Event Title

Developing a head mounted RFID reader to detect salmon smolt consumption with a wild harbour seal

Presentation Abstract

Estimating predation rates on juvenile salmonids is challenging due to the scarcity of reliable data. Opportunities to address the data gap now exist as new sensors are incorporated into telemetry packages that can be deployed across the Salish Sea. Here we report on the development of a field ready sampling scheme for a novel, head-mounted radio frequency identification (RFID) reader designed to detect tagged juvenile salmon as they are consumed by pinnipeds. Feeding trials were conducted in a controlled setting over 8 weeks with a wild-caught harbor seal (Phoca vitulina) and live coho salmon smolts (Oncorhynchus kisutch) carrying passive integrated transponder (PIT) tags. We calculated the passage rates of 4 PIT tag types to maximize fish detections and explored smart sub-sampling techniques to minimize costly RFID field power consumption by logging PIT IDs (8 Hz) and measuring head-strike acceleration (250 Hz) during prey capture attempts. Analyses of the archival instrument revealed that 100% of consumed smolts were detected (n = 505), that time in the RFID field was unrelated to smolt length (R2 < 0.20), and that passage rates were significantly different for each PIT tag class (F3, 501 = 317, p <0.001). Notably, PITs were detected for significantly shorter durations (means < 0.35 sec) during unsuccessful captures (n = 200, p < 0.001) suggesting that false positives may be easily screened from field data. By recording prey capture attempts in a laboratory setting, we developed a behavior based sampling scheme that would significantly extended future field deployments while maximizing the likelihood of detecting consumption of juvenile salmon. We also demonstrated that acceleration based triggers could be useful to activate a variety of on-board sensors or to moderate sampling rates for instrumented free-ranging marine predators.

Session Title

The Salish Sea Marine Survival Project- Novel Approaches, Project Status and Key Findings

Conference Track

Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)

Document Type

Event

Location

2016SSEC

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Comments

Speed talk preferred

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This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

Text

Language

English

Format

application/pdf

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Developing a head mounted RFID reader to detect salmon smolt consumption with a wild harbour seal

2016SSEC

Estimating predation rates on juvenile salmonids is challenging due to the scarcity of reliable data. Opportunities to address the data gap now exist as new sensors are incorporated into telemetry packages that can be deployed across the Salish Sea. Here we report on the development of a field ready sampling scheme for a novel, head-mounted radio frequency identification (RFID) reader designed to detect tagged juvenile salmon as they are consumed by pinnipeds. Feeding trials were conducted in a controlled setting over 8 weeks with a wild-caught harbor seal (Phoca vitulina) and live coho salmon smolts (Oncorhynchus kisutch) carrying passive integrated transponder (PIT) tags. We calculated the passage rates of 4 PIT tag types to maximize fish detections and explored smart sub-sampling techniques to minimize costly RFID field power consumption by logging PIT IDs (8 Hz) and measuring head-strike acceleration (250 Hz) during prey capture attempts. Analyses of the archival instrument revealed that 100% of consumed smolts were detected (n = 505), that time in the RFID field was unrelated to smolt length (R2 < 0.20), and that passage rates were significantly different for each PIT tag class (F3, 501 = 317, p <0.001). Notably, PITs were detected for significantly shorter durations (means < 0.35 sec) during unsuccessful captures (n = 200, p < 0.001) suggesting that false positives may be easily screened from field data. By recording prey capture attempts in a laboratory setting, we developed a behavior based sampling scheme that would significantly extended future field deployments while maximizing the likelihood of detecting consumption of juvenile salmon. We also demonstrated that acceleration based triggers could be useful to activate a variety of on-board sensors or to moderate sampling rates for instrumented free-ranging marine predators.