On the first day of June, ocean advocates around the world celebrated the very first World Reef Day. The event got me to thinking a little more about the role of corals in the most productive ecosystems around the world, as well as the coral reefs located in our own backyards here in the Pacific Northwest.
“Our goal was to stimulate a global conversation about reef conservation and the simple things we can do in our own lives to make huge changes,” said Theresa Van Greunen of Aqua-Aston Hospitality, one of the sponsors of World Reef Day.
The event was launched with a special focus on Hawaii, but the issue of conserving critical coral habitats has worldwide appeal, with 5.5 million people pledging to use reef-friendly sunscreen and reduce their usage of single-use plastics that can harm the marine ecosystem, according to a news release from sponsor Raw Elements and another from sponsor Hawaiian Airlines. While there were elements of fun in this new event, I guess it does not fit my normal criteria for “amusing,” so we’ll have to settle for educational.
Corals are marine invertebrates that live in compact colonies that can grow into extensive reef systems under the right environmental conditions. The individuals in the colonies are soft-bodied organisms called polyps. Reefs begin when a free-floating larva attaches itself to a rock and begins cloning itself over and over into thousands of identical animals.
For genetic diversity, male and female corals release their gametes all at once as an annual event, apparently timed to the lunar cycle and water temperature, as described on a webpage by NOAA’s National Ocean Service and in a video below. The resulting embryo, called a planula, can float for weeks but eventually settles down to start a new colony if conditions are right.
Some coral reefs, such as the Great Barrier Reef in Australia, take shape over thousands of years. Although coral reefs cover less than 1 percent of the ocean floor, they are rich ecosystems, supporting 25 percent of all marine creatures, according to an interesting summary in the National Geographic video “Coral Reefs 101,” below.
Although we think of corals as growing in far-off places, the
Pacific Northwest is home to all sorts of colorful corals. In fact,
deep-water explorations within the Pacific Coast National Marine
Sanctuary off
Washington’s shoreline have found a reef-forming coral,
Lophelia pertusa, previously believed to exist only in the
Atlantic Ocean, as described in a report by the environmental
group Oceana.
To dive deeper into the corals off the Washington Coast, check out the 2007 cruise report the NOAA ship McArthur II: “Observations of Deep Coral and Sponge Assemblages in Olympic Coast National Marine Sanctuary, Washington” (PDF 3.4 mb). If nothing else, it’s worth a look for the pictures of Washington state coral.
“Even Puget Sound contains hydrocorals scattered throughout its various inlets and islands,” according to the Oceana report. “These corals are living habitats that provide structure on the seafloor for other marine life. Biogenic habitat provides feeding areas, shelter from predators, and nursery for juveniles.
“Trawling in the Pacific Northwest has taken its toll,” the report adds, “both on the fish and their habitat. Targeting flatfish, whiting and rockfish, trawlers have flattened many of the corals, sponges and other living seafloor animals before scientists even knew they were there.”
For the full Oceana report, download “Deep Sea Corals: Out of sight, but no longer out of mind” (PDF 2.7 mb).
Another interesting research project involves the discovery of corals along the seamounts northwest of the Hawaiian Islands, where corals were not supposed to grow. Low carbonate levels had been expected to inhibit coral growth, while pH levels were thought to dissolve coral skeletons. See the news release from Florida State University.
While new discoveries help with our understanding of coral, researchers are desperately concerned about the future of coral reefs, which are dying at an extraordinary rate because of global warming. When local conditions are combined with thermal stress, about 75 percent of the world’s coral reefs are at risk of collapse, according to a report from the World Resources Institute.
Peter Harris, a North Kitsap native recognized worldwide for his expertise in marine ecology, told me last year that coral bleaching, caused by warming waters, is one of the top three concerns for the world’s oceans — even above ocean acidification.
“The world is past the tipping point for coral reefs,” according to Peter, who directs GRID-Arendal, a nonprofit foundation that gathers and synthesizes scientific information to help decision-makers. “We are past the point where the corals are under stress,” he told me. “They will keep dying off.” See Water Ways, June 6, 2018.
Reducing greenhouse gas emissions to slow down the warming would surely help, even as other researchers work on developing more resilient strains of coral that might survive the worsening conditions and eventually repopulate the oceans. HBO’s Vice News has produced an informative 14-minute program on this issue. See the video “Scientists are breeding super coral,” above.
Other general information:
- What is a coral reef? Ocean Conservancy blog.
- On World Reef Day, reminders of what you can do to keep coral safe. LA Times.
- Video: What does coral eat? Khaled bin Sultan Living Oceans Foundation
- Dire state of coral reefs highlighted by first-ever World Reef Day. ABC News.
By the way, this past Saturday — a week after World Reef Day — World Oceans Day was commemorated. Launched worldwide in 2002, the event recognizes the importance of and the declining state of our oceans.
