The tiny, sticky globes begin to reveal themselves in clusters as the tide rolls out, easily missed by a passing glance. Stoop down to take a closer look, and they appear first in smaller groups. Then hundreds, thousands, then millions of them come into view, clinging to blades of eelgrass and vegetation as flocks of seagulls eagerly peck at the shoreline, looking for the miniature snacks.

They’re herring eggs that in a historic spawning event appeared on beaches stretching along the length of Agate Pass earlier this month. The sheer number of them is somewhat of a mystery, a welcome one though, as numbers of the critical forage fish have declined in Puget Sound over the last few decades.

Massive schools of herring have been seen teeming in the waters of the passage off the Suquamish waterfront in recent days, said Jon Oleyar, a fisheries biologist with the Suquamish Tribe, as the fish returned in waves to spawn along the shoreline, leaving behind the huge swaths of tiny eggs in an area stretching from Indianola west toward Lemolo across to the northern side of Bainbridge Island.

Oleyar said he’s spoken to tribal members who haven’t seen an event of this size: “Some of them have lived here for 60 years or more and they haven’t seen this before. This is pretty historic.”

“Hopefully it means they start coming back in more regular, concentrated numbers like in the past,” Oleyar said.

“This is absolutely a good sign,” he added. “All I can say is that as we start to see some of our salmon stocks dwindling, baitfish in huge numbers like this is a really encouraging sign. This is one of the key food resources for the salmon in Puget Sound and out on the ocean too, are herring. The more herring we have I can only assume will hopefully bolster our salmon stocks, too.”

Dwindling numbers

The state’s Department of Fish and Wildlife has surveyed the local population, known by researchers as the Port Orchard-Port Madison stock, every year but one since 1975, so it's possible to track the rise and fall of the fish locally. A survey crew will go out on a boat and use a rake-like instrument with curved tines to draw up eggs in the area they’re mapping and use what’s collected to estimate the total biomass of the population.

The largest estimation came in 1987, when the population was figured at around 2,300 metric tons. As recently as 2016 and 2017, surveys of the local population were unable to detect any spawning, said Phillip Dionne, who leads forage fish research and monitoring for WDFW. In 2019, an estimation put the spawning stock back at around 1,900 metric tons, which made it the second largest population in Puget Sound and roughly a quarter of the total herring biomass regionally, he said.

The numbers this year might be even higher. Dionne said surveying will most likely reveal a number even higher than last year’s. He said he wouldn’t be surprised if the 2020 figure became the largest on record.

The event is encouraging, but it’s not unusual for the fish’s population to swing wildly, making a broader view of the numbers important.

“What remains to be seen is if this is a continuing trend for several years,” Dionne said. “There’s so much volatility in herring stock naturally. To say this stock has recovered, I’d refrain from that for a few years until we see that trend continue.”

So why the big event now? It’s a bit of a mystery, although there are a few factors that could be at play, marine experts said. Could the recent full moon have played a role? Did predators, like sea lions, herd the fish into the area? Were the conditions right out in the ocean for more plankton, setting up a larger return? Did some fish come from another population?

“We could guess that there are probably favorable ocean conditions for them, abundant food that’s led to them having a big abundant run,” said Steve Todd, a salmon recovery biologist with the Suquamish Tribe. “It could also be that the eelgrass beds and other vegetation are beginning to recover in certain areas.”

The trend line for herring populations in Puget Sound has generally pointed down over the last few decades, largely because of a steep dropoff in the spawning stock at Cherry Point, north of Bellingham, Dionne said. Fish and Wildlife's largest survey estimate in Puget Sound came in 1980, at around 20,200 metric tons, he said. Last year that same number was roughly 7,900 metric tons.

What is encouraging to Dionne, is seeing strong numbers outside of Hood Canal. Prior to 2019, he said, researchers had seen a trend of more than 50% of the total Puget Sound biomass concentrated in the Quilcene Bay area.

“We get concerned when all of our eggs are in one basket,” he said. “It’s a better sign that things are on the right track when we have multiple stocks with high numbers rather than just one stock.”

Herring sit below predators like salmon on the food web, making their health one of the vital signs for the Puget Sound ecosystem more broadly. Their increased numbers is a good sign for salmon in the form of more abundant food, but they also indirectly benefit juvenile salmon: predators that might have been chowing down on salmon might instead eat herring, Dionne said.

“Herring is the primary forage fish in Puget Sound,” he said. “All the way up the food chain, if herring are doing well, we expect to see that ripple through rockfish, salmon, sea birds, marine mammals and orcas, all the way to the top.”

Nathan Pilling is a reporter covering Bainbridge Island, North Kitsap and Washington State Ferries for the Kitsap Sun. He can be reached at 360-792-5242, nathan.pilling@kitsapsun.com or on Twitter at @KSNatePilling.

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