By Naomi Klouda
A brown sludgy plankton bloom slogging into small bays that rim Kachemak Bay is raising concerns of how it may impact the delicate filtration systems of shellfish and other marine life.
The plant life is described as 4 or 5 deep in its most concentrated areas.
It can appear foamy, accounting for the milky surface.
So far, this plankton from the group Gymnodinium is thought to be more of benefit than a harm, but scientists won’t be sure until they can have it analyzed in a NOAA lab in North Carolina. Kris Holdereid, the NOAA manager of the Kasitsna Bay Laboratory near Seldovia, was midstride into an inquiry on the root beer-colored plankton bloom. Then came the U.S. federal government shutdown.
“I am not allowed to work on it, not even to volunteer to keep studying it,” Holdereid said.
The phenomenon was noticed during the routine water monitoring program conducted each summer in the bay. NOAA water monitoring biologist Dominic Hondolero and Holdereid were tracking, collecting samples and placing them under a photo-microscope in order to document it. The photo samples would then be sent to an Outside lab for identification.
“We gathered more samples on (Oct. 7). It turns the water brown, like when we had the red water from the red plankton bloom, only brownish, indicating an abundance of that particular bloom,” Holdereid explained.
Fishermen and oyster farmers had called agencies expressing concern.
Clem Tillion, a 60-year resident at Halibut Cove, said that in all his years, he had never seen such a breakout. But he feels certain it is not a harmful event.
“Algal blooms gives our oysters and waters nutrients. Clear water has no life,” Tillion said. “This isn’t necessarily bad, but it’s more than we’ve normally seen. I’ve never seen this much algae. It’s one of the biggest localized blooms.”
Tillion counted four toxic red tide events in Halibut Cove waters over the past 60 years. None were caused by brown plankton.
The monitoring program Holdereid has supervised for several summers looks at how environmental conditions, water temperature, salinity and nutrients impact aquatic life. This baseline of data grows each season.
“We’re trying to understand the patterns. Does it (plankton) help because you have food for oysters and clams? Plankton can also be toxic,” she said. “A warm summer could have impacted it. We’re going to try to tease that apart from the other data. We can’t say conclusively right now. Between Kachemak Bay Research Reserve and NOAA, we’ve been monitoring and have more data now. That’s kind of fun in helping to piece together an understanding.”
The harm to an ecosystem could come when an algal bloom is so plentiful that it causes the bundling of too many organics at once. When the plants die, they sink to the sea’s bottom and decomposition eats up the oxygen that fish and other marine life require.
“That’s unlikely in this case, because here we see a lot of tidal circulation,” Holdereid said.
The challenge in Kachemak Bay is understanding how all the pieces fit together. Using the sun’s energy, small animals like zooplankton absorb lots of food and grow larger.
“Small fish like eating those,” she explained. “Everything likes eating the rich phytoplankton. When it blooms it benefits many other things. At the same time, if there’s too much, you could have low oxygen in some areas.”
Though NOAA, as part of the federal government shutdown, is unable currently to continue the plankton inquiry, the Kachemak Bay Research Reserve is still on the job. It conducts routine phytoplankton sampling, with residents all around the bay contributing water samples. KBRR is a hybrid agency made up of the Alaska Department of Fish and Game and NOAA. Because it is administered by a state agency, its employees are not part of the federal furlough.
Catie Bursch, Harmful Algal Bloom program coordinator, who works for KBRR, heads up the seawater monitoring project. She was already alerted by her monitors to the problem about the same time Holdereid and Honolero noticed it.
Bursch said that the brown tidal plankton is covering a broad area, from Bear Cove to Seldovia Harbor. Some species of this plankton group produce foam, which may account for the milkish film on waters when spotted from a plane.
“At this point, we can’t get it identified to the exact species of plankton. The broad group of Gymnodinium is not on our list of toxin-producing phytoplankton, so we aren’t concerned at this point that it will affect human health,” Bursch said, referring to shellfish that filter-feed the phytoplankton and could be harvested by humans.
Tillion said that he and his daughter, Marion Beck, were nervous when they saw the accumulation of brown stuff spreading.
“It’s like fertilizer — too much can be deadly for your roses, but a certain amount would be helpful,” he said. “Once we did our investigation, I didn’t feel worried about it.”
Bursch said that five people brought in samples for examination from various bays.
“Most of the calls came from Halibut Cove and Peterson Bay, but the bloom eventually has moved to the Homer side, Bear Cove, Kasitsna Bay and Seldovia Harbor and probably other areas that we don’t sample regularly,” she wrote in an update for agencies.
She attached a photo of the dinoflagellate responsible for the root beer-colored water.
“Dinoflagellates are microscopic, single-celled organisms with a fast reproductive rate. They can become so numerous that they can change the color of the water,” Bursch explained. “It is characterized by the two lobes on the bottom half and by being flattened-looking when seen from above.”
Bursch couldn’t say for sure that the plankton won’t cause trouble in some way, because they are so thick.
“The most remarkable thing about the slides I looked at today was that Gymnodinium was very, very numerous and in some there were no diatoms or other dinoflagellates in the water,” she said. “Normally we see more diversity, but this bloom has completely dominated in certain areas.”
Jeff Paternoster, with the Plankton Monitoring Network, was contacted about the bloom before the federal government shutdown. He told Bursch not to send the samples yet, as no one would be in the office to accept a UPS package. Paternoster looked at the photos and agreed with the broad identification, then was ordered home until the furlough ends. Science has no choice for now but to wait for politics to get sorted out.
“We will be sending samples to get identified with an electron microscope down to species when the federal government is back up and running,” Bursch said.
Whatever the algae lumped in Kachemak Bay, the hope is it doesn’t bring environmental damage in the meantime.