It's not top news: coral reefs around the world are in a desperate state as a consequence of habitat destruction, marine pollution and climate change. One year after the disastrous tsunami following the Tohoku earthquake 11 March 2011 hit Japan, scientists now fear for one of the most unique and beautiful areas in the Pacific Ocean: the Hawaiian Islands.
Debris from the Japanese tsunami catastrophe threatens to collide with the northwestern islands' reefs, probably the world's largest intact coral reef system and one of the last apex predator-dominated reef systems still in existence.
Papahanaumokuakea, as the area is called in reference to traditional Hawaiian cosmology, has been declared a U.S. National Monument in 2006 and is listed as a UNESCO World Heritage Site since 2010. Situated some 155 miles northwestern of the main Hawaiian archipelago, it comprises many small islands, atolls, shoals and reefs, submerged banks, seamounts and deep water habitats; covering an area of 14, 000 square miles, it is, surpassed only by the Australian Great Barrier Reef, the second largest marine protected area on the planet.
Over 7,000 species inhabit the islands and waters of Papahanaumokuakea, and, according to reef ecologist David Gulko, up to 50% of them are endemic to the NWHIs. The tiny islands provide critical space for nesting and foraging to millions of seabirds, and some already endangered species like the Hawaiian Green Turtle ( XXXX) or the solitarily living, highly threatened Hawaiian Monk Seal use them as breeding and nursing grounds.
Though biodiversity is comparably low in the subtropical Northwestern Hawaiian reef systems since the region is relatively young in a geological sense, they exhibit an astounding level of endemic life, due to their geographic isolation and the lucky circumstance that they have so far gone largely unaffected by human activities. 17 of the 57 coral species described in the region are endemic; they account for up to 53% of coral life thriving in Papahanaumokuakea. What makes the place so unique is its nearly pristine state: Whereas the reefs and marine areas surrounding the Main Hawaiian Islands are gravely impacted by environmental, anthropogenic stress, the remote and wild ocean lands of Papahanaumokuakea have been largely spared from degradation. The fish are greater in size and number, large apex predators like jacks and reef sharks prevail, and also numerous whales and dolfines come to the marine protected area for breeding and calving.
Yet, global warming does not halt at the artificial lines drawn by U.S. or international authorities:
Coral bleaching, a consequence of the loss of zooxanthellae (micro, photosynthetic protozoa that live in symbiotic relationships with corals and also give them their color), along with an increasing number of coral diseases such as Black Band Disease or MWS, Montipora White Syndrome, which have been emerging over the past years and already have led to major destructions in Caribbean reef systems (according to the CRC Reef Research Centre, Caribbean coral has been diminished by 80% in the course of the last 20 years due to such diseases) are very likely the consequences of human-induced climate change and the resulting, progressive acidification of ocean waters.
Marine pollution and floating debris, too, have long before Japan's tsunami been posing a serious threat, as much as anything, to the Hawaiian Islands and the surrounding reef systems: The Hawaiian archipelago is located exactly between what are called the Great East, respectively West Pacific Garbage Patches, huge areas of marine flotsam held in place by the ocean currents of the North Pacific Gyre. According to American oceanographer Charles Moore, who also coined the phrase "Trash Vortex", an area possibly twice the size as the continental U.S. carries approximately 100 million tons of "trash", the great majority of it being tiny, often nano-sized plastic particles that have proved impossible to track via satellite and sometimes are even hard to discern with the naked eye when observed from a boat. Junk thrown off ships and oil platforms, mainland waste and an estimated 10, 000 containers lost each year at sea add to the massive amount of rumble circulating in the oceans and frequently washing up on all shores around the globe, including far away and often hardly accessible locales such as Northwestern Hawaiian's Kure atoll.
Fishing gear, plastic bottles and caps, pellets and nurdles, footballs, lighters and all sorts of household items would litter Hawaiian beaches like Kamilo or Kahuku virtually by the tons if local engagement didn't arrange for regular cleansing actions along affected shorelines; for some, the fuzz about the new wave of plastic expected to carry the tsunami debris to the shores of Hawaii seems almost absurd in the face of the huge amounts of garbage already polluting the area. Debris from the Japanese Tohoku event however appears to be of a slightly different nature: large objects such as refrigerators and television sets, even boats and fishing vessels are possibly heading for the region and could, colliding with the underwater structures of the NWHI, cause grave physical damage to the fragile reefs; also the possible impact of radiation-contaminated waste on the region's delicate ecosystems rings alarming to many.
Tsunami wreckage (the Japanese government talks of 25 million tons of rubble; how much of it has entered the ocean and is still afloat remains unclear) could hit the archipelago any of these days. The National Oceanographic and Atmospheric Administration NOAA and the U.S. Wildlife and Fishery Service are closely monitoring the area.