Environmental DNA (eDNA) technology has been successfully applied to detect organisms in various aquatic ecosystems. However, eDNA has been proven to exist for a long time in environmental samples. The timeliness of eDNA detection results largely depends on the rate of molecular degradation. Environmental RNA (eRNA) is considered an excellent complementary tool because most researchers believe that RNA degrades faster than DNA in vitro, while, to the best of our knowledge, the number of published articles related to eRNA is very limited. To address an important knowledge gap, this study focused on the response mechanism of eRNA degradation to water temperature change as compared with eDNA. Changes in the concentration of eDNA and eRNA of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene from Fenneropenaeuschinensis were detected at four temperatures (10, 15, 20 and 25 °C). The results showed that the degradation rate of eDNA increased with an increase in temperature. The degradation rate constants ranged from 0.011 to 0.486 h−1 and the degradation time ranged from 8 to 383 h for eDNA. The degradation rate of eRNA changed slightly with an increase in temperature. The degradation rate constants ranged from 0.190 to 0.379 h−1 and the degradation time ranged from 11 to 22 h for eRNA. eRNA showed better stability under temperature change and maintained a faster degradation rate at low temperatures. These results provide answers to the questions of whether eRNA and eDNA degradation rates are fast or slow. Furthermore, this study may suggest the potential superiority of eRNA over eDNA and promote further study of eRNA in future research.
China (herein referred as China’s mainland, and excluding Hong Kong, Macau and Taiwan) is the largest contributor to global seafood production. While China’s marine fisheries have been extensively documented, there is a gap in systematically quantifying production of its marine fisheries and the different challenges confronting them at the provincial level. We addressed this gap in spatial detail by providing a review that compares and contrasts the exploitation history of China’s fisheries at both the national and provincial levels based on official statistical data. We expanded upon this to explore aspects of bio-socio-economic challenges faced by the country’s 11 fishing provinces. Our analysis suggested that significant increases in domestic marine catches in China have been accompanied by escalating fishing power, which has had differential impacts at the provincial scale. Catch per unit effort (CPUE) sharply declined at both the national and provincial scales, and many traditionally targeted demersal fish stocks showed clear downward trends in terms of catches. The 11 fishing provinces in China can be grouped into four clusters with distinct biological, social, and economic attributes. Targeted measures are recommended accordingly when implementing fisheries management measures for each specific fishing province in order to deliver an overall improvement in the sustainability of China’s marine fisheries.