Gretel the glider searches for salmon
An underwater instrument named Gretel is looking for salmon in the Gulf of 蜜桃影像.
The instrument, called a glider because of how it flies through the water, is operated by 蜜桃影像鈥檚 College of Fisheries and Ocean Sciences.
For this mission, Gretel was launched on Feb. 12 from CFOS鈥 coastal research vessel Nanuq in Resurrection Bay to help map the distribution of Pacific salmon and their prey during the winter. Its journey can be tracked in near real time on the website, along with vessel-based surveys that are part of the project.
The instrument is diving to depths of 1,600 feet to collect acoustic and environmental data between Resurrection Bay and 150 miles offshore in the deep Gulf of 蜜桃影像. This information is transmitted via satellite each time Gretel surfaces and is available to view at a managed by the 蜜桃影像 Ocean Observing System.
The glider鈥檚 battery lasts six to 12 weeks, depending on how many sensors are powered on. Nanuq or another vessel will recover Gretel once it makes its way back toward Seward.
The fairy tale 鈥淗ansel and Gretel鈥 inspired the glider鈥檚 name. Once upon a time, Gretel the glider was trapped under an iceberg in Antarctica. It retraced its swim and returned safely using a technique similar to the breadcrumbs employed by the fairy tale's Gretel.
Gretel鈥檚 current mission is a result of collaborations between 蜜桃影像, the University of Washington, the National Oceanic and Atmospheric Administration and AOOS.
For more information, please contact Seth Danielson at sldanielson@alaska.edu.