Estimating the selectivity patterns of various fishing gears is a critical component of fisheries... more Estimating the selectivity patterns of various fishing gears is a critical component of fisheries stock assessment due to the difficulty in obtaining representative samples from most gears. We used short-term recoveries (n = 3587) of tagged red drum Sciaenops ocellatus to directly estimate age- and length-based selectivity patterns using generalized linear models. The most parsimonious models were selected using AIC, and standard deviations were estimated using simulations. Selectivity of red drum was dependent upon the regulation period in which the fish was caught, the gear used to catch the fish (i.e., hook-andline, gill nets, pound nets), and the fate of the fish upon recovery (i.e., harvested or released); models including all first-order interactions between main effects outperformed models without interactions. Selectivity of harvested fish was generally dome-shaped and shifted toward larger, older fish in response to regulation changes. Selectivity of caught-and-released red drum was highest on the youngest and smallest fish in the early and middle regulation periods, but increased on larger, legal-sized fish in the late regulation period. These results suggest that catch-and-release mortality has consistently been high for small, young red drum, but has recently become more common in larger, older fish. This method of estimating selectivity from short-term tag recoveries is valuable because it is simpler than full tag-return models, and may be more robust because yearly fishing and natural mortality rates do not need to be modeled and estimated.
Page 1. BAND RETURN MODELS: USE OF SOLICITED BANDS AND SEPARATION OF HUNTING AND NATURAL MORTALIT... more Page 1. BAND RETURN MODELS: USE OF SOLICITED BANDS AND SEPARATION OF HUNTING AND NATURAL MORTALITY KENNETH H. POLLOCK, Department of Statistics, Box 8203, North Carolina State University, Raleigh ...
Estimating the selectivity patterns of various fishing gears is a critical component of fisheries... more Estimating the selectivity patterns of various fishing gears is a critical component of fisheries stock assessment due to the difficulty in obtaining representative samples from most gears. We used short-term recoveries (n = 3587) of tagged red drum Sciaenops ocellatus to directly estimate age- and length-based selectivity patterns using generalized linear models. The most parsimonious models were selected using AIC, and standard deviations were estimated using simulations. Selectivity of red drum was dependent upon the regulation period in which the fish was caught, the gear used to catch the fish (i.e., hook-andline, gill nets, pound nets), and the fate of the fish upon recovery (i.e., harvested or released); models including all first-order interactions between main effects outperformed models without interactions. Selectivity of harvested fish was generally dome-shaped and shifted toward larger, older fish in response to regulation changes. Selectivity of caught-and-released red drum was highest on the youngest and smallest fish in the early and middle regulation periods, but increased on larger, legal-sized fish in the late regulation period. These results suggest that catch-and-release mortality has consistently been high for small, young red drum, but has recently become more common in larger, older fish. This method of estimating selectivity from short-term tag recoveries is valuable because it is simpler than full tag-return models, and may be more robust because yearly fishing and natural mortality rates do not need to be modeled and estimated.
Page 1. BAND RETURN MODELS: USE OF SOLICITED BANDS AND SEPARATION OF HUNTING AND NATURAL MORTALIT... more Page 1. BAND RETURN MODELS: USE OF SOLICITED BANDS AND SEPARATION OF HUNTING AND NATURAL MORTALITY KENNETH H. POLLOCK, Department of Statistics, Box 8203, North Carolina State University, Raleigh ...
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due to the difficulty in obtaining representative samples from most gears. We used short-term
recoveries (n = 3587) of tagged red drum Sciaenops ocellatus to directly estimate age- and length-based
selectivity patterns using generalized linear models. The most parsimonious models were selected using
AIC, and standard deviations were estimated using simulations. Selectivity of red drum was dependent
upon the regulation period in which the fish was caught, the gear used to catch the fish (i.e., hook-andline,
gill nets, pound nets), and the fate of the fish upon recovery (i.e., harvested or released); models
including all first-order interactions between main effects outperformed models without interactions.
Selectivity of harvested fish was generally dome-shaped and shifted toward larger, older fish in response
to regulation changes. Selectivity of caught-and-released red drum was highest on the youngest and
smallest fish in the early and middle regulation periods, but increased on larger, legal-sized fish in the
late regulation period. These results suggest that catch-and-release mortality has consistently been high
for small, young red drum, but has recently become more common in larger, older fish. This method of
estimating selectivity from short-term tag recoveries is valuable because it is simpler than full tag-return
models, and may be more robust because yearly fishing and natural mortality rates do not need to be
modeled and estimated.
due to the difficulty in obtaining representative samples from most gears. We used short-term
recoveries (n = 3587) of tagged red drum Sciaenops ocellatus to directly estimate age- and length-based
selectivity patterns using generalized linear models. The most parsimonious models were selected using
AIC, and standard deviations were estimated using simulations. Selectivity of red drum was dependent
upon the regulation period in which the fish was caught, the gear used to catch the fish (i.e., hook-andline,
gill nets, pound nets), and the fate of the fish upon recovery (i.e., harvested or released); models
including all first-order interactions between main effects outperformed models without interactions.
Selectivity of harvested fish was generally dome-shaped and shifted toward larger, older fish in response
to regulation changes. Selectivity of caught-and-released red drum was highest on the youngest and
smallest fish in the early and middle regulation periods, but increased on larger, legal-sized fish in the
late regulation period. These results suggest that catch-and-release mortality has consistently been high
for small, young red drum, but has recently become more common in larger, older fish. This method of
estimating selectivity from short-term tag recoveries is valuable because it is simpler than full tag-return
models, and may be more robust because yearly fishing and natural mortality rates do not need to be
modeled and estimated.