R: Data: Tow Information from Longspine Thornyhead Survey
towData
R Documentation
Data: Tow Information from Longspine Thornyhead Survey
Description
PolyData of tow information for a longspine thornyhead survey (2001).
Usage
data(towData)
Format
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.
Note
In R, the data must be loaded using the data function.
Source
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.
References
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 Sciences2421, 60 pp.