Description Usage Arguments Details Value Author(s) References See Also Examples
View source: R/largeFishIndicator.R
This function calculates the Large Fish Indicator (LFI) for j areas and i years.
largeFishIndicator(X_length, group, species.table = NULL, metric = "BIOMASS", large.fish = 35, years)
A dataframe of fishery independent data derived from research
vessel survey data or model output, with columns
character string indicating which species to include in the
indicator calculation. If
A table where the column names match the entries in
A character string indicating which column in
Threshold for large fish (cm). Default is
A vector of years for which to calculate indicator.
Large Fish Indicator (LFI):
LFI = Σ B_m(L >35 cm)/Σ B_m
B_m is biomass of individuals in a body size class centered at mass m, and L is the length (cm) of an individual. This indicator describes the proportion (by weight) of the fish community that is larger than some length threshold (default here is 35 cm, i.e., the proportion of biomass occupying the top predator trophic level; Greenstreet and Rogers, 2006).
Returns a dataframe with 3 columns.
If there are no observations of large fish or no observations in
for spatial scale j in year i, indicator value is assigned
Danielle Dempsey Danielle.Dempsey@dfo-mpo.gc.ca, Adam Cook, Catalina Gomez, Alida Bundy
Bundy A, Gomez C, Cook AM. 2017. Guidance framework for the selection and evaluation of ecological indicators. Can. Tech. Rep. Fish. Aquat. Sci. 3232: xii + 212 p.
Greenstreet SPR and Rogers SI. 2006. Indicators of the health of the fish community of the North Sea: identifying reference levels for an Ecosystem Approach to Management. ICES J. Mar. Sci., 63: 573–593.
ICES. 2006. Report of the Working Group on Ecosystem Effects of Fishing Activities. ICES Document CM 2006/ACE: 05. 174 pp.
Other ecosystem structure and function indicators:
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# Compile data data(X_length) data(species.table) # Calculate indicator largeFishIndicator(X_length, group = "FINFISH", species.table = species.table, metric = "BIOMASS", years = c(2014:2019))
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