Tentacle Extension in Pachyclavularia Coral Under Deoxygenated Conditions
Bergen County Academies, Villanova University, USA.
Geena S. Kye, Mrs. Clare Kennedy, “Tentacle Extension in Pachyclavularia Coral Under Deoxygenated
Conditions”, American Research Journal of Earth Science, Vol 3, no. 1, 2023, pp. 5-10.
Abstract
Coral reefs are ecosystems that provide shelter to a variety of marine life, but they are deteriorating at an unprecedented
rate. While factors like pollution and climate change have long been recognized as stressors to coral, the effects of ocean
deoxygenation on coral have not been as deeply studied. Many commercially important fish, such as grouper and snapper,
are dependent on the coral reef. Reef-related fisheries in the United States are valued at more than $100 million. The
purpose of this study was to examine the effects of deoxygenation on the coral species Pachyclavularia violacea. As an
indicator of coral health, tentacle extension was monitored using mobile timelapse-photography recordings taken over a
period of 5 hours. Marine water from the tank was deoxygenated using the GastTM
DOA-P704-AA High-Capacity Vacuum
Pump. Two hundred (200) milliliters of water was added to the tank in which the coral was stationed; the control group
receiving oxygenated water and the experimental group receiving deoxygenated water. It was anticipated that there
would be some tentacle retraction due to the disturbance of the water column, unrelated to the oxygen saturation.
The control group had a 32.5% reduction in tentacle extension compared to the experimental group at 59% reduction
immediately following addition of the water. The average recovery was 20.9 minutes for the control group and 53.1
minutes for the experimental group. Based on these results, the conclusion that can be drawn is that coral fragments
(P. violacea) are impacted by deoxygenation of immediate surrounding water. Future research will focus on completing
additional trials to minimize confidence intervals and determine the hypoxia threshold for the recovery of P. violacea
fragments. Long-range growth studies of corals grown in deoxygenated water should be a follow-up study.
