by Laura Tiu | Jun 23, 2021
A great blue heron enjoying the Gulf of Mexico.
Photo: Chris Verlinde
June is National Ocean Month. Close your eyes and think about just how many oceans there are. Surprise, there is only one! The ocean is huge, covering over 70 percent of the earth’s surface. Traditionally, the ocean was divided into four named ocean basins: the Pacific, Atlantic, Indian, and Arctic. However, most countries, including the United States, now recognize the Southern (Antarctic) as the fifth ocean. No matter where you live, you are connected to our one global ocean.
What do you know about our ocean? The ocean is where life began over 3.5 billion years ago. The ocean covers over 70% of the Earth’s surface and includes over 96% of the Earth’s water. Australia’s Great Barrier Reef is the largest living structure on Earth and can be seen from the moon! The deepest part of the ocean is in the Mariana Trench, and nearly 7 miles beneath the waves! Coral reefs cover only 1/50th of the ocean floor but about one quarter of all the marine species make coral reefs their home. No light penetrates the ocean at depths greater than 3,280 feet. Aided by deep diving rovers and remote sensing cameras, scientists are still discovering new species beneath the waves. The Gulf Stream transports more water than all the Earth’s rivers combined. The mid-ocean ridge crisscrosses the globe for over 40,000 miles and is the largest geological feature on Earth. Did you know that about 95% of the ocean remains unexplored?
What about our beloved Gulf of Mexico? Is it an ocean? No! While both oceans and gulfs are large bodies of saltwater, gulfs are smaller and are bordered on three sides by land. In the case of the Gulf of Mexico, it’s bordered by the United States and Mexico. So, although it is large and salty like the ocean, the Gulf of Mexico is considered part of the Atlantic Ocean.
Happy National Oceans Month!
Reference: National Oceanic and Atmospheric Administration https://oceanservice.noaa.gov/ocean/30days/welcome.html
The equatorial currents of the Pacific.
Image: NOAA
by Rick O'Connor | Jun 3, 2021
With this article we are going to begin a short series on the biogeography of panhandle vertebrates. Biogeography is the study of distribution of life and why species are found where they are. Many are interested in what species are found in a specific location, such as which sharks are found in our area, but understanding why others are not is as interesting.
The Bull Shark is considered one of the more dangerous sharks in the Gulf. This fish can enter freshwater but rarely swims far upstream. Photo: Florida Sea Grant
All species have a point of origin and from there they disperse across the landscape, or ocean, until they reach a barrier that stops that dispersal. These barriers can be something physical, like a mountain range, something climatic, like the average temperature, or something biological, like to abundance of a specific food or predator. There are a lot of barriers that impede dispersal and explain why some species are not present in some locations.
Sharks are marine fish. In general, there is little to impede the dispersal of marine fish. All oceans are connected and there is no reason why a shark found in the Gulf of Mexico could not swim to Australia, and some have. But there are barriers that keep some species of south Florida fish from reaching north Florida – mean water temperature being one.
There are 24 species of sharks from nine different families found in the Gulf of Mexico. Most have a wide distribution range, and some are found worldwide. Nurse sharks are more tropical, common in the Keys, but are found in our area of the northern Gulf of Mexico. They are fans of structure and are often found near our artificial reefs.
Whale sharks and hammerheads are circumtropical, meaning they are restricted by water temperature but found worldwide in warmer waters. Whale sharks are the largest of all fish, reaching a mean length of 45 feet, and are not common near shore. They are plankton feeders and, though large, are harmless to humans. There are five species of hammerheads found in the Gulf of Mexico. They are easily identified by their “hammer” shaped head and are known for their large dorsal fin that, at times, will extend above the surface while they are swimming. Finding species of hammerhead inside the bay is not uncommon.
Several of our local sharks are not as restricted by water temperature and are found as far north as Canada. Sand tigers, threshers, and dogfish seem to prefer the cooler waters and, though found in the Gulf, are not common. There are two members of the mackerel shark family found here. Great whites, of movie fame, prefer cooler waters and are found worldwide – except for polar waters. There are records in the Gulf, but most are offshore in cooler waters. As you know, these are large predatory sharks, reaching up to 25 feet in length, and are known to feed on large prey such as seals. Their cousin the shortfin mako, prefers warmer waters and is more common here. Nearshore encounters with makos is rare but has happened.
The largest family, and best known, are the requiem sharks. There are 13 species in the Gulf, and many are common in our area. Many are not as restricted by water temperature and can be found as far north as New York. Bull sharks are not restricted by salinity and have been found up rivers in Alabama, and Louisiana. Silky sharks are more tropical, and the tiger and spinner sharks are more circumtropical.
The geographic distribution of sharks seems centered on water temperature. Most can easily swim the oceans to locations across the globe but congregate in areas of preferred temperatures and food. Though feared because of attacks on humans, a rare thing actually, they are fascinating animals and world travelers.
by Carrie Stevenson | May 7, 2021
A ghost forest forming along the shoreline of Blackwater Bay in Santa Rosa County. Photo credit: Carrie Stevenson, UF IFAS Extension
As the name implies, they are haunting—wide stretches of standing, dead trees with exposed roots. These “ghost forests” are an unsettling scene in unsettling times for the environment. While coastal erosion is a fact of life—incoming waves, hurricanes, longshore drift of beach sand—the rate of its occurrence is startling lately.
Global rises in sea level due to increased atmospheric carbon levels mean more saltwater is moving into flat, coastal habitats that once served as a buffer from the open water. Salt is an exceedingly difficult compound for plants to handle, and only a few species have evolved mechanisms for tolerating it. Low-growing salt marshes and thick mangrove stands have always served as “first line of defense” buffers to take in wave action and absorb saltwater. If shorelines have too much wave action for marshes to form, wide stretches of sandy beach and dunes serve the same function, protecting the inland species of shrubs and trees. Many coastal areas are flat and stay at or just above sea level for thousands of yards, or even miles. This means that even a small increase in sea level can send saltwater deep into previously freshwater systems, drowning the marsh and flooding stands of oak and pine. The salt and sulfate in seawater will kill a tree quickly, although it may remain standing, dead, for months or years. Hurricanes and tropical storms exacerbate that damage, scouring out chunks of shoreline and knocking down already-unstable trees.
This diagram outlines the changes in coastal vegetation and shorelines as sea level rises. With “ghost forests,” the sea level moves into that coastal forest section. Figure credit: W. Gray, IAN Image Library
A slow increase in sea level could be tolerated and adapted to as salt marshes move inland and replace non-salt tolerant species. But this process of ecological succession can be interrupted if erosion and increased water levels occur too quickly. And if there is hard infrastructure inland of the marshes (like roads or buildings), the system experiences “coastal squeeze,” winnowing the marsh to a thin, eventually nonexistent ribbon, with no natural protection for that expensive infrastructure.
Ghost forests are popping up everywhere. Earlier this month, Popular Mechanics magazine reported on a recently published study that used satellite imagery to document how 11% of a previously healthy forest was converted to standing dead trees along the coast of North Carolina. The trees died within a span of just 35 years (1984-2019). During that time frame, this stretch of coastline also experienced an extended drought and Category 3 Hurricane Irene. These impacts sped up the habitat loss, with over 19,000 hectares converted from forest to marsh and 1100 hectares of marsh vegetation gone, becoming open water.
Exposed roots of a ghost forest forming along the Escambia Bay. Photo credit: Deanie Sexton
Due to increased coastal flooding and saltwater standing in forested areas, U.S. Fish and Wildlife Service employees are concerned that the historic Harriett Tubman Byway in Maryland—part of the famed underground railroad of the Civil War era—will soon be gone. Over 5,000 acres of tidal marsh have converted to open water in the area and large stands of trees have died. Even locally, trees along Escambia and Blackwater Bay are dying due to salt damage and heavy erosion. Hurricane Sally delivered a knockout punch to many remaining trees along the scenic bluffs of the bay.
Sea level has risen over 10” in the past 100 years in the Pensacola Bay area, and even mid-range Army Corps of Engineers estimates expect 0.6 to 1.4 feet of rise in the area by 2045. There are some actions we can take to mitigate future damage. Building a “living shoreline” of vegetation along a piece of waterfront property instead of using a seawall can help, especially if the vegetation growth outpaces sea level rise. You can also visit the City of Pensacola’s Climate Task Force report to learn more about climate action recommended (and being taken) locally, such as increasing the use of renewable energy and dedicating staff to sustainability measures.
by Rick O'Connor | Apr 8, 2021
EDRR Invasive Species
Beach Vitex (Vitex rotundfolia)
Vitex beginning to take over bike path on Pensacola Beach. Photo credit: Rick O’Connor
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:
Beach vitex is native to the coastal shores of Asian countries bordering the Pacific rim. It is also found in Hawaii.
Introduction:
There are conflicting records as to when it was first introduced to the U.S. One record has it in the country as early as the 1950s. However, there are no records of plants from that stock still existing. Most records suggest the release of the plant occurred in the 1980s when it was brought to North Carolina as a potential ornamental plant. It was then used in dune restoration after a series of hurricanes and became a problem. Thus, it was intentionally introduced.
EDDMapS currently list 649 records of beach vitex. Most are in North Carolina. There are 82 records in Florida and 46 (56%) are in the Pensacola Bay area. We currently have 75 records from the Pensacola Bay area. Not all are reported on EDDMapS due to private property restrictions. Records do occur in coastal Alabama, Mississippi, as well as Okaloosa and Franklin counties in the Florida panhandle.
Distribution is most likely due to the high tolerance of salt water by the seeds and dispersal by currents, as well as intentional plantings by local landscapers and homeowners. Vitex rotundifolia is now a noxious weed in Florida and can no longer be sold.
Within our CISMA there are records in all coastal counties (Baldwin, Escambia, Santa Rosa, and Okaloosa)
Description:
Beach vitex is a perennial plant that initiates from a main taproot and extends herbaceous vines across the surface of the substrate in almost a 360° pattern. The vines can grow as much as 20 feet in length and become more woody with age. As the plant grows, secondary roots extend from each of the nodes from the above ground stems (vines) and becomes more of a shrub, reaching a height of about two feet.
The two-inch leaves are ovate in shape, a light green to blue-green color, and are aligned opposite of each other. They turn a reddish brown during the fall and winter and many plants will lose their leaves completely during this time.
The blossom is a lavender color and made of numerous small petals. The blossoms are present during the spring and summer. They will produce numerous charcoal gray fruits in fall and winter. Each fruit can hold up to four seeds. It has been reported that the plant can produce over 1000 seeds / m2.
Issues and Impacts:
After planting for dune restoration in North Carolina, the plant quickly became a monoculture. It is allelopathic creating a hydrophobic situation in the soil. This situation can cause the decline of native plants, such as sea oats (Uniola paniculata). As the plant becomes more of a shrub it decreases the amount of sunlight reaching the surface further decreasing the smaller native plants and the ability for many to germinate.
This altering of the native dune plant community can have potential impacts on the native faunal communities. There are concerns on its impacts to protected species such as beach mice and nesting sea turtles.
Having a taproot system rather than a fibrous one like the sea oat, can comprise dune integrity during tropical storms. It is known that these dune systems provide protection for natural and developed areas behind them.
Management:
Finding the plants early and removing by hand is the first and best option. The plant is relatively new to the panhandle area and smaller ones are often found. Once the small plants are found, you can simply cut the above ground vine into 2 foot sections and place in a trash bag – you should double bag this. Woody vines may puncture the bag so shorter sections may be needed for those.
Once you reach the taproot you may be able to pull it from the ground, or you may need to dig it out. This method works well in loose dry sandy soils, it may require more digging and cutting if soils are more compacted. If you cannot remove the entire taproot, we recommend spot spraying the remainder with glyphosate. Be careful not to over spray, glyphosate is non-selective and will kill any native plants it comes into contact with.
In cases where the patch of vitex is too large to remove by hand then chemical treatment will be needed. Several studies have been published as to which herbicides are effective. Imazapyr, Triclopyr, and Glyphosate are all products that have been used both in foliage application and cut stem with success. The exact concentrations vary with abundance of plants and surrounding habitats and re-treatments over a few years may be required. We recommend you reach out to your local CISMA or county extension office for more direct help on your situation.
For more information on this EDRR species, contact your local extension office.
References
Invasive Species – Beach Vitex. Rick O’Connor. 2017. UF IFAS Escambia County Blog. http://blogs.ifas.ufl.edu/escambiaco/2017/03/20/invasive-species-beach-vitex/.
Early Detection and Distribution Mapping System (EDDMapS)
https://www.eddmaps.org/
Six Rivers CISMA
https://www.floridainvasives.org/sixrivers/
by Erik Lovestrand | Mar 11, 2021
Cobia Researchers use Transmitters as well as Tags to Gather Data on Migratory Patterns
I must admit to having very limited personal experience with Cobia, having caught one sub-legal fish to-date. However, that does not diminish my fascination with the fish, particularly since I ran across a 2019 report from the Gulf States Marine Fisheries Commission titled “Management Profile for Gulf of Mexico Cobia.” This 182-page report is definitely not a quick read and I have thus far only scratched the surface by digging into a few chapters that caught my interest. Nevertheless, it is so full of detailed life history, biology and everything else “Cobia” that it is definitely worth a look. This posting will highlight some of the fascinating aspects of Cobia and why the species is so highly prized by so many people.
Cobia (Rachycentron canadum) are the sole species in the fish family Rachycentridae. They occur worldwide in most tropical and subtropical oceans but in Florida waters, we actually have two different groups. The Atlantic stock ranges along the Eastern U.S. from Florida to New York and the Gulf stock ranges From Florida to Texas. The Florida Keys appear to be a mixing zone of sorts where Cobia from both stocks go in the winter. As waters warm in the spring, these fish head northward up the Atlantic and Gulf coasts of Florida. The Northern Gulf coast is especially important as a spawning ground for the Gulf stock. There may even be some sub-populations within the Gulf stock, as tagged fish from the Texas coast were rarely caught going eastward. There also appears to be a group that overwinters in the offshore waters of the Northern Gulf, not making the annual trip to the Keys. My brief summary here regarding seasonal movement is most assuredly an over-simplification and scientists agree more recapture data is needed to understand various Cobia stock movements and boundaries.
Worldwide, the practice of Cobia aquaculture has exploded since the early 2000’s, with China taking the lead on production. Most operations complete their grow-out to market size in ponds or pens in nearshore waters. Due to their incredible growth rate, Cobia are an exceptional candidate for aquaculture. In the wild, fish can reach weights of 17 pounds and lengths of 23 inches in their first year. Aquaculture-raised fish tend to be shorter but heavier, comparatively. The U.S. is currently exploring rules for offshore aquaculture practices and cobia is a prime candidate for establishing this industry domestically.
Spawning takes place in the Northern Gulf from April through September. Male Cobia will reach sexual maturity at an amazing 1-2 years and females within 2-3 years. At maturity, they are able to spawn every 4-6 days throughout the spawning season. This prolific nature supports an average annual commercial harvest in the Gulf and East Florida of around 160,000 pounds. This is dwarfed by the recreational fishery, with 500,000 to 1,000,000 pounds harvested annually from the same region.
One of the Cobia’s unique features is that they are strongly attracted to structure, even if it is mobile. They are known to shadow large rays, sharks, whales, tarpon, and even sea turtles. This habit also makes them vulnerable to being caught around human-made FADs (Fish Aggregating Devices). Most large Cobia tournaments have banned the use of FADs during their events to recapture a more sporting aspect of Cobia fishing.
To wrap this up I’ll briefly recount an exciting, non-fish-catching, Cobia experience. My son and I were in about 35 feet of water off the Wakulla County coastline fishing near an old wreck. Nothing much was happening when I noticed a short fin breaking the water briefly, about 20 yards behind a bobber we had cast out with a dead pinfish under it. I had not seen this before and was unaware of what was about to happen. When the fish ate that bait and came tight on the line the rod luckily hung up on something in the bottom of the boat. As the reel’s drag system screamed, a Cobia that I gauged to be 4-5 feet long jumped clear out of the water about 40 yards from us. Needless to say, by the time we gained control of the rod it was too late; a heartbreaking missed opportunity. Every time we have been fishing since then, I just can’t stop looking for that short, pointed fin slicing towards one of our baits.
by Chris Verlinde | Mar 5, 2021
On most days, if you walk to the end of the Navarre Beach Fishing Pier, you will find a group of shark anglers that provide valuable data to the National Oceanic and Atmospheric Administration (NOAA) Cooperative Volunteer Shark Tagging program. Led by Earnie Polk, 50-60 team members have participated in the cooperative tagging
program in the twenty-five years he has been involved.
This group not only provides research data to NOAA, but are also stewards of pier etiquette, Navarre Beach and the surrounding area. Tourists and locals alike are treated to stories of local history, fish tales and general information about the area from Earnie and Team True Blue members. In addition, visitors may see a shark tagged and released or the group catching large fish to be used for shark bait
Photo Credit Earnie Polk
The NOAA Cooperative Shark Tagging program has been in existence since 1962. Today thousands of anglers along the Gulf of Mexico and Atlantic Coast have tagged more than 295,000 sharks representing 52 different species. More than 17,500 sharks have been recaptured! This program provides information on shark migration patterns, numbers, locations, migrations, age and growth rates, behavior and mortality.
Earnie estimates he has tagged more than one-thousand sharks for the program. He has refined handling methods to have the least impact on the animal to ensure the survival of the shark after release. The team brings the shark to shore to measure the length and tag the shark just behind the dorsal fin. 
Earnie shared an interesting story about tagging at least eighty Dusky sharks during a red tide event during the late fall of 2015. He noticed as the north winds blew the red tide out, an open area was created along the coast. This allowed clear water for the sharks to travel closer to shore and within distance of the tag and release team.
Today, the tiger shark is the most common shark the team tags and releases. Recently, the team tagged and released a 12’6” tiger shark. Randy Meredith, of the Navarre Newspaper agreed to share the video he edited of the Navarre Fishing Pier and the tag and release of the tiger shark in February 2021.
The team uses heavy gear, 200-pound test line and Everol reels that have drag pressure for a shorter fight to reduce stress on the animal for a better survival rate. Gear is spread along the rails at the end of the pier. Baited lines range from approximately 75 to 400 yards off the end of the pier. You probably wonder how they get their line 400 yards off the pier. Earnie has modified a fiberglass kayak with a battery powered motor. It is lowered to the surface of the water; team members drop their lines onto the kayak and Earnie pilots the kayak out to deeper water. 
Their strategy is that by dropping more lines, at different depths and locations a shark is bound to trip over one of the lines. They use bait they catch on the pier or other fishing trips. Something big had hit on a cow nose ray over the weekend, so most members were using rays for bait. One team member said, “if the fish had hit on a watermelon, we all would be using watermelon for bait.” These guys have a great sense of humor!!
Make sure that the next time you visit Navarre Beach, you take time to walk out to the end of the fishing pier to learn about local sharks, 
history and the area from these interesting, funny and helpful anglers. On clear days you may see sharks, rays, sea turtles and other types of marine life as you venture out.
Be sure to stop at the pier store to pay the $1.00 per-person fee to enjoy the view!
