When you imagine the Florida Keys you picture a string of tiny green islands strewn across an endless blue of water. Every which way you turn there would be water as far as the eye can see. Within this water you most likely would picture fish and corals of every colour imaginable. In the sky there may be hundreds of birds, in the canals alligators and crocodiles. However, in the future we may need to rely on our imaginations to be able to view this type of scene in the Florida Keys and many other aquatic environments around the world. Each and every day humans exert unimaginable pressures on our environment and ultimately the water. This presentation focused on the water quality of the Florida Keys as it has an impact on the many ecosystems found here, and the economic wellbeing of the people living and working in this region.
There are many sources of water pollution that can be found affecting the waters of the Florida Keys, point and non-point, local, such as from cesspits, right through to global scale relating to ocean and air currents. The pollution can come from agriculture, industry, urban areas and shipping to name but a few. Some of the sources will be discussed in more detail and some of the effects this can have will also be presented.
The UN Group of Experts on Scientific Aspects of Marine Pollution estimates that pollution is composed of:
44% land based runoff and discharges
33% atmospheric sources
12% boat discharges and spills
10% deliberately dumped
1% offshore mineral mining
Can be point or non-point pollution
Adds phosphates and nitrates to water, can create explosive algal blooms which reduce the oxygen supply
Nitrogen, phosphorous and various toxins from gardening fertilisers, pesticides and herbicides, urine and feces from pets, leaf litter, cleaning agents used for cars and other surfaces, petroleum products from cars.
Non-point source pollution
On-point and unregulated runoff of pesticides, herbicides (not easily biodegradable so concentrates in the food chain) and fertiliser nutrients, also and fecal coliform bacteria which causes illness in humans.
All landfills but the Cudjoe Key expansion were developed prior to the current legislation requiring bottom liners and leachate collection.
Many sites filling with solid wastes probably originally occurred below the water table in their early stages.
Probably little or no control over materials deposited in the early years.
There is a significant potential for contamination of groundwater and surface water from these inactive landfills.
One of the most destructive and widespread environmental impacts of the 20th Century.
Heavy metals, such as mercury, tin and lead, there are also high tech chemical compounds (synthetic organics). These not only kill some species outright but also contaminate survivors and the food chain.
Survivors affected with diseases, deformities, and lesions, weakens the immune system and can impair ability to resist natural enemies.
Chlorine is a link in many of the worlds notorious environmental toxins, dioxin, DDT, Agent Orange, PCBís and CFCís.
2.4 billion pounds of chemicals per annum from U.S. Industries, of which large quantities end up in the marine environment.
Boats (maintenance, spills, and dumping)
Boats require constant maintenance with engine repairs and the hull scraped, sanded and repainted every 1-2 years.
Weekly or monthly while the boat is in berth owners use cleaning detergents, oils, varnishes or acids to maintain the boats.
All boats from small fiberglass sailboats to large military ships have highly toxic anti-fouling paint on their hulls to ward off barnacles. This paint slowly releases poison directly into the water including Tributyitin (TBT) which is highly toxic to marine organisms in concentrations of less than 1 part per billion. EPA has restricted TBT paints to only aluminium hulls, or vessels greater than 25 metres in length.
Estimated that one third of all fuel that passes through the motor ends up in the water. Estimated that 150-420 million gallons of unburned fuel are exhausted into the environment each year by the nations 12 million gas powered pleasure boats. The Exxon Valdez only spilt about 10 million gallons
U.S. Coastguard estimates that52% of trash dumped in U.S. waters is from recreational vessels.
Dumping at Sea
Marine debris donít just come from dumping at sea but are also often washed out by rivers.
Half of all marine debrisí today are plastics. These are highly visible and long lasting (not biodegradable).
A few more little bits about the Keys
25,000 septic tanks
5,000 cess pools
1,000 injection wells
Documented (USGS) sewage nutrients leaking from groundwater
Documented pollution in canals (FDEP, NOAA)
There is legislation to rid Key West of illegal cesspits recently passed in Nov, 98.
Trying to get new regulations for sewerage plants
***** Florida Keys National Marine Sanctuary was the first NMS to include a Water Quality Protection Programme which include Federal, State and Local agencies, mainly the Environmental Protection Agency and the Florida Department of Environmental Protection
*****1991 Monroe County Commission limited the use of phosphate laden cleaning products. This limitation is now Nationwide.
Problems with Water Pollution
Nitrogen runoff is particularly devastating to coral reefs. If too much nitrogen falls on coral reefs, multi-cellular seaweeds start to grow. The symbiotic relationship that coral polyps have with zooxanthellae is then broken down as the algae are shaded out. This can result in the death of the coral as the algae can no longer photosynthesiseÖÖcoral breaks up and produces sedimentÖÖsediment falls on coralsÖ..
Skeleton like bleached appearance which corals take on when the chlorophyll in the zooxanthellae becomes less concentrated or when the zooxanthellae are expelled from the coral polyps.
Can be triggered by a number of sources such as an abnormal rise or fall in water temperature, excessive dilution of seawater with fresh water, intense sunlight, or pollution.
This results from a rapid increase in the production of dinoflagellates, which are one celled organisms which thrive in water nutrient rich or phosphorous rich. The dinoflagellates literally ravage these nutrients and reproduce "bloom" so profusely they cover the water like a red carpet. By using all of the oxygen in the water and blocking out the sunlight which plants require, an episode of red tide suffocate marine life in what is known as Eutrophication.
Other algal blooms may occur as other types of algae take over due to over fertilisation, which again results in eutrophication. Management for this problem involves herbicide use resulting in further chemical runoff.
As nutrients decompose they use up the oxygen supply which marine organisms need. When the oxygen is depleted, the result is an anoxic or dead zone.
Debris in the Water
Entanglement in lines, nets, traps, and packaging materials. Ghost fishing (monofilament line) entraps indefinitely and can tear soft corals, sea fans, and sponges..
Smothering of coral in large plastic bags and diapers
Ingestion of plastic bags and balloons which are mistaken for jellyfish. Styrofoam pellets mistaken by birds as fish eggs and plankton.
Monofilament line can also entangle and kill divers and other debris can sink boats and damage propellers.
The waters of the Florida Keys are being polluted from many sources. These sources of pollution must be found and tackled before it is too late and we loose one of the most productive environments in the U.S. if not the world. Steps are slowly being taken which is a promising sign by the Florida Keys National Marine Sanctuary and many NPOís such as REEF, and Reef Relief.
Environmental Protection Agency, 1996, Water Quality Protection Programme for the Florida Keys National Marine Sanctuary: First Biennial Report to Congress 1996.
Klee, G.A., 1999, The Coastal Environment: Toward Integrated Coastal and Marine Sanctuary Management, pp. 120-174.
Publishing Company, Flagstaff, AZ.
National Oceanic and Atmospheric Administration, 1996, Strategy for Stewardship: Florida Keys National Marine Sanctuary Final Management Plan/ Environmental Impact Statement, Vol. 1, pp. 208-254.
Shinn E.A., United States Geological Survey, 1998, Ground Water Flow from the Florida Keys,
Shinn E.A., Reich, C.D., Hickey D., & Tihansky A., 1998, USGS, Geology and Hydrology of the Florida Keys: Ground Water Flow and Seepage
Viders, H., 1995, Marine Conservation for the 21st Century: An essential guide for citizens, legislators, environmental professionals, and aquatic sports peopleÖ, Best Publishing Company, Flagstaff, AZ, pp. 95-133.
For Further Info on this Topic, Check out this WWW Site: http://sflwww.er.usgs.gov/projects/grndwtr_flow/abstracts/shinn.html.
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