Meeting Abstract

P2.5  Jan. 5  Sampling Ocean Temperature Using Elephant Seals as Platforms: Behavior and Sampling Frequency Effects on Data Quality. SIMMONS, S.E.*; TREMBLAY, Y.; COSTA, D.P.; UC Santa Cruz; UC Santa Cruz; UC Santa Cruz simmons@biology.ucsc.edu

In recent years with technological advances, instruments deployed on diving marine animals have been used to sample the environment in addition to their behavior. Of all oceanographic variables one of the most valuable and easiest to record is temperature. Here we report on a series of lab calibration and field validation experiments that consider the accuracy of temperature measurements from animal borne ocean samplers. Additionally we consider whether sampling frequency or animal behavior affects the quality of the temperature data collected by marine animals. Rapid response, external temperature sensors on eight Wildlife Computers MK9 time-depth recorders (TDRs) were calibrated against a platinum thermistor standard. TDR performance in the field was validated by comparisons with temperature data from a Seabird CTD. In April/May of 2004, casts to 200m were performed over the Monterey Canyon using a CTD array carrying MK9s. Casts were performed before and after releasing a juvenile elephant seal from the boat. The seal was also carrying an MK9 TDR, to assess any animal effect on temperature profiles. Sampling frequency during these field validations was set at one second intervals and the data from TDRs on both the CTD and the seals was sub-sampled at four, eight, 30 and 300 (5 min) seconds. The sub-sampled data were used to determine thermocline depth, a thermocline depth zone and temperature gradients and assess whether sampling frequency or animal behavior affects the quality of temperature data. Preliminary analyses indicate that temperature sensors deployed on elephant seals can provide water column temperature data of high quality and precision.