Eriocheir sinensis during the fishing season in Jiuduansha, Yangtze River estuary, between 2006 and 2011. The annual yield ranged from 93.3 to769.5 kg/ship (mean: 481.5 kg); the average daily catch ranged from 6.2 to 26.5 kg (mean: 18.5 kg); the total number of crabs captured ranged from 984 to 7 547 (mean: 4 129); the average individual weight ranged from 89.5 to 114.5 g/ind (mean: 100.7 g/ind); the percentage of male crabs ranged from 65.80% to 80.54% (mean: 74.35%); and the average yield of the ships tended to fluctuate among seasons, but generally increased over time with a peak in 2010. The average harvest weight declined after initially increasing, and peaked in 2008. The maximal daily catch generally occurred in early December, but was as early as November 24 (in 2009) and as late as December 12 (in 2010). The percentages of fishing occurring in the early fishing season, peak fishing season, and late fishing season ranged from 4.25%–38.48%, 37.92%–72.81%, and 1.77%–34.00%, respectively. At the beginning of fishing season, the large crabs constituted a higher percentage of the catch and male crabs were more abundant than females. However, the quantity of small crabs in the harvest increased and the size of crabs tended to decrease over time during the seasons. Furthermore, the percentage of female crabs in the harvest increased during the season, resulting in a similar total harvest of male and female crabs. The total catch was significantly correlated to water temperature and tides. Typically speaking, the peak fishing season period starts when the water temperature reaches ~13and the maximal daily catch occurs in temperatures ranging from 10–13.5 The majority of harvest occurred during low tides (maximum: 95.79% in 2008, minimum: 73.41% in 2010).