July 25 – August 1 is Coral Reef Awareness Week!
Kuaihelani has a barrier reef nearly 5 miles wide with 580,392 acres of submerged reef and ocean. The reef and lagoon are home to over 200 marine invertebrates, 29 species of stony coral, and 266 species of fish, many of which are endemic to the Hawaiian islands. They also provide habitat and food for ‘ilio-holo-i-ka-uaua (Hawaiian monk seal), nai‘a (Hawaiian spinner dolphins), and honu (Hawaiian green sea turtle).
Unfortunately, a new species has been discovered that is posing a risk to the reef.
Chondria tumulosa is a red algae that was first discovered at Manawai (Pearl and Hermes Atoll) in 2015. By 2019, it had drastically spread. It covers the reef in thick, intertwining mats which smother and kill the coral. When fragments break off, the small pieces can reattach elsewhere and grow. Such an effective colonizing ability meant that it was able to spread to Kuaihelani. Currently, we do not know where the algae originated from but as it is not present elsewhere in the Hawaiian archipelago, there are concerns about it spreading or accidentally being carried to other islands.
A team consisting of researchers from NOAA, the University of Hawai‘i, and the College of Charleston, spent the past two weeks traveling within and outside the lagoon searching for Chondria. To help us identify the invasive algae, the team took USFWS staff, volunteers, and KUPU interns out to one of the locations where it was found, as seen in the video below. The reddish-brown algae seen on the rocks is Chondria, but other species and coral are still managing to poke through. The fish are not eating the Chondria, rather the invertebrates among it.
So what does that mean for us?
Being discovered only a few years ago, there are still many unknowns. For now, we are still figuring out how to prevent the spread of Chondria. As a part of their time here, NOAA is experimenting in how to ensure that any left on equipment is effectively killed so it doesn’t find its way to other islands. We are also keeping our eyes peeled for any species that may consume or control it, such as the collector sea urchin (featured at the end of the video).
-USFWS Volunteer Percy Ulsamer