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Cottonmouths of Our Barrier Islands

Cottonmouths of Our Barrier Islands

I am going to end 2023 with an article on a project I hope to conduct in 2024.  It will focus on insular cottonmouths and will focus on the western panhandle, though those in the eastern panhandle might be interested and could help.  For obvious reasons, conducting this project as a citizen science one is not the best idea.  Cottonmouths are venomous snakes and can be dangerous, but there could be opportunities where citizens could be of help (a road killed snake for example). 

The cottonmouth is one of the more commonly encountered snakes in the western panhandle. Photo: Bob Jackson

The story is quite interesting.  Most books and articles on cottonmouths indicate they inhabit freshwater habitats where water flow is slower.  Though found in the back waters of rivers, they are not as common within the rivers themselves.  Golf courses, ponds, lakes, and reservoirs are other places they frequent.  There are records of them on coastal barrier islands and in the upper Florida Keys.  Swimming across saltwater is not surprising but existing on a xeric, sandy barrier island would not fit the typical habitat of this snake.  Most of the accounts on barrier islands are in the Big Bend region and many know that there are freshwater habitats on some of these islands.  If a cottonmouth could reach the island, there could be a suitable habitat for them.  But you could argue that these habitats are not large enough to support a large population.  The carry capacity of a population is determined by the amount of space and resources available.  Cottonmouths are opportunistic feeders – so, finding food would not be a big issue – but with limited acreage of needed freshwater the carrying capacity would be lower, and populations of cottonmouths lower as well.  Then there is Seahorse Key.  

Seahorse Key Photo: Courtesy of flicker

Seahorse Key is 3 miles southwest of Cedar Key and can only be accessed by boat.  It is said that the density of cottonmouths is higher there than anywhere in the state.  Dr. Coleman Sheehy (University of Florida) stated they typically encountered 30 snakes while conducting beach walk surveys and they estimated about 600 cottonmouths on the island.  The fact that cottonmouths were there was not surprising, but the high density – in a habitat not really suitable for such – was. 

There is another story on addressing that issue you can read at  – https://nwdistrict.ifas.ufl.edu/nat/2015/08/07/the-mystery-on-seahorse-key/.    

Depending on which source you use, there are up to three subspecies of cottonmouths found in the U.S.  The Florida cottonmouth (Agkistrodon piscivorous conanti) is the one found on Seahorse Key, the rest of peninsula Florida, and in the panhandle as far west as Gulf County.  The eastern cottonmouth (A.p. piscivorous) is found from Bay County west to Escambia County on the Florida/Alabama line, and north into the coastal plains of Alabama and Georgia.  The western cottonmouth (A.p. leucostoma) is found from the Alabama/Florida line west to Texas and north to Arkansas.  Dr. Harvey Lillywhite (University of Florida), and others, were curious as to whether the Florida cottonmouth was adapting to saltwater.  An interesting question and, again, how these snakes are surviving and thriving on Seahorse Key is a part of understanding this story.  In recent years there has been a push to declare the Florida cottonmouth its own species – Agkistrodon conanti.  The Florida Museum of Natural History’s history article1 on cottonmouths list as such.  Dr. Steve Johnson’s article2 lists the snake as Agkistrodon piscivorous and leaves it there, not dividing into subspecies.  Many current researchers agree with the identification of A. conanti for the Florida cottonmouth – the one found on the islands of the Big Bend – and the one of interest in whether it is adapting to saltwater environments.  That brings me back to the project we are planning to begin in 2024 in the western panhandle. 

Cottonmouths definitely exist on the barrier islands in Escambia County.  We have two islands – Santa Rosa Island and Perdido Key.  There are freshwater sources on both islands and suitable habitat for cottonmouths.  The swim from the mainland to reach these islands is much shorter than for those at Seahorse Key.  At Perdido Key a swim of 600 feet would allow a snake to reach the island – easy.  The swim from Perdido Key to Santa Rosa Island is less than a mile (about 4000 feet) but the currents in Pensacola Pass are strong and the likelihood of a cottonmouth accessing Santa Rosa Island this way would be low.  However, there are many locations along Santa Rosa Island where the swim would be no more than a mile from the mainland and some, in Okaloosa County, the trip could be made in about 800 feet.  Island access is easy. 

As the Escambia County Extension Agent, I handle the snake calls that come to our office – and there are a lot of them.  In recent years there has been concern from some Perdido Key residents with the number of cottonmouths they are encountering.  One of their questions was whether this was an unusually high encounter rate – Seahorse Key all over.  Conducting surveys in their neighborhood in 2019 I encountered cottonmouths 70% of the time – all of them were juveniles or subadults.  I recommended some landscape changes to deter the snakes from their yards and in 2020 the encounter rate dropped to about 40% of the surveys.  However, it did not rain as much in 2020 and this could have affected the snakes as much, if not more, than the landscaping changes.  The freshwater ponds in the neighborhood used by the snakes were small and ephemeral – they did not have water unless rainfall was present.  So, we did another survey in 2021, it rained more, and encounters increased to 50% of the surveys.  The landscaping may have helped some.  In 2021 I also conducted surveys in the nearby state park and found no significant difference in snake encounters (50%) but the time of day for encounters was different and I did find adult snakes in the state park. 

Note here… I get very few calls on cottonmouths from Santa Rosa Island.  Rather their calls are about eastern diamondback rattlesnakes, which are not encountered as much on Perdido Key.  The question we have on the table now is whether the cottonmouths found on Perdido Key are the Florida cottonmouth (A. conanti) – the one some believe may be adapting to saltwater conditions.  According to Whit Gibbons and Mike Dorcas’s Snakes of the Southeast3 Escambia County Florida is the border between the eastern and the western cottonmouth.  This same guide suggests that the Florida cottonmouth does not exist here. 

So here is the project… which species/subspecies of cottonmouths exist on our barrier islands in the western Florida panhandle? 

How do you tell them apart?

The difference between the Florida cottonmouth and the eastern/western are very minor.  This makes identification in the field hard and dangerous.  The Florida cottonmouth will have two distinct stripes running vertically across the front of its snout.  The eastern/western cottonmouth will not have these.  To determine whether these stripes exist requires getting much closer to the snake than is recommended.  THIS IS A DANGEROUS SNAKE AND CLOSE ENCOUNTERS ARE NOT RECOMMENDED.  However, a road killed snake can be examined using a stick at least 12” long.  NOTE: SNAKES, EVEN RECENTLY KILLED, HAVE BEEN KNOWN TO BITE.  DO NOT HANDLE A DEAD SNAKE UNLESS YOU ARE SURE IT IS DEAD.  You may have a camera that can get a good photo of the snout FROM A SAFE DISTANCE (cottonmouths like to rest with their head tilted upwards at a good angle for such a photo). 

You can see the light vertical bands on the snout of this snake indicating it is the Florida cottonmouth. Photo: University of Florida.
Notice the light bands across the snout of this Florida Cottonmouth. Photo: Kristen Grace.
This cottonmouth has a uniform coloration across the snout – indicating that it is an eastern cottonmouth. Photo: Ricky Stackhouse.

We are planning a program on this project in early April for Escambia and Santa Rosa Counties.  If you are in Okaloosa, Walton, or Bay counties and would like the program presented there – let me know. 

Rick O’Connor – roc1@ufl.edu

References

1 Florida Museum of Natural History

https://www.floridamuseum.ufl.edu/florida-snake-id/snake/florida-cottonmouth/.

2 Florida Snakes. Cottonmouth or Water Moccasin.  University of Florida Department of Wildlife Ecology and Conservation.  UF Wildlife – Johnson Lab. https://ufwildlife.ifas.ufl.edu/snakes/cottonmouth.shtml.

3 Gibbons, W., Dorcas, M. 2005. Snakes of the Southeast.

The 2023 Year in Review – Water Quality

The 2023 Year in Review – Water Quality

Based on an annual evaluation recent competed, and feedback from my advisory committee, water quality issues are the number one natural resource concern for those who follow my extension programs.  It makes sense.  Poor water quality can negatively impact businesses who depend on clean water, waterfront property values, tourism, and the untold numbers of Florida panhandle residents who recreate in our estuaries and bays.  The water quality issues I provided education on in 2023 are focused on the Pensacola Bay system, but these issues are probably similar across the Florida panhandle.  Those issues include excessive nutrients, fecal bacteria (and other microbes), and salinity.  We also wrote one article on the increasing water temperatures occurring in the summer. 

Let’s begin with the fecal bacteria issue.  In the Pensacola Bay area, it may be our number one concern.  The Florida Department of Health posts local health advisories each week and some bodies of water are issued advisories for over 30% of the samples that are taken.  Frequently Bayou Chico (in Pensacola Bay) is issued an advisory over 50% of the samples taken.  However, in 2023 (in the Pensacola area) the number of advisories never exceeded 30% for any body of water.  Seven of the 13 swimming beaches monitored did not post an advisory at all.  This is one of the best years we have had since I began monitoring them. 

Closed due to bacteria. Photo: Rick O’Connor

In 2023 eight of the 13 water quality articles I wrote were on this subject.  Three additional articles were posted by other extension agents on our panhandle e-newsletter team.  But my annual follow up survey showed very few adopted best management practices (BMPs) they could adopt to help reduce fecal bacteria in area waterways.  The reduction was more likely due to the effort by our local city and county to improve sewage infrastructure and the fact that we were in a drought for much of the year – there is a positive correlation between rainfall and the number of advisories issued for local waterways.  Despite the fact that few readers adopted BMPs this year, and advisories declined – at least in Pensacola – we still believe adopting these practices would help reduce this issue.  We will be developing a fact sheet in 2024 to help homeowners better understand these practices and help reduce health advisories.    

Another local water quality issue that is high on everyone’s mind is excessive nutrients.  This is actually one of the largest concerns nationwide.  Excessive nutrients can lead to algal blooms, which can lead to harmful algal blooms or low dissolved oxygen, which can lead to fish kills.  In the Pensacola Bay area large fish kills have not occurred in decades, but nutrient monitoring continues.  The UF IFAS Lakewatch program trains local volunteers how to collect water samples and measure water clarity.  The samples are analyzed in the Lakewatch lab on campus in Gainesville and the results sent back to the community.  In the Pensacola Bay area, we are currently monitoring six bodies of water (three stations in each).  Nutrients values are stable, or improving, in four of the six locations.  They are slightly elevated in Bayou Chico and one station in Bayou Texar is quite high in total nitrogen.  Despite the values at those stations, no algal blooms or fish kills occurred in either Bayou Chico or Bayou Texar (or anywhere else in the Pensacola Bay area) in 2023.  There are numerous sources for nutrients in local waterways and many behavior practices businesses and residents can adopt to help reduce nutrient pollution.  In 2023 I wrote only one article on this topic but plan to provide more education in 2024.     

A body of water receiving excess nutrients can turn green and unhealthy from too much algae growth. Photo Credit: UF IFAS FFL program

A third topic that caught attention this year was the warm water that occurred this past summer.  Extreme water temperatures can decrease dissolved oxygen below levels where most estuarine creatures can survive.  Many creatures have a thermal tolerance that could have been exceeded this year.  Industries like oyster farming are negatively impacted.  Many varieties of harmful algae thrive in warm conditions.  My extension program does not conduct any citizen science project that monitors water temperatures within the bay.  Working with our local oyster farmers, the local estuary program is beginning to monitor such, and more folks are taking notice of the issue.  Extension agents posted four articles on the subject this year.  Whether the summers of high-water temperatures will become more common is unknown.  The first thought on cause is climate, and management practices on how to reduce climate change are well documented.  It is also understood that adopting such practices will not reduce intense warm summers immediately but should still be adopted for the long term.  It is also possible that the current extreme heat summers are cyclic, and things will cool down (relatively) in coming seasons.  2023 was an El Nino year.  Monitoring and time will tell how this issue will play out.  That said, it would be smart to consider behavior changing practices for the future.  Extension will post more information on this topic in 2024.   

The Gulf of Mexico at sunrise. Photo: Rick O’Connor

One issue of concern personally was the impact of increased rain on the salinity of our bay.  There has been a noticeable (and measured) increase in rainfall in recent years.  For Pensacola, we historically received about 60 inches of rain each year – one of the wetter locations in the southeast.  But over the last decade this has increased to 70 inches per year.  Along with the increase in rainfall, there has been a noticeable increase in development.  This increase in development reduces the surface area of land that would naturally absorb this rainwater and recharge the much-needed aquifer.  Instead, this rainwater is diverted from the new developments to stormwater management projects – some that work well, others that do not.  The question I have on the table is whether this increase in stormwater run-off is decreasing the salinity of area waterways?  And, if so, is it to a level where local marine species (and those we are trying to restore) will be negatively affected?  To answer this question, I have trained volunteers to monitor salinity at locations around the bay area.  They are monitoring once a week, at the surface, near the shoreline.  Though the sampling location is not ideal, it is what our volunteers are able to do.  I had determined that the data would be collected until each volunteer reached 100 readings (about two years).  As of the end of 2023, five of the 13 monitoring locations (38%) have reached that 100-reading mark.  We know that the turtle grass and bay scallops, both species we would like to see increase in our bay, require salinity be at (or above) 20 parts per thousand.  Though there are many more weeks of monitoring needed to reach our mark, current data suggests that salinities have not altered from data posted decades ago and are high enough for these species to return in areas where they historically existed. 

I will finish this review with a comment that articles were posted in 2023 on issues I am not directly involved with, but know they are a concern in many areas of the panhandle.  Private drinking wells being one.  There were several articles posted by Dr. Andrea Albertin addressing this issue in 2023 and for those interested in this topic I recommend they read these, and/or reach out to her directly (albertin@ufl.edu.).  There was also an article that focused on water quality improvement BMPs in general posted by Khadejah Scott (Wakulla County) that may be of interest.  https://nwdistrict.ifas.ufl.edu/nat/2023/10/05/simple-steps-to-improve-local-water-quality/.

With this being a large issue with many in the Florida panhandle, extension will continue to publish articles and have programs on this topic.  Reach out to your local county extension office for more information. 

Between The Hinge, What is an Oyster?

Between The Hinge, What is an Oyster?

They’re consumed worldwide, from 5-star exclusive restaurants overseas to your flip-flop beach bars right here in the Florida Panhandle. They have many different preparation techniques, such as plain and simple with a squeeze of lemon and a dash of hot sauce to “dip-your-bread-innit” chargrilled parmesan Cajun garlic butter (recipe below). However, many of their consumers actually don’t know what an oyster is, and as luck would have it, here’s a quick oyster 101!

Anatomy

Many people ask me what exactly an oyster is? Before becoming an oyster farmer, I always referred to them as “rocks with tasty meat in them,” but I couldn’t be further from the truth. Oysters are actually complex individuals that go through many metamorphoses and transitions throughout the first 2-4 weeks of their life, this includes a period of free-swimming followed by walking around with its “foot.” Let us look under an oyster’s top shell and identify some key organs.

Anatomy of an oyster
The anatomy of Crassostrea virginica (Eastern oyster) – Thomas Derbes

Mantle – A very thin, dark, fleshy layer of tissue that surrounds the oyster’s body. This is where shell formation begins!

Hinge – The shucker’s worst nightmare. This, along with the adductor muscle, is responsible for the opening and closing of the shell.

Adductor Muscle – Helps keep the oyster shut and protected from any predators. This part must be severed in order to fully open the oyster.

Gills – Thin, delicate structures found inside the body of the oyster. They serve a crucial role in respiration and feeding. Gills are shaped like tiny, finger-like projections that provide a large surface area for oxygen extraction, and they also trap and transport food towards the mouth.

Heart – Oysters have a simple circulatory system with a three-chambered heart that pumps colorless hemolymph throughout their body to distribute nutrients and oxygen.

Biology

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 prefer an estuarine environment (mid-salinity) but can be found in some coastal areas with higher salinities, especially in south Florida. As filter feeders, they trap nutrients like plankton and algae from the environment and require a habitat that can handle their filtering power (30 gallons per day).

The first 2 – 3 weeks of an oyster’s life is completely different than most people expect from an oyster. Females and males coordinate their spawning time with different cues and release massive amounts of eggs and sperm into the water. This type of spawning behavior is considered batch spawning, and a majority of the fertilized eggs perish before adulthood due to predation and other environmental causes. Once fertilized, the fertilized eggs go through multiple divisions and approximately 12-24 hours later, the free-swimming trochophore larvae are formed. These larvae swim around in the water column for 2-3 weeks, developing their shell and forming into a veliger, which closely resembles their adult stage. Once ready to settle, the pediveliger is formed. The pediveliger has a “foot” and walks around the bottom, looking for a suitable place to settle (usually another oyster). Once a suitable location has been found, the foot will secrete a substance to cement them into place and the pediveliger will metamorphose into a juvenile oyster, also known as spat. Oysters can grow very rapidly after their settlement, with oysters reaching 3 inches (usual harvest size) within 18 months.

Oysters have been known to establish massive reefs in estuaries, but their numbers have been on a rapid decline across the southern USA since the 1960s. These oyster reefs provided a massive natural, biological filter in the bays, and also were home to many juvenile and adult fish and crustaceans. Currently, there are many agencies and foundations that have oyster restoration at the top of their agenda, and the future is looking brighter for the oyster populations.

Oyster Life Cycle
The Oyster Life Cycle – Maryland Sea Grant

Pearls of Wisdom

I hope this quick oyster 101 helped shed light on the otherwise unknown life of the Eastern oyster. With the holidays coming up, make sure you grab some oysters to shuck and share with family and friends, and look at their shocked faces when you bust out all this wonderful oyster knowledge. Who knew that an oyster was much, much more than a “rock with some meat in it.”

Chargrilled oysters kissed with flame
Chargrilled “DYBI” Oysters Kissed With Flame – Thomas Derbes

“Dip-Your-Bread-Innit” Chargrilled Oysters

24 Oysters

2 Sticks of Butter

2 Tablespoons (or more) of Cajun Seasoning (Uncle Tony, Zatarains, etc)

½ cup of Hot Sauce

½ cup of Lemon Juice

1 Tablespoon of Granulated Garlic

2 cups of Mozzarella Cheese

½ cup of Parmesan

1 Cup Panko (The Razzle-Dazzle)

Sliced Bread (Baguette, Wonder, any bread honestly)

———————————————————————————————————

  • Shuck Oysters – Many instructional videos online, and make sure you use an actual oyster knife, clam knives are no good!
  • Add butter to pan/pot. Melt the butter on medium, then add everything but the oysters and cheese to the butter.
  • Start your grill, charcoal/wood is best for adding a smoky flavor. Once the butter mixture is made, add oysters to the grill and spoon your butter mixture into the oysters.
  • Mix the cheeses together and add the cheese mixture to the oysters once the butter is spooned on. For a little razzle-dazzle, mix 1 cup of panko into the cheese mixture.
  • Cook oysters until bubbling. Make sure to not overcook the oysters, and once you seed the mixture bubbling, they are good to remove.
  • Eat the oysters and dip your bread in the shell to soak up the juices. You won’t regret it.
Farmed Oysters Never Go Out Of Style

Farmed Oysters Never Go Out Of Style

Growing up in the South, I was exposed to many “Old Wives’ Tales,” ranging from not cleaning your house or clothes on New Year’s Day to the one that everyone, including the northern states, knows, “don’t consume oysters in months without an R.”  While most “tales” are full of superstition, the “R” tale was one of biosecurity, and was mainly truthful until two new types of “R” came about; Regulations and Refrigeration. The tale came about due to the rise in food poisonings from shellfish in the warmer summer months that do not contain a “R,” such as June and July. The rise in food poisoning came about from the practices used by the oyster “tongers” at the time. Commercial harvest of wild oysters is a very labor-intensive job that requires long days on the water and constant tonging, measuring, and sorting of oysters as they come off the bottom. During the summer, the oysters would sit on the deck of the boat for hours in the heat, causing microorganisms and bacteria to flourish inside the closed oyster.  Bacteria, like Vibrio, would replicate to harmful levels inside of the oysters and when consumed by a human, could cause life-threatening illnesses.

That was then, and this is now. While the consumption of wild Florida oysters during the summer is not allowed (closed harvest season for wild oysters during the summer in Florida), you can still find oysters from all over the US, and farmed oysters from Florida are still allowed to be consumed during the summer. Biosecurity is a major factor involving food production and aquaculture, and without biosecurity, the consumption of Florida-farmed oysters would be prohibited. Oyster farmers in Florida must follow a very rigorous biosecurity plan that includes State-issued harvest times, water-to-refrigeration requirements, reporting of harvest and planting, and twice-daily temperature monitoring requirements. The regulations for harvest times and refrigeration requirements have scientific backing, showing a statistical difference in Vibrio concentrations between properly handled oysters and neglected oysters, with properly handled oysters having little to no concentrations of Vibrio. For instance, during the summer months, oyster farmers must have oysters harvested and in the cooler before 11am and down to 45°F within 2 hours of storing in cooler.  

Boat Full of Harvest Oysters
A farmer returns early morning from the lease with harvest oysters covered by burlap. This keeps the oysters “cool.” (Photo by: Thomas Derbes)

While there is an increased concentration of harmful bacteria during these warmer months, properly cared-for oysters help limit the growth and proliferation of the bacteria. Another myth is that Vibrio doesn’t exist in cold, winter waters. Vibrio can exist year-round, and people with health risks, including immune-suppressed patients and those with diabetes, should exercise extreme caution when consuming raw seafood. When purchasing seafood for personal consumption, make sure to bring a cooler with ice and place your seafood above the ice, making sure to not allow any fresh water to touch the seafood. When storing seafood at home, make sure they are in a container that can breathe, and cover with a moist paper towel to keep their gills wet. Oysters are typically good for 10-14 days after the harvest date, so make sure you check the tags and consume within time.

Next summer, when you see farmed oysters on the menu, remember the new R’s and order a couple dozen for the table. The need for support from your local oyster farmer is most needed during those months without R, so slurp them down all summer and thank your local oystermen and women!

Oyster with French Mignonette Sauce
Locally Farmed Oyster with French Mignonette (Photo by: Kelly Derbes)

Easy French Mignonette Recipe

Recipe for 2doz Oysters

¼ cup Red Wine Vinegar

¼ cup Champagne Vinegar

1 tablespoon of Finely Chopped Shallot

1 teaspoon of Fresh Crushed Black Pepper

Juice of ½ Lemon

Combine all ingredients together. Spoon over shucked, chilled raw oysters.

The Great Scallop Search; Pensacola Bay 2023

The Great Scallop Search; Pensacola Bay 2023

Introduction

Bay scallops (Argopecten irradians) have been an important part of the economy of many gulf coast communities within the Florida Big Bend for decades.  It was once abundant in all gulf coast counties of the state but beginning in the 1960s populations in many bays began to decline to levels where they are all but nonexistent.  The cause of this decline has been associated with many factors including a decline in water quality, a decline in suitable habitat (sea turtle grass beds – Thalassia), and overharvesting.  Most likely the cause included all of these.  Since the collapse of both the commercial and recreational fishery, Gulf coast communities have been trying to address all three of the stressors above.  Multiple monitoring projects are ongoing in the Pensacola Bay area and one of those is the Great Scallop Search.  

The Great Scallop Search was developed by Sea Grant Agents in Southwest Florida and expanded, through Florida Sea Grant, to Northwest Florida.  In each location volunteers snorkel a 50-meter transect line searching for live bay scallops, as well as monitoring the status of the seagrass habitat.  Since 2015 317 volunteers have logged 634 hours surveying 407 50-meter transects in 106 grids in Big Lagoon or Santa Rosa Sound.  In that time 4 live scallops have been logged, though we hear anecdotal reports of additional scallops being found in these bodies of water. 

Survey Method

Volunteers select and survey one of 11 grids in Big Lagoon, or one of 55 grids in Santa Rosa Sound.  Once on site, the volunteers anchor and record preliminary information on the data sheet provided.  Two snorkelers enter the water and swim on opposite sides of a 50-meter transect line searching for live scallops.  Any live scallop found is measured and returned.  The species and density of the seagrass is recorded as well as the presence/absence of macroalgae on that seagrass.  Four such transects are surveyed in each grid. 

2023 Results

2023SRSBLTotalOther
# of volunteers    72No significant difference between 2022 and 2023
# of grids surveyed8816Slight decrease from 2022.  16 of the 66 grids (24%) were surveyed. 
# of transects surveyed265177A decrease from 2022.  More surveys were conducted in Big Lagoon than Santa Rosa Sound. 
Area surveyed (m2)2600510077001.9 acres
# of scallop found2  24Four live scallops are a record for this project.  It equals the sum of all other live scallops since the project began. 
Scallop Size (cm)4.5, 5.04.0, 4.5  
Surveys with Seagrass    
Halodule5121717/21 surveys – 81%
Thalassia8111919/21 surveys – 90%
Syringodium0222/21 surveys – 10%
Grass Density    
100% grass391212/21 surveys (57%) were 100% grass
90%101Note: Volunteers typically select area for transects
75%314with a lot of grass.
70%101 
50%3912 
5%101 
Macroalgae    
Present448 
Absent2101212/21 surveys (57%) had no macroalgae.
Abundant224 
Sediment Type    
Mud011 
Sand781515/21 surveys (71%) were sandy.
Mixed145 

21 surveys were conducted covering 16 grids.  8 grids were surveyed in each body of water. 

A total of 77 transects were conducted covering 7,700 m2 and four live scallops were found. 

Two of the scallops were found in Big Lagoon and two in Santa Rosa Sound. 

All scallops measured between 4-5cm (1.6-2”). 

The number of live scallops found this year equaled the total number found over the last eight years. 

Most of the transects included a mix of Halodule and Thalassia seagrass ranging from 100% coverage to 5%.  The majority of the transects were between 50-100% grass.  Four transects had 100% Thalassia.  Three of those were in Santa Rosa Sound, one was in Big Lagoon.  The diving depth of the volunteers ranged from 0 meters (0 feet) to 2.4 meters (8 feet).  Macroalgae was present in 8 of the 21 surveys (38%) but was not abundant in most. 

Volunteer measuring one of the four collected bay scallops in 2023 from Pensacola Bay. Photo: Gina Hertz.

Summary of Project

YearVolunteerGrids SurveyedTransects SurveyedLive Scallops Found
201587281010
201696311111
201754160
2018207320
2019136200
202052161
2021176240
20227422872
20237216774
TOTAL3174078
MEAN3514450.4

To date we are averaging 35 volunteers each event, surveying 14 of the 55 possible grids (25%).  We are averaging 45 transects each year (4500 m2), have logged 407 transects (40,700 m2) and have recorded 8 live scallops (< than one a year). 

Discussion

Based on the results since 2016 this year was a record year for live scallops.  Whether they are coming back on their own is still to be seen.  Being mass spawners, bay scallop need high densities in order to reproduce successfully, and these numbers do not support that.  The data, and comments from volunteers, suggest that the grasses look good and dense.  Thalassia, a favorite of the bay scallop, appear to be becoming more abundant.  This is a good sign. 

Though small and few, bay scallops are trying to hold on in Pensacola Bay. Photo: Gina Hertz