Last weekend Richardson Bay was treated to a herring run. Herring are small ocean fish that feed on plankton and aggregate in large schools. In the Pacific ocean, where these fish live, sea lions, sea birds and whales including humpbacks and minkes are major predators. Today they entered Richardson Bay’s shallow water to lay their eggs en masse, in eel grass beds found in the shallows of the bay. They employ a reproductive strategy based on overwhelming predators with numbers. Today thousands of gulls were after their eggs, and seabirds and sea lions the fish themselves.
Herring were once one of the more important fisheries in Europe, their schooling behavior and predictable spawning in calm waters made them easy to harvest. They are considered a very sustainable fishery because the fish reproduce and mature quickly. Unfortunately development and pollution have decimated their nurseries- estuaries like Richardson Bay. And like all fisheries they have been over harvested and are always on the verge of collapse.
I was able to photograph the event- here are pictures of a few herring and the marine life feasting on the bounty the herring bring.
One can only imagine what this spectacle would have been like prior to the arrival of Europeans. The bay, even though it was settled with native Americans, was full of life in numbers we can’t imagine. It would have been amazing to witness, reports from the 1700s related that migrating birds darkened the sky, flocks so large they blocked the sun. In the bay salmon runs up the Sacramento were so thick with fish that early visitors said it appeared they could walk across the river on their backs. Sea otters carpeted the bay in rafts so dense and expansive that explorers noted the surface of the bay was black for vast stretches.
Today’s run was big by modern standards, but spawning takes place under water, so casual observers only see large aggregations of birds. The most conspicuous participants were gulls, on the bay by the tens of thousands, bobbing in the shallows, pulling up eel grass, eating it and the eggs it bore.
Sea lions and harbor seals got their share of fish, to the point that by day’s end they could eat no more, and the pelicans were more or less in the same shape when I got on the water as the afternoon wore on. The fish were not visible, due to the low tide and a shallow muddy bottom, but I was able to get a glimpse of them courtesy of a Fish and Game research crew.
A DF&G survey crew from Santa Rosa was sampling fish to check the general health and reproductive status of the herring, doing so enables them to monitor the population and adjust fishing regulations to actively manage each species.
They were using a transparent mono-filament gill net, weighted at the bottom, it was an invisible barrier that the fish get stuck in as they try to swim through it. The take I witnessed had quite a few jack smelt and a couple of grunions.
The DF&G folks said they have seen grunions in the bay for five years, even though they are not expected this far north. The team leader also said he caught more smelt on one net placement than he had seen in four years. They returned the smelt to the bay as fast as they could free them from the net, they were only after herring.
The gulls, which are not by nature diving birds, were amazing. As the tide fell they congregated in shallow water where they could dunk down deep enough to grab blades of eel grass and the eggs attached to them. The eggs are about a millimeter in diameter and translucent.
They would leap up from the surface of the water a foot or two and dive just under the surface, to the point their tails would still protrude out of the water, then bob right back up.
Gulls are noisy birds, thousands of them in a dense flock, fighting for food was raucous, everyone close enough to hear the noise came to watch.
Lots of people watching, or coming and going on such a beautiful day.