Data used to estimate mortality rates of winter skate in the southern Gulf of St. Lawrence and on the Eastern Scotian Shelf.
Ecological Archives A019-055-S1.
Authors
File list (downloads)
Description
Douglas P. Swain
Fisheries and Oceans Canada
Gulf Fisheries Centre
Moncton, New Brunswick, E1C 9B6, Canada
E-mail: doug.swain@dfo-mpo-gc.caIan D. Jonsen
Fisheries and Oceans Canada
Bedford Institute of Oceanography
Dartmouth, Nova Scotia, B2Y 4A2, Canada
E-mail: ian.jonsen@dfo-mpo.gc.caJames E. Simon
Fisheries and Oceans Canada
Bedford Institute of Oceanography
Dartmouth, Nova Scotia, B2Y 4A2, Canada
E-mail: jim.simon@dfo-mpo.gc.caRansom A. Myers
Department of Biology
Dalhousie University
Halifax, Nova Scotia, B3H 4J1, Canada
(deceased)
EasternScotianShelf_WinterSkate_Zdata.csv contains time series of relative abundance for winter skate on the eastern Scotian Shelf. These abundance indices are based on catch rates in an annual bottom-trawl survey adjusted for size-selectivity as described in Appendix B. These data were inputs to models used to estimate total mortality rates (Z) of winter skate on the eastern Scotian Shelf (e.g., model 1 in Appendix D). Juv1 is the abundance index for juvenile stage 1, defined as skates 36 – 59 cm in total length (TL). Juv2 is the abundance index for juvenile stage 2 (60 – 74 cm TL). Adult is the abundance index for adult skates (TL 75 cm or more). Checksum values are: Juv1 141.1812435, Juv2 42.48867236, Adult 61.60407165.
SouthernGulfStLawrence_WinterSkate_Mdata.csv contains abundance indices and estimates of discarded catch for winter skate in the southern Gulf of St. Lawrence as well as potential covariates of natural mortality for this population. The abundance indices are based on catch rates in an annual bottom-trawl survey adjusted for catchability and availability as described in Appendix B. These data were inputs to models used to estimate natural mortality rates (M) of winter skate in the southern Gulf of St. Lawrence (e.g., model 2 in Appendix D). Descriptions and checksum values for the columns are:
juv.absD: the abundance index for juvenile skate (TL 21 – 41 cm), scaled to estimated absolute abundance (millions) at daytime catchability (checksum: 112.0066529).
ad.absD: the abundance index for adult skate (TL 42 cm or more), scaled to estimated absolute abundance (millions) at daytime catchability (checksum: 82.28637812).
juv.disc: discarded catch (millions) of juvenile skate (checksum: 3.873395661).
ad.disc: discarded catch (millions) of adult skate (checksum: 12.64364398).
seals: estimated total abundance of grey seals in the Gulf of St. Lawrence herd (checksum: 1048800).
lcod: an index of the relative abundance of large cod (TL 60 cm or more) in the southern Gulf of St. Lawrence, based on mean catch rates in the annual bottom-trawl survey (checksum: 225.637674).
intemp: an index of the mean temperature in September in shallow inshore waters of the southern Gulf of St. Lawrence (checksum: 444.01)
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