A stock assessment of blue swimming crab (BSC) in the waters of Kien Giang Province in 2013 (Ha et al. 2014) marked the first study of its kind for the species in the Sea of Vietnam. Data for the study was collected from landing surveys, fisher logbooks, on board surveys, and random biological sampling of commercial catch data. Biological data was used to estimate size distribution, size-weight relationship, size at first maturity, sex ratio, and spawning season. Fishery data was assessed to estimate total annual catch and catch per unit effort, as well as spatial and temporal distribution of catches, fleet and gear specific catch rates and bycatch statistics. Biomass and fishing mortality (F) were estimated via length cohort analysis based on length frequency data, growth parameters, estimated natural mortality, and total annual catch. Fishing mortality reference points Fmsy and F0.1 were estimated via Yield per Recruit analysis (Beverton and Holt model).
Updated assessments of the stock condition in 2014 (Ha et al. 2015, report unavailable) and 2015 (Ha et al. 2016) have been conducted. As of January 15, 2018, there were no more recently published stock assessments available. The 2013 stock assessment was reportedly reviewed by at least one independent scientist (Poseidon ARM Ltd. 2014).
Continued development and regular updating of stock assessments is a priority detailed within the Kien Giang Fishery Improvement Project (FIP) action plan (Poseidon ARM Ltd. 2017) . Specific actions needed to strengthen the stock assessment include assessment of stock and fishery independence with surrounding fisheries, evaluation of how well management actions are achieving their objectives, re-assessment of the number of active fishing vessels in the fishery, development of the model to estimate fishery reference points and performance in terms of biomass rather than fishing mortality, incorporation of statistical error in the model, and consideration of error (statistical and otherwise) when developing harvest control rules.
Scientific advice to date has been taken from stock assessments developed by scientists at the Research Institute for Marine Fisheries (RIMF) (Ha et al. 2016)(Ha et al. 2014)(Ha et al. 2016) . As of the most recent stock assessment, there were only 3 years of biomass estimates available, and abundance based reference points had not yet been developed; thus objectives continue to be framed in terms of fishing mortality and effort management. Since the initial assessment, advice has focused on effort reduction strategies for meeting objectives for fishing mortality "F" or exploitation coefficient (exploitation ratio) "E" .
The 2015 assessment specifically recommended the elimination of Chinese traps, which exploit large numbers of juvenile crab, as well as measures to avoid fishing on nursery grounds after peak spawning, in order to optimize potential regeneration and recovery of the stock (Ha et al. 2016) .
The 2013 stock assessment identified target (Fmsy = 0.8) and precautionary (F0.1 = 0.6) reference points, based on Yield per Recruit analysis (Ha et al. 2014) . The comparative fishing mortality estimate at the time, Fcurrent , was estimated to be 0.1. Updates to the YPR analysis have not been presented in subsequent stock assessments (Ha et al. 2016)(Ha et al. 2016) , which have reported the exploitation coefficient "E" from length cohort analyses as the relative indicator of fishing effort.
The 2015 assessment specifically recommended the elimination of Chinese traps, which exploit large numbers of juvenile crab (Ha et al. 2016) .
The only published reference points for this stock relate to fishing mortality; biological reference points against which current biomass estimates can be directly compared are not available. Based on the 2013 stock assessment, the stock was overexploited, with Fcurrent exceeding Fmsy by 20%, and the exploitation rate "E" 14% over the assumed optimal rate of 0.5. The most recent available stock assessment (Ha et al. 2016) indicated that effort had since decreased to 10% over the optimal threshold, and biomass had increased from 5,200 tonnes in 2014 to 6,100 tonnes in 2015 (though still less than the 7,100 tonnes estimated in 2013). It was noted in the 2016 FIP Action Plan (Poseidon ARM Ltd. 2017) that the status of the stock was now considered to be above the limit reference point. However, the specific benchmarks and statistics informing this determination are not explicit in FIP documents, or in the 2015 or 2016 stock assessment reports (Ha et al. 2016)(Ha et al. 2016) . A decreasing trend is observed in the proportion of immature versus mature crab in the stock biomass from 2013 to 2015 (Ha et al. 2016).
The fishery supports a workforce numbering in the dozens of thousands (Ha et al. 2016) . In 2009, it was estimated that there were 3,823 fishing vessels in the Kien Giang BSC fleet (Ha et al. 2014). A survey of the fleet in 2013 found there were 1,718 vessels registered for BSC fisheries.
Size and catch rates of BSC vary by fleet, gear, area and time of year (BSC are exploited year round) (Ha et al. 2014)(Ha et al. 2016) . In 2013, 53% of the catch by volume was taken by the 1,337 boat gillnet fleet, and 47% was captured by the 381 boat trap fleet. Proportions were similar in 2015 (55% by gillnet, and 45% by trap). The average landing size of crab caught was shown to have increased overall from the 2015 to the 2016 stock assessment, though size composition varied greatly by gear type (Ha et al. 2016). Relative to gillnets, traps ("normal" and Chinese) disproportionally exploit smaller size, immature crab. The majority of trap caught crab, and the smallest average size crab are taken by Chinese trap. In 2015, 57.5% of the individual crab were caught by Chinese trap, and of these 87% were immature. The overall portion of the catch in the Chinese trap increased by both number and volume from 2014 to 2015.
A decline in the total catch from 11,300 tonnes in 2008, to 7,800 tonnes in 2013 was interpreted as an indication of decreased abundance due to overfishing (Ha et al. 2016). Catch volume continued to decrease in 2014 (6,200 tonnes) despite indications of increased fishing pressure (Ha et al. 2016). In 2015, catches were just slightly lower (6,100 tonnes), while an apparent decrease in fishing effort was indicated compared to 2013 and 2014. Because there have been no recent fleet surveys, it is assumed for stock assessment purposes that the number of boats estimated in 2013 has remained constant (Ha et al. 2016) . The 2015 stock assessment highlighted this as a potential source of error.
Relative to gillnets, traps ("normal" and Chinese) disproportionally exploit smaller size, immature crab. The majority of trap caught crab, and the smallest average size crab are taken by Chinese trap. In 2015, 57.5% of the individual crab were caught by Chinese trap, and of these 87% were immature. The overall portion of the catch in the Chinese trap increased by both number and volume from 2014 to 2015 (Ha et al. 2016) .