PORT ALLEN — While conducting a recent diving tour along Kaua‘i’s southern coast, a diver made an alarming discovery: a field of dead heart sea urchins on the ocean floor.
“It’s a massive die off of urchins,” said Linda Marsh, owner of Bubbles Below Kaua‘i dive company. “This is a dive site we normally go to, and this die off is a sudden thing. We have seen evidence of it miles away.”
Marsh, the veteran diver who made the find, called in a report on Feb. 3 to Don Heacock, Kaua‘i’s biologist for the state Department of Land and Natural Resources Division of Aquatic Resources and to Thierry Work, wildlife disease specialist for the U.S. Geological Survey’s National Wildlife Health Center in Honolulu.
“We’re always concerned when urchins die because of what happened in the Caribbean,” Work said. “The Caribbean has lost 80 percent of its coral. The massive coral die off was preceded by a massive die off of urchins. They are a keystone species and an early warning system for large-scale changes in the ocean.”
Marsh led Work and Heacock to the dive site on Feb. 5, and the biologists began a two-day field investigation that included surveys and sample collections. They documented 149 urchin shells littering a 25- by 4-meter sandy stretch, Work’s USGS Port Allen trip report states. Sixty-eight percent of the mortalities were skewed to the smaller (younger) classes.
Dead urchins were found 241 meters southwest and 147 meters southeast of their dive boat moored offshore but, ultimately, the area was too large to fully survey, even with underwater scooters. Based upon their observations and available data, they estimate 52,000 individual heart urchins have recently died off.
The biologists collected 28 specimens of sick and dying urchins. Seventeen of them were suitable for further analysis and sent to California to be processed for cross-section microscopic examination.
“I did see something like this in the past in Johnston Atoll because of a protozoan infection,” Works said. “That’s the only other urchin die off I’m aware of.”
The cause of the Caribbean die off of urchins and coral was never determined, Works said, but what they do know is that urchins play a critical role in the health of coral reef ecosystems and that population crashes may have “important upstream consequences.” Urchins are grazers that keep the algae at bay and a food source for other marine creatures.
They are also useful in laboratories to measure and test toxicity because they absorb chemicals directly through their shells, Heacock said. Because they are highly eco-sensitive, they are the equivalent of “canaries in an oceanic coal mine,” he said.
Heacock hypothesized that genetically modified seed corn crops and related chemicals used for their abundant production along the west and southwestern shores of Kaua‘i may be a contributing factor.
“We can only speculate about what’s killing them right now,” he said, “but here’s something to think about: Kaua‘i produces more GMO seeds than anyplace. Now, there are a whole bunch of people in the genetic engineering camp that say GMO crops need less pesticides, but the new wave of crops is more toxic than ever before.
“The BT corn is meant to kill,” Heacock said. “It has an insecticidal protein in the corn. In the Midwest, they found the residue from GMO corn is related to aquatic insect deaths, which are food for baby fish.”
Kaua‘i seed companies constantly till and grub their soil, which is full of these chemicals, he said. When it rains, the loosened red topsoil flows into streams and rivers that eventually flow out into the ocean and onto coral reefs.
Works said that during his dives near Port Allen the water was cloudy but not red or silty.
“Cloudy water does not mean pesticides,” he said. “It’s easy to start spinning stories. What we need is hard data. This is a detective type of story, with a crime scene and a dead person. We don’t want a preconceived notion to determine what killed the victim. The ideal thing is we arrive at a cause of death, but often times we can’t figure out what killed them. We can figure out what didn’t, such as infectious disease,” Works said.
“Even though what happened in the Caribbean looks similar, I’m not saying it will happen here. We’re just trying to stay ahead of the curve. The major message to the public is to report their findings. We have Eyes of the Reef Network reporting online for unusual mortality events. This particular event we never would have known about without Linda Marsh.”
Marsh said, “It’s a really good thing dive companies are keeping an eye on this and reporting it. We took the right step forward by contacting Thierry and Don. Hopefully, we can stop the point-source pollution.”
The Eyes of the Reef Network website is www.reefcheckhawaii.org/eyesofthereef.htm. To reach the Department of Health Clean Water Branch for Kaua‘i, call 241-3323.
• Vanessa Van Voorhis, staff writer, can be reached at 245-3681, ext. 251, or by emailing vvanvoorhis@thegardenisland.com.
