funded by sea grant

Funded by Sea Grant

Evaluation of the Effects of Sedimentation and Nutrients on Coral

and the Long Term Monitoring of Recovery after Environmental Stress

Wilson R. Ramírez 1 Jack Morelock 2

1 Department of Geology University of Puerto Rico at Mayagüez

2 Department of Marine Sciences University of Puerto Rico at Mayagüez

Marine Sciences

(Preliminary Report)(Preliminary Report)

Questions :o How can we quantify the effects of terrigenous

sediment and nutrient stress on corals in their natural environment ?

o Is it worth to establish more strict regulations ($$$) on sedimentation / nutrient inputs to reefs ?

o Can reefs recover from the terrigenous sediment and nutrient stress they have been exposed to ?

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.

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.

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

MethodologyThe physiography, bathymetry, sediment texture and composition, and sedimentary facies in the area were characterized.

Methodology

Characterization of reef areas

Methodology

Methodology

Total Coral Cover

Coral coverby species

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

MNMN

MIMI

ALAL

ENEN

Coral Transplantation

Thirteen coral species were studied.

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)

Species were selected base on their coral cover and number of colonies present.

Coral Transplantation

Cementing coral to slab

Finished slab & monitor stake

Coral from Escollo Negro are transplanted to:

Manchas northSewer reefAlgarrobo

Control slab transplant at Escollo Negro

MNMN

MIMI

ALAL

ENEN

Transplant pattern:Healthy environment changed to impacted

environment

MNMN

MIMI

ALAL

ENEN

Transplant pattern:Sediment & Nutrient stressed corals are given clean water environment. The environment has been “cleaned up.”

Manchas NorteManchas InterioresAlgarrobo

corals transplanted to Escollo Negro

From Manchas North slab ID - EN 92From Manchas North slab ID - EN 47

From Manchas Interiores 8 slab ID - EN 50From Manchas Interiores 8 slab ID - EN 62

From Algarrobo slab ID - EN 88From Algarrobo slab ID - EN 83

Escollo Negro control - slab ID - EN 189Escollo Negro control - slab ID - EN 188Escollo Negro control - slab ID - EN 69Escollo Negro control - slab ID - EN 49

To Manchas North slab ID - MN 45To Manchas North slab ID - MN 95To Manchas North slab ID - MN 73To Manchas North slab ID – MN 65

To Manchas Interiores 8 slab ID - MI 26To Manchas Interiores 8 slab ID - MI 187To Manchas Interiores 8 slab ID - MI 80To Manchas Interiores 8 slab ID - MI 16

To Algarrobo slab ID - AL 55To Algarrobo slab ID - AL 77To Algarrobo slab ID - AL 31To Algarrobo slab ID - AL 66

Total of Transplants

“clean” to “stressed”“stressed” to “clean”

Average: 12 colonies per slab

Time Line added to each Transplanted Coral

All corals stained with Alizarin Red-S at the time of transplantation

Measurements of Sedimentation Inputs

Sediment traps were place in all locations

Load-Texture-Composition

Measurements of water temperature

Thermometers were place in all locations

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.

Monitoring:Every coral in each slab inspected bi-monthly

EN 50EN 50From Manchas Interiores 8 to Escollo Negro.

From: Feb. 2002To: Oct. 2002

Monitoring:Changes in coral growth and health recorded

Al 55From Escollo Negro to Algarrobo

Harvesting:• After two years samples of the transplanted

corals were collected to measure:Coral growth rate before and after transplantationTrace elements and stable isotopes in skeletonsOther…

A minimum number of corals were sacrificed. Most samples consisted of 20% of the mass of the coral skeleton.

SUMARY of Results: Coral Mortality

SITE SLAB Transplanted CFCF Remain LOSTManchas North 45 12 12 0

65 12 8 473 11 1 7 395 13 1 12 0

MI-8 16 12 3 5 426 9 4 3 280 8 8 0187 12 1 11 0

Algarrobo 31 13 1 9 355 12 11 166 12 11 177 13 11 2

Clean site (EN) to impacted sites: “clean” to “stressed”

From: From: 139 139 coral colonies transplanted :coral colonies transplanted :

1111 colonies lost by concrete failure colonies lost by concrete failure

SUMARY of Results: Coral Mortality

SITE SLAB Transplanted CFCF Remain LOST % Site %Manchas North 45 12 12 0 0

65 12 8 4 3373 11 1 7 3 3095 13 1 12 0 0 15

MI-8 16 12 3 5 4 4426 9 4 3 2 4080 8 8 0 0187 12 1 11 0 0 18

Algarrobo 31 13 1 9 3 2555 12 11 1 866 12 11 1 877 13 11 2 15 14

Clean site (EN) to impacted sites: “clean” to “stressed”

From: From: 139 139 coral colonies transplanted :coral colonies transplanted :

2020 colonies died during the next two years colonies died during the next two years((mostly because of algal overgrowthmostly because of algal overgrowth))

SUMARY of Results: Coral Mortality

Siderastrea siderea

Montastrea cavernosa

Colpophyllia natans

Porites asteroides

Porites porites

From: From: 139 139 coral colonies transplantedcoral colonies transplanted

99 colonies had measurable increase in size colonies had measurable increase in size

From Clean site (EN) to impacted sites: “clean” to “stressed”

SUMARY of Results: Coral Mortality

SITE SLAB Transplanted CF Remain LOST % Site %

Control 49 12 10 2 1769 12 1 11 0 0188 12 1 11 0 0189 13 1 12 0 0 4

“Clean” site to “clean” site (EN): CONTROL

49 49 coral colonies transplanted as “control” :coral colonies transplanted as “control” :

33 colonies lost by concrete failure colonies lost by concrete failure22 colonies lost during the next two years colonies lost during the next two years (coral grazers)

SUMARY of Results: Coral Mortality

SITE SLAB Transplanted CF Remain LOST % Site %FromManchas 47 12 1 7 4 36Norte 92 12 2 10 83 61

From MI-8 50 12 1 11 0 062 12 12 0 0 0

From Algarrobo 83 11 11 0 088 12 11 1 8 4

Impacted sites to clean site (EN): “stressed” to “clean”

48 48 coral colonies transplanted to the “clean” site :coral colonies transplanted to the “clean” site :1 1 colony lost by concrete failure colony lost by concrete failure 11 colony died during the next two years colony died during the next two years

Manchas Norte samples Manchas Norte samples INVALIDATEDINVALIDATED due to changes in the transplantation procedure. due to changes in the transplantation procedure.

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.

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 83

EN 62

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.

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.

Coral Growth Rates• X-rays were taken of each slab.

12 species At least two species per site (replicates)

Coral Growth Rates• X-rays were scanned and digitally manipulated to

enhance high and low density variations and measure the coral bands.

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)

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)

Coral Growth Gates (cm/yr)Coral Growth Gates (cm/yr)

Mna Mna 0.50.5Mnc Mnc 0.30.3Sds Sds 0.50.5Pra Pra 0.50.5

Mna Mna 0.60.6Mnc Mnc 0.40.4Sds Sds 0.30.3Pra Pra 0.40.4

Mna Mna 0.60.6Mnc Mnc 0.50.5Sds Sds 0.40.4Pra Pra 0.30.3

Mna Mna 0.60.6Mnc Mnc 0.50.5Sds Sds 0.50.5Pra Pra 0.30.3

MNMN

MIMI

ALAL

ENEN

Coral Growth Rates• EN188 From EN to EN - Control Slab

• Porites porites

• Transplantation did not caused significant changes in the coral growth rate.

cm

2000200120022003

TRANSPLANTATIONTRANSPLANTATION

time

Coral GrowthRates• “Clean” to “stressed” sites

• Montastrea cavernosaT

RA

NS

PL

AN

TA

TIO

N

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

EN 690

0.4

0.2

0.6EN to EN Control

Growth rate either remain the same or increased !

Escollo Negro to different locations for Pra

00.20.40.60.8

1

Mn-65 Prareplicado

Mn-65 Pra M18-187Pra

MI-880 Pra

Sites

2003200220012000

Coral GrowthRates• “Clean” to “stressed” sites

• Porites asteroidesT

RA

NS

PL

AN

TA

TIO

N

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

EN 690

0.4

0.2

0.6EN to EN Control

Growth rate decreased.

Coral Growth Rates• “Stressed” to “Clean” sites

• Montastrea annularis

• No significant changes visibleFrom AL to En rate increased slightly ?

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

TR

AN

SP

LA

NT

AT

ION

From EN “ Controls”From ALFrom MI 8From MN

Coral Growth Rates• “Stressed” to “Clean” sites

• Montastrea cavernosa

• No significant changes visibleFrom MI-8 to En rate increased slightly ?

From EN “ Controls”From ALFrom MI 8From MN

Sediment Traps• Laboratory analyses

XRD analysis (minerals, pesticides, chemicals) Composition analysis (organics, carbonate,

terrigenous) Grain size distribution Average (yearly and monthly) sediment collection

Sediment Traps• Laboratory analyses

XRD analysis (minerals, pesticides, chemicals) Composition analysis (organics, carbonate, terrigenous) Grain size distribution Average (yearly and monthly) sediment collection

Sediment Traps• Laboratory analyses

XRD analysis (minerals, pesticides, chemicals) Composition analysis (organics, carbonate, terrigenous) Grain size distribution Average (yearly and monthly)

sediment collection Escollo Negro - Octubre 2002

0.0

0.60.3

5.4

10.0

8.3

5.8

23.2

10.9

5.3

2.0

28.4

0

5

10

15

20

25

30

-1 0 1 2 3 4 5 6 7 8 9 10

Phi

Weight (%)

%

Grain Size Analysis for Escollo Negro

Sediment Traps• Laboratory analyses

XRD analysis (minerals, pesticides, chemicals) Composition analysis (organics, carbonate, terrigenous) Grain size distribution Average (yearly and monthly)

sediment collection

Monthly sediment collection comparison

0

5

10

15

20

Mar-

01

M

ay-

01

Jul-

01

Se

pt-

01

N

ov-

01

Jan-

01

Mar-

02

M

ay-

02

Jul-

02

Se

pt-

02

N

ov-

02

Jan-

03

Months

Weight (g)

Manchas Norte Manchas Interiores 8 Algarrobo Escollo Negro

Stations December 2002 March 2003

Algarrobo 41.06 g 171.49 g

Escollo Negro 23.64 g 447.70 g

Manchas Interiores 8 22.31 g 120.93 g

Manchas Norte 20.36 g 36.07 g

Total 107.37 g 776.19 g

Station #4 - Surface

2.46

1.95

3.89

2.89

7.14

0

1

2

3

4

5

6

7

8

April 01 Octubre 01 Febrero 02 Agosto 02 Febrero 03

Month

Sediment Suspended (mg/l)

Station #4 - Depth

2.98

5.20

4.98

3.57

5.75

0

1

2

3

4

5

6

7

April 01 Octubre 01 Febrero 02 Agosto 02 Febrero 03

Month

Suspended Sediments (mg/l)

Suspended Sediment concentration -Surface

Suspended Sediment concentration -Deep

Total weight of sediment collected

Still to do:

• Thermometry in Corals (Calibrations)

Temperature records

Trace elements (Sr/Ca U/Ca Mg/Ca Ba/Ca)

Stable Isotopes (O and C)

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.

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 ……..

Wilson R. Ramírez,Wilson R. Ramírez,11 Jack Morelock,Jack Morelock,22

Further information on the development of the results will be available at:

PREGUNTAS ? QUESTIONS ?PREGUNTAS ? QUESTIONS ?

1 Geology Department University of Puerto Rico at Mayagüez, P.O. Box 9017, Mayagüez, PR 00861-9017 ramirezwilson@aol.com

2 Department of Marine Sciences University of Puerto Rico at Mayagüez, P.O. Box 908, Lajas, PR 00667-0908 morelock@aol.com

Evaluation of the Effects of Sedimentation and Nutrients on Coral and the Long Term Monitoring

of Recovery after Environmental Stress

http://geology.uprm.edu/Morelock/GEOLOCN_/mayaguez.htmhttp://geology.uprm.edu/Morelock/GEOLOCN_/mayaguez.htm