In Part 1 of The Estuary’s Natural Filtration System article, we discussed the major contributors to natural filtration inside of the estuary. These examples included oysters, marsh plants, and seagrasses. In Part 2, we will discuss the smaller filter-feeding organisms including tunicates, barnacles, clams, and anemones.
Tunicates
Pleated Sea Squirt – Photo Credit: Don Levitan, PH.D. FSU
Tunicates, also known as sea squirts, are very interesting marine invertebrates and can be easily confused for a sponge. There are many different types of tunicates in the estuaries and can be either solitary or colonial. You might’ve seen these at an aquarium attached to different substrates, and when removed from the water, their name sea squirt comes into play. Tunicates have a defense mechanism to shoot out the water inside their body in hopes of being released by any predator.
Tunicates are filter feeders and intake water through their inhalant siphons and expel waste and filtered water through their exhalant siphons. Tunicates can filter out phytoplankton, algae, detritus, and other suspended nutrients. The tunicate produces a mucus that catches these nutrients as it passes through, and the mucus is then conveyed to the intestine where it is digested and absorbed.
An invader to the Gulf of Mexico, the Pleated Sea Squirt (Styela plicata), hitched rides on the hulls of ships and found the Gulf of Mexico waters very favorable. You can sometimes spot these organisms on ropes that have been submerged for a long period of time in salty waters. Even though they are non-native, these sea squirts can filter, on average, 19 gallons of water per day.
Barnacles
Barnacles along the seashore is a common site for many. Photo: NOAA
One organism that seems ubiquitous worldwide is the barnacle (Genus Semibalanus and Genus Lepas). The Genus Semibalanus contains the common encrusting barnacle we are accustomed to seeing in our waterways along pilings, submerged rocks, and even other animals (turtles, whales, crabs, and oysters). The Genus Lepas contains Gooseneck Barnacles and can be seen attached to flotsam, floating organic debris, and other hard surfaces and have a stalk that attaches them to their substrate. Interesting fact, certain gooseneck barnacle species are eaten in different parts of the world.
This image from a textbook shows the internal structure of a barnacle. Notice the shrimplike animal on its back with extendable appendages (cirri) for feeding. Image: Robert Barnes Invertebrate Zoology.
Barnacles have over 2,100 species, are closely related to crabs and lobsters, and are a part of the subphylum Crustacea. At first glance, you might not think a barnacle is closely related to crabs, but when you remove the hard plates surrounding it, the body looks very similar to a crab. Barnacles also have life cycle stages that are similar to crabs; the nauplius and cyprid developmental stages. Inside of the hard plates is an organism with large feather-like appendages called cirri. When covered by water, the barnacles will extend their cirri into the water and trap microscopic particles like detritus, algae, and zooplankton. Barnacles are at the mercy of tides and currents, which makes quantifying their filtering ability difficult.
Hard Clams
Clams of North Florida – UF/IFAS Shellfish
Even though not as abundant in the Florida Panhandle as they were in the 1970’s – 1980’s, hard clams (Mercenaria mercenaria and M. campechiensis) can still be found in the sand along the shoreline and near seagrass beds. These clams are also known as Quahogs and are in the family Veneridae, commonly known as the Venus clam family, and contain over 500 living species. Most of the clams in the family Veneridae are edible and Quahogs are the types of clams you would see in a clam chowder or clam bake.
Being the only bivalve on this list does not make it any less important than the oyster or scallop on Part 1’s list. In fact, a full-grown adult Southern Quahog clam can filter upwards of 20 gallons of water per day and have a lifespan of up to 30 years. Clams also live a much different lifestyle than their oyster and scallop cousins. Clams spend the majority of their life under the sand. Their movement under the sand helps aerate and mix the soil, which can sometimes stimulate seagrass growth.
Right outside the Florida Panhandle and in the Big Bend area, Quahog clams are commercially farmed in Cedar Key. Southern Quahog clams are also being used for restoration work in South Florida. Clams are being bred in a hatchery and their “seed” are being released into Sarasota Bay to help tackle the Red Tide (Karenia brevis) issue. According to the project’s website, they have added over 2 million clams since 2016, and the clams are filtering over 20 million gallons of seawater daily.
Anemones
Tube-Dwelling Anemone Under Dissection Scope – UF/IFAS Shellfish
Anemones are beautiful Cnidarians resembling an upside-down, attached jellyfish, which couldn’t be closer to the truth. The phylum Cnidaria contains over 11,000 species of aquatic animals including corals, hydroids, sea anemones, and, you guessed it, jellyfish. Anemones come in many different shapes and sizes, but the common estuary anemones include the tube-dwelling anemone (Ceriantheopsis americana) and the tricolor anemone (Calliactis tricolor), also known as the hitchhiking anemone. If you have ever owned a saltwater aquarium, you might have run into the pest anemone Aiptasia (Aiptasia sp.).
Anemones filter feed with their tentacles by catching plankton, detritus, and other nutrients as the tide and current flows. The tentacles of the anemone are lined with cnidocytes that contain small amounts of poison that will stun or paralyze the prey. The cnidae are triggered to release when an organism touches the tentacles. If the anemone is successful in immobilizing the prey, the anemone will guide the prey to their mouth with the tentacles. Just like the barnacle, anemones are at the mercy of the tides and currents, and filtration rates are hard to calculate. However, if you ever see an anemone with food around, they move those tentacles to and from their mouths quickly and constantly!
In Parting
As you can see, there are many different natural filters in our estuary. Healthy, efficiently filtering estuaries are very important for the local community and the quality of the waters we love and enjoy. For more information on our watersheds and estuaries and how to protect them, visit Sea Grant’s Guide To Estuary-Friendly Living.
The Panhandle of Florida is home to many estuaries along the coast, from the Escambia Bay System in the west to the Apalachicola Bay System in the east. These estuaries are very important and are the intersection where rivers (fed from their respective watersheds) meet the Gulf of Mexico and contain many different organisms that help filter the waters before they reach the Gulf. These organisms include oysters, marsh plants, seagrasses, scallops, tunicates, and other invertebrates. In this two-part article, we will explore marsh plants, seagrasses, oysters, and scallops.
Marsh Plants
Marsh Plants is a broad term for a family of grasses that lines the shore and contain grasses like Smooth Cordgrass (Spartina alterniflora), Saltgrass (Distichlis spicata), and Gulf Cordgrass (Spartina spartinae). These plants help trap sediments before they enter the estuary and are excellent at erosion prevention. When the water encounters the plants, it slows the flow, and this allows for sediments to collect. Marsh Plants are a great tool for shoreline restoration and are a major part of the Living Shorelines Program. The roots of the plants are also very efficient at removing nutrient pollutants like excess nitrogen and phosphorus which are major influencers in eutrophication. Marsh Plants also absorb carbon dioxide from the atmosphere and have been tabbed as “superstars of CO2 capture and storage.” (CO2 and Marsh Plants)
Marsh Grass and Oyster Reef in Apalachicola, Florida – Thomas Derbes II
Seagrasses
Seagrasses are different than Marsh Grasses (seagrasses are ALWAYS submerged underwater), but they offer some of the same ecological services as Marsh Grasses. The term seagrasses include Turtle Grass (Thalassia testudinum), Shoal Grass (Halodule wrightii), Widgeon Grass (Ruppia maritima), and Manatee Grass (Syringodium filiforme) to name a few. Seagrasses help maintain water clarity by trapping suspended sediments and particles with their leaves and uptake excess nutrients in their roots. Seagrasses are very efficient at capturing carbon, capturing it at rates up to 35 times faster than tropical rainforests. (Carbon Capture and Seagrasses) They also provide habitat for crustaceans, fish, and shellfish (which can filter the water too) and food for other organisms like turtles and manatees.
Grassbeds are also full of life, albeit small creatures. Photo: Virginia Sea Grant
Oysters
Crassostrea virginica (or as we know them, the Eastern oyster) is a native species of oyster that is commonly found along the eastern coast of the USA, from the upper New England states all the way to the southernmost tip of Texas. Eastern oysters are prolific filter feeders and can filter between 30-50 gallons of water per day. As filter feeders, they trap nutrients like plankton and algae from the environment. In areas of high eutrophication, oysters can be very beneficial in clearing the waters by trapping and consuming the excess nutrients and sediments and depositing them on the bottom as pseudo-feces. With oyster farms popping up all over the Gulf Coast, the filtering potential of estuaries is on the rise. (Between the Hinge)
Oysters, The Powerful Filterers of the Estuary – Thomas Derbes II
Scallops
Bay Scallops (Agropecten irradians) were common along the whole Florida Gulf Coast, but their numbers have taken a recent decline and can only be found in abundance in the estuaries to the east of St. Andrews Bay in Panama City, Florida. Scallops make their home in seagrass beds and are filter feeders. While scallops do not contain the filtering potential of an oyster (scallops filter 3 gallons of water per day as an adult), they are still a key part of filtering the estuary. Just like oysters, scallops feed off of the suspended particles and plankton in the water column and deposit them as pseudo-feces on the bottom. The pseudo-feces also help provide nutrients to the seagrasses below.
Bay Scallop. Photo: FWC
I hope you enjoyed this first article on filterers in the estuary system. While oysters are known as the filterers of the estuary, I hope this has opened your eyes to the many different filterers that call our estuary home. Stay tuned for Part 2!
I might shock a few people when I say this, but I’d rather be out in the bay somewhere rather than the beach. I just feel like I always bring a gallon of sand back on me even after washing down before getting in the car. However, there is one activity that will always get me out on the beach, and it just so happens to be the right time of the year for it. Florida Pompano (Trachinotus carolinus), aka Pompa-Yes, have started to cruise the white, sandy beaches in search of food as they migrate west to their breeding grounds. While out on a fishing trip this past weekend, the Pompano (and every other fish) eluded me, but I was blessed with an amazing array of wildlife.
When I first arrived at my spot just to the east of Portofino Towers, I was greeted with a pair of Sanderlings (Calidrisalba) playing the “water is lava” game while taking breaks between waves to argue with each other and probe the sand with their beaks from marine invertebrates. When I was doing more research on sanderlings, one comment I saw was that they ran like wind-up toys, and that’s the truth! They were pretty brave too, not a single footprint of mine in the wet sand didn’t go un-probed. Sanderlings are “extremely long-distance” migratory birds that breed on the arctic tundra close to the North Pole and winter on most of the sandy beaches in the Gulf of Mexico and around the world. Non-breeding sanderlings will often stay on sandy beaches throughout the summer to save energy. They were great entertainment for the whole fishing trip.
Sanderlings in the Tide Pool – Thomas Derbes II
Brown Pelicans (Pelecanusoccidentalis) were out in numbers that day. I am not the best photographer, but I was very proud to capture a Pelican mid-flight. These birds are residents of the Florida Panhandle year-round. If you’ve ever been to Pensacola, you might have bumped into one of the many Pelican Statues around the area, and they’re pretty much the unofficial mascot of the area. I am always amazed at how these seemingly big, clumsy birds can effortlessly glide over the waves and water as if they are the Blue Angels doing a low-pass. Pelicans were almost wiped out by pesticide pollution in the 1960’s, but they have made an incredible comeback.
Brown Pelican – Thomas Derbes II
While I was waiting for a Pompano to bite, I had a visit from a small Atlantic Stingray (Dasyatis sabina) that was caught in the tidepool that was running along the beach. He didn’t seem injured or sick, so I quickly grabbed a glove and released him into the gulf. Stingrays are pretty incredible creatures and can get to massive sizes, but they do contain a large, venomous spine on their tail that poses a threat to beach goers. They are not aggressive however, and a simple remedy to make sure you don’t get hit is to do the “Stingray Shuffle” by shuffling your feet while you move in the water to scare up the stingrays.
Atlantic Stingray Cruising the Tide Pool- Thomas Derbes II
As I was getting ready to pack up, I noticed a new shorebird flying in to investigate the seaweed that had washed up on shore. I had a hard time identifying this bird, but once I was able to see it in flight with its white stripe down the back, I realized it was a Ruddy Turnstone (Arenariainterpres). Turnstones get their name from their foraging behavior of turning over stones and pebbles to find food. Even though we do not have pebbles, the turnstone was looking through the seaweed for any insects or crustaceans that might be an easy meal. Turnstones are also “extremely long-distance” migratory birds breeding in the arctic tundra with non-breeding populations typically staying on sandy beaches during the summer. The turnstone made sure to stay away from me, but I was able to get a good photo of it as it ran from seaweed clump to clump.
Ruddy Turnstone – Thomas Derbes II
While I didn’t catch anything to bring home for dinner, I did get to enjoy the beautiful day and playful wildlife that I wouldn’t have experienced sitting on a couch. You can turn any bad fishing day into an enjoyable day if you pay attention to the wildlife around you!
Imagine you’re out on a kayak in a pristine Florida freshwater spring, surrounded by wildlife, beautiful trees, and natural formations. You have all the knowledge of what to expect and get excited to call out the different species of plants and animals you can spot. You’re surrounded by 10-15 like-minded nature enthusiasts who celebrate every species found and share tips and tricks on how to identify species more efficiently (Watersnakes vs Cottonmouths… Very Important!) If this sounds like a great time, then the Florida Master Naturalist Program might be right for you!
A Great Group of Master Naturalist Students Hiking Around Ponce De Leon Springs- Thomas Derbes II
Since I am a fairly new Extension Agent, I am getting to experience the course from a unique perspective. The Freshwater Course was my first time being an instructor, but it was also my first time going through the course. We started in March and are about to do our graduation next week, but this previous Tuesday was by far the best experience I have had in the course. We started the day at Ponce De Leon Springs State Park with a hike along a tannic creek. Once you reach the end of the trail, you can take the route back that is along the crystal-clear waters that flow from the springs. Largemouth Bass and Bluegill were abundant, and we even spotted a Mountain Laurel Tree. There is a beautiful picnic and viewing area along the springs, and you can even take a dip right in the springs. Even though this isn’t the famed “Fountain of Youth” springs, I think Ponce De Leon himself would’ve had a long soak in these waters.
A Flowering Mountain Laurel (Kalmia latifolia) at Ponce De Leon Springs – Thomas Derbes II
We then took a detour to a Pitcher Plant bog that was along the route to Morrison Springs. After a quick hike, we made it down to a bog that was filled with multiple types of Pitcher Plants, Sundews, and my favorite, Orange Milkwort. We also found a creek and found some slimy friends like a cute tiny frog and an unknown larvae/creepy crawly. We then loaded back up and made the very short trek to Morrison Springs, kayaks in tow.
An Orange Milkwort (Polygala lutea) Near a Pitcher Plant Bog – Thomas Derbes II
When we arrived at Morrison Springs, we had a quick lunch and learn from Dr. Laura Tui about the springs and headed over to the boat launch. We launched our kayaks in the almost crystal-clear waters and set out to find the connection to the Choctawhatchee River. We had our own kayak flotilla, and we were able to talk about all the potential species we would spot. Along our nice, relaxing paddle, we spotted many different birds, turtles, and a Green Watersnake (which I missed out on)! We finished the paddle with a trip around the springs and the vent and slowly loaded up the kayaks to call it a day.
FMNP Instructor Rick O’Connor Leading the Kayak Brigade – Thomas Derbes II
If this sounds like something you want to be apart of, you can check out what Master Naturalist Courses are available in your area by Clicking Here!
Day 2 of the Oyster South Symposium was the final day of presentations and the trade show, but it is also the day of the Shuck and Tell closing ceremonies. Another grey sky day greeted us, but the symposium was still full of oyster enthusiasts and farmers. Day 2’s talks focused more on marketing and the future of oyster farming, including discussion of a new program for Federal Crop Insurance and a panel of chefs discussing “What Chefs Want” when it comes to an oyster. The oyster disco ball also made an appearance, and I was finally able to snap a photo of that beauty!
The Famous Oyster Disco Ball! – Thomas Derbes II
Saturday’s talks started with a reflection of what Oyster South is and what it could be. Oyster South is a 501(c)(3) charitable organization that strives to connect communities and provide resources to support oyster farmers, cultivate thriving communities, and promote healthy waters (Oyster South’s Mission Statement Here). While South is in its name, the scope of Oyster South has become national with visitors and farmers from both coasts coming to collaborate and share stories of their oyster farms. I was able to talk with farmers from all over the USA, from California, Washington State to New Jersey, North Carolina and even Texas where oyster farming is still in its infancy.
After the reflection, we were treated to two awesome panels, one discussing what chefs look for in an oyster and another on making the most out of social media. Every chef has a different view of what they want in an oyster, but consistency and a certain salty yet umami taste came up as something they strive to serve. Social media also plays a major role in oyster farming and distribution. I remember when I was an oyster farmer, I quickly had to learn how to do social media as this was the best way to advertise and promote your product. Most people have Instagram or Facebook now-a-days, so being able to post your story and availability was always helpful in increasing your following and sales.
Talking About What Extension Can Do For You at Oyster South Symposium – Thomas Derbes II
After the lunch break, we had a Three-Minute Tech Talk Session. We heard from graduate students that needed input from the oyster community on their research topics, oyster farm innovators discussing their newest and greatest creations to help oyster farmers, and I was even given the opportunity to talk about what extension can do for oyster farmers. After the tech talks, we heard about the federal crop insurance program for oyster farmers, as well as a great talk from Julie Qiu (a well-known oyster blogger, advocate, writer, and founder of the Oyster Master Guild) on oyster stewardship and how important it is to oyster consumers and the oyster industry. Beth Walton, executive director of Oyster South, closed out the talks with Oyster South Looking Forward, and the future of Oyster South and oyster farming is very, very bright.
Before the Shuck and Tell, I was able to grab a quick “linner” at an incredible restaurant named Cochon. I had previously worked with a chef that came from Cochon, and his stories were the reason I made a reservation. The food in New Orleans is top notch, and Cochon was the cherry on top of a great gastronomy tour.
When it comes to oyster parties, the Shuck and Tell is the ultimate oyster experience. Farmers from all over got together to shuck their product and tell their story of why they oyster farm and the story of the oyster being shucked at the wonderful Southern Food and Beverage Museum (aka SOFAB). I was blessed enough to jump in and help shuck for some passionate oyster farmers and learn more about their farms and history. A relatively new oyster farmer at Salt Revival Oyster Company arranged for a second line to come through SOFAB, and it was an incredible way to cap off a great Oyster South weekend. The Coalition to Restore Coastal Louisiana was there to make sure all shells were recycled and used for future restoration projects.
Shucking With Salt Revival Oyster Company at the Shuck and Tell at SOFAB – Thomas Derbes II
The 2024 Oyster South Symposium was definitely one for the record books. The turnout was fantastic, and the camaraderie and collaboration between oyster farmers, researchers, and enthusiasts was a sight to behold. A major thank you to Bill and Beth Walton for always putting on an incredible symposium, and a big thank you to all the farmers who took time out of their busy schedule to share their oysters and stories. The Oyster South Symposium is an annual event, so keep your eyes peeled for the next symposium. I hope to see you at the next one in 2025!
The Second Line To Close Out Oyster South Symposium – Thomas Derbes II
