[Coral-List] coral sedimentation thresholds for dredge induced sedimentation

[Jeremy J. Sofonia]

Hi Andrew,

Here are a few more references for your review/ consideration:

Raaymakers, S. and J. Oliver.  1993.  Advances in reactive monitoring  
– The 1993 Townsville Port Development.  Reef Research.  17:21.

Dodge, R.E. and J.R. Vaisnys.  1977.  Coral populations and growth  
patterns:  Responses to sedimentation and turbidity associated with  
dredging.  Journal of Marine Research.  Vol. 35, no. 4: 715-730.

Brown, B.E., M.D.A. Le Tissier, T.P. Scoffin, and A.W. Tudhope.   
1990.  Evaluation of the environmental impact of dredging on  
intertidal coral reefs at Ko Phuket, Thailand, using ecological and  
physiological parameters.  Marine Ecology Progress Series.  Vol.  
65:273-281.

Berkelmans, R.  1993.  The Heron Island monitoring program: A  
synopsis.  Reef Research.  Vol. 21:3-7.

Marszalek, D.S.  1981.  Impact of dredging on a subtropical reef  
community, southeast Florida, U.S.A.  Proceedings of the Fourth  
International Coral Reef Symposium, Manila.  Vol. 1:147-153.

Sheppard, C.  1980.  Coral fauna of Diego Garcia lagoon following  
harbor construction.  Marine Pollution Bulletin.  Vol. 11: 227-230.


Of these, some site dredging as the source for coral impact while  
others do not.  Note, however, that some of those that do site  
deleterious impacts are often missing data on pre-dredging (i.e.  
baseline) conditions and/or data on natural variation.  Raaymakers &  
Oliver, 1993 is a good example though, and is often sited as a model  
for assessing dredge related impacts.

Honestly though, I wold suggest you do not  depend on these  
references or the values suggested from other studies in regard to  
sediment 'thresholds' and their relationship to coral health.  This  
is a very site specific relationship depending on multiple factors  
including local/ regional environmental conditions (including  
sediment characteristics) and the type/ life history of the species  
present.  Collecting sufficient baseline data (particularly over  
seasons) as well as geotechnical information is key.  Numerical  
modelling of potential dredge plumes is also a useful tool, and I  
would also strongly recommend a fairly robust water quality  
monitoring program...

Apologies for rambling on a bit, it's just that impact assessment  
from dredging works is a good portion of my working life.  I'm  
currently involved in two projects down here in Australia.  Rest  
assured, folks here (government through to client) take this very  
seriously.  I'd be interested to learn more about your project and  
discuss further if that would be helpful.

Good luck,

Jeremy



JEREMY J. SOFONIA
Senior Marine & Environmental Consultant
SKM Australia Pty. Ltd.

7th Floor, Durack Centre
263 Adelaide Terrace
Perth, WA 6000

Tel: +61 (0) 8 9268 4433
Mob: +61 (0) 40 911 8747
Fax: +61 (0) 8 9268 4400

http://www.skm.com.au


On 24/01/2007, at 5:43 PM, Andrew_Jamieson at URSCorp.com wrote:

> Dear Coral Listers
>
> I am trying to track down any  research undertaken into tropical coral
> sedimentation thresholds for dredge induced sedimentation - can anyone
> direct me in the right direction ?
>
> Many thanks
>
>
> Andrew Jamieson
> Senior Environmental Scientist
> andrew_jamieson at urscorp.com
>
>
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