The CO₂ emissions from marine fisheries have a significant impact on marine ecology, despite generally being overlooked in studies on global climate change. Few studies have estimated the carbon emissions from marine fisheries while taking into account all pertinent sectors. This study evaluated marine fisheries’ CO₂ emissions based on three sectors: marine fishing, mariculture, and the marine aquatic product processing industry. Kernel density estimation and the spatial Durbin model were used to investigate the spatial and temporal characteristics and the key socioeconomic drivers of the CO₂ emissions from marine fisheries in 11 coastal provinces of China from 2005 to 2020. The results are as follows: (1) marine fishing is the sector that produces the most CO₂ emissions; trawling operations generate more CO₂ than all other modes of operation combined; (2) China’s marine fisheries’ CO₂ emissions show a rising, then declining, trend, with significant differences in coastal provinces; (3) the development of the marine fishery economy and trade have a positive driving effect on CO₂ emissions, the expansion of the tertiary industry does not decrease CO₂, the technical advancement and income growth of fishermen are negatively related to carbon emissions, and the effect of environmental regulation has failed to pass the significance test; (4) the carbon emissions of marine fisheries have significant spatial spillover effects.

The problem of correlation between the Chinese green bond market and the government bond market may affect the smooth operation of the national economy. In this paper, a total of 3,181 sets of data representing the China’s green bond market and the government bond market for the period 2010–2022 are selected, and the VECM-DCC-VARMA-AGARCH model is used to analyse the spillover effects between the two in terms of information transmission and risk contagion. The results indicate that 1) The dynamic correlation between the China’s green bond market and the government bond market is significant, with obvious information transmission and risk contagion effects. 2) Compared to the government bond market, the green bond market is more sensitive to new information and the intensity of the reflection is stronger. 3) There is a long-term equilibrium relationship between the China’s green bond market and the government bond market, and the government bond market will adjust in the direction of green bonds through an error correction mechanism when deviations occur. 4) There is a significant two-way risk contagion effect between the green bond market and the government bond market, but the intensity of the effect is asymmetric. 5) The dynamic correlation between the green bond market and the government bond market has been deepening. Based on the above findings, we have put forward some rationalisation proposals.

The high-quality development of China’s fishery economy serves as its core objective, with robust financial support playing a pivotal role. This study employs provincial panel data spanning 2005 to 2020 and utilizes the entropy method to evaluate the level of high-quality development in China’s fishery economy across three dimensions: fundamental security, sustainability, and comprehensive efficiency. From the perspectives of formal and informal finance, it compares their support effects on different aspects of high-quality development in China’s fishery economy, while also exploring the mechanisms underlying these effects by considering factors such as industrial uncertainty and economic scale. The findings indicate that, overall, the support provided by both formal and informal finance for high-quality development in the fishery economy is insufficient. Further analysis reveals a significant threshold effect of fishery economic scale, with turning points at 108.44 billion CNY and 232.98 billion CNY for formal and informal finance, respectively. For higher-level indicators, such as sustainability and comprehensive efficiency, formal and informal financial systems demonstrate complementary roles, depending on the scale of the regional fishery economy. Furthermore, industrial uncertainty serves as a significant mediating factor only for formal financial support, with the levels of sustainability and comprehensive efficiency most affected.