Microbial degradation is a useful tool for inhibiting or preventing polycyclic aromatic hydrocarbons (PAHs) widely distributed in marine environment after oil spill accidents. This study aimed to evaluate the potential and diversity of bacteria Bacillus sp. PAH-2 on Benzo (a) anthracene (BaA), Pyrene (Pyr), and Benzo (a) pyrene (BaP), their composite system, aromatic components system, and crude oil. The seven-day degradation rates against BaA, Pyr, and BaP were 20.6%, 12.83%, and 17.49%, respectively. Further degradation study of aromatic components demonstrated PAH-2 had a high degradation rate of substances with poor stability of molecular structure. In addition, the degradation of PAHs in crude oil suggested PAH-2 not only made good use of PAHs in such a more complex structure of pollutants but the saturated hydrocarbons in the crude oil also showed a good application potential.

Marine industries are dependent on the ocean and often have a direct impact on the marine environment. Although previous studies have talked about pollution from marine industries, it is not known to what extent and to what extent these behaviors affect the ocean. Therefore, this study examines the impacts of major marine industries on the marine environment, using China as an example. The Ministry of Ecology and Environment of the People's Republic of China categorizes the quality of seawater into Class I, Class II, Class III, Class IV, and Inferior Class IV in descending order according to the quality from good to poor. In this study, water quality of Class I and Class II are defined as good quality seawater, Class III as average quality, Class IV and Class IV as poor quality, and the proportion of the area of seawater with different water quality to the total area of the sea area symbolizes the overall quality of the marine environment. We use panel data from 11 provinces and cities along the coast of mainland China from 2006 to 2020, estimated by the full feasible generalized least squares (FGLS) method, to study the impacts of the development of coastal tourism, marine transportation, marine shipbuilding, marine salt, mariculture, and marine fishing on the marine environment. The empirical results show that, in descending order of the degree of influence, the marine industries that cause a decrease in the area of good quality seawater are coastal tourism, mariculture and shipbuilding, and the marine industries that cause an increase in the area of poor quality seawater are marine transportation and shipbuilding, while the marine salt industry has no obvious influence on the marine environment, and the development of the marine fishing industry indirectly contributes to the improvement of the marine environment.

PH value is one of the most significant ecological factors affecting the survival and growth of aquatic organisms. But the effect and tolerance of pH value on many aquatic species are still unknown. This study mainly investigated the effects of pH value on the hatching rate of eggs, the adaptability of newly hatched larva fish and the survival of 3-months-old juvenile fish of Takifugu obscurus. Water pH values can cause a great impact on Takifugu obscurus lives, when the fertilized eggs of Takifugu obscurus were incubated at pH 5.0, 6.0, 7.0, 8.0, 8.3 (control group), 9.0, 10.0 and 11.0 respectively. Under the pH of 5.0, 6.0, 10.0 and 11.0, the hatching rate and speed is greatly reduced and the deformity rate of hatching larvae is greatly increased; When the hatch-pH value was 6.0, the acid adaption of hatched larvae was significantly enhanced, but alkali adaptation was weakened; Under the condition of pH gradient of 6.0, 6.4, 6.8, 7.0, 8.0, 8.3, 9.0, 10.0, 10.2, 10.5, 11.0 and 12.0, survival time and survival rate of juvenile fish show a significant difference. Especially when the pH value was 6.0 and 12.0, juvenile fish die immediately after swimming quickly. Within 24 h, half of the fish died at the pH of 6.4 and 10.3, and within 48 h, half died at the pH of 7.1 and 9.9. In addition, the gradual pH value group in which the pH value gradually decreased or increased had stronger acid-base adaptability and a higher survival rate than the acute experimental group. The above results show the relationship between pH value and survival of Takifugu obscurus, which can provide more reference for the introduction of Takifugu obscurus into saline-alkali land in the future. Additionally, the incubated pH value can influence the pH tolerance of Takifugu obscurus, which can be applied to the breed improvement into an appropriate water environment.