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.
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.
In time, lower dissolved oxygen worsened by climate change could increase the abundance of rare species in Puget Sound while putting populations of more common species into a tailspin. Part three of our series "Oxygen for life" looks at how warmer waters will gradually make it harder for many sea creatures to breathe.
Biologists are intrigued by the prospect of island-hopping cougars in the Salish Sea. Could swimming ability lead to improved genetic diversity among the big cats?
Diverse communities of microscopic organisms called phytoplankton make up the base of the aquatic food web. In that role, they are essential to the tiny animals that eat them, but phytoplankton are not dependent on others. Thanks to chlorophyl, these tiny organisms can generate their own energy from nutrients and sunlight. Despite their critical importance to a great diversity of sea life in Puget Sound, phytoplankton can also contribute to low-oxygen conditions, and some can be harmful in other ways.
In a new series we are calling Ask a Scientist we interview local researchers to get their thoughts on some of the important but lesser-known scientific facts about the Puget Sound ecosystem. Today, we speak with University of Washington oceanographer Parker MacCready about Puget Sound’s “underwater Amazon” and why it has profound implications for Puget Sound science and policy. It all begins, he says, with the mixing of fresh and salt water and something called the estuarine exchange flow.
Where do Protection Island's rhinoceros auklets go to find their food? Scientists hope GPS tags will offer new insight into the bird's still mysterious foraging behavior. Biologist and science writer Eric Wagner reports from the field.
A new report says further study may reveal why experts cannot find expected benefits to salmon populations, despite widespread use of wood in stream restorations.
