Both native and invasive species cause imbalances in nature, according to UW researchers.
“The reality is that there are a lot of species that have always been here that are now in such abundant levels that they are starting to behave very much like invasive species,” said Julian Olden, associate professor of aquatic and fishery sciences at the UW.
Olden and other UW researchers have been tracking data and found that the local populations have been negatively impacting each other to a greater extent than they first thought.
Olden, along with three researchers from the National Oceanic and Atmospheric Administration (NOAA), published a paper last month about these local populations and the harm they are doing, in such abundance, to local ecology and the effects human management have produced — both economically and ecologically.
“The term ‘invader’ is typically paired with adjectives such as ‘non-native’ and ‘alien,’ yet native species can also cause ecological and economic impacts that rival those of well-known invasive species,” they wrote in the paper.
Pikeminnow, seals, and terns discovered that juvenile salmon get bottlenecked in the many dammed corridors along the Columbia River Basin as they head downstream, an all-you-can-eat salmon buffet that has negatively impacted the population of juvenile salmon that reach the ocean.
“We thought of getting salmon upstream but not the juveniles going down,” said Wayne Daley, certified fisheries scientist with a bachelor’s degree from the UW School of Aquatic and Fishery Sciences.
Pacific salmon are protected by the Endangered Species Act (ESA), passed by Congress in 1973, because they are at risk of becoming extinct. Eagles, bears, seals, sea lions, terns, and northern pikeminnow all include salmon as part of their diets.
As humans continue to alter habitats, which result in animals adapting their behaviors to the new environment, humans must ask themselves what’s more important: protecting species or society’s progress, Olden said.
Olden believes humanity needs to ask itself a very important question.
“What does society value more?” Olden asked. “The perceived benefits, for example, to Pacific salmon versus the economic costs of spending millions of dollars to pay fishermen to remove pikeminnow?”
The ethical issues involved are very polarizing, Olden said: The public wants to protect all native species, but they want the species to still be managed.
The ethical issues aren’t just important for our society but also for the Native Americans who have fished for salmon for so long that it has become an ingrained part of their culture and history, Daley said.
Seals, sea lions, terns, pikeminnow, and other animals will have to adapt their behavior to survive.
However, humans continue to change the environments of animals, and issues like these increasingly arise, though scientists continue to attempt a balance between destruction of animal populations and continuing human progress.
“There’s a dazzling array of human inventions being applied [to limited populations],” Olden said. He said there are underwater acoustics to ward off seals and sea lions, rubber bullets if the acoustics fail to work, and relocation efforts for the animals.
Daley said the impacts on salmon populations in the Columbia River Basin radiate along the entire West Coast — north and south — and that the predatory creatures have adapted to human interferences, such as acoustic deterrents and animal relocation.
Daley also noted the same issues occur in the wolf population in Eastern Washington, where state officials decided to terminate all wolves in the Wedge Pack due to predation upon a local cattle farm. The wolves had adapted their behavior because of human proximity, necessitating terminal actions by the state.
Olden said one of the first steps is to admit that there’s a problem, not just among the animal populations but one that starts with humanity.
Daley believes that society has become focused on personal gratification, and that we’ve come to feel entitled to the natural sources around us.
“But it’s not just us,” he said. “We need to think twice about how we treat our environment.”
Scientists are tackling issues that create these ecological problems: In Washington, this may mean finding alternative sources of energy besides dams, resulting in society giving some comforts up. But Olden said that’s part of finding a balance. He believes the current methods seem to be “Band-Aids” that don’t get to the core of the problem: People are modifying habitats that promote these species.
“We’re able to manage things to a certain degree, but sometimes it comes back to bite us in the butt,” Daley said when speaking of seals swimming up the lochs to feast on fish.
These “Band-Aid” efforts include the fishing of pikeminnow along the Columbia River, for which monetary rewards can be great — as much as $8 per fish if a fisherman brings in more than 401 in his catch (which adds up to more than $3,000 per catch). Within the past 20 years, more than 3.9 million northern pikeminnow have been caught in conjunction with the Sport Reward Program, saving an approximate 40 percent of the juvenile salmon population and putting ecology first at the cost of the taxpayers.
Some efforts work better than others, such as trucking juvenile salmon past the predatory mongers directly to the Pacific Ocean. Using screens on fish ladders, which prevent the larger pikeminnow and seals from swimming up into the reservoir lakes, has been effective as well.
Both Olden and Daley agreed there is not only one solution to this problem.
“There is no silver bullet,” Olden said.
Hopefully, with the help of these researchers, a better balance will be found, before key species — and those that rely upon them — are lost forever.
Reach reporter Deanna Isaacs at firstname.lastname@example.org. Twitter: @DeeLiteraryOne
Please read our Comment policy.