Coral Reef monitoring Project Executive Summary

EPA Science Advisory Panel

Key Colony Beach, December 5-6, 2000
Summary
Data for each successive sampling year is being compared with prior years' data to obtain a broader understanding of the dynamics of the FKNMS coral reef system.  As the coral reef monitoring is integrated with the seagrass and water quality programs, the results can be used to focus research on determining causality and can be used to fine tune and evaluate management decisions.  The Coral Reef Monitoring Project provides the first real opportunity in the Florida Keys to address these questions at the spatial scales required to detect large-scale patterns and discriminate between hypotheses.

Conclusions

  • There was a significant loss of coral species richness between 1996 - 2000 (67 percent of the 160 stations lost species)
  • From 1996 - 1998, stony coral cover significantly decreased in 45% of the 160 stations.  The greatest percent of stations, which lost significant coral cover were in the Upper Keys.
  • From 1996 - 1999, percent stony coral cover decreased roughly 45% in both Upper and Lower Keys.
  • Diseases have increased in the number of stations where they occur, the number of species that are infected, and a slight number of new disease-phenomena were observed.

PROPOSED CHANGES TO CRMP

  • Reduction in numbers of stations sampled by site based statistical tests.
  • More intensive data collection at selected sites to assist in resolving certain coral population dynamics questions regarding relative abundance and recruitment.

CRMP SAMPLING REDUCTION AT STATION LEVEL
Deciding whether or not to eliminate a station from further sampling is complex.  Criteria presented here can be applied using the point count data from 1996 - 1998.  Two main characteristics must be considered when monitoring stony coral cover at a site: the percent cover and change in percent cover  for a given period.  If a station contributes significantly to at least one of these characteristics, it should continue to be sampled.  A station can be eliminated only if it has similar stony coral cover or similar change in the stony coral cover compared to other stations within the same site.

Here, stony coral is defined as 1) total stony coral cover and 2) presence of the most abundant stony coral species (the list changes from site to site).  Using statistical analysis, elimination of certain stations can be suggested; however, the final decision should take into account other factors such as: geographic location, local topography, priorities in studying certain species, etc.  A broad consensus should be reached from all researchers involved in the study before eliminating a station.  Analysis of each of the 43 sites must be done separately.  The procedure suggested for eliminating station(s) from further sampling, based on the collected data and above two criteria follows.

ALLIGATOR SHALLOW SITE
1. Change in Stony Coral Cover.  In this site the pair-wise year comparisons for change in stony coral shows that only Station 3 has a significant decrease from 1997 - 1998.  We can assume that overall there is no significant change in stony coral cover for this site.

2. Stony Coral Cover.  For stony coral cover, the 4 stations group in two pairs:  Station 2 and 3, and Station 1 and 4.  This grouping is based on chi-square tests for difference in proportions for year year separately, and for the whole period 1996 - 98 combined (see Fleiss, "Statistical Methods for Rates and Proportions" , 2nd. Ed., 1981, John Wiley & Sons.)

3. Most Abundant Species in Stony Coral Category.  Data for 1996 -1998 are combined:

  • Millepora alcicornis - All four stations are similar.
  • Millepora complanata - Two groups are distinguished:  Stations 1 and 2 (greater cover), and Stations 3 and 4 (less cover).
  • Porites astreoides - Two groups are distinguished: Stations 1 and 2 (less cover), and Stations 3 and 4 (greater cover).

Conclusion:  There are two possible configurations of stations for future sampling at the CRMP Alligator Shallow site:  Station 1 and 2, or Station 3 and 4.  it is recommended keeping station 3 and 4 because station 3 showed a significant decrease in stony coral from 1997 to 1998.

Drawback:  If only station 3 and 4 are included in future sampling, observations for Millepora complanata will be reduced, but observations will increase for Porites astreoides.

Acknowledgements of Partners:
Laurie MacLaughlin, John Halas, Steve Baumgartner, Ben Haskall (FKNMS), Phil Murphy, Mel Parsons, Gary Collins, Fred McManus, William Kruczynski (EPA), G.P. Schmahl (FGBNMS), Lonny Anderson (KML), Captain and Crew of OSV Peter W. Anderson, Dry Tortugas National Park Staff.

Expert Review Panel:
Steve Gittings, J. Kenneth Clarke.

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