An integrated tagging model to estimate mortality rates of Albemarle Sound – Roanoke River striped bass

Abstract

We developed an integrated tagging model to estimate mortality rates and run sizes of Albemarle Sound – Roanoke River striped bass (Morone saxatilis), including (i) a multistate component for telemetered fish with a high reward external tag; (ii) tag return components for fish with a low reward external or PIT tag; and (iii) catch-at-age data. Total annual instantaneous mortality was 1.08 for resident (458–899 mm total length, TL) and 0.45 for anadromous (≥900 mm TL) individuals. Annual instantaneous natural mortality was higher for resident (0.70) than for anadromous (0.21) fish due to high summer mortality in Albemarle Sound. Natural mortality for residents was substantially higher than currently assumed for stock assessment. Monthly fishing mortality from multiple sectors (including catch-and-release) corresponded to seasonal periods of legal harvest. Run size estimates were 499 000–715 000. Results and simulation suggest increasing sample size for the multistate component increases accuracy and precision of annual estimates and low reward tags are valuable for estimating monthly fishing mortality rates among sectors. Our results suggest that integrated tagging models can produce seasonal and annual mortality estimates needed for stock assessment and management.

Estimates of Red Drum Mortality via Acoustic Telemetry

“…Mortality of fishes is an essential piece of information for proper fisheries management, stock assessment, and the continued persistence of valuable fish stocks in response to variable fishing and environmental pressures (Hilborn and Walters 1992;Harris and Hightower 2016;Hightower and Harris 2017). Fish mortality rates can be obtained using a variety of techniques, such as catch curve analysis (Ricker 1975;Hilborn and Walters 1992), longevity estimators (Hoenig 1983;Hewitt and Hoenig 2005;Then et al 2015), and/or mark-recapture models (Pine et al 2003(Pine et al , 2013.…”

Symposium Review: Using Electronic Tags to Estimate Vital Rates in Fishes

“…). Next, acoustic, PIT, and conventional tags were analyzed by an integrated multistate model to estimate F from multiple fisheries, M , and discard mortality for Striped Bass (Harris; Harris and Hightower ).…”

“…An added benefit of combining high‐reward and telemetry tags is the ability to estimate population‐level estimates of catch‐and‐release mortality (Kerns et al. , ; Harris and Hightower ). In addition to high cost, there were concerns regarding tag failure and limited detection range.…”

“…The following talk described the use of multiple tags and a large-scale receiver array to examine survival of Gulf Sturgeon Acipenser oxyrinchus desotoi from multiple Gulf of Mexico rivers; this talk stressed the importance of simulation in study design and the possibility of tag failure in a long-lived fish (Pine, University of Florida; Rudd et al 2014). Next, acoustic, PIT, and conventional tags were analyzed by an integrated multistate model to estimate F from multiple fisheries, M, and discard mortality for Striped Bass Harris and Hightower 2017).…”

“…For example, Hightower and Harris (2017) describe two telemetry study designs that include high-reward conventional tags. An added benefit of combining high-reward and telemetry tags is the ability to estimate population-level estimates of catch-and-release mortality (Kerns et al 2012(Kerns et al , 2016Harris and Hightower 2017). In addition to high cost, there were concerns regarding tag failure and limited detection range.…”