GEAR UP 2009

Puget Sound in trouble: Threats and processes facing Washington's marine environment

Summer Institute: Summer 2009

GEAR UP student holding a starfishStudents from the 2009 GEAR UP Summer Institute were treated to two special marine biology labs taught by UW graduate students Mackenzie 'Mac' Gavery and Lisa Crosson from the UW School of Aquatic and Fishery Sciences (SAFS). The labs were designed to introduce students to some of the animals inhabiting Puget Sound and to teach them about the environmental threats facing this unique marine ecosystem. JISAO coordinated the sessions in partnership with SAFS and the GEAR UP Project.

Marine animals facing pollution and other threats to their environment

In Crosson'slab students had the opportunity to touch and hold several types of sea creatures including anemones, sea stars, bivalves, a large moon snail, and a brilliant orange sea cucumber. Students learned about each animal including where it lives, how it feeds, its unique characteristics and general role in the marine environment.

To illustrate the stress that animals experience when exposed to environmental pollutants, Crosson began the lab at a tank holding a hermit crab were students were given counters to record the number of times the crab's antennae flicked. After recording the movement for one minute Crosson then introduced a chemical stimulant - clam juice, which represented a food source for the crab - and students again recorded the movement of the crab's antennae for one minute. With the introduction of a stimulant student's observed that the antennae movement increased at a significant rate.

This simple experiment was used to demonstrate that marine animals respond significantly and immediately to stimuli, including stimuli that may have a detrimental effect upon their health especially with high concentrations and repeated exposure. Crosson used the example of Students feeding fish during GEAR UP labhormonal chemicals, such as those found in hormone replacement therapy and birth control pills, which end up in the Puget Sound from human waste after it has passed through sewage treatment facilities.

Eutrophication creating "dead zones" in Puget Sound and Hood Canal

In Gavery's lab students learned about eutrophication, a process that contributes to dead zones in Puget Sound and the Hood Canal where marine life can no longer survive because there is not enough oxygen in the water. One of the results of eutrophication is an algal bloom which is a rapid increase of algae. When the algae die they sink to the bottom where microorganisms feed on the dead and decaying organic matter.

The microorganisms utilize most of the oxygen in the water thus depleting the oxygen needed for marine life. As the oxygen content of the water decreases, marine animals can die in what is referred to as a "fish kill". In Gavery's lab students learned that dangerous algal blooms can be caused by excessive nutrients in the water that come from numerous sources including sewage, agricultural chemicals and animal waste, and fertilizers used on lawns.

GEAR UP students looking in microscopesTo illustrate how marine animals called filter feeders can help keep an aquatic system healthy, Gavery started her lab with an interesting experiment: she poured algae into a beaker that had about eight clams in the bottom; she poured the remaining algae into a second beaker of similar height that did not have clams. After approximately one hour the clams, which are filter feeders, had eaten all of the algae leaving the water clean and clear. During the remaining portion of the lab students used microscopes to identify some of the planktonic organisms living in the waters of the Puget Sound and they observed the process of filter feeding in musslels that had their shells removed. Students learned about the role of filter feeders in maintaining the health of Puget Sound and some of the dangers these important animals are facing from environmental pollutants and global warming.

Students gathered at the end of the labs to discuss ways to help save Puget Sound and identify simply things we can all do to reduce our impact on our local marine environment. For more information about Puget Sound and what you can do to preserve its unique biodiversity see: