Summary Report of a Workshop on Daylight Measurements for Geolocation in Animal Telemetry

The ability to monitor the detailed geographical movements of fish in the open sea is problematic. Active tracking (e.g., from a research vessel using acoustic devices) is expensive and time-consuming, and radio-based satellite tracking is not normally an option because of the inability to transmit radio signals through sea water. In recent years, various groups of scientists have been using ambient daylight recorded by electronic archival (data storage) tags to estimate the geographical position of fish (Gunn et al., 1994), birds (Wilson et al., 1992), and mammals (Delong et al., 1992; Hill, 1994).