fishmove (version 0.3-3)

fishmove.query: Prediction of Probabilities of Fish Movement/Occurrence based on Leptokurtic Dispersal Kernels

Description

Function to predict probabilities of fish movement/occurrence based on leptokurtic dispersal kernels fitted via multiple regression.

Usage

fishmove.query(fishmove,p=0.67,dist=NA,fromto=NA,prob=NA,reach=NA,w=1,level="fit",...)

Arguments

fishmove

Output object (predicted dispersal kernel) from fishmove. If fishmove-kernel is predicted for multiple values e.g. of stream order, only first values are used for subsequent query.

p

Share of stationary component on the population (0-1). The default value for p is 0.67.

dist

Optional argument for distance (distance from source) where the user wants to know the kernel probability (height of the dispersal density kernel)

fromto

Optional argument for a segment (defined by from distance - to distance) where the user wants to know the cumulative kernel probability (Integral: area under dispersal density kernel between from and to.)

prob

Optional argument: Reverse argument of distance/from to. Probability is provided and distance from source is calculated. Argument used in combination with reachlength.

reach

Optional argument: Length of receiving reach. Argument used in combination with prob.

w

Optional argument: Weighting factor for the dispersal kernel e.g. weight by source population size. When weight is use area under dispersal kernel (and thus the overall cumulative probability) equals the weigthing factor. The default value for weight is 1.

level

If statistical interval is calculated with fishmove, level defines if upper ("upr") or lower ("lwr") level of the calculted interval is used. The default value for level is "fit".

...

do not use.

Value

out

distance (in m) or probability depending on the input

Details

fishmove.query allows querying the dispersal kernel (predicted from fishmove) for several questions e.g.:

(i) what is the probability of occurence in a distance x (distance) from the source population (ii) what is the cumulative probability of occurence in a target reach between from/to distance (fromto) from the source population. (Integral: area under dispersal density kernel between from and to) (iii) where (distance, with a given reach length) is a certain probability (prob) of occurence on the dispersal kernel. So output here is a distance. The movement parameters are calculated by fishmove for a stationary ($sigma_stat$) and for a mobile component ($sigma_mob$) of a fish population. The queried probabilities and distances depend on the parameters defined during the prediction of fishmove e.g. fishlength, aspect ratio, stream order etc. as well as on the share of the stationary component (p) the kernel weighting factor (weight) and the level (level).

References

Radinger, J. and Wolter C. (2014) Patterns and predictors of fish dispersal in rivers. Fish and Fisheries. 15:456-473. DOI: http://dx.doi.org/10.1111/faf.12028.

See Also

fishmove, pdk

Examples

	# Prediction for a selected fish species
	fm <- fishmove(L=100, AR=1.5, T=365, rep=20)
  
  # Query using fishmove.query
  
  # at which distance is the cumulative probability (area under kernel) of a 50 m reach 0.06
  # fishmove.query(fm,prob=0.06,reachlength=50)
  # what is the probability of occurence in a reach between 0 and 50 m from the source population
  fishmove.query(fm,from=0,to=50)