When a large volume of logs were dumped in Gorge Harbour, during the 1970s and 80s, they caused extensive damage to the underwater environment.
One of the questions raised at Mosaic’s Cortes Island ZOOM meeting, last January, revolved around the possibility that reactivating the log dump could also have negative impacts. Mike Moore dove beneath the log dump about fifteen years ago. At that time, he observed a thick layer of wood debris and sediments, covered by ‘bacterial mats.’ Moore was concerned about the possibility a new disturbance of the sediments could pollute nearby shellfish operations.
He returned to that area again after the ZOOM meeting.
“I dove to the bottom, to check some moorings by the big barge that’s anchored just off the log dump. I was happily surprised to see that the bottom was very alive and it was a bouldery bottom with lots of growth on it,” said Moore.
“I have also dove around some docks and their moorings in the immediate neighbourhood and found that the bottom is clean. It was either sand or boulders during the log dumping operation held by the Community Forest and the Klahoose earlier this year.”
He asked both Island Sea Farms and some of the local residents if they have “noticed turbidity in the water, and they said they hadn’t really noticed any difference at all.”
A Mosaic spokesperson emailed, “We have positive working relationships with our neighbours that hold aquaculture tenures directly adjacent to our Gorge Harbour facility.”
The question arose again last week. In a post to the Cortes Tideline, Dr Brian Hayden cited scientific studies from 1977 and 2011 to substantiate his concerns about the log dump.
“This is a recipe for disaster for the marine environment – the benthic environment, the sea, the seabed floor – for Gorge Harbour, and it’s had a bad impact from the time they started dumping logs here until the present,” he said.
Cortes Currents forwarded Dr Hayden’s objections on to Mosaic.
A company spokesperson replied that the log dump site has been in use for 40 years and their operations will only be a fraction of the size that occurred historically at this location.
“The rate of use of a site like this is an important factor. We’re planning a few truckloads a day when active, which is only a portion of the year,” she emailed.
“Over the last few decades, various science and standards, including environmental standards, legislation, Department of Fisheries and Oceans (DFO) Best Management Practices (BMP) and professional requirements, have evolved to improve and to ensure environment values are managed appropriately. Today’s standards ensure environmental values are considered, and Mosaic Forest Management follows or exceeds all legislation. Our team of independent professional biologists, qualified marine biological professionals, engineers and forest professionals have assessed the site to ensure all our activities comply with or exceed federal and provincial legislation. We have completed an environmental assessment (including an underwater SCUBA assessment) that meets or exceeds the DFO requirements.”
This is essentially what Colin Koszman, Mosaics’ Land Use Forester said last January, except in more detail.
Moore is says the volume of logs recently dumped into the Gorge was quite small and he is still concerned about future impacts.
Some of the bark on those logs is toxic for fish and the effects on shellfish are unknown.
“Colin Koszman said, ‘Oh yes, our marine biologists have checked it out and they say, it’s all fine.’ I don’t know if that meant actually taking samples from the bottom and seeing what contaminants and toxins are in those sediments,” explained Moore.
Dr Hayden believes much of the damage has already been done.
“In the past, it was fairly well-documented that the log dumping has resulted in carpeting the bottom of Gorge Harbour with bark detritus from dumping logs. It’s basically putting toxins into the Gorge Harbour here, and that doesn’t go away,” he said.
Moore and Hayden have very different perceptions of the extent that toxins are already in the Gorge.
Dr Hayden believes that while three or four metres of water are flushed regularly, the deeper waters are a dead zone. Some local divers told him that the bottom of the Gorge is like a desert.
This is not what Moore reported:
“I dive moorings and dock lines all up and down the Gorge, including the west end, and that is a clean sand bottom. Wherever rocks or mooring blocks or anything stick out of the sand, they’re covered with growth. As you head into the deeper part of the basin, you do get finer sediments because it is a basin, anything will settle out there, but it appears to be clean to me when you get up underneath the oyster rafts.”
“At the Bee Islets in particular, I’ve been down 90 feet. You get a metrics of plastics coming down off the shellfish industry, that’s layered with a light sediment, but there are sea stars, sea anemones and fish down there. In fact, the oyster wraps themselves provide incredible structure in the water column for creatures to live in. To my eye, again I’m not a scientist but I’ve done a lot of diving, that looks perfectly natural and okay.”
“I would also like to add that the Gorge is not the only area where that heavy muck and aerobic muck with the bacterial mats occurs. That is what the bottom of Cortes Bay is. That’s also what a lot of Squirrel Cove looks like and (decades ago) there were big booming operations in Squirrel Cove. I have to untangle anchors from sunken logs in Squirrel Cove quite regularly, and that is a really low viscosity stinky muck that’s covered in bacterial mats.”
“It’s a problem that’s prevalent all around the island and I would suspect anywhere that there was big booming operations in an enclosed bay with a relatively shallow entrance.”
“The Gorge has a really strong tidal flushing action and it’s actually much cleaner than some of the other bays that go in around Cortes Island.”
Dr Hayden cited the 1977 study, “Gorge Harbour Tidal Circulation and Pollution Study” by Eric Man and Stewart Parkinson.
“They did a survey of the seabed floor and marines in Gorge Harbour here at that time and found that there was a bed of bark and twigs and other organic material that carpeted almost the entire floor of the Gorge, but especially where the log dump is and also in the west end where things tend to accumulate. That was covered by a few centimetres of silt, and this is gradually decaying and the decay of this material used up the oxygen in the seabed floor. As a result, basically it’s a dead zone. Very little is happening there,” he said.
Moore pointed out, “that was in the heyday of industrial logging on Cortes Island. I can just imagine that the Gorge and the log dump area was probably a huge log booming ground, where logs would be tied up on both the east end and the west end, waiting weather and awaiting enough volume so that they could be towed out in the entrance and down south to the sawmills and pulp mills. I can also imagine that there was a lot more impact on the up shore areas of the Gorge due to logging. And there would very likely have been quite a bit of sedimentation coming down from those logging areas surrounding the Gorge.”
He added that his dive at the log dump had been ‘at the request of MacBlo’:
“When I went down directly underneath the log dump, there was a layer of bark and wood fibre mixed with a thick layer of sludgy sediments that had a bacterial mat on top of it and if you dig into that, which I had to do, it was quite black and stinky smelling like hydrogen sulphide, but that was about 15 years ago.”
The second report that Dr Hayden cites appears to have been written shortly after that (in 2011). Five out of the eight samples taken from the east end of the Gorge reported low oxygen levels.
“I don’t know how much sediments may have been stirred up or how much sediments are still on the bottom underneath the log dump. The log dump has had very little use in the last decade or more,” Moore stated.
“I think instead of sitting on the beach and wondering and worrying about what’s happening below the water, it would be very good if an actual dive study was commissioned with divers mapping and identifying the anaerobic zone underneath the log dump and then studying the effects of log dumping later on. There just hasn’t been enough logs entering the water to store that stuff up.”
(There is much more detail in the podcast)
Top photo credit: The log dump in Gorge Harbour – Photo by De Clarke