White coral on local reefs now ’norm’
Dozens of east side residents spent the majority of their weekend — two weekends ago — in the ocean, sifting through rocks looking for octopus and sea urchins. Fathers and sons were seen bonding as they cast their nets into the water, waiting for fish.
Some men came prepared, with goggles and a bucket, knowing for sure that Sunday to’ona’i was going to feature whatever the catch of the day was going to be.
The salty smell of the sea lingered in the air as the ocean floor was exposed to passersby. The tide was so low, that coral and rocks were visible several yards out to sea.
A decade ago, the sight of exposed coral and rocks would have been picturesque; but not this time. Coral bleaching is such a problem in the territory, that looking at white coral on the reef is becoming the new norm.
According to the Department of Marine and Wildlife Resources (DMWR), coral in American Samoa are stressed due to the recent spike in sea temperatures between December 2016 and January 2017, the same timeframe when the territory was experiencing extremely hot weather conditions.
“Preliminary spot checks indicated moderate bleaching (10 to 50%) in the deep waters (10 meters), and more intense bleaching in shallower areas occurring at the moment,” according to information received from DMWR.
NOAA’s Coral Reef Watch predicts that sea temperatures may continue to rise.
The extremely warm water has caused coral to bleach (turn white), hence the term “bleaching”.
“Coral is a unique animal that can only survive with the presence of zooxanthellae, a tiny algae cell that lives inside the coral and provides food for it to grow. Coral bleaching occurs when this relationship is strained, primarily due to rising sea temperatures. The heat stress causes the coral to expel the algae living within it, making it very difficult for the coral to receive enough nutrition. These algae cells give the coral most of its color; so once they are expelled, the coral tissue turns translucent and the bright white skeleton can be seen through it.”
In addition to rising sea temperatures, other stressors that can cause coral bleaching include disease, sedimentation, pollutants, and change in salinity. If the stress continues for an extended amount of time, the bleached coral will die. This is because after losing the tiny alga cells from its tissues, the coral starves.
According to DMWR, “The death of our coral will have a negative effect on the functioning of our reefs, including our fish populations, which rely on the corals for shelter and food. Healthy reefs support healthy fish populations, which benefits everyone in American Samoa.”
The Fisheries Local Action Strategy group recently met to discuss a monitoring plan to assess the impact of coral bleaching. The group is composed of members representing various agencies under the Coral Reef Advisory Group of the Department of Marine and Wildlife Resources (DMWR).
“Recovery of our coral is increased, if healthy living conditions are fostered for these organisms. The sea temperature has dropped with the recent cool weather, which has offered some relief to the coral.
“Cooperation from the community is also essential in the process of recovery. Careful management of land produced waste and water runoff is crucial to support and nurture the health of our vulnerable reefs and fisheries.”
If coral in your village waters has turned white, please inform Maria Vaofanua and the crew of DMWR’s Education and Outreach Division at 684-633-4456.
More information about sea temperatures and coral bleaching can be found online at <HYPERLINK "https://coralreefwatch.noaa.gov/"https://coralreefwatch.noaa.gov>