Road Runoff A No-No for Coho

By | October 26, 2015

Each fall, thousands of coho salmon[银大马哈鱼;银鲑鱼] flock to Northwest rivers to spawn[产卵；大量生产]. But many never get the chance, especially near big cities like Seattle[西雅图]. “And in some of these urban areas, up to 90 percent of the females were dying before they spawned, which is not a good thing for a population long term.” Julann Spromberg, a toxicologist[毒理学家] affiliated with[附属于] the Northwest Fisheries Science Center[西北渔业科学中心].

Researchers suspected[怀疑] these deaths were partly a matter of bad timing. The fish often reach streams during the first showers of the rainy season, which flush[奔涌；被冲洗] chemicals from roads and parking lots[停车场] into the water. Now, Spromberg and her colleagues have produced the first direct evidence that this runoff[流走的东西] kills coho salmon. Their study is in the Journal of Applied Ecology[应用生态学学报].

The researchers found that fish exposed to storm water[雨水;暴雨水] from Seattle-area highways quickly grew sick and died. Surprisingly, though, the salmon did not seem to mind taking a dip[泡个澡;去游泳] in a cocktail of[混合的] common road pollutants, including hydrocarbons[烃类;碳氢化合物] and metals[金属]. That detail suggests the killer ingredient[原料；要素；组成部分] in runoff may be a different kind of chemical or a lethal[致命的，致死的] combination of several compounds[混合物，化合物].

“There’s a whole lot of stuff[东西；材料] in here that we haven’t been able to measure or don’t have the capabilities of[有能力做…] measuring at this point.”

However, Spromberg says there’s a way to help the fish even before scientists hunt down[穷追直至抓获] the culprit[(造成问题或麻烦的) 原因;元凶]. Her team also found that filtering[过滤，滤除] runoff through just a few feet of soil made storm water safe for salmon. Cities can implement this simple form of clean water technology by building more systems, including roadside rain gardens, to collect runoff from paved areas[已铺路面的地区；已铺筑地区] and pass it through soil before it enters urban waterways. Literally[照字面地；逐字地] a quick and dirty solution.

From 60-Second Science