I attended a meeting recently where one of the participants stated – “We have been looking at a lot of water quality parameters within our bay in recent years, and plan to look at more, but has anyone been looking at temperature?”
What he was referring to was that the focus of most monitoring projects has been nutrients, dissolved oxygen, etc. But most agencies and universities who have been conducting long term monitoring in our bays are collecting temperature data as well. His question was not whether they have or not but has anyone looked at this long-term temperature data to see trends.
I know from some of the citizen science monitoring I have been involved with that temperature is collected but (anecdotally) does not vary much. It is like pH, we collect it, it is there, but does change drastically (anecdotally) over time. However, it has been a very hot year. This “heat dome” that has been sitting over the Midwest and southeast this summer has set records all across the region. Someone monitoring water temperature in East Bay recently reported surface water temperature at 96°F (36°C). Many have stated that swimming in our waters at the moment feels like swimming in bath water. It’s not just warm in your yard, it is warm in the bay. And this brings up the question of thermal tolerance of estuarine species.
All creatures have a temperature tolerance range. They resemble a bell curve where you have the thermal minimum at one end, the thermal maximum at the other, and the “preferred” temperatures near the top of the bell curve (see image below). Many creatures have a large tolerance for temperature shifts (their bell curves extend over a larger temperature range). You find such creatures in the temperate latitudes where temperature differences between summer and winter are larger. Others have a lower tolerance, such as those who are restricted to polar or tropical latitudes. Within an estuary you can find creatures with varying thermal tolerances. Some have a larger tolerance than others. Ectothermic (cold-blooded) creatures often have a wider range of temperatures they can survive at than endothermic (warm-blooded) ones. Homotherms (creatures who maintain their body temperature near a fixed point – such as humans 98.6°F/37°C) expend a lot of energy to do this. When environmental temperatures rise and fall, they have to expend more to maintain it at their fixed temperatures.
Image provide by Research Gate.
It is also true that most creatures prefer to exist near their thermal maximum. In other words, the bell curve is sort of skewed towards the warmer end of their range. But what is their thermal maximum? What happens when they reach it? How hot can they go?
Local waters are warmer this year.
Photo: Rick O’Connor
The studies I reviewed suggested that the thermal maximum is dependent on other environmental factors such as salinity and dissolved oxygen. In most cases, the higher the salinity, the higher the thermal maximum was. I looked at studies for the eastern oyster (Crassostrea virgincia), the brown shrimp (Farfantepenaeus aztectus), the blue crab (Callinectes sapidus), the Spot Croaker (Leiostomus xanthurus), and the pinfish (Lagodon rhomboides). The oyster, shrimp, and blue crab support important commercial fishery. The spot croaker is a dominant fish species in the upper estuary where the pinfish is a dominant species in the lower sections. These studies all suggested that again, depending on salinity, dissolved oxygen, pressure, and rate of temperature increase, the thermal maximum could happen as low as 30°C (86°F) and as high as 40°C (104°F), with many having a thermal maximum between 35-40°C.
At these temperatures proteins begin to denature and biological systems begin to shut down. Most of the studies determined the endpoint at “loss of equilibrium” and not actually death. Our estuaries can certainly reach these temperatures in the summer. Again, one recent reading in East Bay (within the Pensacola Bay system) was 96°F (36°C).
So, what do these creatures do when such temperatures are reached?
The most obvious response is to move, find cooler water. These are often found in deeper portions of the bay below the thermocline (a point in the water column where water temperatures significantly change – usually decreasing with depth). However, many sections of our estuaries are shallow and deep water cannot be found. In these cases, they may move great distances to seek deeper water areas, or even move to the Gulf of Mexico. In some cases – like with oysters – they cannot move, and large die-offs can occur. Other responses include lower metabolic rates and decline in reproduction.
We know that throughout history, there have been warmer summers than others and heat waves have happened. In each case, depending on other environmental factors, estuarine creatures have adapted, and some members have survived, to keep their populations going.
We know that large scale die-offs have occurred in the past and the tougher species have continued on.
We also know that the planet is warming, and it would be interesting to look at how the water temperatures have changed over the last few decades. Are they increasing? Are they reaching the thermal maximums of the creatures within our bay? How will these creatures respond to this?
It’s no surprise that it gets hot in Florida during this time of year. We are the “Sunshine State” of course. The National Weather Service issues heat advisories when the heat index is forecast to be over 100°F for at least 2 days and nighttime temperatures are forecast to be above 75°F. The Excessive Heat Warning is when the heat index is forecast to be above 105°F for at least 2 days and nighttime temperatures are not expected to drop below 75°F. If you are like me, I have received many notices of heat advisories and excessive heat warnings over the last few weeks. Just because we are accustomed to this heat does not mean we should not heed these advisories and warnings.
Heat related illnesses include sunburn, heat rash, heat cramps, heat exhaustion, and heat stroke. Heat rash and sunburn can happen even when temperatures are not extreme like now. Remember to apply sunscreen and wear lightweight clothing to protect your skin from the sun’s UV rays. For heat rash, do not allow moisture to stay close to your skin. Wear loose fitting clothing and try to minimize sweating.
Heat cramps, heat exhaustion, and heat stroke are progressive stages of effects of excessive heat on your body. The first stage is muscle cramps or spasms. Once you notice this, you should remove yourself from the heat and physical activity. Drink water or a sports drink and wait for the cramping to subside before returning to physical activity. The next stage is heat exhaustion. The symptoms include heavy sweating, clammy skin, fast heart rate, nausea, dizziness, and fainting. If you experience these symptoms, move to a cool place, and loosen clothing. You can also put cool cloths on your body or take a cool shower or bath. Sip water. If you ignore these symptoms, you can progress to heat stroke. Symptoms of heat stroke include high body temperature, dizziness, headache, nausea, confusion, loss of consciousness. If you find someone with heat stroke, call 9-1-1 at once and move the person to a cool place.
Here are a few steps you can take to avoid heat related illness:
Wear loose fitting, lightweight clothing.
Drink plenty of fluids and stay hydrated.
Avoid excessive caffeine and alcohol intake.
Schedule outdoor activities during the cooler parts of the day.
Plan for breaks in cooler places when enjoying the outdoors.
Don’t forget your sunscreen.
For more information on heat related illnesses and extreme heat in Florida:
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.
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.
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.
Rain garden/biofiltration cell at a medical office in Pensacola, Florida.
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.
