How woody debris becomes orca food

Last month, I was lucky enough to tag along with a large group of Yakima River Basin stakeholders to witness firsthand a massive floodplain restoration project in the Teanaway Community Forest that will benefit Southern Resident orcas.

As we arrived at the first staging area, the sounds of a tandem rotor helicopter could be heard long before we could see it. Looking in the direction of the sound, I saw a bundle of large tree trunks lifted into the sky, on their way to their new home in the Teanaway River.

“Why on earth are we dumping logs into a waterway? " you may ask. "And what does this have to do with our Southern Resident Killer Whales?”

Well, let's look at the Southern Resident killer whales and their diet.

Orcas feed at Columbia River mouth

Resident orcas hunt near the mouth of the Columbia River from January to April, which just happens to be the same time spring Chinook are schooling for their upstream migration to their spawning grounds high in the Cascades.

The Chinook’s large size and high fat content provide orcas with the high calories vital to maintaining their health and replenish fat reserves that will get them through leaner times.

Spring Chinook and other salmon species begin their life in streams and rivers that provide clean and cool water spawning grounds. This important habitat is found throughout the Columbia River Basin, including the Teanaway River and its tributaries in the Yakima River Basin.

However, Chinook numbers are in peril. Along with the overall declining numbers of salmon species, the orcas' food source is becoming scarcer and scarcer. The survival and recovery of our resident orca population hinges on an adequate source of food available year round.

The Yakima Basin Integrated Plan and the Teanaway Community Forest

For over a century, loggers and settlers in the Teanaway altered the landscape to meet their needs. This included the removal of woody debris from these waterways to allow for the easy transportation of timber downstream. Their actions degraded floodplains, reduced channel diversity, increased stream incisement, and devastated vital spawning and rearing habitat for both anadromous and resident fish.

In 2013, the legislature appropriated funds for the state to purchase the 50,000-plus acres in the Teanaway from a private landowner. That same year, the Teanaway was designated as the first community forest in the state. Community forests are managed not only for habitat restoration, conservation, and preservation, but also as a sustainable working forest.

As a sustainable working forest, grazing, logging, and recreational opportunities are overseen in a way to avoid critical habitats and restoration areas, while maintaining a healthy ecosystem. Restoration of both upland and aquatic habitat, as outlined in the Teanaway Community Forest Management Plan, is key to restoring the Teanaway’s overall health. This includes floodplains.

By restoring the floodplain, we are also restoring both aquatic and surrounding upland habitats. Flood events are when the magic happens.
During flood events, the logs and root wads placed in strategic locations slow streamflows by forcing the water to move over the wide and flat adjacent floodplain. As the water spreads across the floodplain, it puts its habitat enhancing powers to work.

Floodplains not only help control streamflows during flood events, they also:

• Act as a sponge to refresh the groundwater table
• Provide resting pools for fish
• Increase stream channel diversity
• Reduce flood damage risks downstream
• Create and maintain vital spawning and rearing habitat for spring Chinook and other anadromous and resident fish

The tour

Inspecting Jungle Creek we got a close up look at what appeared to be a healthy stream, with its crystal clear water and a streambed lined with large beautifully rounded rocks. However, its appearance was deceptive of its true health, according to our tour guide, Scott Nicolai with the Yakama Nation. He explained how despite the looks of the stream, it is actually degraded to the point that fish can no longer be supported.

“It’s important to recognize that we are only giving the stream what it needs to recover from decades of degradation, the stream does the rest of the restoration itself (during high flows),” Nicolai said.

Our next stop was at nearby Jack Creek where large logs have already been placed in the stream. This gave us an idea of what Jungle Creek and other creeks will look like once they've been restored with logs and woody debris. The first thing I noticed was how the logs looked like they were always a part of the landscape, blending in easily with the surrounding habitat.

We are eager to see the results of the Jack Creek floodplain restoration once a large flood event occurs.

Project sites

Some factoids 

• More than 80 percent of the Southern Resident orcas' diet consists of Chinook salmon
• The average orca must consume 18-25 adult salmon daily just to meet its energy requirements
• The Southern Resident population must catch a minimum of 1,400 salmon daily to sustain their calorie needs, which adds up to at least half a million salmon a year
• For the population to grow to 140 whales, an allowance of one million salmon a year is required
• Female salmon lay 2,000 to 10,000 eggs; less than one percent survive and return to their spawning grounds to produce the next generation.