Jack Morelock,1 Wilson R. Ramírez,2 Andy W. Bruckner,3 Milton Carlo,1

1Department of Marine Sciences University of Puerto Rico at Mayagüez, P.O. Box 908, Lajas, PR 00667-0908 morelock@coqui.net
2Geology Department University of Puerto Rico at Mayagüez, P.O. Box 9017, Mayagüez, PR 00861-9017 ramirezw@coqui.net
3National Oceanographic and Atmospheric Administration Fisheries Service Office of Protected Resources, Silver Springs, MD 20910 andy.bruckner@noaa.gov

Abstract

Assessments of coral reefs off the west and south coasts of Puerto Rico, between Mayagüez and Ponce, were conducted over the last 20 years to determine the status and trends of important reef-building species. Species composition, abundance and cover of stony corals were determined from photoquadrats (0.7 m2 area) placed along 30 m transects that followed depth contours. Coral cover varied from more than 50% to less than 1% and has exhibited an accelerating decline over the 20 year study. The most notable changes have been seen on nearshore reefs affected by coastal runoff, nutrient input or river discharge. The healthiest reefs (highest living coral cover) identified in this study were located at the shelf edge of La Parguera - where communities were dominated by massive species such as the Montastraea annularis complex and Colpophyllia natans, and plating species like Agaricia lamarki in deeper water (25-40 m depth). A shift in species composition occurred on turbid reefs, with a dominance by Montastraea cavernosa - and reef-building corals declined in abundance or were absent below 15 m depth. Acropora palmata has been dramatically reduced in abundance over the last 20 years, but areas of Acropora palmata thickets are still present. Some reefs still have fairly extensive populations of Acropora cervicornis.

notes for navigation in this paper

 This document is set in "frames" for maximum useability.

The main frame (on the left, under the heading) holds the text of the paper. Within the text, you will see underlined links that give you a display of the appropriate figure in the display frame to the right.

The upper frame on the right returns you to the non frame version or to the e-mail site of Jack Morelock.

The second frame down, on the right, is the navigation to individual sections of this paper. These remain in place so that you can move to any part of the paper. Depending on monitor size, you may need to use the vertical scroll bar. The "abstract" link returns you to this page. The results section has another set of links that moves you to different parts of that section (individual reef areas) and links that return you to the list of locations.

The bottom frame on the right is for display of figures. Click on the "links to figures" within the text frame to bring up the full figure in the display frame.

For those who want to access the papter in Acrobat pdf format, go to PDF FILES . The PDF document will open separate from the HTML document. Because of the size of this paper, the PDF file may take several minutes to open. Close the PDF document to return to the HTML version. If you cite this paper, refer to the contents of the PDF document which will be fixed as of 2001.

The HTML document will be updated as more coral reef transects are run. Revisions will be marked and dated. The Acrobat document will not be revised.