by Rick O'Connor | Jan 14, 2020
Standing on one of our local beaches, the Gulf of Mexico appears to be a wide expanse of emerald green and cobalt blue waters. We can see the ripples of offshore waves, birds soaring over, and occasionally dolphins breaking the surface. But few of us know, or think, about the environment beneath the waves where 99% of the Gulf lies. We might dream about catching some of the large fish, or taking a cruise, but not about the geology of the bottom, what the water is doing beneath the waves, or what other creatures might live there.
The Gulf of Mexico as seen from Pensacola Beach.
Photo: Molly O’Connor
Scanning the horizon from the beach, you are gazing at 600,000 square miles of open water. It is about 950 miles from the panhandle to Mexico. Traveling at 10 knots, it would take you about 3 days to cross at its widest point. The Gulf is almost an enclosed body of water. The bottom is somewhat “bowl” shaped with the deepest portion slightly west of center at a location known as the Sigsbee Deep. The island of Cuba serves as the “median” between where the ocean enters and exits the Gulf. Cycling water from the Atlantic crosses from Africa, through the Caribbean, and enters the between Cuba and the Yucatan. The seafloor here sinks and spills into the Sigsbee Deep. The pass between Cuba and Yucatan is about 6500 feet deep and the bottom of the Sigsbee Deep is about 12,000. If you are looking due south from the Florida Panhandle, you would be looking at this pass.
If your gaze shifted slightly to the right – maybe “1:00” – you would be looking at the Yucatan. The Yucatan itself forms a peninsula and a portion of it is below sea level extending further into the Gulf. This submerged portion of the Yucatan is what oceanographers refer to as a continental shelf. On the “leeward” side of the Yucatan Peninsula lies an area of the Gulf known as the Bay of Campeche. There is a shallow section of this “bay” known as the Campeche Banks which supports amazing fisheries and some mineral extraction. Off the Yucatan shelf there is a current of water that rises from the ocean floor called an upwelling. These upwellings are usually cold water, high in oxygen, and high in nutrients – producing an area of high biological productivity and good fishing.
Continuing to circle the Sigsbee Deep and looking about “2:00”, northwest of the Bay of Campeche, you enter the western Gulf which extends from Vera Cruz Mexico to the Rio Grande River in Texas. The shelf is much closer to shore here and the marine environment is still tropical. There is a steep continental slope that drops into the Sigsbee Deep. Water from the incoming ocean currents usually do not reach these shores, rather they loop back north and east forming the Loop Current. The shelf extends a little seaward where the Rio Grande discharges, leaving a large amount of sediment. In recent years, due to human activities further north, water volume discharge here has decreased.
In the direction of about “2:30”, is the Northwestern Gulf. It begins about the Rio Grande and extends to the Mississippi Delta. Here the continental shelf once again extends far out to sea. One of the larger natural coral reefs in the Gulf system is located here; the Flower Gardens. This reef is about 130 miles off the coast of Texas. The cap is at 55 feet and drops to a depth of 160 feet. Because of the travel distance, and diving depth, few visit this place. Fishing does occur here but is regulated. This shelf is famous for billfishing, shrimping, and fossil fuel extraction. The Mississippi River, 15th largest in the world and the largest in the Gulf, discharges over 590,000 ft3 of water per second. The sediments of this river create the massive marshes and bayous of the Louisiana-Mississippi delta region, which has been referred to as the “birds’ foot” extending into the Gulf. This river also brings a lot of solid and liquid waste from a large portion of the United States and is home to one of the most interesting human cultures in the United States. There is much to discuss and learn about from this portion of the Gulf over this series of articles.
The basin of the Gulf of Mexico showing surface currents.
Image: NOAA
At this point we have almost completely encircled the Sigsbee Deep and move into the eastern Gulf. Things do change here. From the Mississippi delta to Apalachee Bay west of Apalachicola is what is known as the Northeastern Gulf – also known as the northern Gulf – locally called the Gulf coast. This is home to the Florida panhandle and some of the whitest beaches you find anywhere. Offshore the shelf makes a “dip” close to the beach near Pensacola forming a canyon known as the Desoto Canyon. The bottom is a mix of hardbottom and quartz sand. Near the canyon is good fishing and this area, along with the Bay of Campeche, is historically known for its snapper populations. It lies a little north of the Loop Current but is exposed to back eddies from it. Today there is an artificial reef program here and some natural gas platforms off Alabama.
Looking between “9:00-10:00” you are looking at the west coast of Florida and the Florida shelf. Here the shelf extends for almost 200 miles offshore. Off the Big Bend the water is shallow for miles supporting large meadows of seagrass and a completely different kind of biology. The rock is more limestone and the water clearer. In southwest Florida the grassflats support a popular fisheries area and a coral system known as the Florida Middle Grounds. At the edge of the shelf is a steep drop off called the Florida Escarpment, which forms the eastern side of the “bowl”. Another ocean upwelling occurs here.
Looking at “11:00” you are looking towards the Florida Keys. Between the Keys and Cuba is the exit point of the Loop Current called the Florida Straits. It is not as deep as here as it is between Cuba and the Yucatan; only reaching a depth of 2600 feet. This is mostly coral limestone and the base of one of the largest coral reef tracks in the western Atlantic. The coral and sponge reefs, along with the coastal mangroves, forms one of the more biological productive and diverse regions in our area. It supports commercial fishing and tourism.
We did not really talk about the bottom of the “bowl”. Here you find remnants of tectonic activity. Volcanos are not found but you do find cold and hot water vent communities, which look like chimneys pumping tremendous amounts of thermal water from deep in the Earths crust. These vent communities support a neat group of animals that we are just now learning about. Brine lakes have also been discovered. These are depressions in the seafloor where VERY salty water settles. These “lakes” have water much denser than the surrounding seawater and can even create their own waves. Many of them lie as deep as 3300 feet and can be 10 feet deep themselves. There is one known as the “Jacuzzi of Despair”. They are so salty they cannot support much life.
In the next addition to this series we will begin to look at the some of the interesting plant and animals that call the Gulf home.
Embrace the Gulf.
by Rick O'Connor | Jan 10, 2020
It’s an amazing place really – the Gulf of Mexico. Covering over 598,000 square miles this almost a complete circle of water and home to some interesting geological features, amazing marine organisms, some of busiest ports in the United States, offshore mineral extraction, great vacation locations, and amazing local culture.
View from the Navarre Beach pier Photo credit: Lydia Weaver
As you stand along Pensacola Beach and look south, you see a wide expanse of water that seems to go on forever. However, in oceanographic terms, the Gulf is not that large of a body of water. Though it is close to 600,000 square miles in size, the Atlantic Ocean is 41,000,000 and the Pacific is 64,000,000 square miles. In addition to area, the mean depth of the Atlantic is a little over 12,000 feet and the Pacific is 14,000 feet. In comparison, the deepest point of the Gulf is 14,000 feet and the mean depth is only 5,000. The shape of the bottom is like a ceramic bowl that was not centered well when fired. The deepest point, the Sigsbee Deep, is about 550 miles southwest (about “2:00” if you are looking from the beach). The shape appears like a hole made by a golf ball that landed in a sand trap. As a matter of fact, there are scientists who believe this is exactly what happened – a large asteroid or comet made have hit the Earth near the Gulf forming a large series of tsunamis and created the Gulf as we know it today.
Either way the “pond” (as some oceanographers refer to it) is an amazing place. The bottom is littered with hot vents, brine lakes, and deep-sea canyons. Large areas of the continental shelf support coral reef formation and a great variety of marine life. Some of the busiest ports in the United States are located along its shores, and it supplies 14% of the wild domestic harvested seafood. Everyone is aware of the mineral resources supplied on the western shelf of the Gulf and the tremendous tourism all states and nations that bordering enjoy.
The emerald waters of the Gulf of Mexico along the panhandle.
This year the Gulf of Mexico Alliance will be celebrating “Embracing the Gulf” with a variety of activities and programs across the northern Gulf region. We will be dedicating this column to articles about the Gulf of Mexico all year and discussing some of the topics mentioned above in more detail. We hope you enjoy your time here and get a chance to explore the Gulf’s seafood, fishing, diving, marine life, ship cruises, unique cultures, and awesome sunsets. Embrace the Gulf!
by Scott Jackson | Jun 21, 2019
Panama City Dive Center’s Island Diver pulls alongside of the El Dorado supporting the vessel deployment by Hondo Enterprises. Florida Fish and Wildlife crews also are pictured and assisted with the project from recovery through deployment. The 144 foot El Dorado reef is located 12 nautical miles south of St Andrew Pass at 29° 58.568 N, 85° 50.487 W. Photo by L. Scott Jackson.
In the past month, Bay County worked with fishing and diving groups as well as numerous volunteers to deploy two artificial reef projects; the El Dorado and the first of the Natural Resources Damage Assessment (NRDA) reefs.
These sites are in Florida waters but additional opportunities for red snapper fishing are available this year to anglers that book for hire charters with captains holding federal licenses. Federal licensed Gulf of Mexico charters started Red Snapper season June 1st and continue through August 1st. Recreational Red Snapper fishing for other vessels in State and Federal waters is June 11th – July 12th. So booking a federally licensed charter can add a few extra fish to your catch this year.
The conversion of the El Dorado from a storm impacted vessel to prized artificial reef is compelling. Hurricane Michael left the vessel aground in shallow waters. This was in a highly visible location close to Carl Grey Park and the Hathaway Bridge. The Bay County Board of County Commissioners (BOCC) acquired the El Dorado, January 14, 2019 through negotiations with vessel owner and agencies responsible for recovery of storm impacted vessels post Hurricane Michael.
The El Dorado was righted and stabilized, then transported to Panama City’s St Andrews Marina by Global Diving with support from the Coast Guard and Florida Fish and Wildlife. Hondo Enterprises, was awarded a contract to complete the preparation and deployment of the vessel for use as an artificial reef.
Reefing the El Dorado provides new recreational opportunities for our residents and tourists. The new reef delivers support for Bay County’s fishing and diving charters continuing to recover after Hurricane Michael. Several local dive charter captains assisted in the towing and sinking of the El Dorado.
The El Dorado was deployed approximately 12 nm south of St. Andrew Bay near the DuPont Bridge Spans May 2, 2019. Ocean depth in this area is 102 feet, meaning the deployed vessel is accessible to divers at 60 feet below the surface.
The Bay County Board of County Commissioners continues to invest in the county’s artificial reef program just as before Hurricane Michael. Additional reef projects are planned for 2019 – 2020 utilizing Natural Resources Damage Assessment (NRDA) and Resources and Ecosystems Sustainability, Tourist Opportunities, and Revived Economies of the Gulf Coast States Act (RESTORE Act) funds. These additional projects total over 1.3 million dollars utilizing fines as a result of the Deepwater Horizon Oil Spill. Deployments will occur in state waters in sites located to both the east and west of St. Andrew Bay Pass.
Walter Marine deploys one of nine super reefs deployed in Bay County’s NRDA Phase I project located approximately 12 nautical miles southeast of the St. Andrew Pass. Each massive super reef weighs over 36,000 lbs and is 15 ft tall. Multiple modules deployed in tandem provides equivalent tonnage and structure similar to a medium to large sized scuttled vessel. Photo by Bob Cox, Mexico Beach Artificial Reef Association.
The first of these NRDA deployments for Bay County BOCC was completed May 21, 2019 in partnership with Mexico Beach Artificial Reef Association, Florida Fish and Wildlife Conservation Commission, and Florida Department of Environmental Protection using a $120,000 portion of the total funding. The deployment site in the Sherman Artificial Reef Permit Area is approximately 12 nm south east of St Andrew Bay Pass at a depth of 78 – 80ft.
| Patch Reef # |
Latitude |
Longitude |
| BC2018 Set 1
(6 Super Reefs and 4 Florida Specials) |
29° 55.384 N |
85° 40.202 W |
| BC2018 Set 2
(1 Super Reef and 4 Florida Specials) |
29° 55.384 N |
85° 39.739 W |
| BC2018 Set 3
(1 Super Reef and 4 Florida Specials) |
29° 55.384 N |
85° 39.273 W |
| BC2018 Set 4
(1 Super Reef and 4 Florida Specials) |
29° 55.384 N |
85° 38,787 W |
In 2014, Dr. Bill Huth from the University of West Florida, estimated in Bay County the total artificial reef related fishing and diving economic impact was 1,936 jobs, $131.98 million in economic output and provided $49.02 million in income. Bay County ranked #8 statewide in artificial reef jobs from fishing and diving. Bay County ranked #3 in scuba diving economy and scuba diving was 48.4 % of the total jobs related to artificial reefs. Dr. Huth also determine that large vessels were the preferred type of artificial reef for fishing and diving, with bridge spans and material the next most popular. Scuba diving and fishing on artificial reefs contributes significantly to the county’s economic health.
For more information and assistance, contact UF/IFAS Extension Bay County at 850-784-6105 or Bay@ifas.ufl.edu. Follow us on Facebook at http://faceboook.com/bayifas .
An Equal Opportunity Institution. UF/IFAS Extension, University of Florida, Institute of Food and Agricultural Sciences, Nick T. Place, Dean for UF/IFAS Extension. Single copies of UF/IFAS Extension publications (excluding 4-H and youth publications) are available free to Florida residents from county UF/IFAS Extension offices.
This article is also available through the the Panama City New Herald
by Laura Tiu | Nov 26, 2018
Red Tide has been a persistent presence in the Panhandle since September and responsible for many reported fish kills and respiratory distress in some people. Over the past week, red tide was still present in low to medium concentrations in or offshore of Escambia County to Bay County.
Jack-knife fish killed by red tide Miramar Beach, Florida
Red tide is a natural occurrence and Florida experienced red tides long before humans settled here. The tides originate 10-40 miles off shore and winds and currents bring them inshore. Red tide is fueled by nutrient typically stemming from land-based runoff.
During winter, the northerly winds and southbound currents will push the tide back offshore. There was hope that Hurricane Michael might help carry the red tide back out to sea. Unfortunately, it seems the nutrient run-off from the storm’s heavy rain or retreating storm surge may have contributed to the intensity and duration of the bloom.
In our economy, which is heavily dependent on tourism, the red tide is continuing to take a toll, especially on waterfront businesses. According to the Florida Fish and Wildlife Conservation Commission, store-bought and restaurant served shellfish are safe to eat during a red tide bloom because shellfish are monitored for safety and tested for red tide toxins before they are sold. The edible parts of crabs, shrimp and fish are not affected by the red tide organism and can be eaten, but guts should be discarded.
Many remember the local red tide bloom in 2015. The longest red tide bloom ever recorded lasted 30 months from 1994 to 1997. Warmer water due to climate change is predicted to cause algae to bloom more often, more intensely, and in more water bodies. It is imperative that we reduce nutrient inputs to our lakes, rivers, estuaries and coastal ocean waters today.
by Rick O'Connor | Jan 19, 2018
In the last article, we discussed what phytoplankton are, what their needs were, and their importance to marine life throughout the Gulf and coastal estuaries. In this article, we will discuss the different types of phytoplankton found in our waters.
The spherical shape of the centric diatom.
Image: Florida International University
Marine scientists interested in the diversity and abundance of phytoplankton will typically sample using a plankton net. There are a variety of different shapes and sizes of these nets, but the basic design would be funnel shaped with a sample jar attached at the small end of the funnel. The plankton net would be towed behind the research vessel at varying depths for a set period of time. All plankton collected would be analyzed via a microscope. According to the text Identifying Marine Phytoplankton (1997) there are at least 14,000 species of phytoplankton and some suggest as many as 120,000. Most of these, 12,000-100,000, are diatoms, one of five classes of marine phytoplankton. The majority of the phytoplankton fall into one of two class, the diatoms and the dinoflagellates.
Diatoms are typically single celled algae encased in a clear silica shell called a frustule. The frustule can come in a variety of shapes, with or without spines, and many resemble snowflakes – their quite beautiful. They are found in the bay and Gulf in great numbers, as many as 40,000,000 cells / cup of seawater. They are the dominate phytoplankton in colder waters and are most abundant near upwellings. These are the “grasses of the sea” and the base of many marine food webs. When diatoms die, their silica shells sink to the seafloor forming layers of diatomaceous earth, which is used in filters for aquariums and oxygen mask in hospitals.
Dinoflagellates differ from diatoms in that they produce two flagella, small hair-like projections from the algae that are used for generating water currents and movement. Their shells are not silica but layers of membranes and are called thecas. Some membranes are empty and others contain different types of polysaccharides. Dinoflagellates are more abundant than diatoms in warmer waters. There are about 2000 species of them. One type, Noctiluca, are responsible for what locals call “phosphorus” or bioluminescence. These dinoflagellates produce a blue-ish light when disturbed. Many see this when walking the beach at night. Their footprints glow for a few seconds. At night, boaters can see this as their prop wash turns the dinoflagellates in the water column. The bioluminescence is more pronounced in the warm summer months and is believed to be defense against predation. The light is referred to as “cool” light in that the majority of the energy is used in producing light, not lost as heat as with typical incandescent bulbs – hence the birth of the LED light industry.
The dinoflagellate Karenia brevis.
Photo: Smithsonian Marine Station-Ft. Pierce FL
Several dinoflagellates produce toxins as a defense. Some generate what we call red tides. In the Gulf of Mexico, Karenia brevis is the species most responsible for red tide. Red tides typical form offshore and are blown into coastal areas via wind and currents. They are common off the coast of southwest Florida but occur occasionally in the panhandle. Many local red tides are actually formed in southwest Florida and pushed northward via currents. Red tides are known to kill marine mammals and fish, as well as closing areas for shellfish harvesting.
Like true plants, phytoplankton conduct photosynthesis. Between the diatoms and dinoflagellates, 50% of the planet’s oxygen is produced. These are truly important players in the ecology of both the open Gulf and local bays.
References
Annett, A.L., D.S. Carson, X. Crosta, A. Clarke, R.S. Ganeshram. 2010. Seasonal Progression of Diatom
Assemblages in Surface Waters of Ryder Bay, Antarctica. Polar Biology vol 33. Pp. 13-29.
Hasle, G.R., E.E. Syvertsen. 1997. Identifying Marine Phytoplankton. Academic Press Harcourt Brace and
Company. San Diego CA. edited by C.R. Tomas. Pp. 858.
Steidinger, K.A., K. Tangen. 1997. Identifying Marine Phytoplankton. Academic Press Harcourt Brace and
Company. San Diego CA. edited by C.R. Tomas. Pp. 858.
