TimeDiffStu: Calculates Fishing Times of Sturgeon Trammel Net.

In jasondubois/sportfish: Methods and Function for CDFW Sportfish Unit Data

Description

The CDFW Sturgeon mark-recapture study uses trammel nets to catch sturgeon. Times are recorded four times: twice during deployment and twice during retrieval. TimeDiffStu calculates time differences between retrieval and deployment to ultimately calculate fishing effort. See 'Details' for further information.

Usage

TimeDiffStu(sStart, sEnd, rStart, rEnd)

Arguments

sStart	date-time object. Time first bit of webbing entered water.
sEnd	date-time object. Time last bit of webbing entered water.
rStart	date-time object. Time first bit of webbing pulled from water.
rEnd	date-time object. Time last bit of webbing pulled from water.

Details

Calculated differences are in hours. The returned list contains 5 such calculations as explained below.

• TFT (total fishing time)

• ST (soak time)

• TST (true soak time)

• ETST (estimated true soak time)

• TOEST (true or estimated soak time)

TFT = \code{rEnd} - \code{sStart}

ST = \code{rEnd} - \code{sEnd}

TST = (\code{rStart} - \code{sEnd}) + 0.5 * (\code{rEnd} - \code{rStart}) + 0.5 * (\code{sStart} - \code{sEnd})

ETST = 0.138 + (0.687 * \code{ST})

If ST is NA, then ETST defaults to 1.067. If TST is NA, then ETST is used.

Return list also includes unit of time (currently hours) and function to calculcate effort using TOEST.

Time difference calculations created by M. Donnellan. (<some reference to metadata here for further understanding of calcs.>)

Value

list. See 'Details' for desription of list elements.

Examples

# coming soon.

jasondubois/sportfish documentation built on July 3, 2020, 1:01 p.m.