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Ecosystems 101: Beneath the waves

January 27, 2016/in Education, Science & Life /by Sierra Club

In warm water years, like El Niño years, the majority of the Fraser River sockeye salmon begins their migration to spawn via Johnstone Strait. While some people may argue that this means good things for people fishing in Canadian waters—because less sockeye will run through the trans-boundary waters of the Juan de Fuca—warmer waters bring a slough of other challenges for salmon.

In years with warmer ocean waters, salmon typically have less beneficial food to eat and more predators with whom to contend. Ocean currents carry Californian plankton rather than the more nutritious cold-water plankton that normally upwells on our coast. As majority plankton-eaters, sockeye depend on lots of nutritious phytoplankton and zooplankton to grow and survive.

Additionally, warm water predators that make it to B.C. waters place extra pressure on the sockeye. (The warm water currents also carry other critters too, like this sea turtle, that can be accidentally—and detrimentally—caught in the currents around Hawaii finding themselves stranded in B.C. or Alaskan waters.)

How can we have sustainable human food systems, if salmon don’t have sustainable ecosystems? As waters warm and as El Niños become stronger and more frequent as predicted as a result of climate change, industrial fishing practices will need to change too.

Featured image by Winky, via flickr

Do sockeye salmon take detours?

January 27, 2016/in Education, Science & Life /by Sierra Club

Did you know that the Fraser River sockeye have two migration routes for their journey ‘home’ to spawn? Typically, on an average year, the majority of sockeye migrate to the mouth of the Fraser River via the Juan de Fuca Strait to the south of Vancouver Island. Fewer make the journey via Johnstone Strait, which is to the north and east of the Island.

However, in warmer years, this migration pattern reverses; the majority of the sockeye run – in some – migrates via Johnstone Strait.

During El Niño years, like this one, we can predict that the sockeye run will be ‘detouring’ to the north. Moreover, with climate change and warming ocean waters, we can also predict that this change might become a more regular occurrence.

(El Nino affects other species of Pacific Salmon too. Here’s a good article on some of the changes associated with El Niño and with climate change for Chinook and Chum salmon.)

Featured image by Roger Tabor (USFWS)

My winter of rain

January 27, 2016/in Education, Featured Story, Science & Life /by Sierra Club

I love to ride my bike. Over the last couple of years, I’ve woven this passion into my daily routine by becoming a cycle commuter. Because of this, I’ve also become a bit of an amateur meterologist. When you’re riding a bike every day, you become acutely aware of the weather.

Where I live, on Lekwungen Territories/Victoria, B.C., it feels like we’re having a very rainy winter. At least once a week, I seem to end up at work looking like I’ve just been swimming! But are we having a wet winter? Or does it just feel that way in the wake of last year’s drought? I’ve been hearing news reports that this is an El Niño year. What does this mean for B.C.?

A little bit of research has helped me to refresh my understanding of what an El Niño is. In brief, every 3–7 years or so, the currents of the tropical Pacific reverse, flatten out and then reverse again. Warm water that normally flows from east to west instead flows west to east. The normal upwelling of cold and nutrient water that flows up to the surface along the coast of Peru and Ecuador is squashed. With more warm water at the surface, the atmosphere warms too. This changes water and air currents all around the world.

In North America, a pattern that meteorologists have come to expect is the splitting of the polar jet stream. Where there is normally only one polar jet stream governing weather, two polar jet streams dominate weather patterns in El Niño Years. This ends up creating above normal temperatures in northwestern North America, and below normal temperatures in southeastern regions. Precipitation patterns also change, somewhat predictably. Generally in El Niño years, coastal Canada can expect more precipitation and central Canada can expect less.

Zooming into B.C., this year’s El Niño is even more interesting. While the central and north coasts are expected to get lots of precipitation (above and beyond their average, already wet, weather), the south coast of B.C. is not. In fact, Victoria and Vancouver—along with central and northeastern B.C.—are looking forward to completely average rain years in terms of total volume of rain or snow.

So, I guess I should stop complaining about “all the wet days.”

Or should I?

While we aren’t expected to get above average levels of precipitation this year in Victoria, we are expected (and have already seen) more intense rainfalls. In the words of the Weather Network, “while this [El Niño] should result in fewer than normal rainy days, at times the “Pineapple Express” will bring a few rounds of heavy rainfall that will bring precipitation totals for the season that are near to above average for the season.”

I should stop complaining about all the wet days, and focus my complaining on those particularly wet ones.

And for all you whose favourite mode of human-powered transport is not cycling but skiing? The Weather Network is cautiously optimistic: “While the anticipated pattern for the winter as a whole is not ideal for skiers, it is a lot more favourable than what we saw last year.” As of today, snowpack levels remain a little below normal, but most of our ski hills are still open.

Finally, the million dollar question: How does El Niño and climate change impacts intersect? See Ecosystems 101: Beneath the waves

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