coral "health" criteria

mcrosby at mcrosby at
Thu Jan 18 12:37:39 EST 1996

As part of my interest to formulate draft criteria for success in  
improving the overall "health" or condition of the Florida Keys coral  
reef ecosystem (including all associated habitats such as coral reefs,  
mangroves, seagrasses, associated bays and inlets, etc.), I would greatly  
appreciate input and ideas from those of you with expertise in this broad  
ecosystem.  I am not looking for verbose treatise on the subject of what  
is "healthy" versus "non-healthy".  What I am looking for is what  
specific variables (i.e., biomass, diversity, presence/absence,  
physico-chemical, indicator species) you would feel should increase or  
decrease, and in what magnitude, in order to say the system is improving  
in overall condition.  Note that I am looking for criteria to measure  
significant improvement, not total restoration (that is another kettle of  
fish altogether!) 

Some variable that have been suggested to date (although in many cases  
still requiring some degree of being quantitative) are: 
- Nutrients and suspended sediments reduced (by how much? or to what  
- Macro algae bloom and coverage decrease (by how much? or to what  
- Increase sea urchin population (by how much? or to what level?) 
- Tortugus shrimp harvests restored to recent historic levels to support  
a MSY of 10 million pounds annually 
- Increase in population of common snook (by how much? or to what level?) 
- Increase in recruitment of Gray Snapper (by how much? or to what  
- Restoration of larval and juvenile spiny lobster habitat (loggerhead  
sponges) to their historic range (what is that range?) 
- Increase in sighting of jewfish (by how much? or to what level?) 
- Increase in sighting of sea turtles (which species? by how much? or to  
what level?) 
- An increase in coral cover by 15-20% (is this realistic? to low? to  
high? key species?) 
- Restore coverage and species composition of seagrasses to mid-1980s  
- Increase in wading bird, osprey and brown pelican populations (by how  
much? or to what level?) 

Any input or comments that address the above "by how much? or to what  
level?" questions, and/or additional variable to employ as criteria for  
success would be most appreciated. 

I am not sure if it is best to send your input directly to me at my  
Internet address, or to respond via this coral list server.  The former  
may help to limit loading the server with what some may consider not to  
be of interest, however the latter approach may serve to stimulate some  
useful discussions.  I would appreciate input ASAP. 

Many Thanks and Cheers, 
Dr. Michael P. Crosby 
National Research Coordinator 
Ocean and Coastal Resource Management 
NOAA, SSMC-4, Rm 11437 
1305 East West Highway 
Silver Spring, MD   20910 
phone: 301-713-3155, ext. 114 
fax: 301-713-4012 
Internet: mcrosby at 

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