[Coral-List] Peace Corps- Micronesia: Impacts of coral dredgingoperations in Yap State

Cotter.Patrick at epamail.epa.gov Cotter.Patrick at epamail.epa.gov
Mon Dec 20 08:30:34 EST 2004

Hello Lisa:

I read your email with great interest, and John McManus' recommendations
are very valuable.  In responding to you, I am forwarding your request
for assistance to my colleagues at the U.S. EPA's Regional Office in San
Francisco, CA and Honolulu, HI.  John McCarroll, Nate Lau & Patricia
Young are familiar with environmental projects in the Pacific Islands.
Dr. Wendy Wiltse works on environmental and coral reef projects in
Hawaii.  Brian Ross and Allan Ota are experts in dredging operations.
Perhaps they may have some advice on environmental concerns or
restrictions on dredging operations to assist your management needs.

>From 1979-1981, I was a U.S. Peace Corps Volunteer working in Barbados
on marine park development and management.  Uncontrolled dredging and
filling in beach and nearshore areas of the island was the number one
killer of nearshore coral species, no matter how successful the species
were at handling small to moderate concentrations of sediment.  If the
government resource managers of Yap recognize that value of its coral
reefs for many needs, perhaps they will be receptive to requiring
mitigation measures for dredging and disposal operations.

I wish you luck in your U.S. Peace Corps work,
Patrick Cotter

Patrick J. Cotter
International Affairs Specialist
U.S. Environmental Protection Agency
Office of International Affairs
Mail Code 2660R, Room 31124
1300 Pennsylvania Ave., NW
Washington, DC  20004

Office: (202) 564-6414
Fax: (202) 565-2409
Email: Cotter.Patrick at epa.gov
Website: www.epa.gov/oia

             John McManus                                               
             <jmcmanus at rsmas.                                           
             miami.edu>                                              To 
             Sent by:                 "'Lisa Kristine Johnson'"         
             coral-list-bounc         <johnsolk at gmail.com>,             
             es at coral.aoml.no         coral-list at coral.aoml.noaa.gov    
             aa.gov                                                  cc 
             12/17/2004 11:35         RE: [Coral-List] Peace Corps-     
             AM                       Micronesia: Impacts of coral      
                                      dredgingoperations in Yap State   

Hi Lisa,

An important point about I-P corals is that if the coral patches have
previously been subjected to periodic siltation, then the corals growing
there will probably not be able to tolerate any substantial amount of
(enough to stay on the corals for more than a day). Large Porites heads
to try to evict the silt with mucous, and if the currents are not strong
enough, the mucous-silt mess will kill underlying polyps. Other corals
suffer various forms of damage.

If the coral community is in a chronically very silty area, it will
likely be predominantly Goniopora, a coral with long polyps that can
the silt. Branching corals (Acropora) tend to be sparsely branched and
stretched out, so that sediment does not accumulate on branches. Several
other corals are silt tolerant, but all seem to have ways to remove the
and few of those are found abundantly (at least in the same growth
forms) on
non-silty reefs. Basically, if you see sediment on any coral that lasts
than a day, there is cause for concern. And, of course, lower levels of
sediment can reduce light, which isn't a healthy thing to do either.

Sorry that I cannot give you water turbidity levels, which won't mean
unless one understands the current patterns and velocities, wave action,
etc. My approach would have more to do with monitoring the corals.

Note that silt often includes nutrients -- so watch for seaweed growth
algal blooms. If the dredging becomes periodic, the resilience of the
may be impacted even if the corals are not directly affected. In other
words, the next storm might break corals and new ones may no longer
out-compete seaweed for settling space. Or-- the seaweed may actually
over the corals.

Good luck!


 *** Please note new phone numbers (361 now 421) ***

John W. McManus, PhD.
Professor, Marine Biology and Fisheries
Director, National Center for Caribbean Coral Reef Research (NCORE)
Rosenstiel School of Marine and Atmospheric Science
4600 Rickenbacker Causeway, Miami, FL, 33149
305-421-4814, 305-421-4820,       Fax: 305-421-4910
jmcmanus at rsmas.miami.edu

-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Lisa
Sent: Thursday, December 16, 2004 10:19 PM
To: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] Peace Corps- Micronesia: Impacts of coral
dredgingoperations in Yap State

Dear Coral List serv recipients,

I am a new Peace Corps Volunteer in Yap State, FSM working with the
EPA.  My new colleagues have asked for assistance in assessing the
long term effects of dredging operations around the island.  I am just
getting started with this project, and am faced with obstacles such as
limited academic resources on island and, unfortunately, my background
not being in this field (during my masters I was focused on crustacean
muscle biochemistry/physiology).

There have been about 10 dredging operations since the 1960s in Yap,
with one currently underway- about 3 months left, according to the
operations manager.  The dredging operations are for the purpose of
attaining material to pave roads around the island.  Permits, granted
by the EPA Board, are contingent upon daily monitoring of turbidity by
the Public Works engineering office and weekly submissions of these
readings to the EPA.  (However, daily monitoring of turbidity nor
weekly submissions occur as the permits require...)  The EPA Board has
not yet set turbidity limits, although they are open to

I have read that turbidity around living corals should be no greater
than 10 mg/cm2/d.  Dr. Chris Perry's Feb. 2004 list serv comment
regarding siltation and turbidity around corals acknowledged Rogers,
1990 (Marine Ecology Progress Series 62: 185-202) as as good review on
the topic but warned that this is a complicated issue, and that
Indo-Pacific corals are adapted to varying levels of sedimentation
stress.  Would anyone be willing to assert an opinion regarding
acceptable turbidity limits some distance away from the "mixing zone"?

The long term effects of dredging on this small, marine
resource-dependent island is of grave concern, and I am really
committed to this issue and helping the EPA Board make educated
decisions about granting/or not granting permits in the future- or
possibly not allowing dredging at all, although ideas concerning an
alternative means of acquiring road paving materials would need to be

This study will be conducted by comparing sites- the dredging site
currently in progress, to sites that have been completed, to sites
that have not been dredged, but are potential sites to be approved by
the Board.  Information to include would be water quality
measurements, coral surveys (with the help of a crew of people from
the EPA office and the Yap Marine Resources Management Division),
underwater photo and video footage of sites, and interviews with local

Does anyone have any advice about this subject/project? sources to
suggest?  I am currently using John Clark's Coastal Zone Management
Handbook (1996, CRC press) as a guide, but I know that there must be
information out there on this topic, and I would like some advice.

Thank you!  Kammagar!
Lisa K. Johnson
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