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Wargo Rub AM, Sandford BP
Evidence of a ‘dinner bell’ effect from acoustic transmitters in adult Chinook salmon
This study provides field-based evidence of the ‘dinner bell’ effect whereby marine mammals can hear or otherwise sense soundwaves produced by acoustic transmitters and use these signals to assist them in foraging. We compared survival between adult Chinook salmon implanted with passive integrated transponder (PIT) tags and those implanted with both active and inactive acoustic transmitters. Survival for fish implanted with PIT tags and inactive acoustic transmitters was significantly higher than for fish implanted with active acoustic transmitters. Our study area was replete with pinnipeds and we concluded that predation was the cause of these survival differences. Our findings call into question results of survival studies based solely on acoustic telemetry in areas where marine mammals may be present.