Tuesday, July 23, 2013

Go with the flow (part 2)

Everglades part two

The modern canal systems have introduced an over abundance of nutrients into a system that developed with very low levels (of nutrients), impacting the everglades “in several trophic levels, including microbial, macrophyte, and vertebrate communities” (FDEP, 2011). Species dependent on shallow marshlands are disappearing. An example of a species directly affected by this is the snail kite (Rostrhamus sociabilis), which feeds exclusively on the apple snail (Ampullariidae); the snails have depleted populations as a result of the changing marshlands.

Large highway systems and roads make up much of the landscape of south Florida. All of these anthropogenic changes to the Florida Everglades have presented problems for maintaining biodiversity in south Florida. The highway systems throughout south Florida “serve as barriers, confining many species of wildlife within restricted areas” (Rocus & Mazotti, 2006, p. 1). This leads to inbreeding, genetic depression and reduced adaptability to an environment that is constantly changing (Rocus & Mazotti, 2006). 

The Florida panther (Puma concolor coryi), a flagship species of the Everglades (Ake, 2008), exhibits signs of inbreeding (e.g. thoracic cowlicks and kinked tails) and severe population declines (Johnson, et al., 2010). For larger species, such as the Florida panther (Puma concolor coryi), Florida black bear (Ursus americanus floridanus), Key deer (Odocoileus virginianus clavium) and the American alligator (Alligator mississippiensis), the road barriers cause more difficulties. The natural range of these larger, far ranging animals is extensive, forcing them to cross road boundaries. Vehicle collisions are a major threat to these species (Rocus & Mazotti, 2006).

“Above all, the fragmentation of habitat from human activities across American landscapes is considered to be the leading cause of species decline and the loss of ecosystem integrity” (Peck, 1998, cited by Brody, 2011, p. 819). The fragmented habitats in the Everglades (due to the canal systems and roadways) are also vulnerable to the edge effect. Areas that used to be surrounded by water are now surrounded by urban construction or farm lands, allowing the edge species (e.g. raccoons [Procyon lotor ]) to invade further inward, displacing or depleting those interior species (Beringer, 2004). The white crowned pigeon (Patagioenas leucocephala) is experiencing depleted populations due to predation by edge species (Beringer, 2011).

Only the southernmost part of the Florida Everglades is protected by federal land, (Everglades National Park and Big Cypress National Preserve) “together they encompass over 2.2 million acres of more or less contiguous habitat” (Rocus & Mazzotti, 1996, p. 2). Even with this amount of land, the Everglades are struggling to survive. The urban systems expanding outside the park are now directly affecting “the ability to protect the areas within the park boundaries” (Beringer, 2011).

A multi-agency ecological approach is necessary for restoring the Florida Everglades. The future of the Everglades will be in the hands of county commissioners and zoning boards. According to Brody, land use decisions occur at the local level, not the federal level. The efforts to save the Everglades have been reactionary approaches to a crisis that already exists. The development has already taken place. The conservation strategy should change from damage control to anticipation and prevention (Brody, 2011).
Redirecting some of the water to restore the natural flow would be beneficial to the southern portions of the Everglades. There is a plan to remove 240 miles of levees and canals along the Tamiami Trial from Tampa to Miami. According to Scully, this approach to restoring flow to function as it did prior to all of the drainage is staggering. Scientists must consider roles of individual species, soil, salinity, natural weather patterns and growing human populations (Scully, 2001).

“Because species diversity is perceived as a fundamental component to maintaining viable ecosystems over the long term, the identification and protection of biodiversity lies at the core of planning for ecosystem integrity” (Vogt, et al., 1997, cited by Brody, 2011, p. 819). However, since we have destroyed a large portion of the Everglades, it may be impossible to restore it into the whole system it once was (Scully, 2001). Passing legislation, changing zoning laws to end further development (in areas that could help restore the Everglades) and purchasing contiguous tracks of habitat (that would bring back populations of large predators to the area) may be additional steps toward restoration.


Ake, Anne, 2008. Everglades an ecosystem facing choices and challenges. Sarasota, Florida: Pineapple Press.

Arrrieta, Diane, 2012. Exerpt from unpublished class paper. University of Edinburgh, Scotland.

Beringer, Joe, 2004. Conserving biodiversity in South Florida. [online]: Miami University. Available at: http://jrscience.wcp.muohio.edu/filedcourse04/PapersMarineEcologyArticles/Whathav ew edoneWhattodonow.html. [18 November, 2011].

Brody, Samuel D., 2003. Examining the effects of biodiversity on the ability of local plans to manage ecological systems. Journal of Environmental Planning and Management, [online] 46:6, pp. 817-837. Available through: Taylor & Francis Social Science and Humanities Library [8 November, 2011].

Florida Department of Environmental Protection (FDEP), 2011. Learn About your Watershed. [online] Available at: http://www.protectingourwater.org/watersheds/map/ev erglades/ [9 November, 2011].

Rocus, Denise & Mazolli, Frank J.,1996. Threats to Florida’s Biodiversity, [online]: University of Florida IFAS Extension. Available at: http://edis.ifas.edu/uw107. [8 November, 2011].

Scully, Malcolm G., 2001. Restoring the Fragile Everglades, Evermore. Chronicle of Higher Education [online] 47:18, p. B14. Available through: Academic Search Primer (Ebscohost) [22 November, 2011].

image: http://en.wikipedia.org/wiki/File:Everglades_Sawgrass_Prairie_Moni3.JPG

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