Serge Andrefouet serge at
Thu Mar 18 10:55:23 EST 1999

(Sorry for duplicate mails)

Dear Reefsat colleagues:

We have received about 70 replies to our call for input to the Landsat-7
Long-Term Acquisition Plan (LTAP) for coral reef coverage. The messages
were basically of 3 types:

1) Active projects in mapping, coastal management and categorization of the
reefs:in these projects remote sensing was already an identified tool for
mapping, change detection analysis and comparisons. These projects are
already in progress or will be launched very soon.

2) Planned near-term projects: few reefs were identified for new projects
to be implemented around or after the year 2000. These projects have no
clear plans to incorporate remote sensing.

3) Many people identified reefs of interest because of a special feature (high
biodiversity, sensitive reefs because of human activities, sedimentation,
etc.). These messages showed general interest in using remote sensing, but
no specific projects were identified.

Based on this input and on the queries, we conclude that:

- many people are interested in remote sensing but are unaware of the
potential benefits, limits, or how to handle imagery. They need technical
advice and support.

- nobody identified even one reef in all the area of
Indonesia-Philipines-Malaysia-New Guinea-Papua New Guinea. Same is true for
the West Coast of Africa, except Socotra island. Most of the requests were
for Caribbean reefs, US, French or English reefs in the Pacific or the
Indian Ocean.

- We conclude that the reefs with the most important biological diversity
are poorly studied, or rather that our call for input did not reach
managers and investigators of these remote reefs.

Offshore and isolated reefs still have a lower priority for the LANDSAT
program. The bigger constraints in the selection of the sites are technical
constraints, i.e. it is costly to turn the satellite on to acquire one
image in the middle of the ocean. Routine acquisitions over coastal areas
are planned within the existing LTAP, but this still is bound by a
constraint of the numer of images to be taken globally by the US and the
priority given to each Landsat acquisition (not all the land areas are
taken all the time, and acquisitions ARE prioritized in a complex way).
Because of these technical constraints, NASA will only target reefs that
are the focus of active research.

This choice is certainly not perfect because we had to judge according to
the given information, the interest of the site (for other potential
studies), the diversity in human-use and source of danger for reefs
(sedimentation, aquaculture, fisheries, bleaching,
), the regional
representativeness. We are at this stage unable to include projects from
which we do not hear, but they could take advantage later of the existing

Therefore, we have recommended to NASA that:
-Projects in case 1 and some of case 2 above have high priority all year
round (4-6 images per year).
-Reefs that are identified as sites of potential or future projects be
covered twice a year (each season).
-All other reefs should be covered at least once a year, as possible.

The LTAP was updated using the Reefbase inventory. We recommended that
reefs identified in Reefbase should be (ideally) covered once a year.

The highest priority projects that we have identified are listed below
(without any hidden hierarchy) :
Bahamas (Lee Stocking Island, COBOP project: more info at
Belize: barrier reefs and atolls: mapping, change detection, etc.
Bermuda: Bermuda Biodiversity Project, habitat mapping.
Comores Islands: change detection program.
French Polynesia:  (Tuamotu atoll lagoons) aquaculture activities and lagoonal
phytoplanctonic blooms.
French Polynesia: (Moorea island) change detection, community shifts.
Japan, Ryukyu Islands.
Kiribati (Christmas Island): mapping and change detection of cyanobacterial
Maldives: categorization of reefs, sensitivity to sea-level rise and human
use (particularly around Male, Kafu, Vaavu, Alifu and Ari atolls)
Mauritius, Rodrigues and other Indian Ocean islands (Socotra, Shagos,
Mexico: ICZM project on Alacran reef and several Caribbean islands
New-Caledonia:  Province Sud Reefs: Reef Check site, change detection
Oman: south coast close to Masirah island, conservation project before human
activities (fisheries, gas,
) start in the vicinity of this reef
Seychelles: many sites for diverse applications
Vietnam (con Dao Island) and China (Ha Long Bay and Mirs Bay): Reef check
sites, ICZM projects and impact of sedimentation on reefs.

For US reefs: High priority
Florida Keys: Management
Hawaiian islands: Coastal categorization (geology-oriented program), change

US reefs, Low priority (2 images per year)
All US Pacific Islands and atolls
US Virgin Islands
Puerto Rico
Flower Garden Bank

The others low priority reefs worldwide will be published later in our
website. This will include, for each LTAP path/row (the coordinates used in
the Landsat reference system), the reef index and name as shown in
Reefbase, its LTAP priority, and several maps. We hope to update the list
according to weekly or monthly rate of acquisitions, to ensure people are
aware of reef images available worldwide.

We propose to launch a discussion to define standards methods for use of
imagery in coral reef environments. The standards deal with the sampling
strategy on site (adapted for the spatial resolution of the image and the
topic), atmospheric correction, bathymetric correction, bottom mapping,
spectral unmixing, etc. We hope to formalize conclusions from such
discussions in a guide for field and lab work. It will be useful for people
who need advice and people who have already experience in this type of
application but still proceed in heterogeneous ways. Heterogeneous
methodologies do not allow objective comparisons and the emergence of
quality standards. 
As we work on this, needs, ideas and comments from the community are welcome.


Serge Andrefouet
Frank Muller-Karger
Chuanmin Hu
Dave Palandro
University of South Florida / Department of Marine Science

Serge Andrefouet
Department of Marine Science
Remote Sensing/ Biological Oceanography
University of South Florida              
140, 7th Av. South                       
St Petersburg 
FL 33701

phone: (727) 553-1186
fax:   (727) 553-1103
E-mail: serge at

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