The Fate of the Everglades

Author: Kelsey Roberts, Edited by: Emilyann Ashford

In a world facing the widely known crisis of global warming, we are expected to see drastic changes in very important ecosystems. An example of a particularly affected ecosystem is the Everglades (6). Located in mainly southern Florida, the Everglades span across an enormous 1.5 million acres, and is home to a diverse and unique abundance of species (6). Some species prevalent in the Everglades include the American Alligator, Manatees, Sea Turtles, and a variation of different birds. Other than animals, the Everglades are also home to 27 rare plant species, all of which are feeling the effects of climate change (1). Specifically, almost 70 of all species in the everglades are considered to be threatened or endangered (6).  As temperatures rise across the globe, the plants and animals that inhabit the Everglades are faced with a surplus of adversity. Higher temperatures result in many consequential issues for the Everglades, such as rising sea level, rising surface temperature, precipitation fluctuations, droughts, and loss of biomass (6). So, what does this mean for the species that live there, and how are they going to survive? 

Rising Sea Level

Rising global temperatures are leading to a rise in sea level due to the melting of glacier ice, and the expansion of water itself when heated. Explaining further, the cool deep water in the ocean is warming, causing expansion and then ascension to the surface. Rising sea level is one of the biggest concerns for the Everglades, as its landscape is flat and shallow, with highest elevations reaching up to only 3 meters above sea level. A rise in sea level of up to 2 inches in the next century is expected and can be attributed to numerous factors (1). These rising sea levels will not only leave the Everglades vulnerable to saltwater intrusion, habitat destruction and complete loss of the wetlands, but also facilitate entrance of invasive species. The Everglades are home to a plethora of plant communities, such as mangroves, highly tolerant trees e.g. shrubs, that provide shelter and stability to the brackish waters which could be tarnished if sea levels continued to rise.

Saltwater Intrusion

All species have environmental thresholds they can withstand, that being temperatures, pH levels, and/or salinity which is the amount of salt present in the water. The Everglades are a freshwater habitat and thus they are extremely vulnerable to changes in salinity, and it is uncertain how different species would react to such a change. Higher salt concentrations have forced species to acclimate to their new environment, migrate out of the area, or in the worst cases, become locally extinct in other freshwater habitats causing loss in biodiversity, and changes of community composition in other freshwater environments (5). Another fate of rising sea level and salt intrusion is the complete destruction of habitats in low lying areas where many coastal nurseries thrive which are also vital for marine life. These plant communities serve as a barrier between the freshwater marshes of the Everglades and the saltwater surrounding it. An increase in salinity could decrease the production and survival of these mangroves, and in turn ruin the natural barrier keeping the salt concentrations low.

Unpredictable Weather

Extreme weather conditions are also likely to take a toll on the Everglades. Florida in itself is a hotspot for powerful storm surges, and as temperatures climb, they may only get worse. Warmer waters can result in greater intensity of storms, specifically hurricanes. The warmer the water, the more moisture will be in the air, and the more precipitation will occur. The frequency of the storms has not been proven to be correlated to increasing temperatures, but it has been observed that the intensities are increasing (1). In opposition to this hypothesis, global warming is also resulting in a major lack of precipitation (2). Droughts pose a major threat to the aquatic fauna of the Everglades. Global warming is making these weather patterns unpredictable, as the Everglades are becoming dryer in their wet season, and experiencing much more precipitation during the event of a storm. The abrasive weather is affecting the ecosystems ability to bounce back after it has been hit. Normally, the Everglades are resilient and flourish after extreme weather conditions, but as they get more intense and unpredictable, the inhabitants are taking longer to recover. 

Increased CO2

Increasing temperatures have been linked to an increase in atmospheric CO2, which is soluble in water. Water at higher temperatures contains less dissolved O2, and instead contains more CO2, causing higher levels of acidity and toxicity in freshwater systems. Changes in acidity, or pH, can be harmful to the animals and plants living in that environment (2). Higher acidity can lead to poor seed germination of the differing plants, and range shifts in some species who have low tolerance for pH changes (6). If this is the case, many freshwater plants and fish of the everglades would have to relocate or acclimate to the changes leading to many consequences such as a decrease in native biodiversity and increase of invasive species.

What is being done?

The Everglades are protected as a national forest, and many conservation strategies have been put in place to try keep it alive and thriving. The restoration of the Everglades during global climate change is the most important thing we can do. The Comprehensive Everglades Restoration Plan was put in place in 2000 in order to reserve, restore and protect the native animals and vegetation that supply for such an abundant ecosystem. This restoration plan is viewed as the world’s largest ecosystem restoration effort, and will cost upwards of 7 billion dollars and potentially decades of time in order to be successful. This goes to show how important the wildlife and vegetation of the Everglades are to the health and biodiversity of the planet.

Citations:

  1. ALLAN, R. P., AND B. J. SODEN. (2008) Atmospheric warming and the amplification of precipitation extremes. Science 321:1481–1484. 

  2. Carpenter, Stephen R., et al.(1992) “Global Change and Freshwater Ecosystems.” Annual Review of Ecology and Systematics, vol. 23, pp. 119–139. JSTOR, www.jstor.org/stable/2097284. 

  3. Florida Oceans and Coastal Council. Revised June 2009. The effects of climate change on Florida’s ocean and coastal resources. A special report to the Florida Energy and Climate Commission and the people of Florida. Tallahassee, FL. 34 pp. 

  4. IPCC (INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE). 2007. Climate change 2007: the physical science basis. Contribution of working group I to the 4th assessment report of the Intergovernmental Panel on Climate Change. S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor, and H. L. Miller (editors). Cambridge University Press, Cambridge, UK. 

  5. Kefford BJ, Buchwalter D, Can ̃edo-Argu ̈elles M, Davis J, Duncan RP, Hoffmann A, Thompson R. 2016 Salinized rivers: degraded systems or new habitats for salt-tolerant faunas? Biol. Lett. 12: 20151072. http://dx.doi.org/10.1098/rsbl.2015.1072

  6. Pearlstine, Leonard G., et al. “A Review of the Ecological Consequences and Management Implications of Climate Change for the Everglades.” Journal of the North American Benthological Society, vol. 29, no. 4, 2010, pp. 1510–1526. JSTOR, www.jstor.org/stable/10.1899/10-045.1.

Emilyann Autumn