As important habitats, mangroves are a pool of benthic spawning genes and the biodefense line that intercepts continental pollutants. Ocean plastic pollution could lead to serious physical and toxicological effects on marine life and further threaten the stability and well-being of mangrove biodiversity. This study adopted methods of quantitative field observations and qualitative marine sampling. We, taking Qinglan Port, Hainan Island as the study area, collected marine waste, sediment and benthic organisms as the subjects of research. Visual identification, stereomicroscope observation and infrared spectrum analysis were used during the process to analyze features and sources of serious plastic waste. The findings show that the main plastic wastes include plastic bags, foams and fishing waste. Microplastics are a combination of flakes, fibers, lines, films, particles and spherical shapes, most of which are fabrics as a result of physical compression. The purpose of this study is to provide decisive suggestions to the government departments concerned for management and policy development to ensure maximum protection of mangrove forest habitats and their surrounding environments.

Global warming induced sea level rise is a hot topic in the field of land-sea interaction. Coastal erosion and flooding caused by sea level rise pose a great threat to the environment and economic development. We examined the spatial-temporal distribution characteristics and potential social and economic risks of sea level change in China's coastal areas from 1993 to 2018 based on the sea-level anomaly (SLA) data and the shared social and economic path scenario (SSP_S). The results showed that: (1) During the study period, the average annual sea level and extreme sea level in the study area showed a significant rising trend, with the rate of change reaching up to 3.47±0.50 mm/a and 4.74±1.39 mm/a, respectively. (2) The rising rate of the four major sea areas of China is listed is as follows: East China Sea > Yellow Sea > Bohai Sea > South China Sea. In terms of the provincial scale, Jiangsu, Fujian and Zhejiang have higher sea level growth rates, while Guangdong, Shanghai and Taiwan have lower sea level rise rates. (3) The results of MK test and Sen trend analysis showed that the average annual sea level had a significant increase trend in the whole study area. Specifically, 84.16% of the area had a moderately slow growth rate and 2.32% of the area was going fast. As for the extreme sea level, areas with a significant increase accounted for 76%, of which 59.65% had a slow growth and 2.31% had a fast growth. During the study period, there was no significant reduction in the area. (4) In terms of spatial volatility, the sea level change over the past decades had been at a relatively low volatility level. According to statistical results, the lower volatility area accounts for 61.31%, while the highest and higher volatility areas only account for 3.17%. (5) By 2100, under three shared social and economic development paths (SSP₁, SSP₂ and SSP₃), the potential economic losses in Chinese coastal areas will reach 10-21 trillion yuan, and the population affected by sea level rise is about 3.5-5.5 million. From the provincial perspective, Guangdong has the largest flooded area (accounting for 0.7% of the total land area of the province), and the highest economic and population risks. Therefore, mitigation and adaption to the risk of sea level rise is an important task for maintaining sustainable socio-economic development, resources utilization and environmental protection in China's coastal areas in the 21st century.

The IPCC special report on global warming of 1.5 °C and the IPCC special report on climate change and land both identify aquaculture as one of the key sectors that requires attention on global food security and the upgrading of adaptation policy. Research on the disaster-adaptive behavior and its influencing factors at the farmer level is of great value for enhancing the adaptive capacity to disasters, ensuring the livelihood of aquaculture farmers, and the sustainable development of islands, so as to revitalize fishing villages. However, very few studies have been conducted at the farmer level. Using survey data obtained from 202 aquaculture farmers from the Zhoushan and Dongtou Island regions and applying multivariate probit model, this study analyzes the disaster adaptation strategies of aquaculture farmers during the whole process of disaster management and the influencing factors. The results showed that: (1) Diverse multilevel adaptive strategies were adopted in study areas to deal with typhoon disaster. Up-front strategies, simple early strategies and future-benefits strategies were used significantly less than no-regret reaction and low-regret tactics by aquaculture farmers, making most farmers' adaptation strategies less effective. More than half of the farmers are willing to adopt the up-front, simple early and future-benefits strategies in the future if conditions facilitate usage of these strategies. (2) Each factor affected adaptation strategies of aquaculture farmers negatively and positively at the same time, and there was also significant complementary and substitutive relationship among the adaptive strategies selected by the aquaculture farmers. (3) Age, family labor, and the number of disasters occurring in the past 5 years were important factors influencing aquaculture farmers' adaptive behavior. Input, health status, disaster perception, income, education level, and social capital also had a significant impact on farmers' adaptive behavior. (4) Some influencing factors and their effects on the disaster adaptation behavior of aquaculture farmers in Zhoushan Islands and Dongtou Islands were different from those in other regions, which highlight the uniqueness of island regions. This study identifies the key influencing factors and weakness of adaptation behavior toward typhoon disaster, and the conclusions provide useful insight into the optimization and adjustment of the government and farmers' adaptation strategies.