The Plight of the Bay Scallop

The Plight of the Bay Scallop

Many people enjoy scallops.  Just as many enjoy scalloping.

It is a great Florida family activity where everyone gets to snorkel in relatively shallow – safe waters.  You explore the grassbeds for a myriad of cool marine creatures yelling across the bay to friends about all the neat things you are seeing.

Bay Scallop Argopecten iradians
http://myfwc.com/fishing/saltwater/recreational/bay-scallops/

And of course, there are the scallops.  Sitting on top of the grass blades with their undulated ridged shells and ice blue eyes.  You reach to grab one and they begin the “clap” their shells together to escape being captured.  You finish the adventurous day with your limit of scallops, and it is time to eat – broiled in butter and some seasoning is my favorite.

 

It is great fun.  However, it is becoming harder to find them.

Once found in grassbeds from Pensacola to Miami, the recreational harvest has been restricted to the Big Bend area – the commercial no longer happens.  Everywhere their numbers are down and many locations within their historic range, you cannot even find them.  Since 2015, Florida Sea Grant has conducted scallop searches in the Pensacola Bay area using citizen volunteers and have found only one live animal.  We have found numerous shells of these creatures, who only live a year… maybe two.  We have had reports of live scallops in the bay area outside of our formal search dates, I have personally found some, but the numbers are still very low – low enough that recreational harvesting in the Pensacola Bay area is closed indefinitely.

 

The story is the same from south of the Big Bend.  Scallop searches are conducted every year and returns are low, or non-existent.  So, the focus turns the Big Bend.

 

They are famous for the scallop seasons.  Floridians travel from all neighboring counties, and from across the state, to partake in this fun activity.  It is good business for these local communities.  For some, it is the biggest money maker of the year.  However, now we are hearing stories of low harvest numbers in some parts of the Big Bend.  In recent years, Port St. Joe Bay has suffered from algal blooms and red tide that not only closed the waters to harvesting for swimming safety reasons, but because the scallop numbers declined as well.  One story out of Hernando County indicated that the numbers in this region are now down.  You must consider overharvesting as a problem as well.

Prepared properly: One of the finest meals you will ever have.

FWC is interested in restoring these animals to parts of their range where they were once common.  The Scallop Sitters program is one where volunteers can hang caged scallops raised in state hatcheries from their docks, protected from predators, and allow them to mass spawn.  The first pilot project in our area was in Bay and Gulf counties… last year… when Hurricane Michael came through.  Obviously, they will have to start over.

 

What is needed to extend this project into other bay areas?

 

Well, you certainly do not want to put them into waters where you know they will die.  The scallop populations declined for a reason – primarily habitat loss and overharvesting.  Excessive stormwater runoff decreased much needed salinity and increased grass killing turbidity.  Loss of seagrass equates to loss of scallops.  Florida Sea Grant is currently working with the University of West Florida, and citizen volunteers, to monitor seagrass growth and density in Santa Rosa Sound and Big Lagoon.  We will have a report on this year’s work later this fall.  We are also working with citizen scientists monitoring salinity in these bodies of water hoping for a mean of 20 parts per thousand or better.  We will have the summer salinity reports out at the end of September.  We hope these data will support the argument of extending the scallop sitters program further west.

A pile of cleaned scallops found in a parking lot on Pensacola Bay. harvesting scallop in Pensacola Bay is illegal.
Photo: Rick O’Connor

But there is the question of overharvesting.

In recent years we have found evidence of locals in the Pensacola Bay area illegally harvesting the few scallops we have.  Some residents do not know that it is illegal to harvest in these waters – it is – and the only way we can successfully restore them, is allow them to mass spawn.  To do this, we need large numbers.

 

Each year Florida Sea Grant conducts the Great Scallop Search in the Pensacola Bay area.  We also host a “Bio-Scavenger Hunt” in the fall where scallops are one of the target species.  If you are interested in volunteering, contact Rick O’Connor at the Escambia County Extension Office – (850) 475-5230 ext. 111, or roc1@ufl.edu.

Microplastics Awareness Month

Microplastics Awareness Month

It is an amazing product actually… plastic.  It can be molded into all sorts of shapes and forms.  In some cases, it can be more durable than other products, it is lighter and cheaper than many.  Slowly over time, we began to use more and more of it.  I remember as a kid in the ‘60s Tupperware products were common.  Cups and bowls with resealable lids.  Coffee cups followed, then 2-Liter coke bottles, to the common water bottle we see today.  As I look around the room, I am in right now there are plastic pens, picture frames, suntan lotion bottles, power cords, rain jacket, the cover and keyboard of this laptop.  Plastic is part of our lives.

A variety of plastics ends up in the Gulf. Each is a potential problem for marine life. Photo: Rick O’Connor

Unfortunately, being relatively inexpensive, it is also easily disposed of.  Many forms of plastic are one-time use.  In some cases, we purchase and discard them without really using them – plastic wrap covering fruit, or the famous plastic grocery bags.  Most of this discarded plastic eventually finds its way into the environment.  Data from the 2017 International Coastal Clean Up, showed that globally all the top 10 items collected were plastic.  Most of it was cigarette butts and items related to food and drink.  Even with all the press, the number of plastic grocery bags collected actually increased.  One study conducted in 2015 estimated the amount of plastic in our oceans would be enough to fill 5 plastic grocery bags for each foot of shoreline of the 192 countries they surveyed.

 

There is a lot of plastic out there.  One researcher commented… it’s all still there.  Some have estimated that plastic takes about 600 years to completely break down.  Plastic items degrade while exposed to sun, sand, and saltwater.  But they never go away.  They become smaller and smaller to a point where you cannot even see them anymore – these are called MICROPLASTICS.

 

Microplastics are defined as any plastic items 5mm or smaller in diameter.  Most plastics float, and most microplastics float as well, but pieces of microplastics have been found throughout the water column and even in the deep-sea sediments.  They come in two forms; primary and secondary.

“Nurdle” are primary microplastics that are produced to stuff toys and can be melt down to produce other products.
Photo: Maia McGuire

Primary microplastics are plastics that are produced at these small sizes.  All plastic products begin as small beads called nurdles.  Nurdles are produced and shipped to manufacturing centers where they are melted down and placed into forms which produce car bumpers, notebook covers, and water bottles.  Many of these nurdles are shipped via containers and spills occur.  Other primary microplastics are microbeads.  These are used in shampoo, toothpaste, and other products to make them sparkle, or add color.  As they are washed down our sinks and showers, they eventually make their way into the environment.  Sewage treatment facilities are designed to remove them.

 

Secondary microplastics are those they were originally macroplastics and have been broken down by the elements.  Plastic fragments and fibers are two of the more common forms of secondary microplastics.  These micro-fibers make up 70-80% of the microplastics volunteers find in Florida waters.  Many of these fibers come from our clothing, from cigarette butts, and other sources.

 

Are these microplastics causing a problem?

 

It is hard to say whether they have caused the decline in populations of any group of marine organisms, but we do know they are absorbing them.  Studies have found microscopic plankton have ingested them, and some have ceased to feed until they pass them, if they do pass them.  There has been concerned with the leaching of certain products in plastic to make them more flexible in bottled water.  These products have been found in both plankton and in whales.

The most common form of microplastic are fibers.
Photo: UF IFAS St. Johns County

Another problem are the toxic compounds already in seawater.  Compounds such as PCBs, PAHs, and DDT.  It has been found that these compounds adhere to microplastics.  Thus, if marine organisms consume (or accidentally ingest) these microplastics, the concentrations of these toxins are higher than they would be if the microplastics were not present.

 

Studies have shown:

–          Pacific oysters had decreased egg production and sperm motility, fewer larvae survived, and the survivors grew more slowly than those in the control population.

–          Plastic leachate impaired development of brown mussel larvae.

–          Shore crabs fed microplastics consumed less food over time.

A recent summer research project at the University of West Florida found microplastics within the gut and tissues of all seafood products purchased in local seafood markets.  And recently a study of human stool samples from volunteers in Europe and Japan found microplastics in us.  Again, we are not sure of the impact on our health from this, but they are there.

 

So, what do we do?

 

One idea is to remove these microplastics from the ocean – skimming or filtering somehow.  As you might guess, this also removes much needed phytoplankton and zooplankton.

 

There is the ole “Recycle, Reuse, Reduce” idea we learned when we were in school.  Unfortunately, recycling plastic has not been working well.  Being a petroleum product, the price of oil can dictate the price of recycled plastic.  With low oil prices comes low recycling profits.  In many cases it can be cheaper to produce and purchase new plastic products.  Also, unlike glass, plastic can only be recycled so many times.

Boxes providing garbage bags and disposal.
Photo: Pensacola Beach Advocates

Reuse and reduce may be the better options.  If you must purchase plastic items, try to reuse them.  In many cases this is difficult and the reduce method is the better option.  Reduce the purchase of plastic items such as your own drinking container instead of using the one-time plastic cup at meetings or events.  And of course, reusable grocery bags.  You will have to think on how to reduce some items, but most can be done.

 

There are numerous more suggestions, and more information, on Dr. Maia McGuire’s Flagler County Extension website – http://sfyl.ifas.ufl.edu/flagler/marine-and-coastal/microplastics/.

 

Help make others more aware of microplastics during Microplastics Awareness Month.

Bioluminescence: Light Show Beneath the Sea

Bioluminescence: Light Show Beneath the Sea

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).

glowing jellyfish

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.

The Magnificent Mullet

The Magnificent Mullet

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.

Manatees in Old River

Manatees in Old River

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.

Another Mystery in the Marsh – The Gulf Salt Marsh Snake

Another Mystery in the Marsh – The Gulf Salt Marsh Snake

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.