{"id":568,"date":"2017-08-25T00:00:00","date_gmt":"2017-08-25T07:00:00","guid":{"rendered":"http:\/\/live-hakai-institute-wp.pantheonsite.io\/great-flush\/"},"modified":"2020-02-28T13:36:09","modified_gmt":"2020-02-28T21:36:09","slug":"great-flush","status":"publish","type":"post","link":"https:\/\/hakai.org\/great-flush\/","title":{"rendered":"The Great Flush"},"content":{"rendered":"

Sheets of rain pour down on the Central Coast of British Columbia on a chilly day in November. A pulse of water\u2014the color of chai tea\u2014rushes over the boggy landscape, down a steep slope, and empties into the ocean. That brown color signifies carbon and other organic material dissolved in the water. These temporarily swollen streams may be small, but their size belies their importance.<\/p>\n

In the past few decades, we\u2019ve learned that the ocean has a big influence on the coastal landscape through subsidies, inputs of nutrients like salmon providing nitrogen to aid tree growth. But the sharing goes both ways, and these storm-swollen streams are one big way that carbon from the land is injected into the ocean.<\/p>\n

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A stream rapidly rises and falls on Calvert Island during a single winter storm. Video by Shawn Hateley<\/figcaption><\/figure>\n

Understanding these land-to-sea exchanges of nutrients is critical to calculations of carbon budgets over a larger geographic area. But these calculations had never been measured locally on the BC Central Coast, says Allison Oliver, a Hakai postdoctoral researcher at the University of Alberta and lead author on the new study based at Hakai\u2019s Calvert Island Ecological Observatory that was published last week<\/a> in the journal Biogeosciences<\/em>.<\/p>\n

\u201cWhat sets this area apart is that we have tons of small [streams] that drain directly into the ocean. I was pretty confident the [dissolved organic carbon] numbers coming off this landscape would be high, but you never know until you go out there and actually collect the data.\u201d It turns out those numbers were on the upper end of what they imagined\u2014roughly 33,300 kilograms of carbon entered the sea per square kilometer of land. That\u2019s as much carbon as four and a half elephants.<\/p>\n

In this part of the coast, land plants, mosses, and soils provide most of the dissolved carbon. As the fresh water moves toward the coast via these streams, microbes in the soil, as Oliver puts it, \u201cchew on the carbon,\u201d breaking it down. These streams are critically different from larger, mountain-born watersheds like the Fraser or Skeena. In those mighty rivers, most of the carbon is usually broken down or taken up by plants and animals along the way. The dissolved carbon from small streams that directly enter into the ocean is less degraded. It\u2019s \u201cfresher,\u201d and there\u2019s more of it to feed ocean creatures. Hence, why scientists are so interested to gather data on these streams.<\/p>\n

\u201cIt is really critical to have good stream flow data including big storm events in the winter,\u201d says Oliver. \u201cThe challenge is to be able to get to these watersheds and access them during these storm events when a lot of carbon is entering the system.\u201d<\/p>\n