[Coral-List] Re: Artificial Reefs-predator exclusion

[Todd Barber]

Hi Ben,

Preditor exclusion devices are a way of mitigating for damaged reef systems
that normally provide the natural preditor exclusion effect from complexity
but are suffering from complexity loss.  These devices should only be used
when goals of the project specifically call for additional fish larval
survival rates (i.e. if a stock level is depressed for particular reasons
and it is determined that larval survival rates are a key bottleneck).
Preditor exclusion devices, to my knowledge, are not used extensively and at
this stage are used primarily by researchers studying their effects.

-Todd Barber

----- Original Message ----- 
From: "Ben Richards" <Ben.Richards at noaa.gov>
To: "Todd Barber" <reefball at reefball.com>
Cc: "John McManus" <jmcmanus at rsmas.miami.edu>;
<coral-list at coral.aoml.noaa.gov>
Sent: Thursday, March 11, 2004 9:12 AM
Subject: Re: [Coral-List] Re: Artificial Reefs-predator exclusion


> Todd and John -
>
> This statement from your last message gives me pause for thought.  How
> much should we be manipulating the natural environment and how careful
> do we need to be when thinking of long-term effects?  By excluding
> predators and allowing individuals to survive that would not have done
> so in a natural environment, are we not diluting the "fitness" of the
> adult population.  If ARs are effective and become used on a large
> scale, what long term effects might we be having on natural fish
> populations?  I know this issue has come up in the aquaculture industry
> as farm raised fish are accidentally released or escape into natural
> populations.
>
> ~ben
>
>
> On Mar 8, 2004, at 1:12 PM, Todd Barber wrote:
>
> > I agree that the post larval stage is critical, it is for this that
> > preditor exclusion devices can be used to increase juvinile fish
> > survival rates....once fish make to to 2 cm-3 cm or so, the survival
> > rates are much higher.  Dr. Robin Sherman from NOVA Southeastern
> > University did a nice study on this using artificial reefs with the
> > exclusion devices.
>
> ---
> Benjamin L. Richards
> Program Specialist for Research and Information Technology
> Florida Keys National Marine Sanctuary
> P.O. Box 500368
> Marathon, FL  33050
>
> ben.richards at noaa.gov
>
> phone: (305) 743-2437 x28
> fax: (305) 743-2357
> NEXTEL: (305) 360-1488
>
> http://floridakeys.noaa.gov