Hucuktlis River Fish Fence

The fish fence in the Hucuktlis River has been operational annually since the late 1990s, and was originally implemented in partnership with Uu-a-thluk Fisheries and Fisheries and Oceans Canada (DFO). The fence is made of wooden panels covered with wire mesh, with three mechanical counters that record fish as they pass through. The fence is installed in early summer and is operational until early to mid-September, prior to the start of the rainy fall season. Sockeye are the main salmon counted, although Chinook and coho also begin entering the river before the fence is removed.

The fish fence allows us to monitor the escapement, or the number of salmon that have returned to spawn, into the Hucuktlis watershed. This information helps UTG and DFO understand how many sockeye are returning to the river each year, and whether the population is declining or improving over time. The data that is collected using the fence can shape management decisions for the local fisheries in Alberni Inlet and Barkley Sound.  We can compare fence counts to the amount of sockeye caught in commercial and recreational fisheries to estimate harvest rates. We use the fence counts and the estimated harvest rates to influence weekly fishing plans. UTG can request that commercial fisheries move up Alberni Inlet and into areas where Hucuktlis sockeye are less likely to be found, reducing accidental harvest, and help more fish reach their spawning grounds. The data can also be used in implementing long-term management changes to address conservation concerns.

When collected consistently and combined with other methods of counting returning fish, the fence provides an approximation of returning fish that can be compared to previous years. Estimates are used for in-season and post-season management decisions and helps us better manage the Hucuktlis sockeye population.  It is therefore important for the fence counts to be accurate and for the operations of the fence to continue un-interrupted. Tampering with the fence can cause inaccuracies and can have direct implications for Hucuktlis sockeye.

There are a few limitations with the fish fence in its current configuration. The panels are more susceptible to high flows and large woody debris following rainstorms. The mechanical counters require periodic maintenance throughout the season, which can occasionally result in a small number of tunnels being temporarily blocked while the repairs are conducted. The fence is oriented at an angle to provide additional safety for the technicians working in the river. While this design offers an important safety benefit, it may also mean that sockeye take a little longer to move through the fence as they follow the panels toward the counter boxes.

It should be noted however, that salmon are known to hold in the river and behind the fence during their migration up-river.  This is a common behaviour that is seen in numerous river systems and by all salmon species.  As fish enter the river, they must acclimate to the freshwater as physiological changes begin to take place.  This ‘holding’ behaviour is not a result of the fish fence impeding migration but simply a way for the salmon to adapt a new environment and wait for the high tide when most fish continue moving towards Hucuktlis lake.  Sockeye have been observed in numerous pools within the river, generally deeper and with low current, so they can save up energy that they will need to spawn in a couple of weeks.

If you have any questions or concerns regarding the fish fence, please email Fisheries Specialist Nathan Bendriem at nathan.bendriem@uchucklesaht.ca and he would be happy to go over them.  Here are some of the concerns we have been hearing about:

Bear Predation:  There are several black bears that live in and around Ehthlateese that will feed on sockeye salmon from the river. The bears will often use the fence to get closer to the fish that are holding behind it and are successful in capturing sockeye to feed on.  Predation is a natural part of the salmon life cycle and would happen with or without the fish fence.  Salmon is a big component of a bear’s diet, and they are adept at hunting fish.  We are not concerned with this making a large impact on the sockeye population, as the presence of bears is still limited and the number of fish that they feed on would not make a significant impact on the overall long-term sustainability of the Hucuktlis sockeye population.

Fish cannot get through the fence: While the fish fence can slow down the migration of salmon, it does not impede passage through the fence. Most fish will migrate through the fence overnight when the tide is highest.  The presence of fish holding behind the fence does not mean they are unable to get through.  Holding is a natural behaviour and allows fish to acclimate to freshwater. The openings in the mechanical counter boxes are wide enough to allow fish through, even coho and Chinook, which have been observed on camera.  Once the fence comes out in September, fish have free passage to the lake.

The Hucuktlis fish fence is part of a long-standing monitoring program that is key to the sustainability of the sockeye population. It helps inform management decisions and is used to monitor changes in the status of the population over time. The fence does not lead to excessive predation by bears, nor does it impede passage upriver. The Department of Lands and Resources is continually looking for ways to improve our monitoring techniques by reviewing methodology, staying up to date on the most current knowledge and technology, and applying for funding to improve our infrastructure. We are always open to learning from the knowledge of Uchucklesaht citizens and working together to do what is best for salmon.

Story contributed by Nathan Bendriem, Fisheries Specialist at UTG
Edited by Rippon Madtha