[Coral-List] Securing markers on permanent transects
Helen Sykes
helenthereef at gmail.com
Mon Feb 23 17:28:09 EST 2009
HI Rashad.
I find steel bar markers diffcult to install, unsightly in tourism areas and
potentially dangerous on shallow reef flats.
I cable tie fishing floats onto the reef substrate, and tag every 5 or 10
metres along the transect with cable ties with the staight ends left
sticking out.
Over time these become covered with coralline algae and so less visible to
the eye who is not looking for it, but are still obvious enough to the
trained surveyor laying a line. So far these have remained on the reefs for
over 8 years if carefully situated in none-brittle areas.
Cattle tags work well too, and can be marked with marker pen.
Helen
Helen Sykes
Director
marine ecology
Fiji's leading company for Coastal & Marine Ecology Assessments
Fiji Coordinator
GCRMN and Reef Check
PO Box 2558, Govt Buildings
Suva, Fiji Islands
tel: +679-336-3625 / +679-359-2136
e: helen at marineecologyfiji.com
web: http://www.marineecologyfiji.com/
-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Reshad
Sent: Monday, February 23, 2009 4:56 PM
To: Coral-List at coral.aoml.noaa.gov
Subject: [Coral-List] Securing markers on permanent transects
Dear list,
I have the responsibility of ensuring consistency of data collection in a
Rodriguan coral reef monitoring programme, that has been under way since
2002.
Essentially we survey reef flat and reef slope benthos, fish and
invertebrates, by repeated measure of three permanent transects, at a number
of sites around the island. We are having problems keeping our permanent
transect markers on several of the reef flat sites, due to the effect of
hydrodynamic forces on both markers and substrate. In the past several
markers have been replaced each year, making our repeated measure of benthos
somewhat questionable. This year it has been suggested we abandon these
sites completely because of the problem. I don't particularly agree with
giving up that easily, and would like to know if anyone has found a more
effective method, than we have, to mark reef transects. We currently have
metre long, 2 cm diameter steel T-bars, driven almost all the way into the
reef structure, but we have also tried drilling into the substrate and
fixing the steaks using concrete. We mark our transects at 0, 5, 10, 15, 20
and 50 m. Most eventually loosen then disappear, some after only six
months. Any information on progress in the field would be most welcome.
Cheers,
Reshad
Reshad Jhangeer-Khan
Science Co-ordinator
Shoals Rodrigues
Pointe Monier
Rodrigues
Mauritius
Mobile: +230 733 1769
Office: +230 831 1225
Fax: +230 831 0287
Email: research at shoals.intnet.mu
Web: http://www.shoalsrodrigues.net
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