Hope for habitat: Salmon symposium addressess watershed issues, how they affect species

PALMER — “Stability and productivity of fish derived systems is basically a result of a diverse, but also changing, landscape. We have to allow these landscapes to continue to evolve. They’ve never been static and any disturbance we impose on them is by making them static. We have to allow them to continue to move around....that’s what’s going to make them resilient over the long run.”

That was the main message from Dr. Daniel Schindler at this year’s 2016 Mat-Su Salmon and Science Symposium. The two-day event was hosted by the Mat-Su Basin Salmon Habitat Partnership and featured almost two-dozen speakers. It focused on a myriad of topics ranging from salmon habitat to the effect of invasive species such as northern pike, and the effects on the fishery by removal of man-made structures to conservation.

Schindler is the chair of conservation at University of Washington’s School of Aquatic and Fishery Sciences. Most of his research focuses on understanding the functioning of watersheds that support Pacific salmon in western Alaska, and the dynamics of fisheries that operate in those watersheds. He is a principal investigator for UW’s Alaska Salmon Program that has studied area salmon ecosystems since the 1940s. Schindler’s ongoing research allows him several months annually to focus on the Bristol Bay area.

Schindler pointed out most of the state’s rivers remain free-flowing. He said absence of dams and other infrastructure allows rivers to meander across their floodplains and in doing so, produce complex mosaics of aquatic habitat generated by erosion and sediment deposits.

“It is increasingly recognized that fishes, and wildlife actively exploit (those changes) and that their resilience to environmental change depends on their ability to access a wide variety of habitat options,” Schindler stated in his abstract

Although Thursday morning’s keynote address was for the most part technical and scientific, the bottom line was simple. Schindler said the most important impact humans are having on salmon habitats are the disturbances put forth in infrastructure projects, as well as the effects of global warming. Regarding infrastructure, Schindler said not disturbing diversity regimes is key. He said fisheries are constantly evolving and changing, whether man interferes or not.

“How do we maintain diversity in landscape?,” Schindler queried.

He said allowing rivers to meander across natural flood plains is key. Schindler said the complexity of that makes it more difficult to work in due to its complexity.

“We’ll never know exactly how it functions, but this is a complexity we should be trying to maintain,” he told the standing-room only crowd gathered at the Palmer Train Depot.

During his approximate 45-minute presentation, Schindler showed cause and effect examples of how varying water depth, caused by both man and nature, can have a major impact on fishery deltas, headwaters and the rivers themselves on a year-to-year basis. He gave examples of how salmon separated by as little as one kilometer of water can be genetically different. Additionally, Schindler supplied data showing how naturally-caused water temperature deviations over a season cause dramatic effects on a salmon river.

Regarding man-made temperature changes, Schindler drew an important observation. He said there is no need to sit around and wait for a scientific consensus to see what the future will look like. We need to act on conservation efforts now.

“If we reverse back to emissions right now to where they were in the 1960s nature is still going to be warmer for the next century,” Schindler said about greenhouse gasses contributing to increased temperature changes across the planet. “We need to do things that are tangible right now...to protect the habitat...enable the fish to have a chance to make a go of it.”

Schindler closed his presentation with examples of man trying to reclaim salmon habitat in the Seattle and San Francisco areas. He demonstrated remarkable changes in a Seattle fishery that occurred between the mid 1800’s to mid 1900’s. He said most options had been taken away from fish sustainability.

“They are spending tens of millions of dollars trying to restore and getting back what was there and in some cases, it’s impossible,” Schindler said. He told the audience that he gave a similar talk in California to the San Francisco Bay Science Symposium.

“There are 1,200 scientists working on a single river. They are putting hundreds of millions of dollars ...trying to scrape and claw back. It’s almost unimaginable,” Schindler said referring to the challenge of trying to get back lost delta habitat in the region. “They’re not going to get the habitat back down there; they just simply aren’t.”

Schindler said in places like Alaska, most of the habitat is still intact and is still functioning. He felt the main focus should be on protecting the disturbances regimes earlier discussed. He said little things like culvert and power line or pipeline placement can have a major impact on fisheries. He put up a picture of a stretch of Chena River where a highway was built alongside it.

“Obviously development is going on here. This should just be screaming ‘what we’ve done is taken away a whole bunch of options for the river and for the habitat,’” Schindler concluded.