Many crab fisheries prohibit the harvest of females, e.g. Queensland’s blue swimmer crab pot fishery (Clarke and Ryan, 2004). In Thailand, harvest of females and spawning females is allowed year-round, except during October to December, when taking females with eggs outside the shell is prohibited. Such a short-term restriction being enforced to a
certain group in the population is unlikely to prevent doing harm to the stock, which may be reflected in the higher proportion of females found in the catches in all seasons and, also, the bycatch of egg-bearing females during the restriction. Furthermore, the restriction only covered a small portion of the intensive spawning period, which extends into the hot season (March to early May) (Figure 8). Our interview with the fishers implied that the stock could also be harmed by the fishers’ preference for catching spawning females, especially egg-bearing females, as they provide higher biomass than other crabs. In the Chonburi crab fishery, lenient regulations and fishers’ preference for spawning females are important pressures on the stock.