With the increasing demand for mineral resources and the continuous depletion of terrestrial mineral deposits, deep-sea mining has garnered significant attention from governments, industries, and research institutions. However, the current deep-sea mining technologies remain incompletely developed, and their environmental impacts cannot be overlooked. This review presents a brief introduction to the three primary mineral resources found in the deep sea and the relative deep-sea mining system, along with their potential environmental risks. As the deep-sea benthic ecosystem is particularly vulnerable, the impacts on environment of each phase of deep-sea mining should be monitored and controlled. The movement and operation of seafloor mining vehicles generate both direct and indirect environmental impacts, including seabed destruction and plume generation. These effects pose significant threats to benthic organisms and alter the deep-sea environment. Finally, we present future perspectives and insights for subsequent research and the industrialization of deep-sea mining.

The rapid rise of microcystins (MCs) poses a serious threat to global freshwater ecosystems and has become an important issue of global public health. MCs have considerable stability and are the most widely distributed hepatotoxins. It cannot only accumulate in aquatic organisms and transfer to higher nutrients and levels, but also be degraded or transferred during the resource utilization of cyanobacteria. No matter which enrichment method, it will lead to the risk of human exposure. This review summarizes the research status of MCs, and introduces the distribution of MCs in different components of aquatic ecosystems. The distribution of MCs in different aquatic organisms was summarized, and the potential risks of MCs in the environment to human safety were summarized. MCs have polluted all areas of aquatic ecosystems. In order to protect human life from the health threats caused by MCs, this paper also proposes some future research directions to promote MCs control and reduce human exposure to MCs.

Microorganisms can both indicate the water quality characteristics and the health of the aquatic environment, which have an important influence on the cycling of organic carbon, nitrogen (N), and phosphorus (P) in nature. In this study, we took Taihu Lake, a typical eutrophic lake in China, as the research object, and monitored the northern (Changzhou City) and southern (Changxing County) regions of Taihu Lake for three consecutive years (2019–2021), respectively. We also analyzed the microbial diversity in sediments, and then summarized the effects of different nutrient environments on microorganisms in the aquatic environment. The results showed that the pollution level in the northern part of Taihu Lake was higher than that in the southern region of Taihu Lake, where the pollution was mainly in summer (June–July). The pollution in the southern region of Taihu Lake is relatively stable between 2019 and 2021; the changes in the northern part of Taihu Lake are relatively significant. Microbial diversity in the study area was negatively correlated with the degree of eutrophication of water bodies; microbial abundance was positively correlated with nutrient levels. The functional difference analysis indicated that the microorganisms in the sediments of Taihu Lake in the study area were involved in the nutrient transport and transformation, and played an important role in the purification of the lake water body. This study reveals the relationship between water eutrophication and microbial diversity, and then provides a theoretical basis for the management of eutrophic lakes.

Black soldier fly is a saprophagous insect that has been widely reported in recent years due to its excellent performance in bioremediation. Due to the widespread presence of flocculants in the organic waste treated by black soldier fly larvae, this study aimed to evaluate the potential impacts and risks of flocculant addition (a combination of poly aluminum chloride and polyacrylamide with the ratio of 50:1). Results showed that the growth and weight of BSFL in the high-exposure groups (≥200 mg/L) were inhibited. The bioaccumulation of aluminum (Al) in larvae was estimated, and the proportions of different Al forms in the frass from high to low were the residual state (41.38% to 67.92%), water-soluble state (16.88% to 37.03%), acid-soluble state (8.45% to 18.72%), and alkali-soluble state (3.38% to 5.14%). The relative abundance of bacterial genera related to lipid metabolism decreased with increasing flocculant concentrations while disease-related taxa increased in relative abundance. The results serve as a reference for subsequent research and application of the treatment of flocculant-contaminated waste by BSFL.