Effect of divers on reefs in Sharm-el-Shei Egypt

In this blog I will be discussing the results of a study conducted by Julie P. Hawkins and Callum M. Roberts of the British Ecological Society.  I found the study in a peer reviewed journal called The Journal of Applied Ecology, the study is called Effects of Recreational Scuba Diving on Coral Reefs: Trampling on Reef-Flat Communities.  The study looked at the effects of scuba diving on a reef off the coast of Sharm-el-Shei in Egypt.  The reef is a popular dive spot that sees hundreds of divers each week.  The study compared the health and marine life in the area of this reef with another similar reef that is more difficult to access and therefore much less dived.  The findings are quite shocking!

The study was conducted by randomly choosing 20 sections of the reef and comparing them with 20 sections from the healthy or unvisited reef nearby.  A complete evaluation of the sections was then done, recording each hard and soft coral, broken or fragmented coral and  measuring the size, species, amount and health of all the coral on the reef.  The same was done for the control or unvisited reef. 

Data was then analysed using ANOVA which is a method for analyzing reef quality.   Percentage cover and species composition data are analysed using a cluster analysis and the Bray-Curtis similarity index for cover data, which is a way to analyse clustered and ununiformed data. 

So what were the findings?

Broken and dead coral was much more prevalent on the dived reef.  The percentage cover of hard coral was significantly reduced on the dived reefs, as was the areas of bare substrate, which is where nothing is growing.  The amount of soft coral, as well as the height and diameter were also greatly reduced on the dived reef. 

Although there was a large difference between the coral size and life of the differing reefs, the study found that divers didn’t completely kill any of the living coral communities.  The constant breaks and cuts incurred on the corral from the divers will force the coral to spend energy repairing itself rather than growing.  This makes for shorter, stockier coral and less coral abundance overall but it does not kill the reef completely.  Although the study finds that divers are not threatening to completely kill the reef, they do cause a lot of damage.  The undived reef also had more fish and marine life around it, which may be a sign that divers are scaring the fish away from their natural habitats to go somewhere where they won’t harassed by divers.

Although its bad news, it is interesting to actually get some hard evidence on the effect that divers are having on our reefs!  I hope you enjoyed this blog entry!  Stay tuned next week for my next blog posting!

Below I have attatched the link for the study, and a picture of a beautiful and healthy reef in Sharm-el-Shei!

Makes me want to go diving in Egypt!

http://www.jstor.org.ezproxy.tru.ca/stable/pdfplus/2404267.pdf?acceptTC=true

How are divers destroying the reefs?

In my first blog posting I said that scuba divers are contributing to the destruction of our reefs.  Statistics say that over ¼ of our coral reefs are already dead.  Destination Scuba says that an average of 600 Square miles of living coral reef is completely destroyed in the Pacific Ocean each year, with more being destroyed each year.  But how, you may ask do divers have anything to do with this?  Scuba divers affect and damage reefs in 5 different ways.

1.       Excited divers kicking their fins in an effort to propel themselves can kick and break the corals without even noticing what they are doing.  I have seen people do this many times, people get so distracted by the action going on in front of them that they don’t pay attention to what is behind them.  I have even had my regulator kicked out of my mouth by unaware divers who just kept going oblivious to what they have done.

2.       Divers grabbing coral in an attempt to stabilize themselves.  This is especially true for inexperienced divers who can’t control their buoyance.  They find themselves floating away from the bottom so they grab a hold of the first thing they see which is the coral.  Divers who are unable to control their buoyance also bump and grind down the reef, destroying it as they go.

3.       People stealing parts of the reef to take home.  While most dive outfits strictly forbid this, people still try to snag a piece of the reef as a souvenir. 

4.       Dive boat anchors.  Many dive companies like to get you as close to the reef as they can so when you’re in the water you don’t have to swim as far.  This means that they drop their massive dive boat anchor directly onto the reefs crushing everything beneath it.

5.       Pollution.  Many dive companies, especially in developing countries don’t have rules against littering in the ocean.  I’ve been on dive trips where people are allowed to throw their garbage into the water while having lunch about the reef. 

So these are the five main ways that divers destroy reefs.  You may be thinking to yourself, I’ve touched or seen coral on the beach before and it is as hard as a rock, how can a divers fin kick cause enough damage to destroy a reef?  Most coral reefs are hard on the inside but the outer layer is very delicate and can be damaged quite easily.  Coral is made from an organism called polyps.  These polyps create a hard exoskeleton to protect themselves and when they die they leave the exoskeleton behind.  This cycle repeats over years and this is how many types of hard corals grow.  For this reason the living polyps on the outside are very susceptible to damage.  Soft corals are a different story, they are one single unit and can be destroyed much easier and ripped apart just like a small plant. http://oceanservice.noaa.gov/facts/coral.html.  You could imagine the impact hundreds of people walking through a forest has on the small plants in the area, it is much the same for coral reefs.

So now that we know how coral is damaged and why, next week I will look at some studies done on different reefs around the world examining the impact of reefs dived on vs. untouched reefs.  The findings are startling.  I hope to see you next week!

Introduction!

When one thinks of a coral reef, what do they think of?  Beautiful, vibrant coral exploding with colour surrounded by pristine blue water and spectacular sea life.  Schools of fish chasing one another through a living, growing maze.  Unfortunately, that isn’t the case anymore for many of the reefs around the world.  Our reefs are being destroyed at an alarming rate.  The major culprit is global warming but reefs are also being destroyed from direct contact by scuba divers.  Once healthy living reefs and being killed off, trampled and polluted by humans.  This blog will be investigating the impact that recreational scuba diving has on coral reefs.

Many people don’t think that scuba diving has any impact on coral reefs.  I had an argument on the subject with one of my roommate the other night, which is what inspired me to write my blog about it.  She said that scuba divers don’t harm the reefs, they simply look at them.  They take in the beautiful colours and exotic fish while harmlessly floating overhead, not disturbing a single sea creature from its daily routine.  I asked her how many times she’s been scuba diving.  Her reply was 0.  I’ve been scuba diving probably two dozen times and while I will admit many diving companies have strict rules and take precautions not to harm the reefs or disturb the marine life, it still happens, a lot. 

Throughout this blog I will tell my first hand experience of reef destruction around the world.  I will also include facts and figures to back up my argument and paint a picture of what we are really doing to our reefs. 

Thanks for reading my blog, I hope you stay tuned for the next installment!