Resources of the four major Chinese carps of early life history stages at Huangshi section in the middle reaches of the Yangtze River

In order to estimate the fish resources and distribution of spawning grounds of the four major Chinese carps of early life history stages, we collected samples of fish eggs and larvae at Huangshi section during May to July in 2015 and 2016. A total of 67 fish eggs and 23 948 larvae were collected during the survey, Hypophthalmichthys molitrix and Ctenopharyngodon idella accounted for 77.0% and 18.1% of the total numbers, respectively. In 2015 and 2016, we estimated there were 0.20×10⁸ and 4.69×10⁸ eggs of the four major Chinese carps drifting through the Huangshi section, respectively; while there were 19.40×10⁸ and 13.65×10⁸ larvae, respectively. The spawning grounds of the four major Chinese carps are located in Lijiazhou, Ezhou, Daijiazhou and Daoshifu sections. Compared with the historical data, the location of spawning grounds had no significant change. It is suggested that enhancement and releasing is needed and the spawning habitat of the four major Chinese carps should be well-protected in the channel regulation project.