It’s Been a Terrific Terrapin Season So Far

It’s Been a Terrific Terrapin Season So Far

As the Sea Grant Extension Agent in Escambia County, one of my program areas is to help restore a healthy estuary.  To do this we focus on educating the public how to improve water quality, restore habitat, and manage invasive species, but we also focus on how to monitor fish and wildlife.  The fish and wildlife I focus on are those that were once common in the bay and are trying to make a comeback – such as scallops and horseshoe crabs.  But there is another estuarine creature we are interested in that does not fall into the classic “bring them back” model and that is the estuarine turtle known as the diamondback terrapin.

The diamondback terrapin.
Photo: Molly O’Connor

Unlike scallops and horseshoe crabs, this is not an animal that people remember as a kid.  In fact, very few Floridians in the panhandle have ever heard of it.  Some older distribution maps of their range show that they exist from Cape Cod MA to Brownsville TX, but with a gap in the Florida panhandle.  That was because there was no scientific literature of the animal’s existence here.  And that was when the Panhandle Terrapin Project began – to confirm whether or not terrapins existed here.

 

In 2005, working with students at Washington High School in Pensacola, we began our search by placing “Wanted Posters” at boat ramps in Escambia and Santa Rosa counties near good terrapin habitat, which is salt marsh.  We began to get calls almost right away, but for a variety of other turtle species.  Folks were calling us with photos of box turtles, yellow-bellied sliders, and cooters.  It showed there was interest in the project but was evident they were not familiar with the terrapin.

Around 80% of the terrapin nests are depredated by raccoons, or some other predator.
Photo: Bob Blais

Volunteers log the number of female tracks they see on their beaches.
Photo: Cindy Marvel

I interviewed several ole gill netters to see if they remember ever capturing them – same response, “I never heard of those”.  I did show one gill netter a photo and he responded – “you know, I think we did catch a couple of these”.  But no confirmation of their existence here.  It was time to begin searching ourselves.

 

The team began to survey good terrapin habitat and walking potential nesting beaches looking for any evidence.  We did not find it.  Then one day in 2007 a gentleman working on a construction site responded to one of our “Wanted Posters”.  He said he had seen one of our terrapins.  After all of the calls that led to other species, I was not so sure – but he convinced me it might be.  So, we checked it out.  The sign was placed in good habitat and there were potential nesting beaches nearby.  We searched… and we found.  What we found were nests that had been depredated by raccoons.  There were empty eggshells laying around and two dead hatchlings.  There were also tracks in the sand.  Confirmation… there were terrapins here!

 

It was now time to take the show on the road and see if terrapins exist in other counties along the panhandle.  My wife and I would take part of our summer vacations and camp along the coast searching.  We found at least one record of a terrapin in each of the counties between the Alabama state line and Apalachicola River.  All of this was presented to the Florida Diamondback Terrapin Working Group of which there are members from the Florida Fish and Wildlife Conservation Commission.  Word was out.

Terrapins prefer sandy beaches and lay their eggs during daylight hours.
Photo: Molly O’Connor

A terrapin hatchling.
Photo: Molly O’Connor

 

 

 

 

 

 

 

 

 

 

 

The next step was to assess their status.  How many are here and how are those populations doing?

 

We did this by following a method developed by Tom Mann with the Mississippi Department of Wildlife.  Tom was monitoring terrapins in that state and the subspecies he worked with, the Mississippi Terrapin (Malaclemys terrapin pileata) was the one that was thought to be in Pensacola Bay.  So, it was Tom’s method we decided to follow.  This includes walking nesting beaches and logging individual tracks and depredated nests in 16-day cycles.  Tom’s model assumed that all mature females in the population nest each season and that they do not lay more than one clutch in a 16-day period.  The idea is that each track and nest represented one female, and assuming the sex ratio of male to female is 1:1, doubling the number of tracks and depredated nests found in that period would give an idea of how many adult males and females are in this group.  Seemed easy enough so these surveys became part of our project.

 

Another method learned by attending conferences was a 30-minute head count.  If you can find the lagoons where the terrapins actually live you can sit and count the number of heads you see in a 30-minute period.  It is true that 23 heads does not mean there are 23 terrapins, but the relative abundance can be monitored.  If you typically see 20-23 heads and over time that decreases to 11-15, then the relative abundance is declining.  It is a method that citizen science volunteers can do and so was included in the project.

Modified crab traps is one method used to capture adults.
Photo: Molly O’Connor

A diamondback terrapin being measured and marked before release.
Photo: Rick O’Connor

 

 

 

 

 

 

 

 

 

 

We also wanted to try and capture individuals to mark and tag.  Mark recapture is a method used to estimate populations but capturing terrapins has been historically difficult to do.  Several methods have been used by members of the Working Group and we have tried them as well.  We have captured terrapins, but very few.

 

In 2018 the Team partnered with the U.S. Geological Survey to increase the robustness of the project.  The Florida Fish and Wildlife Conservation Commission became interested in tissue samples from captured animal to study the genetics of the terrapins in this area.  Since 2015 we have trained 228 individuals to conduct surveys, and some have been with me that entire time.  Many of them have spent countless hours helping assess the status of this animal in our bays.  Many days they see nothing.  Others a few tracks or depredated nests.  Some locations have good luck with head counts, but many of them finding nothing.

The Mississippi terrapin found in Pensacola Bay is darker in color than the Ornate terrapin found in other bays of the panhandle.
Photo: Rick O’Connor

This terrapin has the coloration of the Ornate terrapin but was found much further west than the literature suggest it lives.
Photo: Rick O’Connor

I keep track of “Frequency of Occurrence” (FOO) – the number of surveys where some sort of terrapin encounter happens.  This encounter can be as simple as a track in the sand, but they had SOME encounter.  It is my hope that over time encounters with them will increase, just as I hope it does with scallops and horseshoe crabs.  Since 2007 the FOO has ranged from 12-86% of the surveys conducted, with an average of about 25%.  The best year was 2011 (86%), just after the Deepwater Horizon spill.  There was a steady increase in FOO from 2007 to 2012 when it took a significant drop.  However, this is not because the relative abundance of terrapins suddenly dropped.  2012 was the year I moved from the marine science program at Washington High School to Florida Sea Grant Extension.  There were all new volunteers and the learning curve started over.  They were not as good at detecting them as the previous group.  But that is changing.  2022 is looking to be a busy year for the team.

 

So far this year we have seen terrapin activity on almost every nesting beach between here and Apalachicola.  One site had 49 heads in a 30-minute head count!  There have been several active nests, numerous tracks, and plenty of depredated nests.  In addition, we have found one dead hatchling and captured two adults. Tissue from these have been collected for the genetic study.  But the strangest story this year… a security guard has told us of terrapin hatchlings that have been dropped on their guard shack by birds.  Sea birds are known to do this to try and crack open shells of mollusk so they can feed on them.  I have never heard of this with terrapins, not here or anywhere.

A dedicated volunteer is rewarded with a capture.
Photo: Rick O’Connor

It seems it is going to be a terrific year for the terrapin project this year.  It is exciting for our volunteers to have so many encounters and nice to know that the public is becoming more familiar with this animal.  I cannot say whether the population is increasing or not but our knowledge, understanding, and encounters are.

Seagrass Situation

Seagrass Situation

Imagine…

It is 1922 and you are rowing your wooden skiff from a small beach house near what will become the town of Gulf Breeze Florida across Santa Rosa Sound on your way to Santa Rosa Island.  The water is 10-15 feet deep, and you can see the bottom.  It is covered with a lush garden of seagrasses with numerous silver fish jutting in and out of the blades.  Most are there only for a moment before they are lost again.  You notice a brown colored puffer fish hovering over the grass as you past by.  Maybe a small sea turtle grazing, or a tannish colored stingray flying over the meadow.  As you get closer to the island, which is covered with sand dunes reaching 20-40 feet in height and shrubby live oak and magnolia trees, you begin to see Florida conchs and horseshoe crabs, maybe fields of bay scallops littering the grass in every direction.

An amazing meadow of underwater grass.
Photo: Virginia Sea Grant

Sounds amazing, doesn’t it?  And it was actually like this once.

What changed?

 

I asked this question of some ole timers who grew up on Bayou Texar in Pensacola decades ago.  You might be surprised to learn that Bayou Texar resembled this scene.  They described water that was between 10-15 feet deep, had sand and seagrass on the bottom, and you could catch shrimp the size of your hand by tossing out a cast net.  But Bayou Texar no longer looks like this.

 

Most told me the first thing they remember was a change in the water clarity.  The water became more and more turbid.  Then the shrimp went away, then some of the fish.  They mentioned several species of fish that no longer exist there.  The cause of the turbid water? … Development.  They were developing all around the Bayou after World War II and that was when things began to change.  They mentioned the road going in on the east side of the bayou as the point when turbidity issues began.  The houses came later.

With little rain over the last few days the water clarity was excellent and you could see the seagrass very well.

The city of Gulf Breeze was founded in 1935 and was originally called Casablanca because of a white house there that could be seen from Pensacola.  As the community grew the waters became more turbid as well, and the amazing underwater garden declined.  But this was not just happening in Gulf Breeze and Bayou Texar, it was happening everywhere.

 

But it was bound to happen.  As the human population grows more space is needed for homes, businesses, and schools.  More roads are needed to reach these locations and a bridge was placed to reach Santa Rosa Island, so you no longer had to paddle a skiff to reach it.  Once on the island, growth continued.  More homes, roads, and businesses.  With more run-off, turbidity, and the garden continued to decline.

Shoal grass. One of the common seagrasses in Florida.
Photo: Leroy Creswell

The thing was we did not know at the time that (a) we were causing this decline and (b) how much we really wanted that garden there.  I often hear the question “what happened to all of the blue crabs?”  I think they know the answer, but they remember a time when blue crabs were more abundant, can you imagine what it probably was like for our friend paddling across in 1922.  And there has been a noticeable difference in crab numbers in their life.  There are folks, including myself, who remember bay scallops in the Sound and horseshoe crabs on what they called “Horseshoe Crab Island” in Little Sabine.  This is one of the amazing things about this story – how fast the decline was.  Now we better understand how important these underwater meadows were to the function of a healthy estuary and there is interest in restoring them.

Bay scallops need turtle grass to survive.
Photo: UF IFAS

To restore seagrass, you first have to understand, and mitigate, what is causing the decline.  Seagrasses are vascular plants that possess roots, stems, and leaves.  They produce flowers and sexually reproduce using seed.  This is not the case with seaweeds, which are nonvascular and lack the above, but they often mistakenly called seaweeds.  There are three species that dominate our seagrass meadows in the Florida panhandle and a fourth one that is not as common.  The uncommon one has a round blade like a pine needle and is called manatee grass (Syringodium filiforme).

 

The three common species all have flat blades.  Widgeon grass (Ruppia maritima) has blades that branch.  It tolerates a wide range of salinity and is more abundant in the upper regions of our estuaries.  Shoal grass (Halodule wrightii) has a single flat, non-branching, blade that is very narrow (< 3mm) and resembles human hair.  Turtle grass (Thalassia testudinum) is also flat, non-branching, but wide (>3mm) and resembles St. Augustine grass.

 

Like other grasses, these plants require sunlight and nutrients to survive.  They also need to grow in the low energy locations of our estuaries.  Sunlight, of course, is key for photosynthesis and clear water is the key to getting enough of it.  15-25% of the sunlight reaching the surface of the water must also reach the bottom where the grasses are.  Nutrients can be obtained through the water column and sediments.  The stems run horizontal beneath the sand and are called rhizomes.  They help hold sediments in place increasing the much-needed water clarity as well as reduce shoreline erosion.  The blades extend from the substrate up into the water column bathing in the sunlight.  They are covered by microscopic plants and animals that resemble scum when you run fingers over them but provide mush of the food for the creatures that live there.

And live there they do.

It has been estimated that it least 80% of the commercial and recreational important shell and finfish spend at least part of their lives in the seagrass meadows.  Ducks, manatees, and sea turtles are some of the grazers on these plants and sea horses, pipefish, and pinfish are abundant.

Photo: NOAA

When humans began developing around the Sound in the 1940s and 1950s the sediment run-off decreased water clarity, cutting off the much-needed sunlight, and in some locations covered the grasses.  Excessive nutrients from our fertilizers, and detergents increased phytoplankton growth which in turn decreased water clarity more and enhanced the growth of macroalgae which smothered the meadow like a blanket.  Hot water discharges from industrial processing along the shores stressed the grasses as did prop and anchor scars from power boat plowing through and anchoring in them.  These same boats and jet skis increase wave energy with their wake, as do seawalls when waves reflect off of them.  Marinas, bridges, and docks all required dredging in the meadow which not only removed the grasses but increased turbidity even further.  All of this triggered the decline of these amazing gardens.  And with them the decline of the cherished fisheries as well.

The scarring of seagrass but a propeller.

In recent years the Florida Fish and Wildlife Conservation Commission (FWC) conducted surveys across the state to assess the status of our seagrass beds.  They estimated that there was a little over 2 million acres of seagrasses in Florida waters, 39,000 in the western panhandle.  Though much of these beds appeared to be stable, or even increasing acreage, those in the panhandle were still in decline and all of Florida’s seagrass gardens were less than the acreage in the 1950s.

 

In this study they found the Perdido Bay had primarily shoal grass.  Big Lagoon and Santa Rosa Sound were a mix of shoal and turtle grass, with some manatee grass reported from Santa Rosa Sound.  Aerial imagery found –

 

Perdido Bay had 642 acres of seagrass in 1987; 125 acres in 2002 for a net loss of 5.4% / year

Pensacola Bay had 892 acres in 1992; 511 acres in 2003 for a net loss of 3.9% / year

Big Lagoon had 538 acres in 1992; 544 acres in 2003 for a net gain of 0.1% / year

Santa Rosa Sound had 2,760 acres in 1992; 3,032 acres in 2003 for a net gain of 0.9% / year

 

The numbers in the lower portion of the bay are encouraging and suggest some behavior changes we made in recent decades have helped.  Both development and monitoring continue.  We will see.

 

What can be done to help restore the garden?

  1. First, reduce run-off into the bay. This can be done by engineering designs with green infrastructure methods but can also be done by the private homeowner as well.  Using native plants in your landscape reduces the need to irrigate your property and landscape designs which include rain gardens and rain barrels will also help reduce run-off.
  2. The reduction of nutrients begins with the reduction of fertilizers on the landscape. Using Florida Friendly Landscaping principals can lead to a beautiful landscape that does not require fertilizers.  If you choose to use nonnative plants that do require fertilizers, use only what the plant needs – do not over do it.
  3. If you live along the waterfront, you can further reduce nutrients by planting a living shoreline. The plants used in living shorelines are known to remove nutrients from run-off from your property, as well as reduce erosion and provide more habitat for fisheries.  One living shoreline project in Bayou Grande has seen an increase in shoal grass beds since they planted it.
  4. When boating, be aware where seagrasses exist. Lift your motor when moving through them to avoid prop scarring and anchor in open sandy locations.  You can also follow the principals of a Florida Clean Boater to reduce your impact on water quality that could impact the seagrasses.

With a little effort on our part, we can enhance some of the positive numbers we have seen in seagrass assessments and hopefully turn the current negative trends into positives.  Maybe the garden will return.  For more information on how you can apply any of these principals contact your county Extension office.

Identifying Riverine Turtles of the Florida Panhandle Workshop

Identifying Riverine Turtles of the Florida Panhandle Workshop

The Florida panhandle has one of rich biodiversity.  This goes for the variety of turtles found here as well.  Many paddlers and hikers to our waterways see these turtles but have trouble identifying which they are looking.  In response to request by outdoor adventures wanting to learn more, UF IFAS Extension will be offering a one day workshop on field identification of panhandle riverine turtles.

 

The workshop will be held this Monday – May 16, 2022 – in Apalachicola FL.  Participants will attend a classroom session where the biogeography of our turtles will be discussed and visual identification will be practiced.  We will then take a boat ride up the Apalachicola River and practice in the field.

 

The program will begin at 8:30am (ET) at the Franklin County Extension Office.  The cost will be $25 and preregistration is required.  You can register at https://riverine_turtles_florida_panhandle.eventbrite.com/

 

Wildlife on the Beach in May

Wildlife on the Beach in May

It is mid-spring and time of nesting for much of the wildlife in the area.  It is also noticeably warmer than our previous hikes.  Due to my work schedule, and the surveys for other nesting activity, I did this hike earlier in the month and later in the day, than I typically would have.  I began my hike at 1:00pm – near the hottest part of the day, and not the best time to see wildlife, but I definitely wanted to get a hike in this month and so this is when I could.

The Gulf was relatively calm on this early afternoon in spring.

It was warm.  On this day it was 83°F and there was a light breeze from the southeast.  On the previous hikes I needed my fleece.  Though I had it in my backpack, I did not need it today.  My hike was at Big Sabine and as usual, I began on the Gulf of Mexico.  The first thing I noticed when I crossed over the boardwalk was the number of people.  I usually hike in the early morning or late afternoon and see few humans.  But at mid-day the beach was full of people, and I probably looked strange walking among them with my long pants, long sleeved shirt, and boots.  The second thing I noticed was mats of Sargassum on the beach.

 

Sargassum is a floating brown algae we see in the warmer months in our part of the Gulf.  It is first an algae, not a true plant.  Algae lack roots, stems, and leaves.  They produce no cones, fruit nor flowers with seeds.  They are nonvascular, meaning they lack a system of vein-like tubes that move water around the plant.  Plants usually do have these tubes.  They are not called arteries and veins as they are in animals, but rather xylem and phloem.  Because algae lack this circulation system, they live emersed in the water.  Since they lack true roots they anchor to hard substrate, like rocks and coral, using a suction type apparatus called a holdfast.  The flexible, herbaceous stipe, analogous to the stem, flows in the current extending their blades (analogous to leaves) into the light.  Like plants, algae require water, carbon dioxide, and sunlight to photosynthesize their food.  Because of this they need to live in relatively shallow water, and they need a rocky bottom to attach their holdfast to.  We have little hard bottom and therefore less of the classic algae you read about in other parts of the world.

Notice the small air bladders on this Sargassum weed. These are used by the algae to remain near the sunlit waters of the open Gulf.

 

Sargassum has a different plan to deal with this problem.  They float.  When you look at this seaweed on the beach you will notice they have numerous small circular air bladders called pneumatophores.  These air bladders allow Sargassum to float in the sunlit waters of the Gulf and not worry about how, or where, they would attach their holdfast.

 

Large mats of Sargassum can be found floating out in the open Gulf and these mats provide a fantastic habitat for many small and large marine creatures.  There are sargassum crabs, sargassum shrimp, and even a sargassum sea horse.  There is a small filefish and a frogfish known as the sargassum fish.  It is the target for baby sea turtles that successfully made it from the beach, through the surf, and into the open Gulf without being consumed.  Here they will live and feed for many months at which time they are large enough to venture back out.  Larger fish often seek out these mats searching for food, and fishermen seek the mats knowing that larger fish are probably in the area.

 

These mats of Sargassum get caught in the large ocean currents and find their way to the middle of the Atlantic.  Here the ocean is calm, like the eye of a hurricane, and huge mats of Sargassum can be found piled up.  Christopher Columbus found this massive expanse of Sargassum while crossing the Atlantic.  Because it was calm here, and the Sargassum so thick, his ships became becalmed and he noted in his log to avoid this place, which was then called the “Sargasso Sea”.

 

On today’s hike there was quite a bit of this seaweed washed ashore.  Most of the marine life living in the seaweed sense the waves and the impending beaching, and jettison for mats further offshore.  So, you usually do not find many creatures in the seaweed washed ashore, but sometimes you do.  You can take a small dip net out deeper and grab some still floating and you may have better luck.  Today, I explored what was washed ashore and did not find much.  I did find a lot of plastic, and those who study Sargassum ecology will tell there is a lot of plastic debris caught up in the Sargassum mats.  Today I noticed a lot of bottle caps.  Not many bottles, but lots of bottle caps.  As many others do, we encourage everyone to dispose of the garbage properly.  I read this week of a manatee found near Mobile Bay earlier this year who died of cold stress but had swallowed a plastic bag, which was caught in his throat.  Marine debris kills.  Please dispose of your trash properly.

This crab pot float was one of several debris items washed in with the sargassum.

 

Heading inland to the dune field I heard sirens.  The beach patrol was answering a call.  I am not sure where, nor what the issue was, but these again are sounds I do not usually hear when hiking early and late in the day.  There are currents in the Gulf that can suck you out to sea, and each year we have visitors drown not knowing where these currents are, or how to get out of them if they are caught in one.  Pay attention to the colored flags and be careful.  I never saw, nor heard, an ambulance follow the beach patrol.  So, I am guessing everyone was okay on this call.

 

The dune field on this May afternoon was warm.  There was a light breeze from the southeast that kept things from getting too warm, but it was warm none the less.  As we move closer the hot days of summer the wildlife will move more at dawn and dusk, as well as in the evening.  I was not expecting to see a lot on this hike.

 

This flat area of the dune field was quite warm on this afternoon and made me think of crossing a desert.

This was an unusual site, a pigeon walking in the open dune field.

 

 

As always you can see what has been moving by searching for tracks and tracks, I did find.  Many of them were human, indicating the tourist season is upon us, but there were tracks of animals as well.  There were plenty from our friends the raccoon and armadillo.  I did notice more raccoon tracks this month.  I and my volunteers who survey nesting beaches notice more raccoon tracks this time of year looking for eggs.  I also noticed more snake tracks on this hike, they too are mating and moving much more.  The lizard tracks were fresh, and I have noticed these moving during the warmer parts of the day and their tracks running across the dune face told me they were very busy that day.

This straight line the sign of a tail drag by a lizard, most likely the six-lined skink.

Many who visit the dunes of our barriers find these burrow looking trails. These are made by beetles.

I followed this snake track until I found this – what appears to be a “tussle” the snake had with a possible prey.

 

Being spring you would expect flowers, and there were some, just not as many as you might expect.  Most of them were white and were blooming on plants near the boggy areas of the swales.  The conradina that blooms more in the winter, was done and the blossoms were gone.  I did see the early stages of the magnolia flowers trying to come up, but the bright green shoots of new growth on the pines were not visible.  There were bees, lots of bees.

The lavender blossoms of the false rosemary, which appeared in winter, are now gone.

White flowers were common on this spring afternoon. Such as this one on the spiny bull nettle.

Another white flower is seen on this Sagittaria growing in one of the swales between dunes.

 

I hiked through a small pine scrub area thinking I might someone in the shade avoiding the heat of the day but did not find anything.  I went along the edge of the tertiary dunes where they meet the maritime forest looking for the same thing.  Nothing, but there were tracks.  The cactus seemed to be more abundant this month.

 

The pine scrub offered one of the few places with shade.

The dune field of a Florida panhandle barrier island.

From atop of one of the higher dunes you can see the steep drop towards the marsh.

 

 

Along the ridge between the maritime forest and the salt marsh is where I found the otter slide last month.  I did not see any evidence of otters today.  The bird action was slower today as well.  Maybe because of the heat they too had settled somewhere.  I did not see an osprey, which is unusual.

Big Sabine as seen from atop one of the larger dunes.

 

As I reached the beach of the Sound, I did notice a LOT of digging by armadillos.  They had been very active.  There were no snakes or marsh rats.  There were again people, these were on jet skis.  There were a few fishing from small boats.  With no rain over the last week or so the visibility in the Sound was amazing, but I only saw one small blue crab.  No hermit crabs and not any fish.  However, the lagoon of the marsh the killifish, also known as bull minnows, were abundant and the males all aglow with their iridescent blue colors of breeding season.  The males were chasing each other all over the tidal pools and open water of the lagoon designating their territories for current breeding that would follow.  I did notice more crows than I usually do and what made me catch their attention was the constant calling at me and the hovering over me suggesting they too were breeding, and an active nest was nearby.

A blue heron is seen sitting in a pine overlooking Santa Rosa Sound.

A small Seserma crab is seen hiding under grass along the beach of the Sound.

The crows were numerous and active on this spring afternoon.

 

I was not expecting much hiking in the middle of the afternoon, but it is always good to do these just to see what is moving.  I hope to do another hike this month either early in the morning or late in the afternoon.  Maybe we will see more.

It may be hard to see, but there was a small duck enjoying the Sound.

With little rain over the last few days the water clarity was excellent and you could see the seagrass very well.

Six Rivers CISMA EDRR Species of the Month – Guinea Grass

Six Rivers CISMA EDRR Species of the Month – Guinea Grass

EDRR Invasive Species

Guinea Grass (Megathyrus maximum)

 

Guinea Grass
Photo: University of Florida IFAS

 

Define Invasive Species: must have ALL of the following –

  • Is non-native to the area, in our case northwest Florida
  • Introduced by humans, whether intentional or accidental
  • Causing either an environmental or economic problem, possibly both

Define EDRR Species: Early Detection Rapid Response.  These are species that are either –

  • Not currently in the area, in our case the Six Rivers CISMA, but a potential threat
  • In the area but in small numbers and could be eradicated

Native Range:

Guinea grass is native to Africa.

 

Introduction:

The plant was introduced as livestock fodder.

 

EDDMapS currently list 2,614 records of guinea grass.  Most records come from Florida and Texas, but it has also been reported in Hawaii and Puerto Rico.  In Florida it has been reported across the state.  There are 17 records in the Florida panhandle, 15 of those within the Six Rivers CISMA, 12 of those within the CISMA were reported from the Yellow River Preserve area in Santa Rosa County and the remaining three were from Eglin AFB.

 

Description:

This is a large panicum grass reaching heights of up to seven feet and grows in dense mats.  The strap-like blades and smooth and up to three feet long and two inches wide.  The seed inflorescence is large as well, reach two feet in length.

 

Issues and Impacts:

Guinea grass is an aggressive growing plant that will quickly occupy disturbed open spaces and form thick monocultures decreasing native plant abundance and overall biodiversity.

 

Management:

The recommended management is foliar spraying with a 1% solution of glyphosate.  Care should be taken not to overspray because this herbicide is non-selective and will kill other desirable plants.

 

Please report any sighting to www.EDDMapS.org

 

For more information on this EDRR species, contact your local extension office.

 

References

Urochola maximum. Guinea Grass.  University of Florida Center for Aquatic and Invasive Species.  | Center for Aquatic and Invasive Plants | University of Florida, IFAS (ufl.edu).

 

Sellers, B., Smith, H., Ferrell J. 2018. Identification and Control of Johnsongrass, Vaseygrass, and Guinea Grass in Pastures. University of Florida Electronic Data Information System.  SS-AGR-363. pdf\AG\AG372\AG372-16272415.pdf (ufl.edu)

 

Early Detection and Distribution Mapping System (EDDMapS)

https://www.eddmaps.org/

 

Six Rivers CISMA

https://www.floridainvasives.org/sixrivers/