crabs feed on oysters, mussels, clams, worms and other crustaceans.
Recreational harvesters must have a valid Florida Saltwater Fishing licence and are limited to 5 traps that meet the specifications set by FWC. Maximum trap size is 2″x2″x2″ and traps must have a degradable panel that is 5 ½ inches by 3 ½ inches and is made of cypress or untreated pine slat no thicker than ¾ of an inch. These regulations are to protect marine life from ghost fishing, when traps are abandoned or lost.
The recreational bag limit is one gallon of claws per person or 2 gallons per vessel or which ever is less. Only one crab claw should be taken. Crabs are released alive with one claw intact and are able to feed and defend themselves, which allows the crab to be caught again in the future. The claw that was removed will grow back each time the crab molts. Claws must be 2 3/4 inches in length from the tip of the claws to the first knuckle.
Photo credit FWC
Watch the following video from FWC to learn how to harvest a claw correctly without injuring the crab.
Stone crab claws can be enjoyed cold or hot, in the shell or peeled and in many different dishes. Enjoy stone crab claw meat with mustard dipping sauce, in soup and bisque, crab cakes, salads, etc. Many recipes can found on-line.
Use a butter knife, mallet, claw cracker or hard spoon to crack the shells. If you want to prevent shell from flying around, cover the hand that will hold the claw or the surface that the claw will be cracked on with a dish towel. Gently tap the sections of the claws, until they are cracked, be careful not to break the shell into the meat.
Check out this video to learn how to crack stone crab claws:
For more information on commercial and recreational stone crab claw regulations click here.
Oyster Boats on Apalachicola Bay Photo by Erik Lovestrand, UF/IFAS Franklin County Extension Director
A notice has been issued by the California Dept. of Public Health dated June 27 that is seeking public comment on a proposed rule change regarding the allowable level of microbial Vibrio vulnificus in post-harvest processed Gulf oysters.
Post-harvest processed oysters are regulated as raw, but have been subjected to a process to reduce levels of Vibrio vulnificus. The current rule states that levels must be less than 3 MPN/g (Most Probable Number/gram) whereas the proposed change would allow a critera of less than 30 MPN/g of Vibrio vulnificus. Restrictions regarding raw Gulf oysters harvested during April through October that have not undergone post-harvest processing to reduce Vibrio vulnificus will remain in place.
This change would bring California’s molluscan shellfish regulations into alignment with standards adopted by the National Shellfish Sanitation Program of the U.S Food and Drug Administration (FDA) and the Interstate Shellfish Sanitation Conference (ISSC). All other member states of the ISSC have already adopted the less than 30 MPN/g standard in post-harvest processed oysters.
This newer standard has been deemed safe since it has been in use from 2005 with no documented Vibrio vulnificus infections associated with raw oysters processed at the less than 30 MPN/g level according to FDA data. This change is anticipated to increase the amounts and varieties of post-harvest processed oysters imported into California from Gulf states.
If you would like to see materials regarding this action you may access them here. Inquiries about the proposed regulations may be directed to Pat Kennelly, Chief, Food and Drug Branch, Food Safety Section, at (916) 650-6598.
Article Author Contact:
Erik Lovestrand
UF/IFAS Franklin County Extension Director
Sea Grant Regional Specialized Agent II
653-9337
Since the beginning of the summer, panhandle residents and visitors have been reporting numerous sharks hanging out along the sandbars near the passes. , cruising between the 2nd sandbar and the beach. One visitor was even bitten; raising the question – WHAT’S UP WITH ALL THE SHARKS?
The Scalloped Hammerhead is one of five species of hammerheads in the Gulf. It is commonly found in the bays. Photo: Florida Sea Grant
Actually, over the years sharks have been feeding along on the sandbars. While tagging sharks at Dauphin Island Sea Labwe would send an ultralite aircraft up to spot their locations. The pilot often reported seeing sharks hanging out on the sandbars near the pass. The sharks generally moved slowly until the shadow of the aircraft would hit and spook them into swimming off. Surfers and fishermen alike know that sharks frequent the inshore waters near the beach during the warmer months. Some or the larger sharks certainly enter the bays where feeding and breeding probably occur. So, finding them in these locations is not that unusual.
What seems to be unusual this year are the numbers. Locals who have worked these waters for years say they have seen more sharks on the sandbars than they remember in the past. We do not have data on how many sharks typically are found on bars, so there’s no conclusive proof that the number seen this summer is significantly more. However, if the folks out there every day say they are seeing more, then there may be something to it.
The gathering of sharks may be due to feeding. Like any other animal, they gather where the food is. I have seen Jack Crevalle gather at the mouths of our bayous feeding after a fish kill. The big flood this summer dropped salinities below normal and many estuarine animals died; Big Lagoon was littered with dead clams. It is possible that the sharks are feeding on these with the outgoing tides. If there is more food there would be more sharks. Another possible explanation could be temperature control. Like all fish, sharks are ectothermic (cold-blooded) and need warm water to keep maintain their body temperature. Divers searching for lionfish this spring indicated that the bottom temperatures have been colder than normal this year; again, possibly due to the flood waters or an upwelling from the deeper Gulf. The sharks may be gathering where warmer water can be found: shallow water over bars. Outside of nurse and lemon shark species, breeding in sharks has rarely been observed. However, now is the time of year when this occurs and the National Marine Fisherieshas considered the estuaries of the northern Gulf potential breeding areas for some species of shark.
The Bull Shark is considered one of the more dangerous sharks in the Gulf. This fish can enter freshwater but rarely swims far upstream. Photo: Florida Sea Grant
As far as the threat of attacks are concerned, there is really not a high risk. Certainly sharks in feeding mode in shallow water could be a potential threat. But according to theInternational Shark Attack File at the Florida Museum of Natural History only 21 attacks have occurred in panhandle waters since 1882 and 2 were fatal; 1 in Bay County (1988) and 1 in Walton (2005) . Following some simple rules will reduce your risk of shark bite. Swimming in or near baitfish or where recreational fishing is going on could increase your chances; avoid these. Though shark attacks occur all hours of the day and night there seems to be more during dawn and dusk, as these are their primary feeding times. Lifeguards along the coast are constantly watching for these fish along with other hazards. Following these simple rules should allow you to enjoy the water without concern. If you have any questions about sharks contact your county Sea Grant Extension Agent.
