Oregon sees low-oxygen seasons in coastal waters

PORTLAND, Ore. (AP) — Scientists say the waters off Oregon’s coast now have a season of low oxygen caused by warming ocean temperatures.

Oregon Public Broadcasting reports the coastal waters now go through an annual season of hypoxia, a condition resulting in the deaths of sea organisms as dissolved oxygen decreases in water near the ocean floor.

Francis Chan, co-chair of the West Coast Ocean Acidification and Hypoxia Science Panel, says the low-oxygen season is much like the state’s wildfire season.

Some of the first signs of hypoxia appeared in 2002, when dead crabs were hauled up in crab pots. Chan says the hypoxia has been observed almost annually since 2002.

Warmer ocean temperatures trigger excessive phytoplankton blooms, which take oxygen out of the water when they die and sink.