[Coral-List] Rugosity of artifical reefs

Thu Oct 14 17:41:32 EDT 2010

Brian is right. It is difficult to use standard rugosity measures to meaningfully compare artificial and natural reef structures. 

Historically, most measures of reef rugosity have involved comparing linear distances with distances along the reef surface (including benthic organisms), often with fine chains for the latter measure (Porter 1972, Risk 1972). Inspired by Bradbury and Reichelt's (1983) use of calipers to measure reef structure at multiple scales for fractal analysis, we modified the chain method to measure at multiple scales (McManus et al 1996), and showed that small fish tended to be abundant where rugosity at small scales was high, and similarly across the scales (Nañola et al 1989). Subsequently, a number of studies have used acoustic or lidar methods to measure rugosity at multiple scales, including the excellent papers cited by Brian. Wilding et al. (2010) reviewed several in-water measurement approaches. Courtney et al (2007) and Fisher (2007) discuss using a combination of 3D photographic reconstruction and estimation to obtain broad surface measures. 

However, none of these methods account well for cavities. This problem was discussed for reefs by Ginsburg (1983) and for artificial vs natural reefs by  Caddy and Stamatopoulos (1990). For studying fish-cavity relationships, one would have to be able to compare something like the large hollows and hole entrances in reef balls with natural systems such as the protected spaces within dense patches of elkhorn coral. That is a computer problem for which we have a solution not yet implemented. 

Cheers!

John	

Bradbury RH, Reichelt RE (1983) Fractal dimension of a coral-reef at ecological scales. Marine Ecology-Progress Series 10(2):169–171.

Caddy JF, Stamatopoulos C (1990) Mapping growth and mortality rates of crevice-dwelling organisms onto a perforated surface: The relevance of "cover" to the carrying capacity of natural and artificial habitats. Estuarine, Coastal and Shelf Science 31(1):87-106.

Courtney LA, Fisher WS, Raimondo S, Oliver LM, Davis WP (2007) Estimating 3‐dimensionalcolony surface area of field corals. Journal of Experimental Marine Biology and Ecology 351(1‐2):234‐242.

Ginsburg RN (1983) Geological and niological roles of cavities in coral reefs. Pp 148-153 In: Barnes DJ Perspectives on coral reefs. Australian Institute of Marine Science and Brian Clouston, Manuka, Aus.    

McManus JW, Nañola CL, del Norte AGC, Reyes RB, Pasamonte JPN, Armada NP, Gomez ED,  Aliño PM (1996) Coral reef fishery sampling methods. Chapter 5. p. 226-270. In: V.F. Gallucci, S.B. Saila, D.J. Gustafson and B.J. Rothschild (eds) Stock Assessment: Quantitative Methods and Applications for Small-scale Fisheries. CRC Lewis Publishers, New York. 527 p.

Nañola CL, McManus JW, Campos WL, del Norte AGC, Reyes RB, Cabansag JBP, Pasamonte JN (1989). Spatio Temporal variations in community structure on a heavily fished forereef slope in Bolinao, Philippines. pp. 377 380. In: Hirano, R. and I. Hanyu, eds. The Second Asian Fisheries Forum. 991 p. Asian Fisheries Society, Manila, Philippines.

Porter JW (1972) Patterns of Species Diversity in Caribbean Reef Corals Ecology 53(4):745-748

Risk MJ (1972) Fish diversity on a coral reef in the Virgin Islands. Atoll Research Bulletin 153:1-6.

Wilding TA, Palmer EJL, Polunin NVC (2010) Comparison of three methods for quantifying topographic complexity on rocky shores. Marine Environmental Research 69(3):143-151

Fisher WS (2007) Stony Coral Rapid Bioassessment Protocol U.S. Environmental Protection Agency Office of Research and Development Washington, DC 20460 EPA/600/R-06/167. www.epa.gov/ord.

-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Brian Walker
Sent: Thursday, October 14, 2010 10:22 AM
To: 'Clifford J. Hearn'; 'Steven Jachec'
Cc: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] Rugosity of artifical reefs

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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