One of the members of the Science Party here on the NOAA ship Hi'ialakai, Andy Collins, wrote up a great piece about life on the research vessel and the experiences of our first few days at sea.
You can read his blog post below...
First Two Days at Sea and Entry Into Papahānaumokuākea
Enough about the boat--what's under the water! We were lucky that on our first day (yes, the difficult day) we were visited by a grey reef shark and a school of ulua aukea (giant trevally) at our first site. A real treat for the first day off the boat! It is always a treat to see megafauna, especially when they are not accustomed to humans and subjected to fishing pressure. Now, as coral scientists we can appreciate fish and the ecological role they play in coral reef ecosystems, but we're really jazzed about those invertebrate reef corals--but fish are cool, too.
Our group of researchers--the Coral Health Team--are looking at coral disease prevalence and indications of coral "health" as it pertains to coral bleaching, pathogen infection, tissue loss or necrosis, and growth anomalies. In my work, I am interested in the bleaching and physiology of corals under thermal stress. We observed some corals to be pale and some bleaching, but this may be within the normal range for corals in this habitat. This is especially pertinent because French Frigate Shoals is the most southern of the atolls we were visit, and this year a heatwave from El Nino is expected to cause severe bleaching in the Main Hawaiian Islands, with decreased severity in the Northwestern Hawaiian Islands.
So what differentiates a "pale coral" from a "bleached coral?" That's difficult to say, because corals do go through cycles of dark and less-dark (or pale) pigmentation throughout the year. Remember, coral paling is a common process observed in summer months, but the large scale bleaching events observed since the 1980s as a consequence of climate change and ocean warming, well these are not natural events. Rather, this is the extreme end of a natural response, where instead of recovering from paling, corals are pushed over their thermal thresholds for prolonged periods leading to widespread mortality and death. The ability to discern a naturally pale versus an acutely stressed and bleached coral often comes form knowing the ecology of the corals at the taxonomic level as well as the history of these corals in the habitats they are found.