The oyster is our world at Florida Oceanographic

Volunteers deploying shell for reef construction. PHOTO CREDIT: Florida Oceanographic Society.
Volunteers deploying shell for reef construction. PHOTO CREDIT: Florida Oceanographic Society.

[dropcap]W[/dropcap]ith the return of the “R” months, people celebrate the traditional start of oyster eating season. At the Florida Oceanographic Society, we celebrate oysters as well, albeit more for their restoration than their consumption (although we enjoy that too!). Restoring oysters is key to ensuring the health of our estuaries. Oyster reefs are the kidneys of an estuary, with a single adult oyster able to filter up to 50 gallons of water per day! Oyster reefs also provide habitat for numerous species and help stabilize shorelines, acting as natural breakwaters to reduce wave action and erosion.

The need to restore oysters is especially dire as historic losses of living oyster reefs are estimated to be 85% globally, making oyster reefs one of the most imperiled marine habitats in the world. These losses have been attributed to overharvesting, disease, pollution, direct destruction, and man-made diversions of natural waterways. The global loss of oyster reefs is reflected here locally with historic losses in the St. Lucie River estimated to be around 80%, attributed to excessive freshwater inputs from Lake Okeechobee and the surrounding local watershed. When the St. Lucie receives discharges from these sources, the end result is too much freshwater, too soon and often at the wrong time, overcoming oysters’ natural ability to tolerate changes in salinity.

Florida makes a great case study for examining the effects of freshwater diversions on oyster populations. In Apalachicola Bay, recent declines of oysters are attributed to that estuary not receiving enough freshwater, due to upstream diversions of freshwater away from that estuary. Drought conditions likely compounded lower inputs of freshwater resulting in extended periods of high salinity, increasing rates of predation and disease. Oysters thrive best in brackish conditions, when fresh and saltwater are evenly mixed. Somehow, man has figured out how to (mis)manage water leading to situations where an estuary receives too much freshwater (St. Lucie River) and an estuary that receives too little (Apalachicola Bay)!

Despite these the challenges, the wonderful little oyster has shown an amazing capacity to bounce back. When environmental conditions favor oysters, the reefs are a beautiful sight with large clusters of live oysters spitting water at low tide and the sun shining through the thin growing lips of their shells. They are teeming with life, with redfish, snook and trout patrolling reef edges looking for their next meal. It is during those periods, when reefs are healthy, that point to the future potential of restoration (when we get the water right!).

October is Oyster Month at Florida Oceanographic, but we work tirelessly to restore oysters year-round. Our oyster restoration program, FL.O.O.R. (FLorida Oceanographic Oyster Restoration), has been particularly active this year as a result of increased state and county (Martin) support, which has enabled us to sustain and expand our efforts (shown below).

Shell Recycling

Eating oysters is actually the first step in restoration of oyster reefs. Every week 11 restaurants in Martin County donate their leftover oyster, clam and mussel

shell to FL.O.O.R. Shell from the restaurants, local seafood festivals and special events amount to over 25 tons of shell collected per year and kept out of landfills. Shell recycling really is the foundation for our oyster restoration program as oyster shell is the primary (and best) substrate for creating new oyster reefs. Throughout the Indian River Lagoon (IRL), oyster restoration and shell recycling programs exist, so chances are your dozen oyster shells are going to a good cause wherever you are. And if your favorite raw bar does not currently recycle their shell, encourage them to do so. Then, by eating oysters, you are saving our estuaries!

Reef Restoration

After a few months, the recycled shell is packaged into mesh bags, which are the building blocks of each new reef. Oyster larvae attach to the shells within each bag to start their lives as baby oysters, or spat. The creation of the bags and the reefs are also perfect examples of community-based restoration, as thousands of bags of oyster shell are created each year and deployed by volunteers. ‘Bucket brigades’ of volunteers pass bags to one another eventually placing them on the bottom to form each reef. These events are also a fun time, bringing together young and old working toward a common cause of improving our estuaries. Since 2009, over 10,000 square feet of intertidal oyster reefs in the St. Lucie River and IRL have been created by 2200 volunteers contributing over 5400 hours of effort. These intertidal reef restorations complement larger scale, subtidal oyster reef restoration occurring in the St. Lucie River.

Living Shorelines

Another aspect of FL.O.O.R.’s restoration work is the creation of “living shorelines”. Living shorelines are a ‘softer’ approach to shoreline protection vs. traditional ‘hard’ structures, such as seawalls or breakwaters. Living shorelines combine shoreline plantings, such as marsh grass or mangroves with oyster reefs. These integrated habitats will over time, stabilize the shoreline, simultaneously creating self-sustaining habitat. FL.O.O.R., in partnership with Martin County, is installing living shorelines at several sites in the IRL. We are also recruiting private waterfront owners to get involved in building living shorelines on their shorelines. Seagrass will also be planted at our new sites resulting in comprehensive habitat restoration from sea to land.

All of these efforts are ongoing, so in celebration of Oyster Month at Florida Oceanographic this October, please visit our Coastal Center to learn more about our restoration programs and even help out with bagging and deploying shell. Restoration events are scheduled for October 2 (shell bagging) and 17 (reef deployment). To learn more visit www.floridaocean.org and friend us on Facebook. To see a short video of FL.O.O.R.’s program also check https://youtu.be/SaGGk92Jne4.

Vincent Encomio, Ph.D. is the Director of Scientific Research at the Florida Oceanographic Society, specializing in shellfish restoration and ecology. Vincent can be reached at vencomio@floridaocean.org.

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