You might have seen a floating oyster farm while driving over Garcon Point Bridge or along Scenic Highway. Many people know them for the beautiful, tasty oysters they produce, but those farms have a major ecological benefit that many aren’t aware of. First, the oysters in those cages act as a very efficient water filter, filtering upwards of 30 gallons per day. The floating farms also act as an oasis for other marine creatures, from crustaceans to finfish, and can help increase the biodiversity in the area. Oysters are also great at sequestering carbon into their shells. Today, we will go over these ecological benefits and proper etiquette when maneuvering around the farms to enjoy some of the ecological benefits of the oyster farm.
Florida Pompano Caught Off an Oyster Farm – Thomas Derbes II
Besides being tasty, oysters are very well known for their ability to filter massive amounts of water in a single day. Research has shown rates of up to 50 gallons per day in a laboratory setting, but they filter upwards of 30 gallons per day in the wild. With most oyster farms in the area having more than 500,000 oysters on their farm, that’s more than 15,000,000 gallons of water per day per farm! Oysters can filter out any excess sediments from the water, forming them into small packets and depositing the sediment on the bottom of the bay, keeping the sediments from being re-suspended. This is very beneficial to any bay or estuary as eutrophication (More Here on Eutrophication) has been an issue in almost every bay in the southern United States.
Another benefit to oyster farms is that it is a floating oasis for all types of marine creatures. Blue crabs and stone crabs are a common threat to oysters, and they love to congregate around oyster farms waiting for an easy meal from a dropped oyster or oyster spat on cages. Common bay fish, like the Spotted Seatrout, Sheepshead, and Red Drum, have been known to hang out under the cages consuming smaller finfish and crabs, but some uncommon fish like Tripletail and Florida Pompano also patrol the cages looking for a meal. Because of its ability to hold all types of fish, fishermen love to fish around the oyster farms. Fishing around oyster farms is allowed, but most farmers want the boats to stay on the boundary of the farm and not inside of it. This is due to there being lines under the surface of the water that could potentially damage any lower unit and can cut free a line of cages. Also, it is against state law to be within the boundary of the farm if you are not an authorized harvester of that lease, and I have personally seen FWC enforce those rules. As a seasoned oyster farmer once told me “We know our farm holds fish and it is okay for them to fish the farm, heck put out some blue crab traps around it, but do not mess with the cages and stay outside of the boundary and we can all live in harmony.”
Tripletail Caught Off An Oyster Farm – Brandon Smith
Last but not least is the ability of oysters to sequester carbon and excess nitrogen into their shells and pseudofaeces (aka bio-deposits). Carbon and nitrogen sequestration is a crucial service provided by oysters that helps battle global climate change. Just as they do with excess sediments, they deposit excess carbon and nitrogen into bio-deposits that accumulate on the bottom, keeping them from being re-suspended into the waters. Oyster reefs are currently on the decline around the world, and their decline has “resulted in a forfeiture of several ecosystem services” including carbon and nitrogen sequestration and water filtration. (More Here on Carbon Sequestration)
While oysters might be tasty, we have learned about some of the ecological services oysters provide to an estuarine environment. From water filtration to increasing biodiversity to carbon/nitrogen sequestration, oysters are a major benefit to any estuary and can help fight climate change and eutrophication. Next time you see an oyster farm or reef, give oysters (and farmers) a little appreciation for their hard work in helping make the world a healthier place!
Recently I attended a workshop on wildlife tagging projects. Researchers from across the Gulf of Mexico who had projects going on in the northern Gulf were invited to present their updates. I was there to help present what we have learned about diamondback terrapins but there were numerous other talks, and the results were fascinating. Fascinating enough that I thought the public would be interested in them as well. Most of the presentations were on fish or reptiles, but the fish included interesting species such as whale sharks, tiger sharks, cobia, and tarpon. So, I am going to run a series of posts on the different species along with another series on barrier island wildlife.
I thought I would start with an introduction on the methods of wildlife tagging and why scientists tag animals. Some of the reasons may seem obvious, but with today’s modern tags, there is a lot of information scientists can gain from doing this.
Why do they tag?
With the types of tags they used when I was in school there were a few things that you could learn. (1) How far do the animals range, (2) how fast they reached those locations, (3) some idea of live longevity – you at least knew how long they were “at freedom”. With these data you could get a better idea of what their habitat range was and how they used the habitat. Some, like blue sharks, may move great distances all year long. Others, like nurse sharks, may not move more than a few miles from the point where they were tagged. Others may move seasonally, spending summer in one region and winter in another. All of these data are useful to resource managers responsible for maintaining the species population.
With the more modern electronic tags, they can learn such things as how deep they dive, how long they stay at depth, what water temperatures they may frequent, what salinity they prefer, and let you know where the animal is at any given moment in time. Today’s tags are pretty amazing.
This tag is similar to the ones we used in the 1980s on sharks. They provide a number for individual identification. Ours also had a capsule with a note on water resistant paper.
Photo: Hallprint.
How do they tag?
Well… step one to answering this question is HOW DO YOU CATCH THE ANIMAL? – not as easy as you think. Whale sharks and leatherback sea turtles are quite a handful. If your target species is something like a white shark, tiger shark, diamondback rattlesnake, there is an extra danger added. As you plan a method for your safety, you must also plan a method for their safety. The objective is not harm or kill the creature – you will learn nothing from this. When I began my career, I saw a program on how they tagged polar bears in the 1980s. They would fly over the ice in a helicopter looking for the bears. When the bears saw the helicopter, they would run for the safety of water. The scientist would try to shoot a dart into the animal to put it asleep long enough to get a tag on it. BUT if you overdosed the bear, and it made it to the water, it could drown. So, from the air, they had to gauge the weight of the bear, guess what amount of the drug to shoot, and hope they were right. If the bear did fall asleep, how “asleep was it? Did you give ENOUGH drug? Polar bears can be very dangerous. In the episode I watched the bear was asleep, but the researchers did mention that they will “play sleep” and you need to be ready. Such was the world of wildlife tagging 40 years ago.
One of the things that was also discussed when I was in school was what type of tag you were going to place on the animal. They did not have the neat tools they have now. Most tags had a capsule with a piece of paper, sometimes written in multiple languages, to call said person and report where and when they found the animal. There was usually a monetary award for doing so, or sometimes a hat or T-shirt. I remember the hat you got for reporting a tagged redfish was really neat, but I never caught a tagged one.
You did not want to place a tag that would alter the natural behavior of the animal. In the case of the polar bear, they would place an ear tag and paint a large number on its side in black paint. This made sense from the biologist’s side – flying over the ice you could see the large black “3” on a bear and know the individual. But that large black number could also be seen by their prey. Not good. I saw researchers painting the shells of gopher tortoises with all sorts of neon colors to make detection by them easier, but easier for their predators as well.
Radio tagging was used 40 years ago. This involves capturing the animal (as we have already seen – fun in itself), putting it asleep and attaching/inserting a radio tag. This tag provides a radio signal that can be detected by a receiver carried by the research holding an antenna walking/driving around following the animal. You had to be within range to hear the signal and – honestly – good at detecting the signal. Some researchers were better at this than others. As you can imagine this was only as good as your ability to keep up with the animal. At some point your car/boat would need fuel, or the animal crossed a river you could not. It provided some good data, but there were limits.
Today modern tags have solved a lot of these issues. Some new tags do not have typed notes but sensors that can detect the elevation/depth, temperature/salinity, all sorts of information that was unknown in my college days. These tags can be retrieved and downloaded on a computer to give a much better idea of how the animal spends its time and what it seeks.
This modern shark tag could provide additional information such as diving depth, water temperature, and more.
Satellite tags work well for creatures who surface frequently – sea turtles, whales, whale sharks. Satellites can detect them, and you can follow their movements/habitat preferences as they are actually using them.
For species at depth, like some sharks, cobia, tarpon, etc. there are now acoustic tags. The tag emits a signal that is detected by an array of receivers the researchers place in the environment. As the animal passes within range of the receiver it is detected, and the downloaded data gives a similar picture of how the animal uses the environment. A couple of neat things about acoustic tags are that (a) you can track satellite tagged animals while they are diving, and (b) your receivers can detect other species tagged by other researchers and let them know where their creature was. This was one reason for the workshop – so, everyone could meet everyone else and know who has tagged what and how to share information.
No tag is permanent. All are designed to fall off. Battery power will eventually fail. But no animal is stuck with this all of their lives as they could have been when I was in school. In future articles we will look at the results of some of these studies.
This tag with an antenna can be detected by a satellite and tracked real time.
Photo: USGS
Pompano?! More like Pompa-YES! Growing up in the Panhandle of Florida, I was exposed to many great fishing seasons and opportunities, from the Cobia (Rachycentron canadum) run in the spring to the “Bull” Red Drum (Sciaenops occelatus) run of the fall, but my absolute favorite season was the Florida Pompano (Trachinotus carolinus) run on the beaches. While I enjoyed being on the boat scouring the beaches with a small bucktail jig, casting at sliver flashes in the cuts of the sandbar, I had my most memorable trips on the beach with a few rods, sand spikes, and a “flea rake.” There were no bad days on the beach (as they say, it’s better than a day in the office), and when you happen upon a honey hole, it makes for an incredible day with very little effort and usually an incredible dinner to follow. Since we are rapidly approaching peak pompano season, I will pay homage to the “Silver Surfers of the Emerald Coast” with a little overview of the life of a Florida Pompano.
Beach Fishing for Florida Pompano is for Everyone, Young and Old – Thomas Derbes II
Florida Pompano have a very wide range, from Massachusetts to Brazil, and are a member of the family Carangidae (aka the Jack Family). It is a very popular sport and commercial fishery, and its rapid growth rate makes it a prime candidate for aquaculture. Florida Pompano are highly migratory fish, and they can run from the Florida Keys all the way to Texas and back in a season. In the Florida Panhandle, the Florida Pompano run starts in April/May lasting until July, with a bonus fall run in October/November when they are returning south. When fishing off the sandy beaches of the Florida Panhandle, you can run into its cousins the Permit (Trachinotus falcatus) and Palometa (Trachinotus goodei) who often get mistaken for a Florida Pompano. Another thing they have in common with Florida Pompano is their love of crustaceans including the Mole Crab (aka Sand Fleas) (Emerita portoricensis) and Atlantic White Shrimp (Litopenaeus setiferus).
Just like most members of the family Carangidae, Florida Pompano are considered “batch spawners.” A batch spawner is when a female releases her eggs into the water column and a male simultaneously releases his sperm into the water column. Female Florida Pompano can release upwards of 800,000 eggs per spawning season, and Florida Pompano typically head offshore in early spring to October in the Gulf of Mexico to spawn, and their juveniles return to the beach to grow along the shoreline. Florida Pompano can reach an aquaculture harvest size of 12 inches within one year, and males reach maturity in 1 year whereas females mature after 2 to 3 years.
Florida Pompano Eggs 12 Hours Post Fertilization – Thomas Derbes II
When it comes to table fare, Florida Pompano ranks very high on my personal fish list, and many chefs love serving pompano at their restaurants due to the great, mild taste and fillets that are of even thickness. Their diet of crustaceans helps yield a buttery, almost crab flavor and the meat is very flaky and white. There are many preparation techniques for Florida Pompano, from grilled whole to pan-fried, and pompano have even inspired their own cooking technique, “Pompano en Papillote,” or baking pompano in parchment paper.
Beautiful Florida Pompano Caught Off Pensacola Beach, Florida – Thomas Derbes II
When fishing for Florida Pompano off the beach, most anglers employ a large rod (usually a 10ft rod) with a 20lb fluorocarbon double drop loop rig and pyramid weight. The larger rod allows for maximum casting distance from the beach, giving beach anglers a chance to reach behind the first sandbar. Most anglers will bring either fresh dead shrimp or a flea rake with them to catch the prized bait, mole crabs. Pro tip, when casting out the rods, make sure you have a bait close to the shore in the “trough” and not just past the sandbar. (Learn More About Rigging Here!) If you plan to harvest a Florida Pompano, make sure you check your local regulations. In the Florida Panhandle, Florida Pompano must be 11 inches (fork-length) or larger with a daily limit of 6 per angler.
My nephew showing off his prized Florida Pompano – Zach Saway
I hope you have enjoyed this profile for the Florida Pompano. Now is the time to get your rods out of storage and ready to hit the beach!
I am sure everyone has noticed how cold this winter has been. We have had multiple days in the 20’s here in the Florida panhandle, even some snow flurries near Pensacola. I was first told this may happen by a Sea Grant colleague of mine who works with oyster farmers. Six months ago, he said the Farmer’s Almanac mentioned this would be a colder than normal winter. A few weeks later a Master Naturalist mentioned that if it was heavy “mast season” (lots of acorns on the ground) it would be a colder winter. We certainly had a heavy mast season in Pensacola this year, acorns were EVERYWHERE. And here we are. As I type this it is 27°F outside.
Though we do not see snow as often as Colorado, the panhandle does see snow from time to time.
Photo: Rick O’Connor
This past week I was at a Sea Grant meeting. We were discussing this cold and another colleague mentioned that it was an El Nino year. That’s right… it is an El Nino year, and many know that the weather does change when this occurs.
I first heard of the El Nino shortly after receiving my bachelor’s degree. I was teaching at Dauphin Island Sea Lab, and we had a video series on oceanography and one episode discussed it. It explained that commercial fishermen in Peru were the first to notice it over a century ago.
Off Peru’s coast is a large ocean current that originates in the Antarctic, flows north towards the equator passing the west coast of South America along the way. The water is cold and full of life. The Andes Mountains also run north-south along the coast. Cold air at the top of the mountains runs down towards the coast and offshore. As it blows offshore, it “pushes” the surface water of the ocean offshore as well. This generates an upwelling current moving from the ocean floor towards the surface, bringing with it nutrients from the sediments below. This nutrient reach seawater, mixing with the highly oxygenated cold water, and the sun at the surface creates the perfect environment for a plankton bloom, and a large bloom she is. This large bloom attracts many plankton feeding organisms, including the commercially sought after anchovies and sardines. This in turn supports the tuna fishery that comes to feed on the small fish. These are some of the most productive fisheries on the planet.
Based on records kept by Peruvian fishermen, every three to seven years the surface waters would warm, and the fish would go away. It was lean times for them. When it did occur, it would do so around Christmas time. So, the fishermen referred to it as the El Nino – “the child”.
Based on the video episode we showed the students, others began to notice warming along the western Pacific and realized it was a not a local event, but a global one. A high school friend of mine does sound for nature films and one of his first projects was to video the effects of the El Nino on the seal nesting season in California. As in Peru, the cold waters become warm, the bloom slows and the fish go away, with less fish the mother seals have no food so, cannot produce milk for their newborns waiting on the beach. As horrible as it sounds, and was to watch in Mike’s film, the mothers eventually abandon the newborns to starve.
The video we showed at Sea Lab followed marine biologists studying corals along the western coast of Central America. Here the waters were warming as well, warmer than normal, and the corals were stressed and dying. With orbiting satellites now in place oceanographers were able to view this event from space and watch the entire thing unfold. These images showed that during a normal year the western Pacific had cold water along California and much of South America. The waters along western Central America were warm. But during an El Nino year, warm water replaced the cold, particularly near Peru. Scientists were able to connect several events to El Nino seasons. Increases in wildfires in the western US, people were viewing the northern lights at lower latitudes, droughts occurred where it was usually wet, floods occurred where it was usually dry, and during one El Nino season the Atlanta Falcons made it to the NFL playoffs. Weird things were happening.
The obvious question for science is what drives these El Nino events?
It is understood that our weather and climate are driven by ocean currents. The “dry air” everyone talks about in the western US is driven by the cold California Current. Likewise, the “humid air” of the southeastern US is driven by the warm Gulf Stream. If you alter these currents, you alter the weather and climate of the region. How do you alter ocean currents?
Warm water in the eastern Pacific indicates an El Nino season.
Graphic: NOAA
In the 1980s, when I was teaching at Dauphin Island Sea Lab, the video suggested a connection to sunspots on the surface of the sun. At the time, they were not sure whether the increased sunspot activity triggered the El Nino, or whether there was something else going on, but there was a correlation between the two.
One explanation comes from a textbook on oceanography I used when I was teaching marine science during the 1990s1. It explains the event as such…
During “normal years” cold water from the Arctic and Antarctic runs along the western coasts of North and South America – both heading towards the equator. Once there, the earth’ rotation moves this water westward towards Australia and Indonesia, warming the water as it goes.
Apparently, the ocean currents cannot transport and disperse these warm waters effectively once they reach the western Pacific. Thus, warm water begins to build there.
This accumulating warm water seems to reverse the trade winds that normally flow from the eastern Pacific to the western along the equator. This wind reversal occurs between November and April. It mentions that in the late 1990s the cause of this wind reversal was not well understood.
This wind reversal is often followed by the development of twin “super typhoons” (very strong typhoons) north and south of the equator.
The extreme warm water in the western Pacific affects the weather in the region and this “heat mass” expands spatially. During this expansion, the high-pressure system that sits over the eastern Pacific, bringing them the dry air we know California for, weakens. At the same time, the normal low-pressure system over the western Pacific weakens and, in a sense, things are flipped. This atmospheric change is called the Southern Oscillation, and the entire event was termed the El Nino Southern Oscillation (ENSO).
The power of the typhoons moves warm water from the western Pacific across the equator to the America’s. The waters there warm and the historic El Nino occurs. This movement takes several months.
The El Nino will persist for one to two years. When the warm water eventually releases its heat, the waters cool, and normal conditions return. Until the next El Nino forms.
In the 1990s they had already noticed an increase in the frequency of El Ninos (based on old fishermen’s logs). They suggest climate change may be driving this.
During El Nino years weather patterns change globally, as mentioned above. This altering of the weather impacts all sorts of biological processes, as mentioned above.
Often, the “return” of colder water along the western Pacific “overshoots” normal temperatures and the ocean becomes colder than normal. This has been termed the La Nina.
I kind of imagine the whole process like a sloshing pool of water flowing towards one end of the pool, bouncing off and sloshing back to the other. But instead of water “sloshing around” it is temperatures.
But this was 1996. Have scientists learned anymore about this event?
Not much has changed in their explanation, other than we are much better at predicting when they will happen and alert the public so that farmers, fishermen, fire fighters, etc. are prepared. They do seem to be increasing in frequency.
For the 2024 El Nino, which NOAA began alerting the public in the summer of 2023, they are predicting it to continue for several seasons2. There is no doubt that this winter is colder than normal. The Florida panhandle also experienced a drought this past fall. But… during most El Nino years, hurricanes are few in the Gulf of Mexico. We will see, and watch, how the rest of the year rolls out.
Reference
1 Gross, M.G., Gross, E. 1996. Oceanography; A View of Earth. 7th edition. Prentice Hall. Upper Saddle River, New Jersey. Pp 472.
2 El Nino / Southern Oscillation (ENSO) Diagnostic Discussion. Jan 11, 2024. National Weather Service Climate Prediction Center. National Oceanic and Atmospheric Association.
And it’s a good thing! Green gill oysters are prized in the oyster community. In the Carolinas and Northern France, green gill oysters are a seasonal, cherished crop and a product of the saying “You are what you eat!” The phytoplankton, Haslea ostrearia, is the typical culprit, and their distribution is measured by direct observation from plankton tows or the occurrence of green-gilled oysters. The exact distribution is unknown, but there are reports of H. ostrearia throughout the Atlantic, Pacific, and Indian oceans. Haslea ostrearia is a beautiful pennate diatom that contains a water-soluble blue pigment known as marennine (More Here). Marennine’s production is stimulated by long photoperiods, blue light, and high light/low cloud weather. It can also be released into the water and into the flesh of organisms (typically oysters) that consume them.
Fresh out of the water Grayson Bay Oyster with green gills! – Brandon Smith, Grayson Bay Oyster Company
Pensacola Bay, and surrounding areas, had a pretty mild fall in terms of rainfall, and the bays have turned a beautiful green-blue hue as the bays have risen in salinity and phytoplankton typically found in the Gulf of Mexico were able to survive. Brandon Smith, owner of Grayson Bay Oyster Company, was out working his farm January 7th, 2024, and sent a text to me saying “take note of the green gills,” and I was very shocked and happy to see actual, green-gilled oysters in our local waterways. He graciously harvested a few dozen to examine (and let me taste test), and I was able to confirm the presence of green gills in the oysters. After further research on H. ostrearia, it seems as though the pennate diatom made it into our bays and is the culprit of this wonderful surprise.
A local Grayson Bay Oyster displaying green-gills – Thomas Derbes II
When I shucked my graciously donated oysters from Grayson Bay, I was reminiscing on the first time I came across green-gilled oysters. The first batch of green gill oysters I ate came from an oyster farm in North Carolina called N. Sea Oyster Company. Their green-gilled beauties “Divine Pines” were requested by a wedding I was catering for, and I was able to slurp down one to get talking and tasting notes. The seasonal Divine Pines offered a sweet yet salty taste and became one of my favorite out-of-area oysters to serve at events and to personally consume. While beautiful, the green-gilled oysters are usually only found in the fall/winter months. These green-gilled Grayson Bays were very comparable and offered a salty yet very sweet and minerally finish. The H. ostrearia is responsible for not only the green gills, but the sweet tasting notes, and I highly recommend adding any green-gilled oyster to your fall/winter raw bar selection.
References:
Turpin, Vincent & Robert, J-M & Philippe, Goulletquer & Massé, Guillaume & Rosa, Philippe. (2008). Oyster greening by outdoor mass culture of the diatom Haslea ostrearia Simonsen in enriched seawater. Aquaculture Research. 32. 801 – 809.
