Ku’ulei Rodgers is a coral scientist at the Hawaii Institute of Marine Biology. Dr. Rodgers told us that many sea creatures depend on coral. Her work is to assess the health of Hawaii’s coral reefs, and she said that, because of changes in ocean chemistry, Hawaii’s corals are growing less robust.
Ku’ulei Rodgers: One of the main things that we found is that there will be a net ecosystem calcification loss. And this means that the reefs will be dissolving.
And the reefs will be dissolving faster, she said, than they can build back up. Rodgers explained that’s partly because carbon dioxide is increasing in the atmosphere and being absorbed by the world’s oceans. As a result, the oceans are becoming warmer and more acidic. This acidity, she explained, makes if more difficult for corals to produce the material they use to build their skeletons. Rodgers said this makes reefs more susceptible to stress and disease.
Ku’ulei Rodgers: Once ocean acidification occurs, you’re going to see more fragile coral skeletons. Some of the more sensitive species of corals will be completely eliminated.
She added that, unless drastic measures are taken to curb carbon dioxide emissions worldwide, severe damage to coral beds will almost certainly occur in Hawaii, and worldwide. Rodgers explained that the marine creatures who live in Hawaii’s reefs are truly dependent on coral.
Ku’ulei Rodgers: Some species are obligate coralovores. They eat only coral and can’t survive without it. Other fishes, and other marine organisms, use the reef for protection. And then other species rely on those species. So it’s a cascading effect. Once you get rid of the foundation, you’re going to have a problem with all other trophic levels.
She added that corals are sensitive to changes in the ocean.
Ku’ulei Rodgers: Corals live within 1 to 2 degrees of their summer maximum temperatures. Anything beyond 1 to 2 degrees for extended periods of time, and they begin to bleach, and they eventually die.
Rodgers said that Hawaii’s corals have survived two recent bleaching events due to changes in ocean temperatures – one in 2002 and the other in 2004. During a bleaching event, the corals turn white, because the algae-like organism responsible for giving corals their color and nutrients is expelled from the coral. The Hawaii reefs have recovered from these events, but Rodgers is concerned that increasing temperatures and ocean acidity will permanently damage the reefs.
Ku’ulei Rodgers: When corals are stressed, then they’re more likely to have disease come in. Here in Hawaii, we have located 8 different diseases in the main Hawaiian islands, and another 10 diseases in the northwestern Hawaiian islands. As the corals lose resilience due to bleaching, higher temperatures, and ocean acidification, diseas can come in, although we are seeing them at very low prevalence now.
Our thanks today to NOAA Pacific Services Center – linking culture, science, and people to build resilient Pacific Island communities.
A friend of mine laments the death of coral while diving in Fiji on her blog:
http://awaypoint.spaces.live.com/blog/cns!C0984D45E2D3590C!1570.entry
I find myself hoping we won’t be discovered by other intelligent life in our universe, given the way we treat our fellow species on this planet.
I truly believe Ku’ulei Rodger’s observations are valid and are are telling us something about the state of the coral’s environment but I challenge how the problem is framed and its implied solution.
I’m not convinced that water temperatures and acidification poses as much of a threat and would pose no lasting threat if it weren’t for the host of local assaults on the coral’s environment that result from mankind’s modern activities. Destructive storms, shifting warm ocean currents, periods of ocean chemical changes have been the environment coral evolved in. However, nothing in their evolutionary path prepared them to adapt to industrial pollution, over fishing and its resulting imbalance on the local ecosystem, silting from construction run-off, and humans marching around on top of them.
Much of the limestone deposits around the world are made up of ancient coral. Indeed geologic record clearly demonstrates that coral flourished in periods of much warmer and more acidic oceans that we have today. Many studies I’ve read (Scopelitis et al., 1989, 1997, and 2003 to name one of them) concluded that coral is quite resilient to devastating natural events, climate variability, changes in salinity and pH levels. Their pattern of recurrent recovery is remarkable.
We need to look beyond the convenience of making the observation fit the science du jour headlines and realize that there’s far more going on in the coral beds than the statistically insignificant warming and acidification of the oceans. We need to understand the local impacts of man’s activities and take action to reduce it through highly targeted changes in land use policies, improvements in industrial waste processing, run-off management, and more effective management of the local ecosystem. Otherwise, we can only wring our hands, throw money at grossly over-generalized [non] solutions that offer no real impact on the observed problem, and wait on world politics to solve the problem for us – which isn’t going to happen.
The local community needs to be re-engaged and see it as a local problem they can do something about. As long as bleaching of coral beds is framed as a global problem, requiring a global political solution, the local community will continue to ask “when will world leaders do something about it” and remain disengaged waiting for the answer.
Oops. I meant to say “Indeed geologic record clearly demonstrates that coral flourished in periods of much warmer and more acidic oceans [than] we have today.”
I believe that we needn’t imagine how such corrals survive so terrible conditions!it’s only our responsibility to return our diversity.
It’s also happening to the great barrier reef here in Australia.
The way we treat the world everything will die. Things do need to change people!
I’ve read the same too in other article. I think that it’s inevitable :( And we can’t change it already
it is already happened. it can’t be change!