Immature Bald Eagle harassing gulls at herring spawn off Jamestown Beach, 3/25/22. Photo by Bob Boekelheide
Herring Spawn in Outer Dungeness Bay, March and April, 2022
by Bob Boekelheide
May 2022
Pacific herring (Clupea pallasii) is a classic “forage fish.” What’s a forage fish? Throughout the world, forage fish are super-abundant schooling fish that hold a critical place in the middle of marine food webs. They concentrate lots of energy and biomass from what they eat – mostly zooplankton – into catchable prey coveted by predators like bigger fish, seabirds, and marine mammals.
Pacific herring. Photo from Alaska Fish and Game website.
Besides herring, forage fish include things like sardines, anchovies, juvenile rockfish, and, here in the Salish Sea, sand lance and smelt. These fish are certainly unique and fascinating creatures on their own right, but, like it or not, when there’s a gazillion little fish swimming together, the predators love to eat them. Hence the name “forage fish.”
I admit that I take a predator-centric view towards herring. Large squabbling masses of birds above the water indicate that something big is happening below the water. When the herring start spawning in winter and spring it is a really big deal for predators, providing prey at a time of year when food might otherwise be scarce. It is also when birds must fatten up for migration and the upcoming nesting season.
Between January and April is the time when herring typically spawn in the Salish Sea, releasing their sticky gelatinous eggs into the cold waters around headlands and bays. The eggs cling to eelgrass and algae, where birds pick off the eggs like eating corn on the cob. Tens of thousands of birds may gather at big herring spawns. Fish predators like salmon, halibut, and dogfish sharks similarly attack herring schools and roe from below.
Some birds like Glaucous-winged Gulls and Red-breasted Mergansers feast on the fish, but other birds such as scoters, scaup, goldeneyes, Bufflehead, and Short-billed Gulls (formerly Mew Gull) specialize in gobbling up the sticky herring eggs. Even Brant possibly time their northward migration through the Salish Sea in March and April to get an additional protein hit from herring eggs plastered to their favorite eelgrass and algae. Bald Eagles hang out to steal adult herring whenever they can, mostly from gulls. The eagles may also prey on unsuspecting birds in the feeding flocks, if they can catch them.
Immature Bald Eagle harassing gulls at herring spawn off Jamestown Beach, 3/25/22. Photo by Bob Boekelheide
Unfortunately, herring stocks have declined throughout the Salish Sea over the last 40 years. There used to be a commercial fishery for herring in our local waters, but that stopped when herring stocks dwindled after the 1980s. There has been a regional uptick in herring spawns in just the last couple years, but not in Dungeness Bay, as far as anyone knows.
That’s why on March 24, 2022, while walking on Gibson Spit outside Sequim Bay, I was puzzled to see several large, very active feeding flocks of birds about a half-mile from shore, stretching from the mouth of Sequim Bay all the way north of Graysmarsh. There were also California sea lions and harbor seals swimming about the flocks.
There were several unusual things about these feeding flocks compared to the typical feeding flocks we see in the same area during summer and fall. Other than the time of year, one thing is these flocks sounded different. The gulls seemed to have different voices in these flocks compared with their usual summer flock cacophony. Is that possible? Curiously, I’ve since read that Tlingit Indians in SE Alaska also say that gulls sound different when herring are spawning.
Second, these feeding flocks were scattered all over, not tightly concentrated like the bait-ball flocks we typically see associated with sand lance in summer and fall. Third, there were many more diving ducks in these flocks, but very few of certain piscivorous birds we usually see in fall feeding flocks, like loons, grebes, and cormorants.
The next day, March 25, Gary Bullock and I stopped by Jamestown Beach as part of a monthly raptor survey. The first thing we noticed was a gang of 37 eagles standing along the shore and perched in nearby trees. Next, we tried to count all the mergansers, scoters, Bufflehead, Brant, auklets, and gulls swimming in tight offshore flocks (see https://ebird.org/checklist/S105564183 for our list). Our estimate reached 8,000 to 10,000 birds in the flocks, some feeding, but many others just swimming lazily at the surface, looking fat and sassy. It began to look very much like other herring spawns I have witnessed elsewhere in Washington and British Columbia.
I notified WA Dept of Fish and Wildlife biologists, who, along with the Coastal Watershed Institute, came to check for themselves. WDFW ran a boat survey with expert forage fish observers on 3/30/22, finding herring spawn spread over five miles between the mouth of Sequim Bay and Three Crabs (see map). Herring eggs washed up on Jamestown and Three Crabs Beaches, mostly attached to a type of kelp called Witch’s Hair, Desmarestia aculeata (see photo).
Herring eggs washed up on Jamestown Beach attached to the brown alga called Witch’s Hair, Desmarestia aculeata, 3/29/22. Photo by Bob Boekelheide.
What makes this herring spawn so special? As far as anyone knows, it has been years since there was a significant herring spawn anywhere near Dungeness Bay. Past WDFW maps of herring spawns show their former spawning area was far inside Dungeness Bay, to the west of Cline Spit. The area where they spawned this year is in outer Dungeness Bay and off Port Williams, previously labeled on WDFW maps as a “pre-spawning herring holding area.” Anne Schafer of the Coastal Watershed Institute called this year’s event a “novel” herring spawn, because it occurred at a brand-new area where spawning has not been recorded before.
Washington Dept of Fish and Wildlife herring spawning map, created during their boat survey on 3/30/22. The blue areas are where they found spawning herring. The red line is their cruise track, from the mouth of Sequim Bay (at the bottom) to north of the Dungeness River mouth (at the top).
The intense spawning activity and bird feeding flocks in outer Dungeness Bay continued through the last week in March and into the first week in April. Herring eggs continued to wash ashore along several miles of beaches from the mouth of Sequim Bay all the way to Three Crabs.
Does this mean that herring have now returned to their past glory? It’s certainly too soon to say. There needs to be more years of observations to make sure that this was not a one-time event. Regardless, seeing a large spawning event in our local waters is incredibly exciting, not only for herring, but also for birds and birdwatchers.