Fish linked to land puzzle

Expert says stream flows impact fish food such as algae, as well as fish themselves, in different stages of their life cycles.


Black Press

There’s much more to providing an environment for fish than just ensuring there are adequate flows in a stream at key times, warns biologist Jason Schleppe, a principle in Ecoscape Environmental Consultants.

He was speaking to the Okanagan Water Stewardship Council about fish and environmental flows recently.

The council makes recommendations on technical issues to the Okanagan Basin Water Board, which is made up of representatives from the three Okanagan regional district boards.

Schleppe admitted frankly to being a ‘fish-centric’ person who loves fish.

He pointed out that stream flows impact fish food such as algae, as well as fish themselves, in different stages of their life cycles.

“When you begin changing flows, it’s hard to image all the consequences; the webs and linkages.”

He described a river in Texas that went dry one summer.

All of the vegetation along the river died too, not just the fish and aquatic vegetation. That impacted a heron rookery alongside the river, because their habitat died with the mature cottonwoods in which they’d built their nests.

“It’s important to realize what could be impacted and linkages are a key part of the puzzle.”

Stream flow management should not be entirely fish-focussed, but he said it’s important to plan for both people and fish. There are lots of rare and endangered species living in the Okanagan.

For instance, he said, kokanee are a keystone species in the Okanagan. They’re the lifeblood of large lakes like Okanagan Lake, where they are the driving force for biodiversity.

“Kokanee make big rainbows and such fish are a good economic driver.”

And, local government plays an important role in what land uses are permitted adjacent to riparian areas, he noted.

“It can become costly if you need to begin purchasing land adjacent to streams. The biological world is complicated, but if we left it alone, it would probably be fine.”

With our world in a rapid state of change, there’s far more risk to the natural world.

“We need champions to work through conflicts as part of a good planning process,” he added.

With climate change, extreme flows will begin to happen more often, he warned, and managing flows will be a challenge.

Compromise and adaptability will be important and education will be key to leaving an environment where fish can survive.

“It’s a lot more than just fish,” he explained.

In fact, it’s not about protecting particular species now, but about protecting the highest value habitat, he said.