towData: Data: Tow Information from Longspine Thornyhead Survey

Description Usage Format Note Author(s) Source References See Also


PolyData of tow information for a longspine thornyhead survey (2001).




Data frame consisting of 8 columns: PID = primary polygon ID, POS = position of each vertex within a given polygon, X = longitude coordinate, Y = latitude coordinate, depth = fishing depth (m), effort = tow effort (minutes), distance = tow track distance (km), catch = catch of longspine thornyhead (kg), and year = year of survey. Attributes: projection = "LL", zone = 9.


In R, the data must be loaded using the data function.


Nicholas M. Boers, Associate Professor – Computer Science
MacEwan University, Edmonton AB
Last modified Rd: 2008-09-03


The GFBio database, maintained at the Pacific Biological Station (Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7), archives catches and related biological data from commercial groundfish fishing trips and research/assessment cruises off the west coast of British Columbia (BC). The longspine thornyhead (Sebastolobus altivelis) survey data were extracted from GFBio. Information on the first 45 tows from the 2001 survey (Starr et al. 2002) are included here. Effort is time (minutes) from winch lock-up to winch release.


Starr, P.J., Krishka, B.A. and Choromanski, E.M. (2002) Trawl survey for thornyhead biomass estimation off the west coast of Vancouver Island, September 15 - October 2, 2001. Canadian Technical Report of Fisheries and Aquatic Sciences 2421, 60 pp.

See Also

makeProps, PolyData, towTracks.

PBSmapping documentation built on Jan. 15, 2021, 3:41 p.m.