This week brings two cautionary tales about overstressed systems. Puget Sound’s Hood Canal, which has long suffered from low oxygen levels whose effects on marine life are exacerbated by the Canal’s deep, narrow shape, is reporting the lowest oxygen levels on record for this time of the year. Some predict a fish kill along the lines of last fall’s. The main culprit is probably excess nitrogen from sources such as septic systems, stormwater runoff, manure and fertilizers: Up to 300 tons of pollutants are being released into the canal each year, says Puget Sound Action Team. (In 2000, Washington’s coast was spotlighted by NAS as a problem area for nitrogen-related algae blooms.)

Further south, the BPA may reduce its salmon-saving spills over Columbia River dams by 39 percent this summer, largely to save money. It’s a more moderate proposal than one aired earlier and BPA promises expanded salmon conservation efforts. But it’s not a move likely to enhance the long-term prospects for biological diversity and healthy aquatic ecosystems in Cascadia’s greatest watershed.

Sooner or later, as climate systems, economies, and biology get stretched, you get moments like these: the state desperately seeking ways to protect Hood Canal from imminent fish kills; BPA sacrificing salmon to help pay its debt. In both cases, the situation has long since reached the point where low-cost, high-leverage solutions are at hand. The moral of these cautionary tales is not to stretch systems so far.