Series:

Oxygen for life: The biological impacts of low dissolved oxygen

About the series

Scientists are reporting a decline in oxygen-rich waters throughout the world, raising concerns for sea life. In parts of Puget Sound, low oxygen levels can occur naturally but may be worsened by human-caused pollution. In this five-part series, Christopher Dunagan reports on the critical nature of oxygen to Puget Sound species. Scientists are finding that changes in oxygen levels can lead to physiological adjustments, shifts in predator-prey relationships and other repercussions throughout the food web. Read the latest story.

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Latest story posted: 4/07/2023

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A purple sea star attached to a rock covered with mussels and seaweed.

Oxygen for life: How low dissolved oxygen affects species in Puget Sound

Scientists are reporting a decline in oxygen-rich waters throughout the world. Causes for the decline vary from place to place but may involve climate change and increasing discharges of tainted water. In Puget Sound, low oxygen levels can occur naturally or due to eutrophication from human-caused pollution. In this five-part series, we describe the critical nature of oxygen to Puget Sound sea life. Scientists are finding that changes in oxygen levels can lead to physiological adjustments, shifts in predator-prey relationships and other repercussions throughout the food web.


Water quality, Species and food webs, Algae, Invertebrates, Fishes, Marine habitat, Phytoplankton, Food web, Hypoxia, Nutrient pollution

A person holding a rope attached to a wire cage holding recently captured Dungeness crabs.

How crabs respond to low oxygen in Hood Canal

As observed in Hood Canal, low-oxygen conditions can upend the lives of Dungeness crabs trying to stay alive. Levels of dissolved oxygen can alter predator-prey relationships for a multitude of species, affecting populations throughout the food web. Part two of our series "Oxygen for life" examines a crab case study.


Water quality, Species and food webs, Invertebrates, Marine habitat, Dungeness crabs, Hypoxia, Nutrient pollution, Eutrophication