There are times during the spring when the area downstream from Willamette Falls at Oregon City looks and sounds a lot like a battle zone - especially on mornings when cracker shells and seal bombs explode in the air, while rubber bullets are fired at sea lions swimming near the falls.
Two days each week, hazing teams from the Oregon Dept. of Fish and Wildlife round up a dozen or more California sea lions and force them down the river under a barrage of fireworks.
Each sea lion can eat up to twenty wild or hatchery salmon a day near the falls. Fishery managers say that's too many of the protected wild salmon.
However, hazing alone doesn't seem to solve the problem. While the teams and their tools are effective at moving the animals away from the falls, the 800-pound mammals will often simply haul out onto nearby docks. Once planted on the docks, the massive animals rest and recover and wait until the morning patrol ends. Then they head back to the river, the falls and the salmon.
John Krauthoefer, a Local fishing guide, said there seemed to be more sea lions than ever in the Columbia River tributaries -- and they seem to have figured out how to catch a lot of fish.
Everywhere you go, you see them, noted Krauthoefer. Fishermen are losing fish and the sea lions are quite good at catching them on their own too, so I think the damage these animals are doing to our fish runs is a lot higher than we realize.
Krauthoefer may be right. Last winter, biologists estimated that several thousand California sea lions evacuated San Francisco Bay and migrated north to the central Oregon coastline near Heceta Head and popular Sea Lions Cave. The massive mammals spent most of the winter there.
The huge herd is part of a population boom that s estimated at more than 300,000 sea lions for the entire the West Coast.
Todd Alsbury, an ODFW Fishery Biologist, said that no one had ever seen such a huge sea lion exodus before. That was also about the same time that they showed up in the Willamette River.
They ve been here since December and normally don t start showing up until the Spring Chinook run is under way, but they re showing up earlier and earlier, said Alsbury. They have found a good source of fish and chosen to come here and set up in this stretch of the Willamette.
But the Willamette River isn t the only Oregon waterway that s seen more snacking sea lion problems than ever before. Until four years ago, the Rogue River estuary at Gold Beach had so many sea lions that people gave up on fishing. According to Denny Hughson, a longtime fishing guide, the sea lions had learned to hunt for fishermen.
It just about shut the sport fishery down, noted Hughson. People were not going to come here anymore to fish. The sea lions learned that when everybody is standing up in the boat and there s a net waving around, it s a free lunch and they head for that boat.
The community took a unique stance to solve their sea lion problem - a problem that had also seen a downturn in tourism.
Local fishermen, both sport and commercial, developed the Curry Sportfishing Association and collected donations to support a three-pronged approach that included a comprehensive, seven-day-a-week hazing program.
They took the strategy even further and installed barricades on many of the docks that the sea lions hauled out on. The barriers prevented the animals from resting out of the water.
They also stopped feeding the sea lions at fish cleaning stations where fish carcasses were flushed into the bay. Instead, the carcasses were trucked to a compost site and converted into fertilizer.
Todd Confer, an ODFW Fishery Biologist, said the three-pronged deterrent worked. There have been fewer sea lions in the bay during peak periods of the salmon runs. As a result, the local community did not kill one sea lion.
Confer said the secret is in the consistency of the hazing and other methods.
To have long term success, you need to make the estuary less hospitable to the sea lions and that s what we did - not only by hazing them, but by disrupting their haul outs and reducing any easy food sources for them, said Confer. It s worked out well without harming them too.
Fish biologist Todd Alsbury said that some of the Rogue River ideas could work in the Oregon City area too. In fact, he said they had already made plans to install barricades on the more popular sea lion haul out dock sites this summer. Next year, they will begin the hazing program earlier and keep at it each day.
We can quickly move them out so that they ll understand this isn t an easy place to come and feed hopefully, we move them further downstream where they won t take so many of the wild fish we re trying to protect, said Alsbury.