The fight over using man-made chemicals to control burrowing shrimp in Willapa Bay has now been going on about three times longer than the Trojan War — close to three decades. Like that ancient conflict, the great Willapa pesticide controversy pits two diametrically opposed world views.

On one side are the bay’s traditional shellfish growers. Essentially farmers who plant their crops of oysters and clams on Willapa’s privately owned tidal mudflats, they practice a farmer’s kind of conservation. Resistant to disruptions of established business practices, they have worked hard to keep commercial development away from the waterfront and contaminated runoff out of the water.

They played a key role in pushing for better septic treatment in Pacific County and led the charge against invasive spartina — which threatened to transform the bay into a vast expanse of worthless grass. They regard chemical sprays like that used to eradicate spartina and the one proposed to curb a burrowing shrimp population explosion as an unavoidable necessity, no different than a farmer spraying weeds or harmful pests.

On the other side are a growing number of Pacific Northwest residents who sincerely believe there is no safe level of artificial pesticide, especially in water. The Washington Toxics Coalition succeeded in obtaining a 2003 settlement to phase out use of the pesticide carbaryl by 2012. Used in the bay since the 1960s, carbaryl remains an option for controlling fleas on pets, but came to be regarded as too harsh in an aquatic setting. That set off a scramble for a different way to control shrimp, which smother oysters by churning up sediment while digging and maintaining burrows. To use a farming analogy, it is like planting tomatoes only to have them buried beneath countless gopher mounds.

There are literally billions of these native shrimp in the bay. Inedible by humans, they are far out of balance in the environment.

Some craft-scale oyster operations manage to get along without spraying, as do some very large ones. Taylor Shellfish, by concentrating on the specialized half-shell market and by operating across a large geographical area, was able to walk away from spraying in the face of intense political pushback in 2016 to the proposed replacement for carbaryl. A chemical similar to nicotine, imidacloprid was tested and found to be considerably less impactful than carbaryl. It initially won state approval for use against shrimp. A Seattle newspaper columnist fired up opposition to it — fairly predictably, considering it has been implicated in honeybee die-offs. The bay isn’t a hangout for bees, but anything that can be labeled a “neurotoxin” was certain to stir an urban backlash, even if those neurons belong to shrimp.

In many ways, the facts are the side of Willapa’s mainstream shellfish growers. Environmentally, imidacloprid is a big improvement on carbaryl. It doesn’t contaminate oysters or clams. Tideland treated with it recovers a healthy and nutritious biological film, a foundation of the bay’s natural food chain that is wrecked when there are too many shrimp. The state ecology agency was all for imidacloprid, and then wilted like a sprayed dandelion in the face of urban politics.

This is a case when the facts apparently don’t matter. It’s clear that the state’s top elected leaders, starting with the governor, are unlikely to ever go along with spraying. They believe such a decision would cost them support from a segment of the population to whom all pesticides are evil.

So, what’s next? State Lands Commissioner Hilary Franz has cobbled together potentially helpful funding to increase experiments on other control mechanisms, such as mechanical harrowing of infested tidelands. Considering the softness of the surface, successful use of heavy equipment is hard to envisage. But every idea deserves to be explored.

As Taylor and others have shown, there are ways to rear oysters off the silty bottom. However, these methods typically involve greater labor costs and use of man-made materials — often plastics — that come with their own practical, economic and regulatory drawbacks. Most Willapa oysters are sold to be prepared in recipes, not on the expensive half-shell. Any alternative growing method has to keep prices at a level acceptable to the class of consumers for whom oysters are an occasional meal option and not a splurge while standing at a bar.

A few pesticide opponents are sanctimonious know-it-alls, but others have the potential to offer constructive support to keep Willapa’s farmers on their tideland. The industry must do a much better job of building alliances, finding new ways to survive until better answers are found.