The paper Low prey abundance leads to less efficient foraging behavior in Steller sea lions details research done by Elizabeth Goundie, David Rosen, and Andrew Trites, in order to explain the recent and significant decline of Steller sea lions. Steller sea lions are a specie of sea lion that live in the Gulf of Alaska and Bering sea, which is located in the Western part of Alaska. In Western Alaska, the four seasons are clearly distinguishable, and Western Alaska generally has warm summers, 15.5 degrees Celsius, and cold winters, at -15 degrees Celsius. Most rain occurs during the summertime in between the middle of June and until October. Western Alaska also has a coastline longer than most of the coastlines of the United States, and most …show more content…
The data was collected during the summertime, between the months of June and August of 2013. The sea lions that were used as a part of this experiment were collected from a rookery when they were still pups, and they dove regularly for 4 to 8 years in order to conduct research over the diving behaviors of Steller sea lions. The sea lions that were used in the experiment were acquainted with the research material that was being used during the progression of the experiment, and the experiment was done under the control of the trainer of the sea lions. The method used to record the diving metabolic rate of the sea lions was flow-through gas respirometry, and was recorded during the various foraging conditions simulated. Resting metabolic rate was measured through the use of a Plexiglass dome placed at the surface of the water, where air was drawn through the dome at the rate of 475 L min^-1. The amounts of carbon dioxide and oxygen were recorded using a Sable System and CA-1B analyzers, that were connected to a 500H flow generator. The measurements were taken every .5 seconds that elapsed. The data the was collected was analyzed using LabAnalyst X, and the rate of oxygen consumption was determined by the change in the concentrations of gas from the baseline level. Pre-dive metabolic rates were recorded when each sea lion was at the surface of the water resting and in the dome, and this measurement was collected during the last two minutes of a resting period of 5-10 minutes. Rates of oxygen consumption post-dive were collected to represent the amount of oxygen used during the dive as well as the amount of oxygen used to return within 5% of the recovery time. The average metabolic rate was determined by the dive cycle and the duration of the dive cycle, and was calculated by