Record herring-spawning whitens area waters


Nearly two years after a herring-spawning event whitened the waters of Discovery Bay, history is repeating itself with what the Coastal Watershed Institute in Port Angeles described as  “record levels” of herring spawning in the Salish Sea, over a period of at least two weeks as of March 18.

While the Washington Department of Fish and Wildlife recorded “very light” levels of herring spawn in Quilcene Bay as of March 17, that same survey showed “medium-heavy,” “heavy” and “very heavy” levels of herring spawn in Dabob Bay, just off Brinnon.

The Coastal Watershed Institute supplied The Leader with photos of herring spawn covering the underwater vegetation of WaWa Point, also just off Brinnon, which led to a convergence of scoters and gulls feeding on the herring spawn at WaWa Point on March 15.

Even farther south, the CWI captured images of eelgrass beds covered with herring spawn at the eastern Agate Passage on March 17, which had already turned those waters white on March 12.

The CWI’s Anne Shaffer explained that “white water” is the colloquial term for the milt sprayed by males to fertilize the newly laid eggs.

“Scores of marine mammals and thousands of birds congregate to feed on the thick carpets of eggs laid on eelgrass and Sargassum seaweed along the shore,” Shaffer said. “The eggs are still developing but will soon hatch, marking the beginning the 2020 spring plankton season that, in turn, supports the rest of our Salish Sea food chain.”

Shaffer credited Adam Lindquist and his fellow members of the Department of Fish and Wildlife with diligently mapping the spawn distribution—“Be sure and say ‘thank you’ to them for their dedicated, prompt, heavy-lifting field work in these unprecedented times.” He also noted that landowners, including Kirie Petersen and Brian Whitlock, have provided “dedicated, accurate and timely” updates of “these uplifting events.”

Shaffer elaborated that the herring eggs, and those feeding on them, can be seen at low tide at nearshore, “an uplifting time and place that brings everything together again.”

Shaffer freely admitted that researchers such as herself don’t know the reason for this upswing in spawning, but she expressed confidence that the improved ocean conditions, as well as the Salish Sea-wide restoration actions over the past decade, have “undoubtedly” contributed.

Such a prodigious herring spawn brings with it a “myriad of benefits,” Shaffer said, starting with the herring shoals feeding scores of diving birds and marine mammals.

“The eggs are providing critical resources for sea ducks—surf scoters are the most abundant—allowing them to make their last leg north to Arctic breeding grounds,” Shaffer said. “This migration is timed in part to this spawning.”

The herring spawn is also timed to the start of plankton blooms as the daylight hours grow longer.

“Once the herring larvae deplete their tiny yolk reserves, they not only are plankton, they feed on plankton,” Shaffer said. “Just about everything feeds on plankton.”

Zooplankton, which includes juvenile herring, is a critical link between systems in the marine world, since newly emerging chum and Chinook salmon, which are themselves critical for orca recovery,  feed on zooplankton.

“As the herring grow, they become the target for larger predators, from flounder, ling cod, salmon, rockfish, murres and alcids to humpback whales,” Shaffer said. “The young herring stay in the nearshore from the time of their hatching—when they migrate from their natal spawning grounds of eelgrass and shallow Sargassum and Fucus understory kelp beds—until the late fall, when they head to deeper water. The following spring, they come inshore, shoal up to the nearshore and spawn again. Brilliant!”

On March 22, the CWI shared its monthly photo of the Elwha nearshore, “a beautiful moment in an unprecedented time,” but asked those from outside the region not to visit until the coronavirus crisis is over, citing the number of local and regional parks that have either closed or gone on restricted use.

“And yet, the visitor counts are at record levels,” Shaffer said. “These are likely folks displaced by spring break travel disruptions and school closures, and drawn by the ‘social distance in nature’ messaging playing on media now. The problem is, the area is literally being overwhelmed with out-of-area folks, and it’s straining, and likely risking, our small and remote community health and resources.”

As such, if you don’t live on the Olympic Peninsula, Shaffer asks you stay home until this has passed.