Geomorphology, geology and geochemical studies of coral reef limestones of the Truk and Kupp Islands
A Fundamental Approach to Coral Reef Monitoring and ... · Processes Regulating Reef Development...
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A Fundamental Approach to Coral Reef Monitoring and Assessment in the CNMI and American Samoa Marine Biologist Peter Houk PhD Candidate CNMI Division of Florida Institute of Environmental Quality Technology
Transcript of A Fundamental Approach to Coral Reef Monitoring and ... · Processes Regulating Reef Development...
A Fundamental Approach to Coral Reef Monitoring and
Assessment in theCNMI and American Samoa
Marine Biologist Peter Houk PhD Candidate CNMI Division of Florida Institute of Environmental Quality Technology
Fundamental Approach to Monitoring and Assessment of
Reefs
• Processes Regulating Reef Development• Example 1 – Northern Mariana Islands,
CNMI • Example 2 – Southern Mariana Islands,
CNMI • Example 3 – American Samoa
Processes Regulating Reef Development
• Initially, volcanic activity created islands, substrate for reefs to grow
• Location and extent of reef growth are dictated by (Macro-scale Factors) – Temperature – Historical sea level
fluctuations – Tectonics – Wave energy
• Historical Temperature and Sea Level Relationship – Historical growth created
today’s reef structure
Foram fossil cores
Processes Regulating Reef Development
• Tectonic Activities on Rota – Uplifting – Cores identify coral
reef growth in the past – Uplifted Holocene
deposits prevent “normal” Mariana Islands reef flat communities
Processes Regulating Reef Development
• Wave energy – Determines the type of
community growth – Wave energy acts
differently along a depth gradient
Geister, 1977
Munk and Sargent, 1948
Processes Regulating Reef Development
The integrated result that we see is the – reef geomorphology (reef
structure) – Living “organic” reef
Understanding macroecology is key for present monitoring and assessment of coral reefs
Fundamental Approach to Monitoring and Assessment of
Reefs
• Processes Regulating Reef Development• Example 1 – Northern Mariana Islands,
CNMI • Example 2 – Southern Mariana Islands,
CNMI • Example 3 – American Samoa
Example 1 – Northern Mariana Islands
• Situated on active Marianas Ridge
• 1 – 5 million years old • Mostly uninhabited • Few previous studies • Management plans for coral
reefs desired
NMI
0 - 2 cm 2 - 4 cm 4 - 8 cm 8 - 16 cm 16 - 32 cm 32 - 64 cm >
Size Class
Holocene Deposits
Volcanic Boulders
nity Evenness (Margalef s DStat st c) X 10
Population Density Coral Coverage
HoloceneVolcanic
Example 1 – Northern Mariana Islands
• Different present communities from different geologicalsettings
• What processes are acting against thesesettings?
• Is it possible to classify setting beforecompare and contrastsites?
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64 cm
Perc
enta
ge o
f Cor
al C
olon
ies
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Commu ' -i i
?
Example 1 – Northern Mariana Islands
• To begin to understand impacts of feral animals we first use regional Feral
characteristics Animals
– GUG 2, ALA 3 have living, organic reef situated mainly on limestone reef deposits, not volcanic rock
– wave energy No Feral Animals
Example 1 – Northern Mariana Islands
• Several coral community measuresshow little difference between sites
• What is impact of feral animals compared with naturalcommunity regulationprocesses at thissite?
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Community Evenness (Margalef's D-Statistic)
Population Density Geometric Diameter Coral Species Richness
GUG - 2
ALA - 3
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0 - 2 cm 2 - 4 cm 4 - 8 cm 8 - 16 cm 16 - 32 cm 32 - 64 cm > 64 cm
Size Class
Perc
enta
ge o
f Col
onie
s ALA-3 GUG-2
Fundamental Approach to Monitoring and Assessment of
Reefs
• Processes Regulating Reef Development• Example 1 – Northern Mariana Islands,
CNMI • Example 2 – Southern Mariana Islands,
CNMI • Example 3 – American Samoa
SMI
Example 2 – Southern Mariana Islands
• Increased complexity in geological settings – 1) Antecedent,
Holocene Deposition (indicator)
– 2) Pleistocene or earlier only (indicator)
• Wave energy consideration
Example 2 – Southern Mariana Islands
• Holocene (recent) deposits not related to exposure
• Deposits = topographic complexity, result ofsediment trapping
• In circular nature, topographic reliefprovides refuge fromscouring physicalenvironment, and continues to build
Holocene
Deposition
No Holocene Deposition
Example 2 – Southern Mariana Islands
• Living organic reef community
– Favia, Leptastrea, Pocillopora account for >30% of measured coral
– * = significant difference – = no significant difference 0.00
2.00
4.00
6.00
8.00
Acr
opor
a
Ast
reop
ora
Favi
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Gon
iast
rea
Lep
tast
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Mon
tipor
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Pavo
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Poci
llopo
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Pori
tes
Styl
opho
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Cor
al P
opul
atio
n D
ensi
ty (#
per
m2 ) Holocene Deposits
No Holocene Deposits
*
** **
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*
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0 - 2 cm 2 - 4 cm 4 - 8 cm 8 - 16 cm 16 - 32 cm 32 - 64 cm Geometric Diameter Size Class
% o
f Col
onie
s
Favia, Holocene Deposits Favia, No Holocene Deposits
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0 - 2 cm 2 - 4 cm 4 - 8 cm 8 - 16 cm 16 - 32 cm 32 - 64 cm Geometric Diameter Size Class
% o
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Leptastrea, Holocene Deposits Leptastrea, No Holocene Deposits
with Holocene deposition
Exp
osur
e Fa
ctor
(rad
x m
)
Example 2 – Southern Mariana Islands
• Wave energy considerations– Holocene reefs From NOAA buoy data – P. rus dominant reefs in
extremely sheltered locations
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Y = 7.81 - 1.38x R2 = .52
N4
2
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Quadrant Exposure Direction Exposure Degrees Average Wave Height (m) 1 N - NE 0 - 45 1.5 2 NE - E 45 - 90 1.4 3 E - SE 90 - 135 1.2 4 SE - S 135 - 180 0.7 5 S - SW 180 - 225 0.7 6 SW - W 225 - 270 0.7 7 W - NW 270 - 315 0.7 8 NW - N 315 - 360 0.9
0.0 1.0 2.0 3.0 4.0 5.0
Log Abundance of Porites rus (cm2)
Example 2 – Southern Mariana Islands
• Porites rus dominance, lower species diversity in extremely sheltered regions expected =
Example 2 – Southern Mariana Islands
• Macroecology information required before assessments of land based disturbances and such
• Compare site in questions with regional information
• Use watershed characteristics, stream flow rates, water quality data, and others, to complimentreef community data (sitespecific studies)
?
Talakhaya Watershed, Rota Island
Turf Algae Cover
Coralline Algae Cover
Fundamental Approach to Monitoring and Assessment of
Reefs
• Processes Regulating Reef Development• Example 1 – Northern Mariana Islands,
CNMI • Example 2 – Southern Mariana Islands,
CNMI • Example 3 – American Samoa
Example 3 – American Samoa • Watershed based
management and water quality monitoring
• Reefs used as bio-criteria indicators to water quality health (EPA guidance)
• Simultaneously, initiate long term monitoring baseline
Arrows indicate similar geomorphology
Example 3 – American Samoa
• Similar geomorphology at Aoa, Leone, and Alofau
• This setting allows for larger corals, greater coverage, dueto stable abiotic environment
• NOT imply “better condition”(low community evenness)
• Stability ≠ Diversity
Example 3 – American Samoa • Size Distribution of Coral
Colonies
• Multivariate exploratory techniques (Multi-DimensionalScaling), using coral relativeabundances
Houk, Didonato, and Iguel, submitted EMAS
Example 3 – American Samoa • Compare Sites with same
regional characteristics • Coral cover crude indicator
for reef health assessment based upon coral community
• Community evenness • Geometric diameters • Overall diversity Acropora clathrata
Houk, Didonato, and Iguel, submitted EMAS
Conclusion • Environmental settings
are important forunderstanding living reefs
• Elucidate processes that regulate coralcommunities
• Gain regional understanding to providecontext for local assessments
Aguijan Island, CNMI
Conclusion
• Through monitoring we greatly enhance the ability to properly manage and protect coral reefs
• Thanks to: – US Environmental Protection Agency – CNMI Division of Environmental Quality – CNMI Coastal Resources Management Office – American Samoa Environmental Protection Agency – CNMI Marine Monitoring Team – NOAA MARAMP, NOAA CREI Division
