[Coral-List] Rugosity of artifical reefs

[Brian Walker]

Hi Cliff,

We have done some work off of SE FL trying to link fish populations to
topographic complexity on the natural reef and found there are many
confounding factors to this relationship including depth, habitat, the
operational scale of the fishes comprising the assemblage, the resolution of
the bathymetry, etc. In situ measurements of rugosity showed the strongest
relationship to the assemblage and their relationship to topographic metrics
derived from bathymetry data (4m lidar) were very weak.

There are a host of issues with trying to compare populations between
natural and artificial substrates. Teasing out the relationship with
rugosity or some other topographic metric from this would be very
challenging.

Also measuring the rugosity of an artificial reef would be difficult
depending on the type. Most methods cannot account for the porosity of the
structure which would be very important in most artificial reef types. It is
not as simple as acquiring bathy/topo data because this will not account for
the interior spaces.  

Much work is still needed to understand this complicated issue. I'm not
saying  it's not worth a shot, but it won't be as straightforward as it may
seem.

______________________________________

Walker, B.K., Jordan, L.K.B., Spieler, R.E., 2009. Relationship of Reef Fish
Assemblages and Topographic Complexity on Southeastern Florida Coral Reef
Habitats. J Coast Res 53, 39-48.

Walker, B.K., 2009. A Model Framework for Predicting Reef Fish Distributions
Across the Seascape Using GIS Topographic Metrics and Benthic Habitat
Associations, Proceedings of the 11th International Coral Reef Symposium,
Ft. Lauderdale, Florida, pp. 657 - 661.
________________________________________

Cheers,

Brian K. Walker, Ph.D.
Research Scientist
National Coral Reef Institute
Nova Southeastern University
Oceanographic Center
8000 N Ocean Drive
Dania Beach, FL 33004
954-262-3675


-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Clifford J.
Hearn
Sent: Wednesday, October 13, 2010 4:29 PM
To: Steven Jachec
Cc: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] Rugosity of artifical reefs

Sorry, about the confusion. Better to call it rugosity. We are not talking
about surface roughness. In the topographic world we use the tern
'roughness' which is the log of rugosity. 
 
Let me try again:
 
 I wonder whether it would be worthwhile our comparing the rugosity of
artificial reefs with that for natural reefs. If rugosity is a good measure
of topographic complexity and this is related to ecology and fish habitat,
we could see some important science. We have good bathymetry for some
natural reefs and would just need bathy/topo data for artificial reefs.

Cliff


Clifford J. Hearn

--- On Wed, 10/13/10, Steven Jachec <sjachec at fit.edu> wrote:


From: Steven Jachec <sjachec at fit.edu>
Subject: Re: [Coral-List] Roughness of artifical reefs
To: "Clifford J. Hearn" <clifford_hearn at yahoo.com>
Cc: "coral-list at coral.aoml.noaa.gov" <coral-list at coral.aoml.noaa.gov>
Date: Wednesday, October 13, 2010, 4:02 PM


I believe the roughness over natural reefs has been pursued by Stanford
folks:  graduate students C MacDonald, R Lowe, M Reidenbach. Profs Koseff
and Monismith. 

Cheers
Dr Steven Jachec

Sent from my iPhone...forgive any  mis-spellings. 

On Oct 13, 2010, at 3:27 PM, "Clifford J. Hearn" <clifford_hearn at yahoo.com>
wrote:

> Dear Listers
>  
> I wonder whether it would be worthwhile our comparing the rugosity
(roughness) of artificial reefs with that for natural reefs. If rugosity is
a good measure of topographic complexity and this is related to ecology and
fish habitat, we could see some important science. We have good bathymetry
for some natural reefs and would just need bathy/topo data for artificial
reefs..
> Your thoughts?
> Cliff
> Clifford J. Hearn
> Working Science Consultancies
> 200, 2nd Avenue South #519, St Petersburg, Florida 33701
>  
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list
> 
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