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Wednesday, Oct. 1, 2008
OLD NIC'S NOTEBOOK
Helping a healthy river flow
By C.W. NICOL
My eldest daughter, Miwako, gave birth to twin girls in March of this year, raising the number of my grandchildren to five. So, when my busy schedule finally permitted, I recently nipped over to Vancouver to see them all and to help out Miwako and her partner, Don McCubbing, by being houseboy and chief bottle-washer for a while.
Miwako and Don have a house in the little community of Port Hardy, way up on the coast on the mainland side of Vancouver Island, which was where they first met. Back then, Don was a consultant with Bruce Ward, a veteran fisheries scientist with the British Columbia Ministry of Water, Air and Land Protection. Bruce has long been fighting to protect salmon, char and trout habitat, and also to restore rivers that have been devastated by flash floods, erosion and blockages brought on by clear-cut logging, poorly built road culverts and so on.
Among his many projects, for 30 years Bruce has studied, monitored and campaigned for the restoration of the Keogh River. Miwako and Don's fateful meeting occurred when I went over there from my home in Kurohime, Nagano Prefecture, to make a documentary on bears and salmon for the Hokkaido Broadcasting Company. Miwako was my co-ordinator, and Don was monitoring the success of efforts to bring back salmon and steelhead trout to the Keogh.
River-restoration work on the Keogh included stabilization of the banks by planting willows, alders and other water-loving plants whose roots would hold them together and prevent them from being washed away in floods. It also involved putting various large objects in the river — including big logs, boulders and the stumps and root wads of big trees — in order to create eddies that would help to control the stability and speed of the flow. That way, gravel beds could re-form, with enough water flowing over the stones even in dry periods to oxygenate the golden fish eggs and tiny fry in among them — and prevent silt choking this vital habitat.
In addition, it is vital for the health of a river or stream that silt on its bed doesn't block the flow of colder groundwater. This water rises from below or drains in from the sides and can make a huge difference to overall temperatures — 10 degrees or more in some places — which means the difference between life and death for sensitive fish such as salmon, trout or char.
Back eddies created by the big logs and boulders and wotnot also create calmer, well-protected havens for small fish and other aquatic creatures, and provide adult fish with slower-flowing, deep places in which to rest and seek refuge from predators on their return migrations.
And as a vital bonus, trees and bushes lining rivers not only stabilize the banks, but provide cooling shade and a cornucopia of tasty tidbits for fish to snatch when they drop from the foliage into the water.
The Keogh River flows just 33 km from Lake Keogh into Queen Charlotte Strait which separates Vancouver Island from the mainland of British Columbia. It is a short, fast little river that is easily damaged by bad logging practices. However, to give the timber companies some credit, in recent years they have been helping to fund river-restoration projects.
In the Keogh and other rivers in Canada, off-channel habitats have also been created to mimic natural spawning and nursery areas for fish. River water is directed into winding, forest-shaded spawning creeks into which cold, clear groundwater also drains. Ponds are also created, with woody debris that hides the fry of Coho salmon until they grow big enough to migrate to the sea.
In streams that have lost their salmon, following the construction of fish-friendly places like these, studies were carried out and efforts made to mimic the release of essential minerals into the water that had previously been provided by the bodies of dead, spawned-out salmon.
At first, real salmon carcasses from fish farms were put into these renewed streams, but that was costly and carried a risk of bringing in disease that, in a fast-flowing stream, could not be cured as it is on fish farms with applications of antibiotics. It was also dangerous for the people trekking in with loads of dead fish on their backs. Bears have an excellent sense of smell! Would you want to traipse around in the woods with 30 kg of smelly fish? Not me!
Instead, slowly dissolving mineral-rich pellets were created. These could be spread by hand or from a helicopter — an altogether much quicker, safer and more cost-effective method. Of course, once the salmon started returning from the sea, bringing these minerals in their bodies, then nothing more needed to be added to the rivers and streams.
After all this effort and expense had been put into reviving a stream, you obviously want to know if the salmon, char and trout are returning, and if so, in what numbers. Without this data you cannot allow fishing. You need numbers to establish new quotas on the catch — if, indeed, a catch is to be allowed.
Smolts heading off to the sea from a river can be stopped and diverted by weirs or rotary screw traps that don't harm the little fish, and only stop them long enough to count them, or to mark or tag them in some way. With a rotary trap, a large, meshed Archimedes screw run by the force of the water, the smolts are diverted to trap boxes, which can hold them for 24 hours without injury. These methods need people to be constantly monitoring and counting.
Don, a Scot, is the president of InStream Fisheries Research Inc., a company that uses a unique fish- monitoring system first developed in Europe. The system involves placing in the stream to be studied a weir whose height can be altered by removable boards. Into the weir are set sturdy narrow passages or water slides that allow the fish to pass through. In these "thoroughfares" sensors are placed to record changes in electrical resistance such as occur when a fish passes through. That way a count can be made, giving not only the date and time of the fish going through, but also an estimation of their size. These counts are accurate for individual fish down to a length of 15 cm.
These "resistivity fish counters" (Logie 2100C fish counters, manufactured by Aquantic Ltd., Dingwell, Scotland) are powered by solar panels or wind generators. The weirs can be of any size, with fish counters of various heights to allow for the difference in the flow of a river during sudden rains and so on. The counts go into a device that stores the data until somebody comes along with a laptop computer to download it. This means that remote streams can be monitored, with just regular visits by a scientist or other monitors.
Sensors can also be installed to activate underwater cameras to capture video images of what is passing through. If funds are available, and with solar panels big enough to provide the power, this data can be relayed to a satellite so you can count the fish returning to a remote mountain stream — and get live images of them as well.
This surely would make a superb education tool for encouraging the public to be aware of what is happening in their rivers. Towns that have gone to the effort of preserving or restoring their rivers for migratory fish could relay this data and images directly to a classroom, visitor center or even to home television systems of interested parties.
While staying with Don, Miwako and the twins in Port Hardy, I visited both the Keogh River and the more remote Glendale River, which has a 1 1/2-km-long salmon spawning channel that was built in 1988. Don has a fish counter on this channel, which he hadn't monitored for a month. To get there entailed a 2 1/2-hour ride aboard a fast fisheries department boat from Port McNeil across the strait and down the 125-km-long, and 2 to 3 km-wide Knight Inlet to the Knight Inlet Lodge on Glendale Cove, just 60 km from the mouth. This lodge, normally reached by floatplane from Campbell River, is famous for Grizzly bear viewing.
We got to the lodge in time to grab a bowl of soup before heading across a cove in a shallow-draft boat to land in bear territory. A battered old school bus took us along a dirt road to the spawning channel. Don's fish counter was feeding information into a recorder that was housed in a steel cupboard on a bear-viewing platform overlooking the fish-counter weir.
When we arrived, an old male Grizzly bear with a crippled back left leg was already there. Despite his disability the old bear was extremely adept at catching the Pink salmon (Oncorhynchus gorbuscha) that now returning to the channel. Pinks are the smallest of the salmon tribe, adults weighing an average of 2.2 kg. When spawning, the males develop a distinct hump in their backs, which gives them their other name — Humpbacks. They have a distinct 2-year cycle, with those hatched in alternate years not mixing. The bear was very hungry, and devoured these small salmon whole, on the spot. With a couple of short breaks, this one bear caught and ate about 30 while we were watching.
Later in the year would come the migration of larger species of salmon, a proportion of which bears would catch and take into the woods to enjoy in peace and quiet. Bears eat the soft roe and other tasty parts of the larger fish and leave the rest in the forest. Marine nutrients from these salmon are vital to vigorous forest growth.
While Don was downloading his data we were able to watch this old male, a young female, then a pair of 2-year-old sibling Grizzly bears whose mother joined them later, and then another mother bear with two young cubs — all feeding at the same weir.
Don's data told us that so far 3,000 Pink salmon had passed over the counters. He expected that the final count would be about 60,000. All of these salmon are returning through a man-made channel, and these numbers do not include the later migrations of Chum and Coho salmon. A wonderful bounty of nature for which, I am sure, ursine mothers with twins are profoundly grateful. For Miwako, it will be a while before she can just toss a fish to her twins, but knowing my daughter, that day will surely come.