JARA: ‘Just Another Red-List Assessment’

Abstract

Identifying species at risk of extinction is necessary to prioritise conservation efforts. TheInternational Union for Conservation of Nature's (IUCN) Red List of Threatened Species is the global standard for quantifying extinction risk, with many species categorised on the basis of a reduction in population size (Criterion A). We introduce the Bayesian state-space framework 'JARA' (Just Another Red-List Assessment). Designed as an easy to use, rapid and widely applicable decision-support tool, JARA allows both process error and uncertainty to be incorporated into IUCN Red List assessments under criterion A. A key output of JARA is an easy to interpret graphic in which the probability distribution of the population decline is displayed against the IUCN Red List categories, where each category is assigned a probability given process and observation uncertainty. We provide fully commented R code on the global open-source platform GitHub (https://github.com/henning-winker/JARA), so that JARA can be modified and applied by conservation practitioners to their own count or relative abundance data. We illustrate the application of JARA using two real-world examples: (i) relative abundance indices from scientific trawl surveys for two elasmobranchs, Yellowspotted Skate Leucoraja wallacei and Whitespot smoothhound Mustelus palumbes; and (2) absolute abundance data (census counts) from the global Cape Gannet Morus capensis population.

Assessments of 16 Exploited Fish Stocks in Chinese Waters Using the CMSY and BSM Methods

“…Four of the sixteen stocks in the study, i.e., E. japonicus, Coilia mystus, L. polyactis and Muraenesox cinereus with more than one SSB or CPUE time series, we used a routine "Bcrumb, " to interpolate and average SSB or CPUE for them. This routine was developed as a component of JARA (Just Another Redlist Assessment) described in Winker and Sherley (2019). Moreover, considering the technological improvement of the fishery, the CPUE is corrected by 2% increases every year according to Palomares and Pauly (2019), given gear and other technological improvements of the industrial sector.…”

Estimating IUCN Red List population reduction: JARA—A decision‐support tool applied to pelagic sharks

“…), necessitating sensitivity and counterfactual analyses. A more objective solution is needed and although JARA is somewhat constrained by the values at the start and end of a timeseries (e.g., Figure S16), it is far less sensitive to outliers and more accurately captures the rate of population change than traditional regression approaches (Fox et al., ; Winker & Sherley, ). At the workshop, we found JARA especially useful in preventing the need to subjectively exclude putative outliers from individual timeseries.…”

“…Regional relative abundance datasets for each species were analyzed using JARA, a generalized BSSM tool for global extinction risk estimates under IUCN Red List Criterion A (Winker & Sherley, ; Sherley et al., in press). The input timeseries were either formal stock assessment outputs (trends in biomass), or standardized or nominal catch per unit effort (CPUE) from scientific surveys, fisheries data or bather protection nets, depending on the data available for each species and region (Table , see Supporting Information for details).…”

“…Here, we outline how a BSSM tool, Just Another Red List Assessment (JARA, https://github.com/henning-winker/JARA; Winker & Sherley, ; Sherley et al., in press), facilitated the assessment of 13 wide‐ranging pelagic and coastal‐pelagic sharks at an IUCN Species Survival Commission Shark Specialist Group (IUCN SSC SSG) Red Listing workshop (Dallas, USA, 5–9 November, 2018). We illustrate our approach using four circumglobal shark species: Blue Shark ( Prionace glauca ), Shortfin Mako ( Isurus oxyrinchus ), Dusky Shark ( Carcharhinus obscurus ), and Great Hammerhead ( Sphyrna mokarran ).…”

The conservation status and population decline of the African penguin deconstructed in space and time

“…To determine the trend and rate of change of the African penguin population, we used JARA, a generalized Bayesian state-space tool for IUCN Red List assessments under Criterion A (Winker et al, 2020) that has been applied recently to the Cape gannet Morus capensis (Sherley et al, 2019) and several pelagic sharks . JARA assumes that the underlying trend in the population (I t ) follows a conventional exponential growth model (Kéry & Schaub, 2012):…”