Research
| Title： | Life tables and elasticity analyses of Yangtze River fish species with implications for conservation and management |
|---|---|
| First author： | Wang, Teng; Gao, Xin; Jakovlic, Ivan; Liu, Huan-Zhang |
| Journal： | REVIEWS IN FISH BIOLOGY AND FISHERIES |
| Years： | 2017 |
| DOI： | 10.1007/s11160-016-9464-8 |
| Abstract： | In conservation biology, knowing the life history strategy of a species is crucial for deciding which stage needs the greatest protection: reproduction, juveniles, or adults. Here, we compiled biological data for 83 Yangtze River fish species, constructed their life tables and conducted elasticity analyses, which calculates the proportional contribution of each vital rate (age-specific survival and fecundity) to the annual population multiplication rate. Life tables showed that, for our analyzed species, the survival rate of age 0 fish was extremely low, ranging from 1.25 x 10(-6) to 1.74 x 10(-2) year(-1). All species showed a type III survivorship curve. Elasticity analysis revealed slow-fast continuum life histories ranging from species with a high contribution of fertility elasticity to the population growth rate, but lower juvenile and adult survival elasticity, as well as early maturation and short generation time to species that mature late, possess a long generation time, exhibit low fertility elasticity, and a high adult or juvenile survival elasticity. In addition, the analysis of all the species showed that fertility elasticity was significantly smaller than the sum of juvenile and adult survival elasticity, indicating the need to increase the juvenile and adult survival rates of Yangtze fish rather than focusing only on protecting reproduction and age 0 survival via a breeding season fishing ban which is the current conservation practice. Since overfishing has been proposed as the major factor responsible for the decline of Yangtze fish populations, we further suggest that controlling fishing pressure on juvenile and adult fish is another key conservation requirement. |
