Why global warming bleaches coral in Hawaii
Warmer-than-normal ocean temperatures around Hawaii could create the worst year ever for coral bleaching, experts say.
Corals have a symbiotic relationship with the microscopic algae called zooxanthellae that live in their tissues, (NOAA). But when the coral becomes stressed due to warmer water, algae leaves the coral, taking with it the coral鈥檚 color and immunity.
鈥淐oral bleaching is the result of a loss of algae living within the coral鈥檚 tissue that provide them with energy and give them their colors,鈥� explained aquatic biologist Brian Neilson from the Hawaii Department of Land and Natural Resources . 鈥淭his loss results in the pale or white 鈥榖leached鈥� appearance of the impacted corals. When corals bleach, they lose a supply of energy and become particularly vulnerable to additional environmental stress.鈥�
Coral have been known to recover from a singular bleaching episode. But if the algae loss is prolonged and the stress continues, the coral will eventually die, warns NOAA.
The islands survived a mass bleaching event in 1996, and another in 2014. However, Chris Brenchley, a meteorologist for the US National Weather Service in Honolulu says this year鈥檚 temperature increase of three to six degrees Fahrenheit will cause
鈥淵ou can鈥檛 stress an individual, an organism, once and then hit it again very, very quickly and hope they will recover as quickly,鈥� , the director of the Hawaii Institute of Marine Biology.
But the reefs might not be the only ones to feel the heat.
鈥淭here is a concern about corals dying from bleaching because degraded reefs diminish shoreline protection and the availability of habitat for fish and other marine species, which negatively impacts ocean-related businesses and tourism, availability of fish, as well as quality of life for humans,鈥� notes the state Department of Land and Natural Resources last week.
鈥淚f we fail to protect [coral reefs] and lose them, it could have tremendously negative impacts not only on the overall ocean ecosystem but on Hawaii鈥檚 economy,鈥� , the chair of the Department of Land and Natural Resources.
, the average annual value of the coral reef ecosystem in Hawaii amounts to $364 million, with 85 percent of that value coming from tourism and a majority of the remaining from property value.
鈥淭hese high numbers certainly indicate that it is worthwhile, both from an ecological and an economic perspective to take care of this valuable resource,鈥� concludes the report.
And although the public can鈥檛 immediately reverse the high oceanic temperatures, Neilson asks people not to add to the coral鈥檚 problems. This means avoiding fertilizing lawns where the chemicals could flow into the ocean and not walking on the reefs. Using pono fishing practices 鈥� based on traditional conservation methods 鈥� could also be helpful to coral reef health.
The state encourages people to report coral bleaching to the volunteer organization so experts can help coral reef ecosystems during this time of high stress.
