Sediment from logging roads is negatively impacting fish habitat, according to the most recent report from British Columbia’s forestry watchdog.
The Forest Practices Board looked at five watershed sites in the province and found that four of them were facing risk to fish habitat due to sediment coming off of logging roads. Those watersheds were the Ainslie (near Boston Bar), the Memekay (near Campbell River), the Owen (near Houston), the Pennask (near Kelowna) and the Woodjam (near Horsefly).
From the results, the board concluded that government legislation is too vague, making it hard to enforce effective sediment management.
B.C.’s Forest and Range Practices Act requires operators to ensure “primary forest activity does not have a material adverse effect on fish passage in a fish stream.”
But board Chair Kevin Kriese told The Narwhal that “material adverse effect” is hard to prove and therefore the regulation is difficult to enforce. He said the legislation should be clear about what is and isn’t required in sediment management.
“What we think would be much more clear is to say to operators ‘you must minimize the deposit of sediment into streams,’” he said.
Kriese said there is no question that excessive sediment has a negative impact on fish. Sediment buildup can lead to shallower, warmer waters. Road infrastructure, like culverts, can cause sediment accumulation and block fish movement upstream.
(The Ministry of Forests, Lands, Natural Resource Operations and Rural Development did not respond to The Narwhal’s request for comment in time for publication.)
On behalf of the board, a team of three biologists and one forest hydrologist conducted rapid assessments in the five watersheds. Despite the addition of sediment from logging roads and risks to fish populations, the board found operators to be meeting or exceeding legal requirements for managing riparian areas.
However, there are many critics who say B.C.’s legal requirements for logging have been too lenient since Gordon Campbell’s Liberal government relaxed industry regulations in 2004.
Ecojustice executive director Devon Page previously told The Narwhal, “B.C.’s forestry laws aren’t actually laws. At best, you could call them guidelines.”
Sediment can ‘smother’ salmon eggs
Increased sediment can be caused by human activities and natural occurrences like landslides and wildfires. Elevated sediment in streams can decrease the abundance of plant life, which impacts the fish that feed on those plants.
The Department of Fisheries and Oceans reported that juvenile coho and Chinook salmon behave irregularly in streams with elevated turbidity (sediment suspended in the water) by surfacing and making themselves more vulnerable to birds.
Sediment can also be detrimental to salmon spawning beds.
Hotter temperatures and sedimentation combined can kill salmon eggs, or “smother” them, as Misty MacDuffee phrased it. A biologist and program director for Raincoast Conservation Foundation’s wild salmon program, she emphasized the bigger picture of how logging can impact salmon and how clearcut logging impacts stream flow.
“There are a lot of implications from logging on salmon,” she said. “Sedimentation is just one of them.”
Scott Hinch, an ecology professor at the University of British Columbia’s Faculty of Forestry, said sediment build-up can make streams wider and shallower and even cause parts to dry up. Small pools can be filled with sediment, which Hinch said is especially dangerous for species like coho salmon, which rear there.
Hinch said that in addition to fine sediment being deposited from logging roads, they can also contribute to sediment on a larger scale by destabilizing areas with steep terrain.
“If you build a lot of roads in a watershed, you tend to have more avalanches associated with these roads that cut across steep terrain,” he said.
Hinch said “there’s no silver bullet” to prevent sediment runoff, but ongoing monitoring to ensure the health of riparian areas that surround streams is key to their protection.