Human interaction with coral reef systems:
The effects of Scuba Diving

By Kameron Pence.

"We will kill the coral reefs.... Ignoring their silent plight and loving them to death."

The rain forests of the sea...

With their rich diversity of life, coral reefs are the rain forests of the sea. Every year, thousands of people learn to dive so that they can enjoy the reefs in a personal way, but are they aware that their presence in a coral ecosystem can damage it? Would they stop diving or be more cautious if they knew? Should they stop diving to save the reefs from damage? No, but people need to be made more aware of the potential threat they pose. This is a report on several studies concerning diver interactions with coral reefs. Numerous studies have looked at the effects of boat pressure on reef systems, but there has been little investigation into the direct impact divers have (Hawkins). Yet divers can damage reefs in several ways. Pressure from boat propellers can cause strong, damaging currents. Divers can damage coral heads by kicking, bumping into, touching, standing and trampling (Hawkins). This damage can cause the corals to be unable to fight off disease and parasites (Richmond).

In 1991, Dr. J. Hawkins of the Marine Research Centre, Sharm-el-Shiekh, Egypt, and her colleague Dr. C. Roberts tested the diver damage hypothesis at three very popular red sea shore dive sites. The scientists recorded several key attributes (numbers of hard coral species, colonies, broken coral, loose fragments of coral and abraded coral) at the three sites. They did the same for several non dived sites to be used for comparison, monitoring all sites for a year. The study found significant differences between the dived and non dived sites, the former containing more damaged coral, thus indicating that divers do cause damage to coral reef systems (Hawkins). Dr. Hawkins also noted that after the study had started, a permanent dive campsite was established near one of the testing sites. This camp provided diving opportunities to tourists and took about 15 divers per week out to the reefs. The reef area where the camp directors sent divers was the most damaged of the three dived sites (Hawkins). The study also showed that the conversion from pristine to highly damaged reefs can occur very quickly in the absence of regulations controlling diving tourism (Hawkins).

Dr. Hawkins and Dr. Roberts did a second study in 1993 that looked at the effects of coral flats trampling by divers and snorkel, comparing a trampled to an un-trampled area. The trampled areas were those where divers and snorkel walked out over the reef flats to reach deeper water. Dr. Hawkins discovered that while the divers damaged the flats uniformly, the snorkel caused more uneven, very patchy damage by standing up on the coral. While doing so, the snorkel would have trouble controlling their fins and caused coral damage in this way (Hawkins). The snorkler damage was spread over the coral flats because of the snorkeling activities, while the divers followed a narrow path to deep water (Hawkins). Dr. Hawkins cites a 1988 study done at the Virgin Islands national park in which it was determined that snorkel caused considerable damage to corals by bumping into or standing on them. Not only does trampling cause damage to the coral, it reduces the aesthetic appeal of the coral flats.

The Fall of Pennekamp

In a 1990 article in the July issue of National Geographic magazine, Fred Ward reported the devastation to the Pennekamp Park corals by Key Largo, Florida. Ward notes that Pennekamp became a very popular dive site in 1962 after a National Geographic article about it was published. Early in the decade, Pennekamp was in pristine condition but it has fallen to decline because of human presence.

Ward says "their boats pollute the water and everything in it with petroleum products and sewage.Incompetent operators crash into reefs. They litter the sea with plastic foam cups, aluminum cans, glass bottles, plastic bags, and miles of fishing line.... Thousands of swimmers routinely bump scrape, and step on coral... If only one person in a hundred scars or breaks off a piece of coral that took a century to grow, the cumulative devastation is enormous."

Ward talked with Randy Pegram, operator of the private park concession, who has all severe damage to the natural features recorded. There was an increase of nearly 300 percent from 1984 to 1989. Ward also reports that not only do divers and snorkel cause damage, but also take reef inhabitants such as lobster. He said that after the first couple of weeks after lobster season opens, it is impossible to find a mature lobster anywhere on the reef. The legal limit the was 24 lobsters per boat per day (ward). Multiply that by several boats over just a few weeks. This can seriously devastate the lobster population for the future. Ward ends his article with: "we will kill the coral reefs if we're not careful by ignoring their silent plight and loving them to death."

Compared to the effects of pollution, the ill-advised diver or snorkeler can only cause minimal damage, but the combined effects of many divers can have serious impacts on the reefs (wells). A Florida study shows that divers touched coral heads an average of seven times during a 30 minute interval. The study also showed that male divers caused more damage than female divers because they were more energetic and adventurous (wells). Just a few ways that divers unknowingly harm the reef:

¥ Photographers crash into the reef while trying to get that perfect shot, stirring up sediment while treading water

¥ Scuba bubbles get trapped in caves and overhangs, killing delicate animals or plants

¥ Several divers crowd into one area to look at something special (wells)

What can be done to help stop reef damage? Here are ideas that have been implemented at different locales worldwide (wells).

¥ In the Philippines on Balicasag Island, a diving hotel was set up. The profits are directed to marine conservation in the marine parks. Divers are charged extra to dive in the marine reserves.

¥ On Koh Samui Island, Thailand, a Coral Festival is held, helping the tourists that visit the reefs appreciate the need for conservation.

¥ Marine reserves and parks with entry fees that go toward the conservation of the area have been created.

Conservation The Only Hope For Survival

These are just three ideas; there are many other things that can be done to increase coral reef conservation awareness. In my opinion, the dive certifying organizations need to change their curriculum to incorporate a more comprehensive conservation lecture as part of the required dive training. Even the quick dive courses for people with little time should include this conservation curriculum. It should not be left up to the dive instructor whether to teach about marine conservation or not, it should be mandatory. If people were aware of what accidental damage they could do to the reef and just how delicate coral is, they would be more careful in their underwater activities.

In summary, here are a few of my ideas on conservation awareness:

¥ Make a comprehensive conservation lecture mandatory for all dive training courses (including short dive classes for the visitor with little time, all dive training done on cruise ships and any others).

¥ Get the community involved - when the reefs are gone, so is the revenue from the thousands of visitors who came to see them.

¥ Make more marine reserves and parks.

¥ Charge a fee for diving in marine parks that would go toward their upkeep.

¥ Close off more damaged areas of marine parks and reserves to give the coral more time to recuperate.

¥ Prohibit anchoring in reef areas. The anchor causes considerable damage to the reef. Install mooring buoys in reef areas so boats will not have to anchor.

¥ Require dive shops and resorts to inform divers and snorkel that they can/will cause damage to the coral reef.

Literature Cited:

1. Hawkins, Julie and Roberts, Callum. "Effects of Recreational SCUBA diving on fore-reef slope communities of coral reefs." Biological Conservation. 62.3 (1972):171-8.

2. Hawkins, julie and Roberts, Callum; effects of recreational scuba diving on coral reef; trampling on reef-flat communities Journal of Applied Ecology. 30.1 (1993):25-30.

3. Richmond, Robert. "Coral Reefs: present problems and future concerns resulting from anthropogenic disturbance." American Zoologist 33.6 (1993) 524-36

4. Ward, Fred. (1990). "FloridaÕs coral reefs are imperiled." National Geographic. July, p115-32

5. Wells, Susan and Hanna, Nick. The Greenpeace book of coral reefs. New York: Sterling Publishing Co. Inc., 1992

Sources - 3rd Quarter - 1997 copyright 1997 NAUI. All rights reserved.

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