Our Intense Weather and Climate Change

Our Intense Weather and Climate Change

Everyone has noticed the intense weather that crossed the United States in recent years.  Tornadoes are hitting communities throughout the Midwest, but are also hitting places like Seattle, southern California, and even recently Pensacola Beach.  Thunderstorms, though common, are occurring in waves.  Typical summer days here in the panhandle include afternoon thunderstorms, but recently there have been daily squall lines beginning as early as 9:00am.  I was recently camping out west and we encountered three hailstorms.  Though these do occur out there, they were becoming a common thing and were also encountered in multiple states.  And of course, there are hurricanes.  Some are more intense and increase intensity as they come ashore, instead of decreasing as has been the rule over the decades. 

This squall line formed early in the morning. One of many morning thunderstorms formed over a period of a week in the summer of July 2023. Photo” Rick O’Connor

Many have pointed the finger at climate change as being part of the reason why these intense weather events are increasing, and climatologists have said for decades this could happen.  To better understand what is driving these storms, I decided to grab one of my old college textbooks from the shelf and read what actually forms and fuels these weather events.  The Nature of Violent Storms was published in 1961, and reprinted in 1981, by Dr. Louis Battan.  Though many things that were unclear at the time of the writing have been discovered, the mechanisms that generate and fuel these storms were understood. 

The mechanism that begins storms is convection cells within the air rising from the earth’s surface.  The air moving over warm land or water warms as well and begins to rise.  The rising air lowers the air pressure at the surface and is called a low pressure system.  We associate low pressure systems with storms.  These storms form due to unstable air masses in this rising column of air.  The greater the temperature difference between the warmer air near the ground, and the cooler air in the upper atmosphere, the more unstable the air becomes and the faster the column of air rises.  As the air rises it begins to cool, become denser, and falls back to earth like a water fountain shooting water into the air.  This is the convection cell we have heard about. 

However, if the air mass holds a lot of moisture (humidity) the release of heat from this humid air mass rising in the column can warm the environmental air mass surrounding it enough to cause the rising air mass to continue higher into the atmosphere increasing its speed while doing so.  We can see this as cumulus clouds building over the landscape and, if humid enough, you can literally watch the thunderhead build.  If supplied with enough water vapor and heat, these thunderheads will grow all the way to the tropopause (the lower layer of the stratosphere where the atmosphere itself begins to warm, not cool) and form the “anvil” shape of a thunderhead we are all familiar with.  As a college student taking coastal climatology (the class this book was associated with) we would sit outside of Dauphin Island Sea Lab at mid-afternoon and bet on which thunderhead would reach the tropopause first. 

The upper layer of the lower atmosphere is quite cold.  Here the releasing water vapor condenses into rain droplets, ice, and often hail.  They fall back towards earth.  Much of the ice and hail melt before reaching us but under intense conditions this frozen precipitation can reach the earth’s surface as hailstones, some being as large as three inches across.  One storm we encountered in Colorado this year had hailstones about the size of a large marble.  We heard that at a nearby amphitheater the hail reached the size of golf balls and many who were there to see a concert (and there was no cover to hide) were taken to the hospital. 

A hail storm encountered by the author in Colorado. Photo: Rick O’Connor

The one common denominator in the formation of such storms is the presence of a warm landmass or water body.  The warmer these land masses and water bodies are, the more energy there is for the enhanced convection and severe storm formation.  And these land masses, and water bodies are getting warmer. 

Hail stones are formed from ice that manages to remain solid as precipitation in very unstable air masses. They can reach three inches across. Photo: Rick O’Connor

What has changed is the atmosphere itself.  There are gases within the atmosphere that allow solar rays to pass through reaching the surface of the earth, but do not allow the warmed air caused by the warming of land and sea from this solar radiation to escape back into space – the so called “greenhouse effect”.  This is actually good; it keeps our planet at a warmer temperature than it would be if these gases were not present and allows life to exist here.  However, an increase in these “greenhouse gases” can increase the overall temperature and create problems – intense storms being one of them.  The surface of the planet Venus is around 900°F.  Even though the planet Mercury is closer, Venus is warmer due to the heavy amount of greenhouse gases in its atmosphere.  At temperatures like this, it is understandable that life does not exist there, and scientists do not believe it could.  Getting scientific instruments to the surface of Venus is difficult due to the large amount of sulfuric acid in the clouds, much of this coming from intense volcanic activity there. 

The greenhouse effect. Image: NOAA

On Earth, our temperatures are climbing – slowly, but climbing.  As the atmosphere warms due to the greenhouse effect, it increases the temperature of the land mass and water bodies.  Increased temperatures in Pensacola Bay have triggered some die offs of oysters, and the warming Mobile Bay has increased the number of jubilee’s occurring there.  Remember, high water temperatures mean low dissolved oxygen levels.  Increased surface temperatures will create more unstable air masses and a breeding ground for the formation of vortices that can, and do, lead to more intense thunderstorms and tornadoes.  Surface temperatures are increasing in locations where historically such weather events have not been common, like Seattle.  Recently, I had to make a trip to a department store at one of our local malls.  Leaving the house, as I crossed our wooden deck and walked through the yard to the truck, it was definitely warm – it was July.  However, when I arrived at the store, where all was concrete and asphalt, the temperature difference was striking.  It was MUCH warmer.  Actually, at the store front it was almost unbearable.  In many of our large cities, and even in smaller ones, we have converted much of the natural landscape to concrete and asphalt, which is increasing the surface temperatures even more, and enhancing unstable air even more.  We have all heard that large cities create their own weather, and it is true. 

So…

How do we turn this around?

I see two paths.  (1) Reduce the source of the heating – greenhouse gases.  (2) Mitigate the impacts of the heating. 

There are several sources of greenhouse gases, and these have been discussed in other articles, but certainly the use of fossil fuels is a major one and reducing our dependency on these would be a good start.  But we are moving very slowly on this, the will to do it just is not strong enough. 

To mitigate the impacts, we would need to re-think how we grow and develop the landscape.  Even today, many of the new subdivisions I see clear all of the vegetation, place the houses close together with little or no green space, use asphalt roofs, and replace little or none of the vegetation.  It seems our development plan does not have the will to make some much needed changes in planning either.  There are many ways in which we can develop our landscape to help mitigate the warming that is occurring.  Many researchers at the University of Florida have been working on this for many years.  For ideas and suggestions, just contact your county extension office. 

Based on the 2021 Intergovernmental Panel on Climate Change’s report, we may be past the tipping on sea level rise, but we are not on other negative impacts of climate .  It is understood that with any mitigation efforts right now, there will be a lag time of several years before things begin to turn around, it is not too late.  We can do this. 

We Are HOT!! So Are Our Ecosystems: The Effects of Increasing Climate Change on Agriculture and Natural Resources

We Are HOT!! So Are Our Ecosystems: The Effects of Increasing Climate Change on Agriculture and Natural Resources

De’Anthony Price

Agriculture & Natural Resources

UF/IFAS Extension Jefferson County

It is no surprise how hot it has been this summer. With increasing temperatures, the danger also increases for our agriculture and natural resources. Our agriculture and natural resources are an economical and lifestyle treasure that provides favored services like timber, water supply protection, livestock forage, recreation, fisheries, and hunting. Our forest and ecosystems are declining in health and biodiversity due to changed climate activity. Climate change impacts every type of natural resource. Plant and animal species distributions will continue to change as rising temperatures alter ecosystems and amplify existing environmental concerns.

Climate change refers to the range of changes that will occur locally and globally due to this ‘global warming.’ These changes include changes in rainfall patterns, melting of glaciers, rising sea levels, and increasing temperature. To understand how our climate is changing, one must first know how our climate works. Greenhouse gases allow the sun’s rays to enter our atmosphere. Once the rays reflect off the earth’s surface, greenhouse gases trap them in the atmosphere and warm the planet. This act is called the greenhouse effect, and it is necessary for life on earth; the world would be too cold to live without it. Some greenhouse gases are present naturally and others are byproducts of human industry. Natural greenhouse gases include water vapor, carbon dioxide, methane, and nitrous oxide. Over the past 150 years, humans have caused a significant increase in the concentration of greenhouse gases occurring naturally and those made by humans in the atmosphere. Due to these increases, scientists have recorded environmental changes, projected to continue warming our planet to unprecedented levels.

Explaining what The Greenhouse Effect is

Biodiversity are one of the primary aspects at risk. Species that can adapt in wide geographic ranges, such as white-tailed deer and feral hogs, will likely continue to thrive. Species that depend on specific habitats, aquatic and coastal ecosystems, are at risk. Food and forage production will decrease in agricultural areas experiencing increased droughts. Higher temperatures decrease soil moisture, causing crop stress and water demand issues—further stressing U.S. surface and groundwater supplies used for irrigation. Many crops decrease in yield as temperatures rise beyond the heat tolerance range. Warmer winters increase the incidence of pests and diseases in our ecosystems. Extreme heat, especially nighttime heat, decreases animal activity. Impacts vary from different areas, depending on warming and adaption levels.

American Public Health Association Explains how climate change affects your health

Climate action does not always require grand gestures or massive lifestyle changes. We can all play a part in combating climate change by making small adjustments in our daily routines. A fundamental step in tackling climate change is to adopt the “reduce, reuse, and recycle” mantra in your everyday life. By reducing waste, reusing items, and recycling materials, you can positively impact the environment. Energy consumption and water usage directly affect greenhouse gas emissions and water scarcity. You can significantly reduce your carbon footprint by adopting energy-efficient practices and conserving water.

For more information on climate change and “what you can do”, please visit Climate Change – UF/IFAS Extension (ufl.edu)

Florida Climate Institute at the University of Florida (floridaclimateinstitute-uf.org)

How Climate Change Affects Your Health (apha.org)

Nature-Based Stormwater Solutions in the Florida Panhandle

Nature-Based Stormwater Solutions in the Florida Panhandle

Summertime always makes me think of the supermarket. At least one time each of the past few summers, I clearly remember being at the supermarket during a rainstorm and watching the water wash over the parking lot, talking with all the other people debating whether to run to their car with a buggy full of food. Supermarkets, home goods stores, medical facilities, libraries, and shopping centers all provide important services that we depend on for our everyday life, but their development has altered the natural processes that control the movement of water from the landscape to creeks and ultimately to the bays and bayous around us (collectively referred to as receiving waters). Concrete, asphalt, and building roof surfaces are impervious, meaning that water cannot pass through them. As a result, more water washes off the rooftops, parking lots, driveways, and roads than before the area was developed. Less water sinks into the ground to move slowly toward receiving waters and to recharge aquifers. More impervious surface leads to more runoff to receiving waters, resulting in greater erosion and higher levels of pollutants like nitrogen, phosphorus, and silt in these waterways. These extra pollutants from the landscape and from eroding stream banks have harmful effects many types of organisms that call these waterways home.

New development in Florida is required to include features that “treat” a fraction of the surface water that runs off impervious surfaces before flowing into receiving waters. Treating surface water runoff means holding it back and preventing it from running quickly off the developed landscape; as it is held back, some pollutants may settle out or be consumed by plants. Treatment is commonly accomplished through features like dry retention basins or wet detention ponds, where water is stored and then slowly moves through soil pathways toward receiving waters. These features are common parts of our developed landscape: the big pond behind the supermarket or in front of the new truck stop, or the grassy pit next to the gas station. While these satisfy regulations, they occupy a considerable amount of land, typically are aesthetically lacking, and may not actually reduce pollutant runoff or stormwater volume as intended. They also can be neglected and become a nuisance in the landscape.

Nature-based stormwater infrastructure projects can play an important role in protecting communities in northwest Florida from the effects of heavy rainfall that occurs periodically in the region. Nature-based stormwater projects are designed primarily to incorporate the natural processes of infiltration that occur in undeveloped areas in the developed landscape, treating stormwater by reducing volumes of surface runoff and concentrations of pollution that could otherwise flow directly into receiving waters. Depending on their design, these features can also provide aesthetic enhancements that can increase the value of properties and the overall wellbeing of the communities where they are implemented. When used in coordination, nature-based projects such as roadside treatment swales, bioretention cells, rain gardens, green roofs, and porous pavement can provide similar levels of stormwater treatment as dry retention basins and detention ponds while also enhancing the aesthetic, recreational, or functional potential of the landscape.

Local government and extension staff across northwest Florida are working to introduce more nature-based stormwater projects into the panhandle landscape. To learn more about recent demonstration projects that have been implemented in our region, visit the WebGIS project https://arcg.is/1SWXTm0.

Ghost Forests

Ghost Forests

As the name implies, they are haunting—long 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.

Exposed roots of a ghost forest forming along the Escambia Bay. Photo credit: Deanie Sexton

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.

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.

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

Ghost forests are popping up everywhere. Last year, 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.

A ghost forest forming along the shoreline of Blackwater Bay in Santa Rosa County. Photo credit: Carrie Stevenson, UF IFAS Extension

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.

Are Our Bays Becoming Less Salty?  2022 Annual Report

Are Our Bays Becoming Less Salty? 2022 Annual Report

Introduction

Historically the average rainfall in the Pensacola Bay is around 60 inches per year.  However, over the past 10 years that has increased to slightly more than 75 inches per year (see Table 1).  The frequency of those levels over the past decade shows that most are between 60 – 80 inches but there have been two years with over 90 inches reported.  In the last decade, nine of the 10 years had total rainfall above the historic mean for the area. 

Along with the increase in rainfall has come an increase in development.  This increase reduces the amount of the excess rainfall to percolate into the ground and recharge our aquifer.  Instead, it is directed into stormwater projects to reduce flooding in the community.  Some of this stormwater will eventually find its way to the estuary or the tributaries that feed the estuary.  The question is whether this increase in freshwater run-off is enough to decrease the salinity of the bay system. 

There are several restoration projects ongoing within the bay.  Two of them Sea Grant has been involved in.  One is monitoring the status of seagrass and the other is status of bay scallops.  The species of seagrass in lower bay, such as turtle grass (Thalassia testudnium) and shoal grass (Halodule wrightii) require salinities to be at, or above, 20 parts per thousand.  Bay scallops depend on turtle grass for their life cycle and also require the salinity at, or above, 20 ppt. 

Citizen volunteers are assisting Florida Sea Grant by monitoring the salinity of the bay on a weekly basis.  

Table 1 – Annual Rainfall for Pensacola FL (National Weather Service)

YearRainfall (in.)
201266.63
201374.61
201483.17
201575.69
201664.62
201791.91
201890.01
201952.56
202076.49
202188.43
202265.69

Table 2 – Frequency of Rainfall Amounts in Inches

Inches of RainfallYears with totals in this range
50 – 601
60 – 703
70 – 803
80 – 902
90 – 1002

Method

Volunteers are trained to use a refractometer and asked to monitor their assigned beach once a week, reporting their results to Sea Grant and calibrating their instrument once a month. 

We are asking our volunteers to continue to monitor until they have logged 100 readings. 

Currently 21 locations around the bay are being monitored.  Nine are in the Big Lagoon area, eight near downtown Pensacola, and four near Pensacola Beach. 

12 of these sites are actively being monitored at this time, 3 have reached the 100-reading mark, and 6 have not been monitored in some time. 

Note:

Our volunteers are monitoring the water at the surface near the beach due to ease of access.  The seagrass and scallops we are interested in grow at the bottom and at depth.  However, saline water is more dense than fresh, and it is assumed that the water on the bottom at depth is saltier than the data being found at the surface near the beach. 

There are other agencies who are monitoring salinity at depth. 

Data for Each Site as of the end of 2022

Table 3 – Salinity Mean, Median, and Mode from Around the Pensacola Bay Area

Water BodyNo. of samples loggedMeanMedianMode
Bayou Chico71055
Bayou Grande29202121
Bayou Texar1087ND
Big Lagoon15232020
Big Lagoon SP51161514
Big Sabine64222222
Bruce Beach11818ND
Ft. McRee4212119
Galvez Landing65222322
Hawkshaw24161515
Kees Bayou100202114
Little Sabine100232325
Lower Perdido Bay100161520
Navy Point SE21171720
Navy Point SW22161710
Old River36232325
Oriole Beach51252525
Perdido Key SP33212015
Sanders Beach70181818
Siguenza Cove11222121
Shoreline Park10252525
TOTAL824191919

Table 4 – Salinity Mean, Median, and Mode from the Big Lagoon Area

Water BodyNo. of samples loggedMeanMedianMode
Big Lagoon15232020
Big Lagoon SP51161514
Ft. McRee4212119
Galvez Landing65222322
Kees Bayou100202114
Lower Perdido Bay100161520
Old River36232325
Perdido Key SP33212015
Siguenza Cove11222121
TOTAL415202019

Table 5 – Salinity Mean, Median, and Mode for the Downtown Pensacola Area

Water BodyNo. of samples loggedMeanMedianMode
Bayou Chico71055
Bayou Grande29202121
Bayou Texar1087ND
Bruce Beach11818ND
Hawkshaw24161515
Navy Point SE21171720
Navy Point SW22161710
Sanders Beach70181818
TOTAL184151515

Table 6 – Salinity Mean, Median, Mode for the Pensacola Beach Area

Water BodyNo. of samples loggedMeanMedianMode
Big Sabine64222222
Little Sabine100232325
Oriole Beach51252525
Shoreline Park10252525
TOTAL225242424

Discussion

A glance at Table 3 will show all 21 bodies of water that have been involved in this project.  Three of those, Lower Perdido Bay, Kees Bayou, and Little Sabine have reached the 100-reading mark. 

For Lower Perdido Bay the mean salinity was 16 ppt ±5.  The highest reading was 24 ppt and the lowest was 6 ppt.  The median was 15 ppt and the mode was 20.  These data suggest that this body of water would not support turtle grass or bay scallops, but it is not believed that historically lower Perdido Bay did.  We would like to thank Bob Jackson for his effort on collecting these data

For Kees Bayou the mean salinity was 20 ppt ±6.  The highest reading was 31 ppt and the lowest was 5 ppt.  The median was 21 ppt and the mode was 14 ppt.  These data suggest that turtle grass and bay scallops could survive here.  It is noted that Kees Bayou is a shallow basin located next to a highway and during intense rainfall the salinities could drop drastically to cause a decline of both target species.  We would like to thank Marty Goodman for his effort on collecting these data

For Little Sabine the mean salinity was 23 ppt ±4.  The highest reading was 30 ppt and the lowest was 12 ppt.  The median was 23 ppt and the mode was 25 ppt.  These data also suggest that both turtle grass and scallops could survive in Little Sabine, and there are records that scallops were once there.  Turtle grass exist there now.  We would like to thank Betsy Walker and Liz Hewson for their efforts on collecting these data

The Big Lagoon Area

These data suggest that most of the sampled areas could, in fact, support both turtle grass and scallops, and there are records that they have supported both in relatively recent years.  One note of interest is the lower salinities near Big Lagoon State Park.  Most of the sites have data at 20 ppt or higher – except Lower Perdido Bay (understandable) but we are not sure why the numbers are below 20 ppt. at the state park.  We would like to thank our active volunteers in the Big Lagoon area Jessica Bickell, Glenn Conrad, John Williams, and Emogene Johnson for their effort in collecting these data. 

The Downtown Pensacola Area

These data suggest that this area of the bay would not support turtle grass nor bay scallops.  But historically they did not.  Seagrass does exist in these bodies of water but much of it is widgeon grass (Ruppia maritima) which can tolerate lower salinities.  We would like to thank our active volunteers for the downtown area Tim Richardson and Glenn Conrad for their efforts in collecting these data.  

The Pensacola Beach Area

 These data suggest that Santa Rosa Sound could support, and do support, populations of turtle grass and scallops.  During our scallop searches conducted in July we have found one live scallop in Big Lagoon and two in Santa Rosa Sound over the last six years.  Again, these data suggests that all of these locations could do so with the highest salinities in the bay area based on these data.  We would like to thank our active volunteers in the Pensacola Beach area Ann Livingston, Gina and Ingo Hertz, and Holly Forrester for their efforts in collecting these data

Though we have not reached the targeted 100-readings for most of our sites, these early results suggest the rainfall may not be lowering the salinity.  We will continue to monitor until we do reach the 100-reading for each and have a better idea. 

We are seeking new volunteers.  The water bodies needing help are Bayou Chico, Bayou Texar, Big Lagoon, Bruce Beach, and Sanders Beach.  If you are interested contact me at roc1@ufl.edu

Mangroves in the Western Panhandle

Mangroves in the Western Panhandle

Mangroves in the northern Gulf of Mexico are a relatively new thing for most coastal counties.  Some residents are aware they are arriving and are not concerned.  Some are aware and are actually excited about it.  Some are aware and are concerned.  Some are not aware.  And others have no idea what a mangrove is.  Let’s start with that group.

Black mangroves growing near St. George Island in Franklin County.
Photo: Joshua Hodson.

Mangroves are salt tolerant trees that are found all around the globe within the tropics.  They grow along the shorelines in areas where they are protected from ocean wind and waves – they like estuaries.  There are several species and their location along the shore depends on how long they can be submerged in water.  There is a definite zonation of these trees.

 

The red mangrove with their distinct prop roots.
Photo: University of Florida

The red mangrove (Rhizophora mangle) is found closest to the waters edge.  They can be identified by their prop roots which are designed to keep it standing when the water is moving and shifting the sediment below it.  These prop roots also useful during tropical storms when the wave energy increases.  The have distinct looking propagules, which are elongated floating seeds which allows the plant to disperse their offspring using the currents and tides.  The propagules often wash ashore on northern Gulf beaches but usually in locations not conducive to growth, or they do not survive the winters.  These plants can tolerate temperatures in the 30sF for a night or two, but when it drops into the 20sF, and certainly into the 10sF, they will not survive.  Despite not being cold tolerant, they have been found growing in the northern Gulf of Mexico.  All the mangroves found in the Pensacola area have been of this species.

 

Black mangroves with their pneumatophores.
Photo: University of Florida

The black mangrove (Avicennia germinans) is found higher in the intertidal zone.  It lacks the prop roots of the red but rather has what are called pneumatophores, which resemble the knees of the cypress trees.  These pneumatophores have structures that help increase the oxygen uptake for the plant, being that the sediments they live in are quite hypoxic.  The seeds of the black mangrove are not elongated but rather resemble a bean.  These trees are more tolerant of cold weather than the red mangrove and it is they that have led the march north.  There are large stands of these trees in the Apalachicola area as well as barrier islands in Mississippi, Louisiana, and Texas.  We have not found a black mangrove growing in Pensacola as of yet.

 

The larger white mangrove.
Photo: University of Florida

White mangroves (Laguncularia racemosa) grow more inland than the other two.  This species can grow into a large tree (up to 40 feet).  Their leaves can excrete salt allowing them to live in saltier conditions.  There are no records of this tree in the northern Gulf of Mexico to my knowledge.

 

 

 

 

 

 

 

Why would anyone be concerned about mangroves dispersing into the northern Gulf?

 

Those who are concerned are aware that is a shoreline tree that will grow and possibly block their view of the water.  They also are aware that this tree is protected by the state, and they are not allowed to remove or trim the tree without a permit.  In south Florida trimming mangroves is allowed in some counties during certain times of the year and only by certified arborist.  Those concerned are not excited about potentially loosing their water view.

A red mangrove growing near the pass of Pensacola Bay.
Photo: Whitney Scheffel.

 

Why would anyone be excited about mangroves dispersing into the northern Gulf?

 

Folks who are excited about the possible coming of the mangroves are so because they have spent time snorkeling and fishing in and around them in more southern locations.  The prop roots of the red mangrove create an underwater wonderland of marine life.  Small fish, crabs, anemones, starfish, mollusk and more find the large openings formed by the roots as great habitat.  These in turn attract larger fish like snook, tarpon, rays, and flounder.  Many species of larger fish are popular targets for anglers.  Manatees are often found in mangrove swamps grazing on the algae and seagrasses growing nearby and enjoying the relatively calm water.  Those who have experienced this in south Florida are excited they may have it here in the north.

 

How many mangroves, and which species, have dispersed into the northern Gulf is still being studied.  Florida Sea Grant has partnered with Mississippi-Alabama Sea Grant and three of the National Estuarine Research Preserves to survey for mangroves in our panhandle counties and along coastal Mississippi and Alabama.  Ten transects have identified in each that are surveyed once a year by volunteers using paddle craft.  The presence of a mangrove is documented, measured, photographed and shared with the team, which is overseen by Whitney Scheffel of the Pensacola-Perdido Bay Estuary Program.  If you are interested in participating in a survey, contact your county Sea Grant Extension Agent.