Aquaculture and Fisheries , 2019, 4(2):74-. doi:10.1016/j.aaf.2018.12.002
摘要:The sea area surrounding Baishishan Island has abundant fishery resources because of its plentiful food and rocky reefs that provide refuge from predators. However, overfishing has occurred in many areas and some species' local populations need to be replenished through stocking programs. This case study, using Sparus microcephalus as the test species, designed and analyzed detailed stocking strategies to improve the survival ratio and control the active range of the released fishes. Controlled variables included release location, release time, and tidal level. Two stocking strategies were designed, executed, and evaluated for comparison. A traditional stocking method was applied to the high flow area of Baishishan Island in Xiangshan Bay, East China Sea. The released fry were transported by boat and released to the sea using buckets. Released fish were traced using plastic tags. The average distance of the 19 recaptured fry from the release point was 7.6 km with 52.9% mortality rate. The distance at recapture and mortality rate among recaptured individuals showed that the traditional releasing method was not successful. An in situ stocking method was used in a low tide area and natural process was imitated to decrease the stress response and promote physiological adaptation. The purpose of this method was to prolong the release process applying temporary net cages at the release location, which resulted in a regional distribution of the released fish and possibly improving the food availability. A new Sr + tagging technique was adopted to evaluate the release effect and quantify comparative release data. Only 1 fish among the 354 caught was found farther than 1 km from the release point in the following 6 months. The results validated the promotion of the new stocking technique.
Aquaculture and Fisheries , 2017, 2(2):94-. doi:10.1016/j.aaf.2017.03.003
摘要:Understanding the dynamics and regulation of a particular ecological process requires monitoring of the process at appropriate spatial and temporal scales. Information collected at an inappropriate spatiotemporal scale may be insufficient for capturing spatio-temporal dynamics of fish populations and community. In this study, a Monte Carlo method was developed to evaluate the detectability performances of different sampling frequencies, sampling timings and sampling intensities on fish community indices and fish species. Species richness indices tended to decrease with an increased sampling frequency, while species diversity indices had small changes in response to changes in sampling frequency. The diversity index was more likely to be influenced by the choice of sampling timing compared to the richness index. The total number of species, especially seasonal and rare species present in the simulated sampling, increased with sampling frequency. Although sampling frequency is more important than sampling intensity, sampling intensity is also important for the detectability of fish species. This study showed that sampling frequency and intensity could greatly influence the estimation of fish community. Choices of sampling timing, sampling frequency and intensity may result in different estimates of fish species compositions and community structure. It is very necessary to consider the importance of sufficient sampling frequency and intensity in a survey program.