Ready the Cannons! Salmon Passage Solutions In The PNW

 You may have heard someone say that you can't solve every problem with a sword. While that may certainly be true, I'm ascribing more and more to the idea that a ton of problems can be solved (at least partially) with a cannon.

This story involves a lot of interesting parts: machine learning and artificial intelligence, endangered salmon, competing interests and technologies, invasive species, novel and adaptive conservation techniques, stakeholder challenges, economic concerns, and yes, a salmon 'cannon'.

A Washington State Dept. of Fish and Wildlife employee loads a tule chinook salmon into the cannon in Washougal, WA. Image taken 9/23/14. Image Credit: AP
https://www.idahostatesman.com/news/local/environment/article234369752.html

I'm from the Pacific Northwest, so salmon have always been a part of my life to some extent. I grew up near Flaming Geyser State Park (the 'flaming geyser' is more of a candle-sized flame; gotta hand it to the marketers,) which surrounds a portion of the Green River in Auburn, Washington. I used to wander the trails and take in the forests for hours some afternoons while in community college. Every Fall as the leaves were turning, the hordes of returning salmon began slowly working their way upstream. If you don't mind the smell, it's a remarkable experience to just sit and take the whole scene in. While the bodies of salmon line the shores, still more fish meticulously trek on with an admirable focus. Some seem out of some sort of zombie film; white specks of fungus dotting the dull grey of what was once vibrant reds and silvers. Still others somehow remain mobile despite decaying flesh hanging from their bodies. And yet, some seem still unchanged: for one reason or another, or maybe none at all, there's more time in their hourglass. In thousands of rivers and streams across the Pacific coast, millions of salmon make similar journeys, leaving their oceanic feeding grounds to spawn inland.

A spawning coho salmon on the Salmon River, Oregon. Notice white patches of fungus. Image Credit: Bureau of Land Management Oregon and Washington
https://www.flickr.com/photos/blmoregon/

I'm going to breeze through a few million years of evolution in a few paragraphs. Most people in the U.S. and East Asia have at least a basic idea of the lifestyle and reproduction habits of Pacific salmon, and for our East Coast and European friends, the Atlantic salmon shares a similar lifestyle (one interesting difference being Atlantic salmon don't always die after spawning.) So let's take a quick look at what makes salmon special enough to jettison them through a tube at high speeds.

A Master of Two Worlds

'Anadromous' is a term for fish who spend part of their life cycle in salt water and part in fresh water. For most saltwater fish, fresh water will kill them, and vice versa for our freshwater friends (Euryhaline is the term for fish which can live in a range of salinities, while Stenohaline fish require a relatively specific salinity to survive.) Salmonids happen to be both anadromous, and euryhaline. The physiological changes required for fish to pull off a transition from fresh water to salt and back again is no joke. The biggest changes involve adjusting the osmotic pressure, and specifically the sodium pumps, of their bodies cells to match that of the water they are moving into (here's a breakdown for the biology nuts.) Simply put for those of you like me: while in fresh water, a fish's cells can pump in sodium. When entering a saltwater environment however, the cells must transition to pumping out sodium instead, in order to maintain osmotic balance. The bodies of salmon are specially designed to undergo such transitions.

Saltwater fish (yellow jack) Image Credit: Wikipedia

Freshwater fish (brown trout) Image Credit: Wikipedia

This allows for a number of cool behaviors that are not possible for other, less transmutable aquatic creatures. Rivers, as far as most fish inside them are concerned, can be considered closed ecosystems. The amount of nutrients available is determined by the physical and geographical nature of the river itself, and any life inside these rivers must make due with what is available. In a sense, there is only so much food to go around. This factor limits the size, density, and many other aspects of the life each river can sustain. To make a long and fascinating story a short and somewhat boring one, salmon are able to break free of this closed system. At some point in their evolutionary history, salmon decided that they were tired of being limited in size and stature by their puny rivers, and made the daring move to grow big in the high seas. An interesting move for the salmon, and a gamechanger for the rivers they inhabit.

As we know, salmon don't just leave home to live off the fat of the sea forever. For some bizarre and awesome reason, they decide to come back after a few years (depending on the species). It's not just a trip to their grandfish's house either. Some salmon will travel over 2,000 miles, covering over 30 miles a day against rapids, currents, predators, and everything else the rivers can throw at them. After spawning, the Pacific salmon complete a process they literally began en-route (returning salmon can no longer digest food, and they stop eating): they die, leaving their carcasses to line the rivers they called home.

A bald eagle feasts on a salmon. Image Credit: Jerry McFarland
https://www.flickr.com/photos/56509109@N04/

The salmon's story, though somewhat macabre, is a defining one for the rivers they inhabit. Every salmon that enters the ocean acts as a sack of nutrients (aren't we all?) They live their lives, nourishing themselves on seafood, then bring it back to their rivers of origin and drop it all off when they die. This provides an immense amount of sustenance to the rivers. So much so that, according to some estimates, trees near salmon-bearing streams receive almost 25% of their nitrogen from salmon. Incredible considering salmon only come once a year. Basically, salmon act as conveyor belts for bringing nutrients far upstream, especially nitrogen and phosphorous. Salmon are also vital for the oceans. If you include eggs, juveniles, and adults together, salmon are involved in the food webs of over 50 species of mammals, birds, and fish, whose notable members include bald eagles and the endangered Southern Resident Orca Pod.

While their contributions to their environment make them a defining keystone species, these fish also play an integral role in the communities which depend on them. It is impossible to understate the importance of salmon to the native communities which have lived alongside them for thousands of years. For the tribes of the Northwest, salmon remains an integral food source, a source of spiritual and cultural identity, a means of passing down traditional cultural and ecological knowledge, and much more. Drying, smoking, salting, pounding, and underground storage are all used to preserve meat allowing it to keep for long periods. As such, dried salmon became the dominant trade good for coastal groups, and found its' way far inland where it was often traded with other native groups inhabiting the Great Plains. The Lewis and Clark expedition first report tasting salmon upon reaching the Lemhi Shoshone people of central Idaho, convincing them that they were indeed approaching the Pacific Ocean.

Native Americans fishing at Celilo Falls on the Columbia River. The falls were a tribal gathering spot for thousands of years. They were covered under 40 ft of water after the construction of The Dalles Dam in 1957. Image Credit: A. Davey
https://www.flickr.com/photos/adavey/

After the Indian wars, when many tribes were forced (often under duress or false pretenses) to sign treaties with the U.S. government, the rights to fish for salmon at their ancestral lands became a line in the sand. The Treaty of Point Elliott, signed in Washington State in 1855, reads:

“The right of taking fish at usual and accustomed grounds and stations is further secured to said Indians in common with all citizens of the Territory, and of erecting temporary houses for the purpose of curing, together with the privilege of hunting and gathering roots and berries on open and unclaimed lands. Provided, however, that they shall not take shell-fish from any beds staked or cultivated by citizens.”

Treaties signed by tribes in the Columbia River basin, western Washington, and the Great Lakes region all contained similar language. There was relatively little conflict between tribes and non-native settlers for decades after these treaties, largely due to the continued health of the salmon fisheries. By the 1960's however, after the construction of dozens of dams along major rivers of the U.S., salmon populations had decreased substantially, and many native communities dependent on them were hurting. The saga of the Grand Coulee Dam is a prime example. It's construction flooded native communities and sacred lands, including burial grounds, displacing thousands. Even more destructive, the dam was constructed without fish passage, meaning no salmon could return to the upper Columbia River. This cut off 645 river miles of salmon habitat from the Columbia, which nearly doubles when including the tributaries formerly utilized by the salmon. Tribes upriver of the dam were completely cut off from their way of life. The Spokane Tribe has not held the 'First Salmon' ceremony in almost 70 years, and are still fighting for compensation for their incredible losses. While fisheries have stepped in to fill the void in the upper Columbia, the numbers pale in comparison to the lost wild stocks.

Flight of the Dammed

Things were probably pretty great for salmon for a few million years. So good that when Lewis & Clark came upon the Columbia River in 1805, they remarked that the nearby streams were so thick with salmon, one could almost walk on them. But things change, and just over 200 years later, dozens of salmon runs across the West Coast are now in decline; with populations listed as endangered or threatened. You can only legally buy farmed or otherwise cultivated Atlantic salmon in stores. What happened to the salmon is pretty obvious (in a word: dams, lots and lots of dams.) What's also fairly obvious is why the clear solution (not having so many dams) has been such a struggle. I'm not going to focus on dam removal in this piece, even if it is indisputably the best thing we could do for salmon, and likely our rivers as well. Instead, I'm going to focus on how people found a way to use the skills and resources they had available, and make the best of the situation.

People have been trying to find ways to help salmon get around dams for a long time. By the 1930's, legislation required planning for potential impacts from dams on fish populations (see the Fish and Wildlife Coordination Act). Unfortunately, much of the damage had already been done. What followed was a series of band-aids to try and cover the damage from over 60 major dams on the Columbia River system. Just about everything you could think of has been tried. The simplest (though certainly not the easiest for the fish) involve fish ladders: a series of steps allowing fish to jump their way up. Some of these are quite complex and massive in order to scale the height of the dams, and the sheer physical energy required to make it up is a significant tax on the fish (salmon do okay passing through 4 or fewer dams on the lower Columbia, but show a significant decline when faced with more.)

Thompson Falls Fishway, Thompson Falls, MT. Image Credit: USFWS Mountain-Prairie
https://www.flickr.com/photos/usfwsmtnprairie/

Other methods don't ask quite so much from the fish, but require us humans to help them on their journey. While energy intensive, these workarounds aren't exactly high tech. The earliest methods involved filling barges with fish and moving them to a different point on the river. Modern methods have improved somewhat, but aren't much better. Most simply involve filling trucks with fish and driving them to the top of dams to be dumped. Still others take this sky-high, and use helicopters to move the fish upstream. No matter the method, they all involve people investing a lot of time, energy, and resources into getting fish over a series of walls.

Enter the innovators. In 2011, a man watched some of these helicopters carrying buckets full of salmon go about their work. Vincent Bryan III, who worked in the fruit industry, had a unique insight. Bryan had already been working with a system used to transport fruit through soft tubing (many fruits are bruised easily, making large-scale handling and transportation difficult) and had the genius realization that fish could be handled the same way. So, they set up a line of tubing, turned it on, and started testing it on fish. The results were satisfactory, and the 'salmon cannon' was born. The company, Whoosh Innovations, now has their fish transporting technologies at work around the world inside processing plants, assisting commercial aquacultures, and launching salmon over dams. So let's blast right into the tech!

From Fruit to Fish

If you read my introductory blog, you may remember I have a background working in food processing facilities, especially the fruit packing industry which dominates eastern Washington and Oregon. This is the technology that sparked my 'aha' moment in conservation.

A Spectrim Optical Defect Sorter-Sizer from Compac sorts apples into 5 grades and 17 sizes. Image Credit: Dan Wheat/Capital Press
https://www.capitalpress.com/state/washington/new-washington-apple-lines-speed-packing/article_f1dda1ce-67f2-5281-95e2-d15452ec494d.html

In modern apple packing facilities, the fruit is brought in from the fields (or from storage) and placed into a water flume. This flume floats the apples to a conveyor belt, which guides them to a device called a sizer, sorter, or sizer-sorter (or even sorter-sizer.) The fruit is lined up and pushed through the sizer, which uses a high-powered light and camera to take a detailed picture of every single piece of fruit. These pictures are sent to a computer program, which analyzes the fruit for things like color, size, and if there are internal impurities inside (such as rot or insects.) Based on this information, the computer decides which line that piece of fruit should go to. Fruit of similar size and quality are boxed together, while any with abnormalities detected are sorted out. The process is incredibly fast, highly reliable, and can handle massive volumes of fruit. For more on the algorithms and deep learning used in the fruit industry, check this piece out.

You can probably already see where Whoosh Innovations was heading. The tubing transport system devised for moving fruit was specially designed to move things quickly and gently, without damaging the product. As far as the engineering was concerned, the differences between a 4-inch diameter apple and a 3-foot long salmon were almost negligible. The trick was the scale: no one ever needed to get an apple to go up 180 feet or more to the other side of a dam. So with what I can only assume was a lot of trial and error, a pneumatic powered system was devised that allowed for the distance and height to be covered, while still keeping the fish safe (though likely a bit confused.) At the bottom of the dam, fish are loaded into the cannon (in the wild, fish enter of their own volition.) The system then uses air pressure to move the fish up up and away, at speeds between 16 and 26 feet per second. The system uses only air to move the fish, so it does not rely on a water column (this means the system can theoretically work on dams of any height.) The fish then emerge on the other side, ready to continue their journey.

A Whoosh fish passage system. Image Credit: Whoosh Innovations
https://www.whooshh.com/Press%20Room/photos

So the fish could now be sent from one side of a dam to the other, relatively unscathed. Hooray! But this is only part of the story. When Whoosh ripped apart their fruit packing facility for parts to build the cannon (isn't that what they did?), they also had the forethought to keep the imaging and analysis components as well. While they weren't too concerned with the size or color of the salmon, they realized that sorting could come in handy with making sure that the fish they send up are actual salmon. So, they tweaked their computer program for taking glamour shots of apples, and gave it an eye for fish. Instead of taking a single picture, however, this system collects eighteen photos of every fish which passes through.

A chinook salmon passing through a Whoosh 'FishL Recognition' scanner.
https://www.whooshh.com/What%20We%20Do/scanning-and-data

Almost instantaneously, an advanced algorithm begins analyzing the 18 photos and uses them to decide what species the fish is. If it's a salmon of some type, or some other native species, it gets a green light for a one-way passage to higher waters. If it's dubbed to be an invasive species, the computer changes the pathway, and sends the unwelcome visitor to a separate containment area for removal. What's truly amazing is that a computer program can accurately pick out the fish species so quickly. I have no doubts that experienced anglers, ichthyologists, and a handful of other talented individuals could identify species with similar or even better accuracy. But can they do it in a split-second, and for hundreds of fish in a row? Maybe, but I doubt it would be fun. This program will do it all day long if you let it, and with a smile.

The scanning segment of the Whoosh Innovations fish passage system. Image Credit: Whoosh Innovations
https://www.whooshh.com/Press%20Room/photos

So how does the AI accurately identify fish so quickly? While only the brains at Whoosh know the exact details, we can surmise some basic info based on what has been released. First: the series of images are taken with some lag in between, allowing the fish to change positions as they move through the scanning box. Second: the scanner itself is placed inside a box which is slightly larger than the tube, giving the fish a wider range of motion. Third: we know measurements of different parts of the fish are being taken, and calculations are being made with this data. Fish identification can be tricky for many species, even for experts familiar with what details to look for. Coloration, size, and so on can be difficult to differentiate, and even human identification of fish involves measurements and examination of fin placement, etc. This is likely why the Whoosh scanner does not try to ID fish based on coloration and markings (such as using a horizontal, side image) and instead focuses on the ratios and other relationships between physical features such as fin placement, tail shape, and so on (hence the top-down imaging.) At some point, the software must be searching for a pattern between these dimensions and measurements found at different points in the fish's movement. The fish doing a boogie for the cameras is likely essential to the accuracy of the program.

Whoosh Passage Portal scanner images, showing measurements and analysis. Image Credit: Fisheries and Oceans Canada.
https://www.haidagwaiiobserver.com/news/salmon-arrive-in-larger-numbers-at-big-bar-landslide/

This whole thing sounds pretty cool, but does it work? Only time will tell, but the results so far are promising. Studies have shown the fish remain healthy after passage, and that the system does not damage the eggs of females passing through it. The willing entry of fish into the system has been shown to be effective, removing the need for human handling. The Whoosh system has been shown to increase the speed of migration for fish using the cannon, when compared to control populations using traditional fish ladders (this is crucial considering migrating salmon are literally racing against a clock.) Other great news: the salmon cannon has been shown to safely allow passage for a range of other aquatic species which are also both amazing and important for river ecosystems, including the Columbia River sturgeon. Whoosh's published study data can all be found here.

All in all, the salmon cannon is pretty inspiring. It shows that we can make the best of our situation, even when the battle is uphill (or upstream,) and that the solutions for many of the problems we face just may be right under our noses. It's also a great example of how high-tech software (the fish scanning software) can both reform and modernize what was low-tech equipment (pneumatic transport systems) to solve new challenges. Last but certainly not least, it just looks fun.

As an end-note, I would like to include some links to some of the fantastic organizations who have been working on salmon recovery for decades. I encourage you to learn more about their work, the glories of salmon, and even help out if you're so inclined. Much of the work is being done at a local level, so I encourage you to search for groups and activities particular to your area (most of these are biased toward central WA.)
- Atlantic Salmon Recovery Project
- North Olympic Salmon Coalition
- Northwest Salmon Research
- Salmon Restoration Association
- Save Our Wild Salmon Coalition
- Sound Salmon Solutions
- WA residents can find your local Fisheries Enhancement Group here
- WA residents can find your local salmon recovery Lead Entity Group here
- Yakama Nation Fisheries