catchability {LobsterCatch}

This function calculates the probability of entry into a trap, also known as catchability. It includes the parameters described in Addison and Bell (1997), and can also incorporate the length of the catch while calculating the catchability.

Description

This function calculates the probability of entry into a trap, also known as catchability. It includes the parameters described in Addison and Bell (1997), and can also incorporate the length of the catch while calculating the catchability.

Usage

catchability(
  q0,
  qmin,
  saturationThreshold,
  Ct,
  lengthBased,
  lobLengthThreshold,
  lobSize = NA,
  sexBased,
  lobSex
)

Arguments

q0

is the initial probability of entry into an empty trap (range is from 0-1). Default value is 0.5.

qmin

is the asymptotic minimum probability of entry with default value being 0.

saturationThreshold

is the number of lobsters in a trap at which the probability of another lobster entering the trap is zero (i.e. no more entry due to agnostic behavior of trapped lobsters).

Ct

is the number of caught lobster

lengthBased

Logical. If TRUE the length of lobsters caught will be taken into account

lobLengthThreshold

Logical.If TRUE the carapace length (in milliliters) beyond which there is no chance of catching another lobster due to bold agnostic behavior of large lobsters.

lobSize

is a size frequency dataset that is representative of the population and can be incorporated to the model.

sexBased

Logical. If TRUE, lobster sex is taken into account and user must provide a list containing sex distribution for the simulated population

lobSex

is the sex of trapped lobster

Value

Returns the probability of entry to trap.

References

Julian T. Addison and Michael C. Bell (1997), Simulation modelling of capture processes in trap fisheries for clawed lobsters, Marine Freshwater Research, 48(8), 1035-1044, https://www.publish.csiro.au/MF/MF97169