We've been traversing the Papāhanaumokuākea Marine National Monument for over a week now--traveling from the Main Hawaiian Islands to French Frigate Shoals, Maro Reef, and now at Pearl and Hermes Atoll--and we've seen and learned so much. With such a large undertaking into a remote place like the Northwestern Hawaiian Islands, we are constantly reminded that our first priority is safety and health. During our first days of transit from O'ahu to French Frigate Shoals we spent a lot of time familiarizing ourselves with safety protocols and emergency procedures--as well as learning to navigate with our sea legs. That last part can take time....
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
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
credit: A. Collins, Office of National Marine Sanctuaries
The first stop on our trip was at French Frigate Shoals. It took approximately 3 days of transit to reach the atoll from Pearl Harbor, O'ahu. We arrived at French Frigate Shoals in the evening, and conditions appeared to be in our favor, but on the horizon we could see a building lightning storm and a harbinger for the conditions to come. During the night a squall moved in and we awoke to 6+ foot seas and less than desirable conditions. For a first day out, it was a wild experience. The crew on board the Hi'ialakai is well trained and accustomed to launching boats in all sorts of weather conditions, so we were in good hands, but the wind, swell, and strong current conditions made our research difficult. Personally, I've never been on a small boat being lifted by a crane off a ship into the middle of the Pacific, so this was quite the experience. A good day to dust off and get accustomed to life in the Monument!
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.
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.
 Coral Health Team ASSEMBLE! credit: C. Wall |  Diver Kanoe Steward and a big 'ole ulua. credit: C. Wall |
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 Niño is expected to cause severe bleaching in the Main Hawaiian Islands, with decreased severity in the Northwestern Hawaiian Islands.
 Acropora cytherea at French Frigate Shoals. credit: C. Wall |  A bleached Acropora cytherea (center) and Porites lichen (left) and Porites lutea (right). credit: C. Wall |
At French Frigate Shoals, some coral taxa not found in the rest of the Hawaiian archipelago can dominate select reefs. These corals, such as the tabular (i.e., table form) Acropora cytherea, are in a general sense sensitive to heat stress relative to more robust corals in the genus Porites--you might have seen these corals before (see image above), they look may look like colorful boulders, branching fingers, or encrusting skirts. Indeed, we observed the dominant coral on most of these reefs (Porites lichen) to be quite yellow (nearly florescent in color!), while others, such as the encrusting Montipora corals and branching Acropora were much more pale.
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.
As a scientist working in the Monument, we are concerned about coral bleaching, and whether this area which is has experienced relatively few widespread bleaching events in the past will begin to have more bleaching in the future as the oceans continue to warm. Indeed, the first ever recorded bleaching event in the Northwestern Hawaiian Islands occurred in 2002, and since then two subsequent bleaching events have occurred. Hopefully, this year will not mark a fourth mass bleaching event. For now, we must continue our expedition and data collection in the hopes that by the time we have ended our surveys we will have a better understanding of the physiology, ecology, and "health" of reef corals in the Papāhanaumokuākea Marine National Monument.
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