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Funded by Sea Grant

Evaluation of the Effects of Sedimentation and Nutrients on Coral and the Long Term Monitoring of Recovery after Environmental Stress. (Preliminary Report). Wilson R. Ramírez 1 Jack Morelock 2. 1 Department of Geology University of Puerto Rico at Mayagüez

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Funded by Sea Grant

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  1. Evaluation of the Effects of Sedimentation and Nutrients on Coral and the Long Term Monitoring of Recovery after Environmental Stress (Preliminary Report) Wilson R. Ramírez 1 Jack Morelock 2 1Department of Geology University of Puerto Rico at Mayagüez 2Department of Marine Sciences University of Puerto Rico at Mayagüez Marine Sciences Funded by Sea Grant

  2. Questions: • How can we quantify the effects of terrigenous sediment and nutrient stress on corals in their natural environment ? • Is it worth to establish more strict regulations ($$$) on sedimentation / nutrient inputs to reefs ? • Can reefs recover from the terrigenous sediment and nutrient stress they have been exposed to ?

  3. Possible alternatives to answer these questions : 1. Study and compare reef systems in impacted vs. non-impacted areas. 2. Develop and apply better regulations for land development and sewage management to study how reef systems respond. 3. Move impacted corals to clean areas and monitor their responses.

  4. Objectives : • Measure recovery of coral cover after reduction in sediment/nutrient stress. • Measure the impact on “healthy” corals moved into stress conditions. • Determine which species are the more and less resistant to and nutrient sediment stress. • Produce information that will lead to better ability to manage reef systems.

  5. Methodology The Mayagüez-Añasco watershed was selected due to the high sedimentation and nutrient impact present in the area.

  6. Methodology The physiography, bathymetry, sediment texture and composition, and sedimentary facies in the area were characterized.

  7. Methodology Characterization of reef areas

  8. Methodology

  9. Methodology

  10. Total Coral Cover

  11. Coral cover by species

  12. Methodology: A set of locations in Mayagüez and Añasco bays were chosen to provide a variety of conditions consistent with the goals of thisproject. MN MI AL EN

  13. Coral Transplantation Colcophyllia natans (Cln) Dichocoenia stokessi (Dis) Diploria labyrinthiformis (Dpl) Diploria strigosa (Dps) Dendrogyra cylindrus (Dyc) Madracis decactis (Mad) Meandrina meandrites (Mem) Montastrea annularis (Mna) Montastrea cavernosa (Mnc) Porites asteroides (Pra) Porites porites (Prp) Siderastrea sideria (Sds) Undaria(Agaricia)agaricites (Aga) Thirteen coral species were studied. Species were selected base on their coral cover and number of colonies present.

  14. Coral Transplantation Cementing coral to slab Finished slab & monitor stake

  15. Transplant pattern: MN Healthy environment changed to impacted environment MI Coral from Escollo Negro are transplanted to: Manchas north Sewer reef Algarrobo Control slab transplant at Escollo Negro AL EN

  16. Transplant pattern: MN Sediment & Nutrient stressed corals are given clean water environment. The environment has been “cleaned up.” MI Manchas Norte Manchas Interiores Algarrobo corals transplanted to Escollo Negro AL EN

  17. Total of Transplants “stressed” to “clean” “clean” to “stressed” To Manchas North slab ID - MN 45 To Manchas North slab ID - MN 95 To Manchas North slab ID - MN 73 To Manchas North slab ID – MN 65 To Manchas Interiores 8 slab ID - MI 26 To Manchas Interiores 8 slab ID - MI 187 To Manchas Interiores 8 slab ID - MI 80 To Manchas Interiores 8 slab ID - MI 16 To Algarrobo slab ID - AL 55 To Algarrobo slab ID - AL 77 To Algarrobo slab ID - AL 31 To Algarrobo slab ID - AL 66 From Manchas North slab ID - EN 92 From Manchas North slab ID - EN 47 From Manchas Interiores 8 slab ID - EN 50 From Manchas Interiores 8 slab ID - EN 62 From Algarrobo slab ID - EN 88 From Algarrobo slab ID - EN 83 Escollo Negro control - slab ID - EN 189 Escollo Negro control - slab ID - EN 188 Escollo Negro control - slab ID - EN 69 Escollo Negro control - slab ID - EN 49 Average: 12 colonies per slab

  18. Time Line added to each Transplanted Coral All corals stained with Alizarin Red-S at the time of transplantation

  19. Measurements of Sedimentation Inputs Load-Texture-Composition Sediment traps were place in all locations

  20. Measurements of water temperature Thermometers were place in all locations

  21. Bi-monthly Monitoring for two years Photographs and notes describing the status of the corals. Sediments in traps collected bi-monthly. Continuous (every 2 hours) temperature measurements for two years.

  22. Monitoring: Every coral in each slab inspected bi-monthly EN 50 From Manchas Interiores 8 to Escollo Negro. From: Feb. 2002 To: Oct. 2002

  23. Monitoring: Changes in coral growth and health recorded Al 55 From Escollo Negro to Algarrobo

  24. Harvesting: • After two years samples of the transplanted corals were collected to measure: • Coral growth rate before and after transplantation • Trace elements and stable isotopes in skeletons • Other… A minimum number of corals were sacrificed. Most samples consisted of 20% of the mass of the coral skeleton.

  25. SUMARY of Results: Coral Mortality From: 139 coral colonies transplanted : 11 colonies lost by concrete failure Clean site (EN) to impacted sites:“clean” to “stressed” SITE SLAB Transplanted CF Remain LOST Manchas North 45 12 12 0 65 12 8 4 73 11 1 7 3 95 13 1 12 0 MI-8 16 12 3 5 4 26 9 4 3 2 80 8 8 0 187 12 1 11 0 Algarrobo 31 13 1 9 3 55 12 11 1 66 12 11 1 77 13 11 2

  26. SUMARY of Results: Coral Mortality From: 139 coral colonies transplanted : (mostly because of algal overgrowth) 20 colonies died during the next two years Clean site (EN) to impacted sites:“clean” to “stressed” SITE SLAB Transplanted CF Remain LOST % Site % Manchas North 45 12 12 0 0 65 12 8 4 33 73 11 1 7 3 30 95 13 1 12 0 0 15 MI-8 16 12 3 5 4 44 26 9 4 3 2 40 80 8 8 0 0 187 12 1 11 0 0 18 Algarrobo 31 13 1 9 3 25 55 12 11 1 8 66 12 11 1 8 77 13 11 2 15 14

  27. SUMARY of Results: Coral Mortality From: 139 coral colonies transplanted From Clean site (EN) to impacted sites: “clean” to “stressed” 9 colonies had measurable increase in size Siderastrea siderea Montastrea cavernosa Colpophyllia natans Porites asteroides Porites porites

  28. SUMARY of Results: Coral Mortality 49 coral colonies transplanted as “control” : 3 colonies lost by concrete failure 2 colonies lost during the next two years (coral grazers) “Clean” site to “clean” site (EN): CONTROL SITE SLAB Transplanted CF Remain LOST % Site % Control 49 12 10 2 17 69 12 1 11 0 0 188 12 1 11 0 0 189 13 1 12 0 0 4

  29. SUMARY of Results: Coral Mortality 48 coral colonies transplanted to the “clean” site : 1 colony lost by concrete failure 1 colony died during the next two years Impacted sites to clean site (EN): “stressed” to “clean” SITE SLAB Transplanted CF Remain LOST % Site % From Manchas 47 12 1 7 4 36 Norte 92 12 2 10 83 61 From MI-8 50 12 1 11 0 0 62 12 12 0 0 0 From Algarrobo 83 11 11 0 0 88 12 11 1 8 4 Manchas Norte samples INVALIDATED due to changes in the transplantation procedure.

  30. General Conclusions on Slab Monitoring • Concrete slabs were quickly covered with turf algae mats at the stressed sites. • Most of the coral loss at these sites seemed to be due to overgrowth of the coral colonies by turf algae. • Most loss of coral colonies was within the first few months then reduction of living colonies remaining was slow.

  31. General conclusions on Slab Monitoring • Porites asteroides and Montastrea cavernosa showed significant growth when moved from “stress” into a “clean” environment. • Montastraea cavernosa colonies also showed active budding when moved from “stress” into “clean” environment. EN 62 EN 83

  32. General Conclusions on Slab Monitoring • Montastrea annularis can keep a slow growing rate in sediment-stressed reefs. Porites asteroides and Siderastrea sidere, showed more growth than Montastrea cavernosa when moved “stress” into “clean” environment.

  33. Coral Growth Rates • Alizarin Red-S Line was identified in the coral slabs. • This line represent the time 0 or the time of the transplantation.

  34. Coral Growth Rates • X-rays were taken of each slab. • 12 species • At least two species per site (replicates)

  35. Coral Growth Rates • X-rays were scanned and digitally manipulated to enhance high and low density variations and measure the coral bands.

  36. Coral Growth Rates • Bands are measured before and after transplantation using the Alizarin Red-S line as a reference. • A set of 2 bands(high & low density) represent 1 year. • 4 years measured (2 years before and 2 years after transplantation)

  37. Coral Growth Rates • Bands are measured before and after transplantation using the Alizarin Red-S line as a reference. • A set of 2 bands(high & low density) represent 1 year. • 4 years measured (2 years before and 2 years after transplantation)

  38. Coral Growth Gates (cm/yr) Mna 0.6 Mnc 0.5 Sds 0.5 Pra 0.3 MN MI Mna 0.6 Mnc 0.5 Sds 0.4 Pra 0.3 AL Mna 0.6 Mnc 0.4 Sds 0.3 Pra 0.4 EN Mna 0.5 Mnc 0.3 Sds 0.5 Pra 0.5

  39. Coral Growth Rates • EN188 From EN to EN - Control Slab • Porites porites • Transplantation did not caused significant changes in the coral growth rate. TRANSPLANTATION cm 2002 2003 2001 2000 time

  40. EN to EN Control Coral GrowthRates 0.6 0.4 • “Clean” to “stressed” sites • Montastrea cavernosa 0.2 0 EN 69 TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION Growth rate either remain the same or increased !

  41. EN to EN Control Coral GrowthRates 0.6 0.4 • “Clean” to “stressed” sites • Porites asteroides 0.2 0 EN 69 TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION Growth rate decreased.

  42. Coral Growth Rates • “Stressed” to “Clean” sites • Montastrea annularis • No significant changes visible • From AL to En rate increased slightly ? TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION TRANSPLANTATION From MN From MI 8 FromAL From EN “ Controls”

  43. Coral Growth Rates • “Stressed” to “Clean” sites • Montastrea cavernosa • No significant changes visible • From MI-8 to En rate increased slightly ? From MN From MI 8 FromAL From EN “ Controls”

  44. Sediment Traps • Laboratory analyses • XRD analysis (minerals, pesticides, chemicals) • Composition analysis (organics, carbonate, terrigenous) • Grain size distribution • Average (yearly and monthly) sediment collection

  45. Sediment Traps • Laboratory analyses • XRD analysis (minerals, pesticides, chemicals) • Composition analysis (organics, carbonate, terrigenous) • Grain size distribution • Average (yearly and monthly) sediment collection

  46. Sediment Traps Grain Size Analysis for Escollo Negro • Laboratory analyses • XRD analysis (minerals, pesticides, chemicals) • Composition analysis (organics, carbonate, terrigenous) • Grain size distribution • Average (yearly and monthly) sediment collection

  47. Sediment Traps • Laboratory analyses • XRD analysis (minerals, pesticides, chemicals) • Composition analysis (organics, carbonate, terrigenous) • Grain size distribution • Average (yearly and monthly) sediment collection Total weight of sediment collected Suspended Sediment concentration -Surface Suspended Sediment concentration -Deep

  48. Still to do: • Thermometry in Corals (Calibrations) • Temperature records • Trace elements (Sr/Ca U/Ca Mg/Ca Ba/Ca) • Stable Isotopes (O and C)

  49. Conclusions:(Preliminary) • Significant differences in coral cover between impacted vs. non impacted sites (up to 10%). • Successful transplantation (7% loss by concrete failure). • Significant loss of colonies moved to impacted sites (14 -18%). • 4% of the colonies moved to non-impacted sites died (coral grazers, transplantation procedure ?). • Most of the coral loss at impacted sites were primarily affected by overgrowth by turf algae. • Siderastrea siderea, Montastrea cavernosa, Colpophyllia natans, Porites asteroides, and Porites porites showed resistance to stress.

  50. Conclusions:(Preliminary) • Similar coral growth rates between impacted vs. non-impacted areas. • Transplantation procedure did not influenced the growth rates (control colonies). • Statistics needed to explore differences in growth rate between sites and before and after transplantations. • Seasonal variability in terrigenous vs. carbonate sedimentation at Escollo Negro. • Seasonal and event driven variability in sedimentation input into the bay (redistribution). • More to come ……..

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