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Estimating Fish Mortality Rates Using Telemetry and Multistate Models
Author(s) -
Hightower Joseph E.,
Harris Julianne E.
Publication year - 2017
Publication title -
fisheries
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 79
eISSN - 1548-8446
pISSN - 0363-2415
DOI - 10.1080/03632415.2017.1276347
Subject(s) - telemetry , fishing , statistics , stock assessment , mark and recapture , environmental science , fish <actinopterygii> , mortality rate , fishery , computer science , mathematics , biology , demography , population , telecommunications , sociology
We simulated and evaluated multistate capture–recapture models to estimate mortality rates using telemetry data. Four field designs were considered: (A) fixed receivers to estimate total instantaneous mortality ( Z ), (B) manual searches to estimate instantaneous fishing ( F ) and natural ( M ) mortality, (C) fixed receivers combined with external high‐reward tags to estimate F and M , and (D) manual searches combined with external high‐reward tags to estimate M and fishing mortality rates associated with harvest ( F h ) and catch‐and‐release death ( F cr ) as well as the probability of death due to catch and release (α). Estimates generally appeared to be unbiased for a simulated study with five periods and releases of telemetered fish at the start of periods 1–4. Compared to estimating Z , larger sample sizes are needed to achieve reliable estimates of component rates ( F and M ). Estimates of component rates were more precise when that source of mortality was directly observed ( M in design B, F in design C). The field design using fixed receivers and high‐reward tags should be especially useful in practice, because manual searches are not required to estimate F and M . Multistate models are useful for clarifying the connection between field observations and ecological processes. Reliable estimates of mortality rates, coupled with information on behavior, habitat use, and movement, make telemetry a highly valuable tool for improving fisheries management and stock assessment.