by Thomas Derbes II | Aug 23, 2024
Oysters are not only powerful filterers, they also provide a home and habitat for many marine organisms. Most of these organisms will fall off while the oysters are being harvested or cleaned, but some will stay behind and can be found inside or outside of your oyster on the half shell. Seeing some of these creatures might give you the “heebie jeebies” about eating the oyster, they are perfectly safe and can either be removed or, in some cases, consumed for luck. These creatures include mud worms (Polydora websteri), “pea crabs” (Pinnotheres ostreum or Zaops ostreus), and “mud crabs” (Panopeus herbstii, Hexapanopeus angustifrons or Rhithropanopeus harrisii).
Mud Worms (Polydora websteri)
A Mud Worm in an Oyster – Louisiana Sea Grant
One of the more common marine organisms you can find on an oyster is the oyster mud worm. These worms are typically red in color and form a symbiotic relationship with the oyster. Mud worms can be found in both farmed and wild harvest oysters throughout the United States. These worms will typically form a “mud blister” and emerge when the oyster has been harvested. Even though the worms look menacing and unsightly, they are a sign of a fresh harvest and a good environment. Mud worms do not pose any threat to humans and can be consumed.
If you find a mud worm on your next oyster and are still unsure, just simply remove the worm and dispose of it. Dr. John Supan, retired professor and past director of Louisiana Sea Grant’s Oyster Research Laboratory on Grand Isle, mentioned in an article that oyster mud worms “are absolutely harmless and naturally occurring,” and “if a consumer is offended by it while eating raw oysters, just wipe it off and ask your waiter/waitress for another napkin. Better yet, if there are children at the table, ask for a clear glass of water to drop the worm in. They are beautiful swimmers and can be quite entertaining.”
“Pea Crabs” (Pinnotheres ostreum or Zaops ostreus)
“Pea Crabs” are in fact two different species of crabs lumped together under one name. Pea crabs include the actual pea crab (Pinnotheres ostreum) and the oyster crab (Zaops ostreus). These crabs are so closely associated with oysters that their species name contains some form of the Latin word “ostreum” meaning oyster! Pea crabs are known as kleptoparasites and will embed themselves into the gills of an oyster and steal food from the host oyster. Even though they steal food, they seem to pose no threat to the oyster and are a sign of a healthy marine ecosystem.
A Cute Little Pea Crab – (C)2013 T. Michael Williams
Pea crabs are soft-bodied and round, giving them the pea name. Pea crabs can be found throughout the Atlantic coast, but are more concentrated in coastal areas from Georgia to Virginia. While they might look like an alien from another planet, they are considered a delicacy and are typically consumed along with the oyster. If you are brave enough to slurp down a pea crab, you might just be rewarded with a little luck. According to White Stone Oysters, “historians and foodies alike agree that finding a pea crab isn’t just a small treat, it’s also a sign of good luck!”
“Mud Crabs” (Panopeus herbstii, Hexapanopeus angustifrons or Rhithropanopeus harrisii)
Smooth Mud Crab – Florida Shellfish Lab
Just like pea crabs, “mud crabs” is another name for two different species of crabs commonly found in oysters. These crabs, the Harris Mud Crab (Rhithropanopeus harrisii), Smooth Mud Crab (Hexapanopeus angustifrons), and the Atlantic mud crab (Panopeus herbstii) to name just a few, reach a maximum size of 2 to 8 centimeters and are hard-bodied, unlike the pea crabs. Mud crabs can survive a wide range of salinities, but need cover to survive as these crabs are common prey for most of the oyster habitat dwellers, such as catfish (Ariopsis felis), redfish (Sciaenops ocellatus), and sheepshead (Archosargus probatocephalus). These crabs are not beneficial to an oyster environment as they will seek out young oysters and consume them by breaking the shell with their strong claws. If you find a mud crab in your oyster, this is one to dispose of before consuming. However, these crabs typically live on the outside of an oyster and are typically only found when you buy a sack of oysters and do not have an effect on the quality of the oyster.
Don’t Be Afraid
Hopefully this article has helped shed some light on the creatures you might experience when shucking or consuming oysters. Here is a helpful online tool to help identify some marine organisms associated with clam and oyster farms (Click Here). While most of the organisms can be consumed, we recommend the mud crabs be disposed of due to their hard shells. Remember, some of these organisms can bring you luck and with college football season around the corner, some of us might need all the luck we can get! Bring on the pea crabs!
References Hyperlinked Above
by Rick O'Connor | Aug 10, 2024
I was recently conducting a survey for diamondback terrapins from my paddleboard in a small estuarine lagoon within the Pensacola Bay System. Even if we do not find our target species during these surveys – I, and our volunteers, see all sorts of other cool wildlife. On this trip I was treated to nesting osprey, a kingfisher, large blue crabs, and even a swimming eel. But one neat encounter was the numerous stingrays.
The Atlantic Stingray is one of the common members of the ray group who does possess a venomous spine.
Photo: Florida Museum of Natural History
They were lying in the sand and grassbeds, lots of them, and they all seemed to be of one species – the Atlantic stingray. My brain immediately went to “breeding season”, but when I checked the literature, I found that it was not breeding season, but pupping season – the babies were being born.
Atlantic Stingray (Dasyatis sabina) are true stingrays in the family Dasyatidae. This means they do possess the replaceable serrated venomous barb that makes these animals so famous. They are one of the smaller members of this family. Females can reach a disk width of two feet while the smaller males will only reach about one foot. Atlantic stingrays are a warm water species, migrating if they need to find suitable temperatures. They have been found in water as deep as 80 feet but are more common in the warmer shallower waters near shore. They are very common in our estuaries and being euryhaline (they tolerate a large range of salinity), are found in freshwater systems. There is a population that lives in the St. Johns River. Atlantic stingrays feed on a variety of benthic invertebrates and have special cells in the nose to detect the weak electric fields their prey give off while buried in the sediment. They also like to bury in the sand to ambush prey as they move by.
Breeding occurs in the fall. The smaller males possess two modified fins called claspers connected to their anal fins that are used to transfer sperm to the female. The males have modified teeth they can use to bite the fins of the females. They do this to hold on and make sperm transfer more successful.
The females do not begin to ovulate until spring. So, though they receive the sperm in the fall, fertilization does not occur until the spring. Instead of laying eggs, as some rays and skates do, baby Atlantic stingrays develop within the mother. This is not the same as mammals, who produce a placental to feed the developing young, but more like an internal egg with no hard shell. The embryo is attached to, and feeds from, a yolk sac. Gestation takes about 60 days at which time the yolk sac is depleted, and the young must emerge. Birth usually occurs in late July and early August, and each female will produce 1-4 small pups whose disk are about 10cm (4in.) wide. It was this birthing/pupping period I witnessed.
I returned the following day to search for terrapins and the number of stingrays was significantly fewer. It may be that the birthing process is fast, and the adults leave the coves afterwards. It may have been because that day was the day Hurricane Debby was making landfall east of us and the water levels were abnormally high – something the rays may have noticed and decided to leave – I am not sure.
I was really hoping to see the young rays swimming around – I did not – but plan to search again soon. Stingrays make many people nervous. I witnessed several adult rays whose tails had been cut off – which is very unfortunate – but they are actually cool creatures and fun to watch while paddleboarding. Maybe I will see a baby soon.
References
Dasyatis sabina. 2023. Florida Museum of Natural History. https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/dasyatis-sabina/.
Johnson, M.R., Snelson Jr., F.F. 1996. Reproductive Life History of the Atlantic Stingray, Dasyatis sabina (Pisces, Dasyatidae), in Freshwater St. Johns River, Florida. Bulletin of Marine Science, 59(1): 74-88.
by Thomas Derbes II | Jun 21, 2024
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.
by Ray Bodrey | Jun 3, 2024
The University of Florida/IFAS Extension & Florida Sea Grant faculty are reintroducing their acclaimed “Panhandle Outdoors LIVE!” series on St. Joseph Bay. This ecosystem is home to some of the richest concentrations of flora and fauna on the Northern Gulf Coast. This area supports an amazing diversity of fish, aquatic invertebrates, turtles and other species of the marsh and pine flatwoods. Come learn about the important roles of ecosystem!
Registration fee is $40. You must pre-register to attend.
Registration link: https://www.eventbrite.com/e/panhandle-outdoors-live-st-joseph-bay-by-land-sea-tickets-906983109897
or use the QR code:
Meals: Lunch, drinks & snacks provided (you may bring your own)
Attire: outdoor wear, water shoes, bug spray and sunscreen
*If afternoon rain is in forecast, outdoor activities may be switched to the morning schedule
Held at the St. Joseph Bay State Buffer Preserve Lodge: 3915 State Road 30-A, Port St. Joe
8:30 – 8:35 Welcome & Introduction – Ray Bodrey, Gulf County Extension (5 min) |
8:35 – 9:20 Diamondback Terrapin Ecology – Rick O’Connor, Escambia County Extension |
9:20 – 10:05 Exploring Snakes, Lizards & the Cuban Tree Frog – Erik Lovestrand, Franklin County Extension |
10:05 – 10:15 Break |
10:15 – 11:00 The Bay Scallop & Habitat – Ray Bodrey, Gulf County Extension |
11:00 – 11:45 The Hard Structures: Artificial Reefs & Derelict Vessel Program – Scott Jackson, Bay County Extension |
11:45 – Noon Question & Answer Session – All Agents |
Noon – 1:00 Pizza & Salad! |
1:00 – 1:20 Introduction to the Buffer & History – Buffer Preserve Staff |
1:20 – 2:20 Tram Tour – Buffer Preserve Staff |
2:20 – 2:30 Break |
2:30 – 3:00 A Walk in the Mangroves – All Agents |
3:00 – 3:15 Wrap up & Adjourn – All |
by Rick O'Connor | May 17, 2024
Recently I participated in a local festival to educate the public about the Rice’s Whale – the newly described species in the Gulf of Mexico that is now listed as critically endangered, possibly the most endangered whale in the world’s oceans. I honestly did not know enough about it to provide much education and chose to do terrapin conservation at my table instead (something I know more about) but have since learned much about this new member of the Gulf community.
One of the more frequent comments I heard during the event was “I did not know we even had whales in the Gulf”. This is understandable since we rarely see them – most of us have never seen one. When we think of whales we think of colder climates like Alaska, New England, and the colder waters off California. But many large whales must give birth to their smaller calves in warmer waters – so, they make the trek to tropical locations like Hawaii and Florida to do so. But there are also resident whales in the tropical seas.
You first must understand that the term “whale” does not only mean the large creatures of whale hunting fame, but any member of the mammalian order Cetacea. Cetaceans include both the large baleen whales – like the blue, gray, and right whales – but also the toothed whales – like the sperm, orca, and even the dolphins.
The Right whale is another critically endangered whale found in the Gulf of Mexico. Image: NOAA.
There are 28 cetaceans that have been reported from the Gulf, 21 of those routinely inhabit here. Most exist at and beyond the continental shelf – hence we do not see them. Only two frequent the waters over the shelf – the Atlantic Bottlenose Dolphin and the Atlantic Spotted Dolphin, and only one is routinely seen near shore – the Atlantic Bottlenose Dolphin.
This image shows the location of the continental shelf and thus the location of most of the whales found in the Gulf of Mexico. Image: NOAA.
But offshore, out at the edge of the continental shelf, exists several species of large and small cetaceans. The endangered Sperm, Sei, Fin, Blue, Humpback, and Northern Right whales have been seen. Of those only sperm whales are common. Others include several beaked whales (which resemble dolphins but are much larger), large pods of other species of dolphins, pygmy and dwarf sperm whales, pygmy and false killer whales (as well as the killer whale itself), and other baleen whales such as the Minke and Bryde’s whale.
The Bryde’s whale is one of interest to this story.
The Bryde’s whale (pronounced “brood-duss” – Balaenoptera edeni) is a medium sized baleen whale, reaching lengths of about 50 feet and weighing 30 tons. It is often confused with the larger sei whale. They are found in tropical oceans across the planet and are not thought to make the large migrations of many whales due to the fact it is already here in the tropics for birth, and its food source is here as well. They reside in the northeastern Gulf of Mexico extending from the DeSoto Canyon, off the coast of Pensacola, to the shelf edge near Tampa. They appear to travel alone or in small groups of 2-5 animals. They feed on small schooling fish, such as pilchards, anchovies, sardines, and herring. Their reproductive cycle in the Gulf is not well understood.
The Bryde’s whale was thought to be the only resident baleen whale in the Gulf of Mexico. Photo: NOAA.
Strandings have occurred – as of 2009, 33 have been logged. There are no records of mortality due to commercial fishing line entanglement, but vessel strikes have occurred. Due to their large population across the planet, they were not considered for listing under the Endangered Species Act, but that may change in the Gulf region due to human caused mortality. Between 2006-2010 it was estimated that 0.2 Bryde’s whales died annually due the vessel strikes.
In the 1960s Dr. Dale Rice described the Gulf of Mexico population as a possible subspecies. It is the only baleen whale that regularly inhabits the Gulf of Mexico. And ever since that time scientists examining stranded animals thought they may be dealing with a different species.
In the 1990s Dr. Keith Mullin began examining skull differentiation and genetic uniqueness from stranded animals of the Gulf population. Dr. Patricia Rosel and Lynsey Wilcox picked up the torch in 2008. In 2009 a stranded whale, that had died from a vessel strike, was found in Tampa Bay and provided Dr. Rosel more information. In 2019 a stranded whale, that had died from hard plastic in gut in the Everglades, was examined by Dr. Rosel and her team and, with data from this skull, along with past data, determined that it was in fact a different species. The new designation became official in 2019.
The newly described Rice’s whale only exists in the Gulf of Mexico. Photo: NOAA.
The new whale was named the Rice’s whale (Balaenoptera ricei) after Dr. Dale Rice who had first describe it as a subspecies in the 1960s. With this new designation everything changed for this whale. This new species only lives in the Gulf of Mexico, and it was believed there were only about 50 individuals left. Being a marine mammal, it was already protected by the Marine Mammal Protection Act, but with this small population it was listed as critically endangered and protected by the Endangered Species Act.
New reviews and publications began to come out about the biology and ecology of this new whale. Rice’s whales do exist alone or in small groups and currently move between the 100m and 400m depth line along the continental shelf from Pensacola to Tampa. Diet studies suggest that it may feed near the seafloor, unlike their Bryde’s whale cousins. They may have lived all across the Gulf of Mexico at the 100-400m line at one time. They prefer warmer waters and do not seem to conduct long migrations.
The area where the Rice’s whale currently exists. Image: NOAA.
Being listed under the Endangered Species Act, NOAA National Marine Fisheries (NMFS) was required to develop a recovery plan for the whale. NMFS conducted a series of five virtual workshops between October 18 and November 18 in 2021. Workshop participants included marine scientists, experts, stakeholders, and the public. There were challenges identified from the beginning. Much of the natural history of this new whale was not well understood. Current and historic abundance, current and historic distribution, population structure and dynamics, calving intervals and seasonality, diet and prey species, foraging behavior, essential habitat features, factors effecting health, and human mortality rates all needed more research.
At the end of the workshop the needs and recommendations fell into several categories.
Management recommendations
- Create a protected area
- Restrict commercial and recreational fishing in such – require ropeless gear
- Require VMS system on all commercial and recreational vessels
- Require reporting of lost gear and removal of ghost gear
- Risk assessment for aquaculture, renewable energy, ship traffic, etc.
- Prohibit aquaculture in core area and suspected areas
- Reduce burning of fossil fuels
- Prohibit wind farms in core area
- Renewable energy mitigation – reduce sound, night travel, passive acoustic
- Develop spatial tool for energy development and whale habitat use
- Require aquaculture to monitor effluent release
- Develop rapid response focused on water quality issues
- Develop rapid response to stranding events
- Reduce/cease new oil/gas leases
- Reduce microplastics and stormwater waste discharge
- Work with industry to use technologies to reduce noise
- Reduce shipping and seismic sound within the core area
- Restrict speed of vessels
- Maintain 500m distance – require lookouts/observers while in core
- Consider “areas to be avoided”
Monitoring recommendations
- Long-term spatial monitoring
- Long-term prey monitoring
- Electronic monitoring of commercial fishing operations
- Necropsies for pollution and contaminants
Outreach and Engagement are needed
Top Threats to Rice’s Whale from the workshop Include:
- Small population size – vessel collisons
- Noise
- Environmental pollutants
- Prey – Climate change – marine debris
- Entanglement – disease – health
- Offshore renewable energy development
The Endangered Species Act (ESA) requires the designation of critical habitat for listed species. In July 2023 NOAA proposed the area along the U.S. continental shelf between 100-400 meters depth as critical habitat. Comments on this designation were accepted through October 6, 2023.
The proposed protection zone for the Rice’s whale including the core area. Image: NOAA.
Vessel strikes are a top concern. It is understood that the most effective method of reducing them is to keep vessels and whales apart and reduce vessel speeds within the approved critical habitat.
On May 11, 2021, NOAA Fisheries received a petition submitted by five nongovernmental agencies and one public aquarium to establish a year-round 10-knot vessel speed limit in order the protect the Rice’s whale from vessel collisions. The petition included other vessel mitigation measures. On April 7, 2023, NOAA published a formal notice in the Federal Register initiating a 90-day comment period on this petition request. The comment period closed on July 6, 2023, and they received approximately 75,500 comments. After evaluating comments, and other information submitted, NOAA denied the petition on October 27, 2023.
NOAA concluded that fundamental conservation tasks, including finalizing the critical habitat designation, drafting a species recovery plan, and conducting a quantitative vessel risk assessment, are all needed before we consider vessel regulations. NOAA does support an education and outreach effort that would encourage voluntary protection measures before regulatory ones are developed.
On that note, the Bureau of Ocean Energy Management (BOEM) did issue voluntary precautionary measures the industry could adopt to help protect the Rice’s whale. These include:
- Training observers to reduce vessel collisions.
- Documenting and recording all transits for a three-year period.
- All vessels engaged in oil and gas, regardless of size, maintain no more than 10 knots and avoid the core area after dusk and before dawn.
- Maintain 500m (1700 feet) distance from all Rice’s whales.
- Use automatic identification system on all vessels 65’ or larger engaged in oil and gas.
- These suggestions would not apply if the crew/vessel are at safety risk.
So…
This is where the story is at the moment…
This is what is up with the Rice’s whale in the Gulf of Mexico.
We will provide updates as we hear about them.
References
1 An Overview of Protected Species in the Gulf of Mexico. NOAA Fisheries Service, Southeast Regional Office, Protected Resources Division. 2012. https://www.boem.gov/sites/default/files/oil-and-gas-energy-program/GOMR/NMFS-Protected-Species-In-GOM-Feb2012.pdf.
2 Rosel, P.E., Mullin, K.D. Cetacean Species in the Gulf of Mexico. DWH NRDA Marine Mammal Technical Working Group Report. National Marine Fisheries Service. Southeast Fisheries Science Center.
https://www.fws.gov/doiddata/dwh-ar-documents/876/DWH-AR0106040.pdf.
3 A New Species of Baleen Whale in the Gulf of Mexico. 2024. NOAA Fisheries News.
https://www.fisheries.noaa.gov/feature-story/new-species-baleen-whale-gulf-mexico.
4 Rice’s Whale. NOAA Fisheries Species Directory.
https://www.fisheries.noaa.gov/species/rices-whale.
5 Rice’s Whale. Marine Mammal Commission.
https://www.mmc.gov/priority-topics/species-of-concern/rices-whale/.
6 Rice’s Whale: Conservation & Management. NOAA Species Directory. 2024.
https://www.fisheries.noaa.gov/species/rices-whale/conservation-management.
7 BOEM Issues Voluntary Precautionary Measures for Rice’s Whale in the Gulf of Mexico. 2023. U.S. Department of Interior. Bureau of Ocean Energy Management.
https://www.boem.gov/newsroom/notes-stakeholders/boem-issues-voluntary-precautionary-measures-rices-whale-gulf-mexico.
8 NOAA Fisheries Denies Petition to Establish a Mandatory Speed Limit and Other Vessel Mitigation Measures to Protect Endangered Rice’s Whales in the Gulf of Mexico. NOAA Fisheries News. FB23-079. Gulf of Mexico Fishery Bulletin. October 27, 2023.
https://www.fisheries.noaa.gov/bulletin/noaa-fisheries-denies-petition-establish-mandatory-speed-limit-and-other-vessel-0#:~:text=NOAA%20Fisheries%20denied%20a%20petition,with%20rulemaking%20at%20this%20time..
9 Petition to Establish Vessel Speed Measures to Protect Rice’s Whale. NOAA Fisheries. Protected Resources and Actions.
https://www.fisheries.noaa.gov/action/petition-establish-vessel-speed-measures-protect-rices-whale.
10 Denial of Gulf Protections Could Lead to the “Permanent Loss” of Rice’s Whale. Jim Turner. WUSF News. October 31, 2023.
https://www.wusf.org/environment/2023-10-31/denial-of-gulf-protections-could-lead-to-the-permanent-loss-of-rices-whales.
by Thomas Derbes II | May 10, 2024
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!