Yea, seafood… who doesn’t like seafood… actually, based on a small scale survey I conducted with marine science students over the last 28 years I have found a slight increase in the number of those who do not. Curious about this, I followed up by asking whether their concern was seafood safety or other. Almost all said they just did not like the taste. Okay… I can take that… there are something I do not like either BUT I LIKE SEAFOOD. The survey also showed that almost every year with young/old or male/female – shrimp was at the top of their favorite list. After shrimp the next 3-4 choices for males was some type of fish. For females it varied – fish, lobster, calamari, to name a few.
Shrimping depends on healthy estuaries. Photo: NOAA
So what does this have to do with estuaries…
Well, you may not know this but 90% of the commercial important marine species require estuaries for at least part of their life cycles. Just as humans select a neighborhood to live and raise their kids based on safety and schools – “fish parents” find everything they want for their “kids” in an estuary. They are shallow – allowing light to reach much of the bottom where submerged plants, like seagrasses, can grow. These seagrasses provide hiding places and a place for small algae to attach – which is an important food source for many of them. There are other places for them to hide as well – emergent salt marshes and oyster reefs are biologically very productive habitats. Many of the developing larva and juveniles require lower salinities to begin and complete their life cycles; venturing to the open Gulf only when they have developed a tolerance for the higher salinities. The freshwater discharge not only lowers the salinity it also brings nutrients. These nutrients, along with the sunlight reaching much of the water column, produce an abundance of microscopic plankton – food for the young. The nutrients, thermal mixing, low salinities, and variety of habitats provide a combination for one of the most biologically diverse ecosystems on the planet – a great place to grow up… and much of it we enjoy eating.
Most of what we consume in the seafood world is divided into shellfish and finfish. Some of it is harvested and sold commercially, some we collect recreationally. In the shellfish world we are talking mollusk and crustaceans – two of the most popular seafood groups on the planet. The mollusk include snails, oysters, clams, mussels, scallops, and cephalopods like squid and octopus. Many of these species live in our estuaries their entire life cycle. Most are slow moving creatures – if they move at all – and have provided a living for some humans, recreation for many, for decades – though the landings of these species are on the decline… more on this in a later issue.
Oysters are one of the more popular shellfish along the panhandle. Photo: FreshFromFlorida
Crustaceans include the ever popular gulf shrimp. We actually have three different species of bay shrimp we like – white, brown, and pink shrimp. There are other varieties found offshore we are now consuming, but these have been the big three. Blue crab – my personal favorite – is another popular crustacean. Though these are still harvested commercially, “crabbing” with your kids is a long time popular panhandle activity – and the day always ends well with a great meal. Crustaceans are more mobile and conduct small migrations during their life cycles. Shrimp develop within the estuary and then move offshore for breeding where the incoming tide brings the larva back to the estuary. Blue crabs migrate to the head of the bay for breeding and the females return to the lower end of the estuary for egg development and larva release – they may enter the Gulf during this process but tend to stick to the bays for the entire cycle.
The famous Gulf Coast shrimp. Photo: Mississippi State University
In the finfish world we are talking drum, snapper, grouper, trout, whiting, mullet, flounder, sheepshead, and many more. These species have provided both a living for the commercial fishermen and recreation for families for years. Many species breed and grow within the estuary while others make trips in and out of the bay to complete their cycles. In addition to commercial and family recreation charter fishing has increased as a business along the Gulf coast.
One of the more popular finfish – the grouper. Photo: Bay County Extension, UF IFAS
We hope you and your family enjoy local seafood from our bays. There are several websites and apps, such as Seafood@Your Fingertips, that can help you locate local seafood – or you can go catch some yourselves! If harvesting recreationally be reminded that there are regulations and licenses required. You can read more about those at MyFWC.com.
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.
Worldwide, oysters and their habitats have declined in population. National concern over the reduced oyster populations and potential failure of the Oyster fishery in Apalachicola Bay have been recently featured in the news.
In September, Jack Payne, University of Florida IFAS Senior Vice President for Agriculture and Natural Resources announced the formation of the UF Oyster Recovery Task Force. This group, now called the UF Oyster Recovery Team, includes members from various stakeholders including scientists, industry, public health representatives and more. Florida Sea Grant is leading the team and director Karl Havens is the Chair.
“The recovery team has multiple priorities, including learning why oyster populations declined, finding ways to help them bounce back, and identifying solutions for social and economic impacts”, Havens said. A firm date has not been set for the recovery team’s final report, but the team is hoping to deliver some results to the community by early 2013.
Courtesy of Florida Sea Grant
Eastern oysters are more than just a tasty treat! They provide a variety of functions to the bays and estuaries. They are a staple to the health and wellness of our bay. These organisms are hearty and tolerant of a wide range of salinity conditions from fresh to full-strength seawater. However, they are most “happy” when they are living in brackish water (a mixture of fresh and salt water).
Oysters are considered an important keystone species because of the variety of functions they provide for the areas they inhabit. Considered biofilters, oysters have the ability to filter up to 24 gallons of water per day. They help to control algal blooms, lower the amount of suspended sediment, silt and nutrients, and improve water quality/clarity. Oysters also provide critical food and habitat by creating solid three dimensional structures, referred to as reefs in the areas they grow. This reef structure provides habitat to many other fish and invertebrate species that live in the estuary.
Historically, the oysters harvested from Apalachicola Bay represent approximately 10 percent of the U.S. oyster harvest and about 90 percent of Florida’s harvest. This oyster fishery is an icon of our state and many jobs are dependent on this industry. The future is uncertain. However, the members of the Oyster Recovery Team are hopeful that by working together, the oyster resources will rebound and that a sustainable oyster management plan will be in place to insure the future of this vital fishery.
To help with support of seafood workers and disaster relief efforts in Franklin County visit the BAYAID website or Franklinspromisecoalition.org
UF/IFAS scientists and UF Oyster Recovery Team Members, Bill Pine and Peter Frederick, have been studying oyster communities along the Big Bend of Florida and hope that by studying these un-impacted oyster beds, they can help restoration efforts in Gulf and around the world be more efficient and effective.
