Divers: Do they do more harm than good? Final

This discussion topic submitted by Lynn Anderson (Lynn.Anderson@miamioh.edu) on 8/2/98.


The attraction of coral reefs as beautiful and fascinating natural environments, where people can experience the wilderness

The magnitude of diver recreation/tourism
In 1992 Tabata described SCUBA as "one of the world's fastest growing sports, with dive travel being the fastest growing aspect of the sport". While Davis & Tisdell in 1995 stated that "recreational SCUBA diving is an important and growing componenet of the international tourism market". It has became much easier for divers to visit coral reefs as they have became much more accessible and the visitor facilities have improved tremendously. It is of no surprise the numbers of divers who take to the waters around the southern shores of Florida in search of a great dive

Tolerance of Coral Reefs
Coral reefs have a low tolerance to disturbance as the following quotes show, and so divers can have an adverse impact on these fragile environments
Richmond, 1993 described coral reefs as "stenotypic, exhibiting a narrow range of tolerances to environmental conditions, hence small changes in environmental quality can affect critical biological processes". Coral reefs are highly susceptible to disturbance in relation to other nearshore ecosystems, such as mangrove forests and seagrass beds (Goenaga, 1991).

Divers can create problems for reefs in a number of ways
whether accidentally with their fins, equipment or poor bouyancy control, or on purpose by walking, standing, kneeling, feeling, holding, or collecting souveniers.
By touching the coral this can remove mucus which may leave it open to disease, bacteria or algae. Touching can also cause actual breakage of the reef.

Divers stir up sediment if they swim too close to the reef or sandy areas between and also if they make contact with the bottom. This can affect a reef in a number of different ways
Physical interfers with coral nutrition by coating feeding surfaces responsible for catching prey items, this can exact a high energetic cost as coral uses mucus secretion and ciliary action to shed sediments. It also interfers with the recruitment of coral larvae, as this requires a solid surface upon which to settle and metamorphose. Sediment can also abrade the corals.
Biologically causes a reduction in available quantity and quality of light which effects coral nutrition, growth, reproduction and depth distribution as photosynthetic output of zooxanthellae is decreased. It also reduces feeding periods and/or alters heterotrophic and autotrophic feeding efficiences, and increases potential for bacterial infection.
Chemical Changing levels of chemicals in the sea-water can cause coral death and reduce larval settlement

So whats actually good about divers?
It increases awareness about the environment we live in, opening up a new world.
Diving is not a cheap hobby and diver expenditure is great bringing in money for the surrounding communities through dive rental and charters, accomodation, food, gifts, services and sales tax.
It creates employment for many people such as those at dive stores and charter shops, and also those involved with the provision of services such as those in the hotels, restuarants and aslo the entertainment industry.
Another important advantage of recreational divers is that they are an untapped resource. Volunteers can help with long term monitoring of coral reefs with a little training. This can be through events such as the Great AMerican Fish Count, or through non-profit organisations such as Raleigh International and Frontier.

What can be done to combat the effects of divers?
Management plans and techniques. Different plans needed for different areas due to differeing diversity, size and use.
Some suggestions are to: establish zoning systems
Provide mooring buoys
Ban certain activities
Limit areas for inexperienced divers
Create alternatives glass bottom boats
viewing chambers

Enforcement of regulations
People observing divers and boats and fining those who break the regulations This requires a lot of time, money and people and is not always successful.

Education of users
Difficult problem of actually contacting users as their is no actual entrance gate where people must pass through. The Florida Keys National Marine Sanctuary has set up an education plan that involves a numner of different activites such as meetings, exhibits and brochures.

Other issues
Divers influencing water quality
"Urine, sunscreen, lotions, insect repellant, fish food and boat effluents add nutrients to reef waters, but are the amounts significant and do they remain over and around the reefs long enough to fertalise reef communities?" Talge, 1992

Snorlellers and divers
"Snorkellers...usually they float face down causing little damage. However, when snorkelers stand up, the damage caused by cumbersome, uncontrolled fins is severe. Unlike trampling by divers, which follows a narrow path across the reef, the activities of snorkelers are distributed over a much wider area" Hawkins & Roberts, 1993

Irony of Marine Parks
" More than 200 coral reelocalities were proclaimed as natural reserves or marine parks as a result of increasing levels of anthropogenic pressures....ironically, the conventional management plans increased accessibility to many reef localities and enhanced dramatically the impact of tourism on reef habitiats" Rinkevich, 1995

Another website relating to this is
Some references are supplied in my second draft proposal

For Further Info on this Topic, Check out this WWW Site: http://wave.nos.noaa.gov/ocrm/nmsp/nmsfloridakeys.html.
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