Spawning divers

[Brylske at aol.com]

    A question arose recently from a diver that I was hesitant to answer 
until I gathered some expert opinion. It relates to the issue of diver impact 
on coral reefs. But unlike the usual concern, which involves direct damage to 
reef structure, this query involved another form of potential 
impact—disturbance during mass spawning events. A similar issue has already 
arisen with respect to the closure of the Tortugas South reserve if to scuba 
diving. The rationale, which I’m proud to say that the diving industry has 
largely supported, is the avoidance of disturbance to known fish spawning 
aggregations in this area. However, the question at hand does not involve 
fish, but coral spawning. The diver wondered whether there might be some 
detrimental impact when scuba divers are present during mass spawning events. 
The concern was raised because many dive operators are now promoting tours 
specifically to observe these events. 

    My gut, less-than-expert reaction was that, given the large area of such 
spawning events and the relatively small area where diving activities might 
take place, the presence of divers is likely to be negligible, if not totally 
inconsequential. Further, my understanding is that the lipid content of the 
gamete packets make them buoyant, so fertilization does not occur under 
water, but at the surface when the packets break up. This would seem to 
further negate the effect of divers in the water.

    So, I’d love to hear experts in this arena chime in and wax poetic. Do 
you believe that such diving activity could have any significant detrimental 
consequences, and if so how? Might the mere presence of divers inhibit gamete 
release? Could the exhaust bubble actually facilitate the breaking up the 
packets? I can't promise that this thread will be as entertaining as the 
recent discussion of the role of overfishing, but it’s a legitimate concern 
of some of the more environmentally-aware members of the recreational diving 
community. Your insights would be much appreciated.


Alex F. Brylske, Ph.D.
Marine Conservation & Education Specialist
Project AWARE Foundation

Please respond to:
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brylske at aol.com (Email)
www.projectaware.org
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