by Erik Lovestrand | Aug 16, 2019
If you like summer fireworks events, there is a great show ongoing during our warm summer months that you shouldn’t miss. Find an unlit dock along our coastal environs and take the time to pause, get down on your knees, and gaze into the starry… water. Our night skies are quite impressive in their own right, but our night waters will also put on an amazing show of glowing critters and flashing lights if you take the time to notice. Thousands of different marine organisms have the ability to produce light and the purposes served by this trait are many. Some animals use this tactic as camouflage and others to stand out for one reason or another. Being seen by others can assist with predation (luring), defense (startling or warning), or even reproduction (attracting a mate).
Thousands of marine creatures create their own light, including many jelllyfish
Bioluminescence is the most accurate term for light emitted by living organisms; although sometimes you will hear it referred to as fluorescence or phosphorescence. Fluorescence however, is the term describing something that absorbs light energy from an external source and then almost immediately re-emits it. When the external source goes away, so does the fluorescence; i.e. it doesn’t keep going in the dark. Phosphorescence describes when something absorbs light energy from an external source and then slowly re-emits it over a longer timeframe, i.e. glowing stickers. In contrast to these other terms, bioluminescence results from a chemical reaction within the body of an organism. The trigger mechanisms can be quite varied in nature and some are even directly controlled by linkages with an animal’s brain and nervous system. Other times the light is triggered simply by a physical disturbance. This is the most common phenomenon observed by people as the water seems to sparkle from a boat’s wake at night or waves breaking in the surf. One of my earliest memories of this was as a teenager in the Keys while wading along the shore at night. Each splash would trigger a shower of sparks.
So, what is taking place to create this chemical reaction that gives off light? Well, scientists have learned a lot about it but still don’t have all of the answers regarding the incredible variety of ingredients and processes involved in the bioluminescent realm. In general, a molecule called luciferin is involved and when exposed to oxygen, it gives off light. An enzyme named luciferase acts as a catalyst to help speed up the reaction. There are apparently many types of luciferins utilized by different animals; and I’m guessing, many variations on the actual luciferases involved too.
During summertime the warm waters of the Gulf and our coastal estuaries are rich with planktonic life. If you look close at a dock post beneath the water you will see continual, tiny flashes being triggered as water moves around the stationary post. When you walk down the dock (very carefully, without a flashlight), you can also see streaks of light from startled fish swimming away. This light is emitted by single-celled dinoflagellates that are triggered by a disturbance near them. One fascinating account I’ve read, told the story of Jim Lovell (Apollo 13 astronaut), who used bioluminescence to find his way safely home. When the navigation equipment failed at night in the navy plane he was flying, he was able to turn off his cockpit lights and see the glowing wake from his carrier and follow it. I’m sure he was forever grateful to the tiny marine creatures that made this possible! If you can get to a coastal dock near you this summer, be sure to turn out the lights, and look down in the water for a spectacular, miniature fireworks show. No earplugs required.
by Rick O'Connor | Jun 28, 2019
Or just mullet… maybe you prefer “mu-lay”…
Either way it is a fish we all know and love. Those of us who grew up here on the Gulf coast know this fish as part of our culture. I remember numerous family gatherings where fried mullet was the order of the day. Along with grits, baked beans, cole slaw, and iced tea you had your “mullet plate”. It is the fish of choice for Catholic fish fries during Lent. It is the icon of the “Mullet Toss” event at the Flora-Bama, which draws huge crowds and people plan for all year. It almost became the mascot of minor league baseball team. One my favorites was a story told to me by a colleague who used to teach at the old Booker T. Washington High School when it was on “A” street. He told me each morning the janitorial staff would catch mullet for the school lunches. They would have your classic “mullet plate” for lunch everyday – fresh from the bay – how good is that. It is the fish that “jumps” and everyone knows what it is.
The Striped Mullet.
Image: LSU Extension
I paddle area waters monitoring a variety of things assessing the health status of Pensacola Bay. While out there I see a lot of wildlife, but mullet is one of the more common ones. Wherever I go, open intracoastal waterway, grassbeds, bayous, marshes, even backwater creeks where the water is almost stagnant, I find mullet. You see their swirls, schools gliding beneath your paddleboard or kayak, I even watched one make unusual circles with its head above water once. And always the “jump”, they are always jumping. But I had never really thought much about their biology. Many folks observe and study more unusual, or problematic fish, like lionfish. But the mullet slips by the radar. It is more like… “oh yea, then there is the mullet”, and we do not think of them more than that.
Local recreational and commercial fishermen are aware of their movements and behaviors. They know when and where they will be at different times of the year. But I thought I would do some digging and educate the rest of you about this amazing fish who is like part of the family.
There are actually two species of mullet swimming in area waters. The striped mullet (Mugil cephalus) is more common. It is one that the commercial fishermen seek, FWC lists as the “black mullet” on their commercial guides. The other is the white mullet (Mugil curema). They differ in that the anal fin of the white mullet has 9 soft rays; the striped has 8. Large striped mullet will have stripes, which the large white mullet lack. The juveniles of both species lack stripes. When caught and still alive, the white mullet will have a bright gold spot on the operculum (the bone covering the gills), this is lacking on the striped mullet.
A fisherman throws a cast net to catch mullet at White Point in Choctawhatchee Bay
Mullet are euryhaline… meaning they can tolerate a wide range of salinities and can be found in fresh or saltwater. They travel in schools, feeding off of the bottom. Their diet consists of bacteria and single-celled algae found attached to plants. They pick at the bottom, and scrape seagrasses consuming these.
They spawn most of the year, but the peak is between October and December. Spawning takes place in the open Gulf of Mexico, sometimes far offshore. They become sexual mature at three years old and can produce 0.5 – 4 million eggs. Mullet roe (fish eggs) is a local delicacy for some. They have been reported at an age of 16 years – long time for a fish.
While studying marine biology in college, I remember someone asked our professor why mullet jump. He paused for several seconds and then replied – “for the same reason manta rays jump”… there was a long pause… so we bit the bait – “okay, why do manta rays jump?” “We don’t know”. Classic…
However, they now have an idea why. It is believed they clean their gills doing this and also oxygenate those gills in stagnant, warm, low oxygen waters that mullet find themselves in periodically.
A striped mullet died during cold stress.
It is a local commercial fishery. Between 2018-2019 412,421 pounds of mullet were landed in Escambia County, another 151,638 pounds in Santa Rosa. This made it the number one fish for the season. Between the two counties the value of the fishery was $456,892 but sells better as a bait than as food.
It is truly a magnificent fish. Their numbers have increased since the 1995 net ban and has become one of the more common fish we see while exploring local estuarine waters. I certainly will not take them for granted any longer.
by Rick O'Connor | Jun 7, 2019
This is becoming an annual summer encounter – manatees in (near) the Intracoastal Waterway of Pensacola Bay area. They have been before, it is not uncommon for them to be seen at Palafox Pier Marina, but in the last few years groups of five to nine manatees have been spotted drifting along the shorelines and hanging around docks in Gulf Breeze and the Perdido Key area.
Manatee swimming in Big Lagoon near Pensacola.
Photo: Marsha Stanton
I cannot say what this means but we are not alone with these new visitors along the Gulf coast. There are enough manatee sightings in the lower portions of Mobile Bay that manatee signs have been placed along Magnolia River and a manatee watch hotline has been set up at Dauphin Island Sea Lab. There are at least 40 resident manatees in the Wakulla River. And now, at least in the last two years, small groups have been seen in our area. Concerned whether these manatees were returning to southwest Florida for the winter during the red tide, there were plans to tag some of them – I am not sure if that was done or not.
So, what does this mean for us?
Well, your first thought is the concern over boat strikes. The manatee has actually been protected by Florida law since 1893. Their numbers have increased to 6600 animals and so their status has been changed from endangered to threatened. That said, they are still protected by both the Endangered Species Act and the Marine Mammal Protection Act.
According to an FWC report, in 2018, 824 manatees died in Florida. The top five causes were (1) Natural causes – 27%, (2) Undetermined – 20%, (3) Watercraft – 15%, (4) Perinatal death – 14%, and (5) Unrecovered – 13%.
There were 17 deaths reported from the Florida panhandle. Wakulla (7), Franklin and Escambia (3), Bay, Gulf, Okaloosa, and Walton (1).
Cold stress was the #1 cause of death (7) – Bay, Escambia, Franklin, Okaloosa, and Walton
Followed by boat strikes (4) – Wakulla (2), Escambia (2)
Unrecovered (3) – Franklin, Gulf, and Wakulla
Undetermined (2) – Wakulla
Perinatal (1) – Wakulla
Natural (1) – Wakulla
So far, in 2019 there have been 259 manatee fatalities. The top five causes were (1) Watercraft – 25%, (2) Undetermined – 24%, (3) Cold stress – 15%, (4) Unrecovered – 13%, and (5) Natural – 13%
In the Florida panhandle there have been four deaths so far. Bay County has had two due to cold stress and Wakulla has had two – one was unrecovered and the other was “other” but human related.
Manatees hanging out in Wakulla Springs.
Photo provided by Scott Jackson
So, statewide watercraft are still a big concern. Two of the three deaths in Escambia were boat related. The manatees tend to stay out of the boat channels, so it is recommend boaters remain in the navigable channels while heading to a destination and, when leaving the channel to reach that destination, go idle speed and have a lookout.
Manatees have actually benefitted the management of invasive hydrilla in the Wakulla River. FWC no longer has to treat it – the manatees are eating it all. Pensacola Bay is currently experiencing a bloom of epiphytic (attached) drift algae on the seagrass beds. Maybe, just maybe, the few manatees we see will consume as much algae they can.
I can understand the concern some boaters may have with manatees in the area. However, they do provide some benefits and are the highlight of the day for any local or visitor who may see them. We should welcome them and do what we can, within the law, to keep them safe. If you spot a manatee, please report it to the Dauphin Island Sea Lab hotline: 1-866-493-5803. Or email manatee@disl.org.
by Rick O'Connor | May 17, 2019
I am writing about this animal because, though it is rare to see them, our terrapin volunteers saw two this past week; and maybe you will too.
The round pupil and vertical jaw stripes indicate this is the nonvenomous Nerodia. Photo: Carole Tebay
The Gulf salt marsh snake is one of those, like the eastern coral snake, that is actually common – just rare to see. It is rare to see because (a) it lives in muddy salt marshes, where we rarely venture, and (b) it is mostly nocturnal – and even fewer of us venture into muddy salt marshes at night.
It is in the genus Nerodia, which includes the common water snakes like the banded water snake (Nerodia fasicata). It is a harmless nonvenomous snake. However, because of where it lives, it is often confused with a cottonmouth and is killed. A common name for this snake in Alabama is “bay moccasin”.
Their name is Nerodia clarkii, but it is a subspecies of this group – so the actual name is Nerodia clarkii clarkii. The other two subspecies are found in Florida. The Mangrove salt marsh snake (Nerodia clarkii compressicauda) is found from central Gulf coast of Florida, around the Keys to Indian River County on the Atlantic coast. The Atlantic salt marsh snake (Nerodia clarkii taeniata) has a very small range. Originally reported in Volusia, Brevard, and Indian River counties – due to the northern expansion of mangroves, it is believed to only be in Volusia County now. It is listed as THREATENED both federally and with the state. Our Gulf salt marsh snake is found from central Florida to Texas.
The nonvenomous Gulf Salt marsh Snake.
Photo: Molly O’Connor
It is a relatively small snake, only reaching a length of around 15-20 inches, though some have been reported at 30 inches. They possess two long yellowish-tan stripes running laterally the length of its body, the only species of Nerodia to do so. Again, they move at night feeding on small crabs, shrimp, frogs, and small fish. During daylight hours they hide beneath the wrack or other vegetation avoiding herons, egrets, and larger blue crabs. Lacking the needed glands, they cannot desalinate seawater the way sea turtles and terrapins can. All of their freshwater comes from their food and from rainfall.
They breed in the spring, possibly why we are seeing them now, and give live birth to about 10 young in midsummer. They are of moderate conservation concern in Alabama due to the loss of salt marsh. The loss of salt marsh habitat and rise of sea level are their major concerns at this point.
I do need to warn you, though it is a small, nonvenomous snake, they will bite. If bitten, soap and water will do the job. For me, and others, it is actually exciting to see them because of their reclusive nature. If you see one while exploring our intracoastal waters, know that you are not in any danger but rather lucky to see this “mystery of the marsh”.
The Gulf Salt Marsh Snake swimming in a local marsh.
Photo: Carole Tebay
References
Gulf Salt Marsh Snake – Texas Parks and Recreation – https://tpwd.texas.gov/huntwild/wild/species/gulfsnake/.
iNaturalist – https://www.inaturalist.org/guide_taxa/776612.
Outdoor Alabama – Alabama Department of Conservation and Natural Resources – https://www.outdooralabama.com/non-venomous-snakes/gulf-saltmarsh-snake.
Atlantic Salt Marsh Snake – N.c.taeniata – U.S. Fish and Wildlife – https://www.fws.gov/northflorida/Species-Accounts/Atl-Salt-Marsh-Snake-2005.htm.
by Laura Tiu | May 3, 2019
There are five species of sea turtles that nest from May through August on Florida beaches, with hatching stretching out until October. The loggerhead, the green turtle, and the leatherback all nest regularly in the Panhandle, with the loggerhead being the most frequent visitor. Two other species, the hawksbill and Kemp’s Ridley nest infrequently. All five species are listed as either threatened or endangered under the Endangered Species Act. Due to their threatened and endangered status, the Fish and Wildlife Conservation Commission/Fish and Wildlife Research Institute monitors sea turtle nesting activity on an annual basis.
A group checks out a recently hatched sea turtle nest on the dunes in south Walton county in Florida.
Annual total nest counts for loggerhead sea turtles on Florida’s index beaches fluctuate widely and scientists do not yet understand fully what drives these changes. From 2011 to 2018, an average of 106,625 sea turtle nests (all species combined) were recorded annually on these monitored beaches. In 2018, there was a slight decrease in nests with only 96,945 nests recorded statewide. This is not a true reflection of all of the sea turtle nests each year in Florida, as it doesn’t cover every beach, but it gives a good indication of nesting trends and distribution of species.
2015-2018 Florida Panhandle turtle nesting totals for all species.
If you want to see a sea turtle in the Florida Panhandle, please visit one of the state-permitted captive sea turtle facilities listed below, admission fees may be charged. Please call the number listed for more information.
- Gulf Specimen Marine Laboratory
222 Clark Dr
Panacea, FL 32346
850-984-5297
Admission Fee
- Gulf World Marine Park
15412 Front Beach Rd
Panama City, FL 32413
850-234-5271
Admission Fee
- Gulfarium Marine Adventure Park
1010 Miracle Strip Parkway SE
Fort Walton Beach, FL 32548
850-243-9046 or 800-247-8575
Admission Fee
- Navarre Beach Sea Turtle Center
8740 Gulf Blvd
Navarre, FL 32566
850-499-6774
The Foundation for The Gator Nation. An Equal Opportunity Institution
by Rick O'Connor | Apr 18, 2019
Oysters are like snakes… you either like them or you hate them. You rarely hear someone say – “yea, their okay”. It’s either I can’t get enough of them, or they are the most disgusting thing in the sea.
Courtesy of Florida Sea Grant
That said, they are part of our culture. Growing up here in the Florida panhandle, there were oyster houses everywhere. They are as common on menus as French fries or coleslaw. Some like them raw, some like them in gumbo or stews, others are fried oyster fans. But whether you eat them or not, you are aware of them. They are part of being in the northern Gulf of Mexico.
In recent decades the historic oyster beds that supported so many families over the years have declined in production. There are a variety of stressors triggering this. Increased sedimentation, decreased salinity, overharvesting, not returning old shell to produce new reefs, and many more. The capitol of northwest Florida’s oyster coast is Apalachicola. Many are aware of the decline of harvest there. Certainly, impacted by the “water wars” between our state and Georgia, there are other reasons why this fishery has declined. I had a recent conversation with a local in Apalachicola who mentioned they had one of their worst harvest on record this past year. Things are really bad there.
An oysterman uses his 11 foot long tongs to collect oysters from the bottom of Apalachicola Bay
Photo: Sea Grant
Despite the loss of oysters and oyster habitat, there has not been a decline in the demand for them at local restaurants. There have been efforts by Florida Sea Grant and others to help restore the historic beds, improve water quality, and assist some with the culture of oysters in the panhandle.
Enter the Bream Fisherman’s Association of Pensacola.
This group has been together for a long time and have worked hard to educate and monitor our local waterways. In 2018 they worked with a local oyster grower and the University of West Florida’s Center for Environmental Diagnostics and Bioremediation to develop an oyster garden project called Project Oyster Pensacola. Volunteers were recruited to purchase needed supplies and grow young oysters in cages hanging from their docks. Participants lived on Perdido, Blackwater, East, and Escambia Bays. Bayous Texar, and Grande. As well as Big Lagoon and Santa Rosa Sound. The small, young oysters (spat) were provided by the Pensacola Bay Oyster Company. The volunteers would measure spat growth over an eight-month period beginning in the spring of 2018. In addition, they collected data on temperature, salinity, and dissolved oxygen at their location.
After the first year, the data suggests where the salinity was higher, the oysters grew better. Actually, low salinity proved to be lethal to many of them. This is a bit concerning when considering the increase rainfall our community has witnessed over the last two years. Despite an interest in doing so, the volunteers were not allowed to keep their oysters for consumption. Permits required that the oysters be placed on permitted living shoreline projects throughout the Pensacola Bay area.
Oyster bags used in a bulkhead restoration project.
Photo: Florida Department of Environmental Protection
We all know how important oysters are to the commercial seafood industry, but it turns out they are as important to the overall health to the bays ecology. A single oyster has been reported to filter as much as 50 gallons of seawater an hour. This removes sediments and provides improved water clarity for the growth of seagrasses. It has been estimated that seagrasses are vital to at least 80% of the commercially important seafood species. It is well known that seagrasses and salt marshes are full of life. However, studies show that biodiversity and biological production are actually higher in oyster reefs. Again, supporting a booming local recreational fishing industry.
This project proved to be very interesting in it’s first year. BFA will be publishing a final report soon and plan to do a second round. For the oyster lovers in the area, increasing local oysters would be nothing short of wonderful.
