A combined telemetry – tag return approach to estimate fishing and natural mortality rates of an estuarine fish
A joint analysis of tag return and telemetry data should improve estimates of mortality rates for exploited fishes; however, the combined approach has thus far only been tested in terrestrial systems. We tagged subadult red drum ( Sciaenops ocellatus ) with conventional tags and ultrasonic transmitt...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Main Authors: | , , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
2009
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Subjects: | |
Online Access: | http://dx.doi.org/10.1139/f09-076 http://www.nrcresearchpress.com/doi/full-xml/10.1139/F09-076 http://www.nrcresearchpress.com/doi/pdf/10.1139/F09-076 |
Summary: | A joint analysis of tag return and telemetry data should improve estimates of mortality rates for exploited fishes; however, the combined approach has thus far only been tested in terrestrial systems. We tagged subadult red drum ( Sciaenops ocellatus ) with conventional tags and ultrasonic transmitters over 3 years in coastal North Carolina, USA, to test the efficacy of the combined telemetry – tag return approach. There was a strong seasonal pattern to monthly fishing mortality rate (F) estimates from both conventional and telemetry tags; highest F values occurred in fall months and lowest levels occurred during winter. Although monthly F values were similar in pattern and magnitude between conventional tagging and telemetry, information on F in the combined model came primarily from conventional tags. The estimated natural mortality rate (M) in the combined model was low (estimated annual rate ± standard error: 0.04 ± 0.04) and was based primarily upon the telemetry approach. Using high-reward tagging, we estimated different tag reporting rates for state agency and university tagging programs. The combined telemetry – tag return approach can be an effective approach for estimating F and M as long as several key assumptions of the model are met. |
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