[Coral-List] Coral Spawning Report
Alex Mustard
atmu at soc.soton.ac.uk
Tue Sep 23 06:36:34 EDT 2003
Dear all,
Here are our observations from 3 days in Grand Cayman last week. This
was the first time we had observed coral spawning on Grand Cayman's
reefs, and are most grateful for guidance from coral list.
Alex Mustard with staff and guests at Oceanfrontiers Dive Centre, Grand Cayman.
SPAWNING REPORT: Playing Field Reef, East End, Grand Cayman
Location: 1917.567N, 8106.300W
Dates: 15-17/Sept/03
Species spawning: Acropora cervicornis, A. palmata, Montastraea
annularis, M. faveolata, Diploria strigosa, + 2 species of sea rod
gorgonians (have photos but no I.D.s!).
Images available at http://www.soc.soton.ac.uk/GDD/hydro/atmu/coral/1.html
Depth: 5-14 m
Day 1 15/09/03
Sunset: 18:29
Tides H:14:03, L:17:30, H:21:12,
Sea state: waves 2ft, wind 5 mph
A. cervicornis bundle appearance: 20:35-21:12
A. cervicornis spawning: 20:12-21:35 (~20% of popn)
Spawning activity not correlated with colony size.
Day 2 16/09/03
Sunset: 18:28
Tides L:06:26, H:20:20,
Sea state: waves < 1ft, wind 0 mph
2 species of gorgonians spawning 20:45-21:15 (~10% of popn)
A. cervicornis bundle appearance: 20:35-21:12
A. cervicornis spawning: 20:12-21:35 (~10% of popn)
A. palmata spawning 21:45 (1 colony only, 1 observer only!)
Montastraea spp. bundle appearance: 21:40-22:15
Montastraea spp. spawning: 22:15-23:35 (~70% of popn - noticeably all
large colonies)
Diploria strigosa spawning: 22:25 (~25% of popn)
Day 3 16/09/03
Sunset: 18:27
Tides L:07:22, H:20:05,
Sea state: waves 0 ft, wind 0 mph
1 species of gorgonians spawning 20:45-21:10 (~5% of popn)
Montastraea spp. bundle appearance: 21:35-22:05
Montastraea spp. spawning: 22:15-23:35 (~30% of popn)
Diploria strigosa spawning: 22:10-22:20 (~5% of popn)
Same species of gorgonian was spawning again at 22:35-22:50
Siderastrea sidereal, Colpophyllia natans and Montastraea cavernosa
were common on the site but were not observed to spawn. Ophiuroids
spawned at 22:30 on 16 & 17/09/03
State of local reefs: Study site was selected because it had good
coral cover >30%, with all our "target" species present and covering
a reasonable depth range. A. palmata ~5-7 m, A. cervicornis 7-12 m,
Montastraea spp. 7-14 m. Occurrence of disease was low.
Comparison to previous years: we are not aware of any previous
spawning observations on any of the Cayman Islands (sources: coral
list, reefbase.org, peer-reviewed literature databases and talking to
people on the Islands) but expect that there has been. I hope that
this post will help us get in touch with other people who have
observed spawning in the Caymans.
--
Dr Alexander Mustard T +44 (0)23 80 59 60 16
George Deacon Division F +44 (0)23 80 59 62 47
Southampton Oceanography Centre M +44 (0)78 76 52 31 10
European Way, Southampton E atmu at soc.soton.ac.uk
SO14 3ZH, UK
More information about the Coral-List
mailing list