Spawning divers

Alina M. Szmant szmanta at
Thu Jun 21 00:34:12 EDT 2001

As one who has spent a lot of time trying to catch spawn, I will venture an
opinion:  I largely agree with your assessment that a few divers in the
water during spawning can cause little harm.  However, since humans are so
prone to excess, I caution that large numbers of divers and boats in more
confined reef areas might concern me especially if the boats could be
leaking fuel or oil that could cause a toxic surface slick (gametes could
become contaminated).  That the corals spawn so late at night will
hopefully preclude spawn watching from becoming too big of an attraction.

Alina Szmant

 At 05:24 PM 6/20/2001 -0400, Brylske at wrote:
>    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
>on coral reefs. But unlike the usual concern, which involves direct damage
>reef structure, this query involved another form of potential 
>impact—disturbance during mass spawning events. A similar issue has
>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
>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
>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
>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
>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:
>3324 SW 8th Court
>Cape Coral, Florida 33914
>800-729-7234, ext. 675 (phone-US toll free)
>941-945-1987 (phone)
>941-945-1926 (fax)
>alexb at (Email)
>brylske at (Email)
>For directions on subscribing and unsubscribing to coral-list or the
>digests, please visit, click on Popular on the
>menu bar, then click on Coral-List Listserver.
Dr. Alina M. Szmant
Center for Marine Science
University of North Carolina at Wilmington
One Marvin K. Moss Lane
Wilmington NC 28409
TEL:  (910)962-2362 FAX:  (910)962-2410
email:  szmanta at
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