Sustainable farming practices of the Chinese mitten crab (Eriocheir sinensis) around Hongze Lake, lower Yangtze River Basin, China

Abstract

Results of a survey of 156 Chinese mitten crab (Eriocheir sinensis) grow-out farms around Hongze Lake (118.48-118.72°E; 33.36-33.38°N) are reported. Area farmed has remained relatively unchanged but production (59 932 t in 2012) increased steadily over the last 7 years, indicative of the viability and sustainability of the farming system that has gradually replaced intensive Chinese major carp polyculture around Hongze Lake. Results showed that production range was 135-2400 kg ha -1 cycle -1 (mean 1144 ± 34). Crab yields correlated linearly to stocking density and conformed to a normal distribution curve, with 66.7 % of farms yielding 900 kg ha -1 cycle -1 or more. Yield was negatively correlated to pond size and capture size (p\0.01), and farms with macrophyte coverage rate lower than 30 % of water surface were significantly (p\0.05) lower than those exceeding 30 %.

Farming system transformation yields significant reduction in nutrient loading: Case study of Hongze Lake, Yangtze River Basin, China

“…1). The relevant details of the mitten crab farming practices around Hongze Lake have been described previously (Wang et al, 2016).…”

“…Tables 1 and 2 show the amounts of TNL and TPL per hectare of mitten crab farming for each of the three feed types used and the total, respectively. In this computation the findings that 21% and 23% of farms surveyed used trash fish and pellet feed respectively, and 56% of farms surveyed used the combination of trash fish and pellet feed (Wang et al, 2016) were used. The analysis showed that there were no significant differences in TNL and TPL from mitten crab farms for different feed types (p N 0.05) (Tables 1 and 2).…”

“…The N and P contents of each types of feed and mitten crab were based on published information Dai et al, 2010;Cai et al, 2012b). The amounts of each types of feed, biomass stocked and yield of mitten crab were obtained from our previous study (Wang et al, 2016).…”

“…The development of mitten crab farming around the Hongze Lake has been described previously (Wang et al, 2016). Briefly, in the Hongze Lake wetlands mitten crab is farmed in shallow ponds, ranging in size from 0.15 to 6.39 ha (average 1.32 ± SE 0.09), transplanted with aquatic macrophytes to regulate water quality.…”

“…Crablets (one year old posthatch), artificially propagated in hatcheries in coastal areas, ranging in weight from 2.1 to 16.7 g individual − 1 (average 5.9 ± SE 0.1) are stocked at densities ranging from 5025 to 48,000 individuals ha − 1 (average 24,232 ± SE 472) between February and April, for growing out. Crabs are harvested after 6-8 months grow-out period (Wang et al, 2016). Generally, mitten crab farming is regarded as a relatively more environment-friendly farming practice compared with most other farming practices.…”