Based on the hydrographic observations carried out in the austral summer during 2013 and 2015 from the continental shelf to the front regions of Vincennes Bay, East Antarctica, this study utilizes an optimum multiparameter analysis method to evaluate the export pathway of Vincennes Bay Bottom Water (VBBW) and its contribution rate to Antarctic bottom water (AABW). The results show that the freshest, coldest, and most oxygen-rich bottom water is distributed above the northwestern ridge of Vincennes Bay. The highest proportion of local Dense Shelf Water (DSW) on the bottom over this ridge was (28.58 ± 1.75)%, which exceeded the proportion observed at all other stations on the offshore side of the continental slope. The VBBW, a mixture of local DSW and modified Circumpolar Deep Water, was also maximized in the AABW layer on this northwestern ridge. The results suggest that topography plays an important role in guiding the outflow of local DSW and even VBBW, and the northwestern ridge could be the main pathway for VBBW export. In the vertical direction, the proportion of DSW decreases with the shallower depth at most stations, but patchy DSW contribution layers were commonly observed in the sub-bottom layers, which means that the proportion of DSW increases in some depth ranges. According to the anomaly distribution of seawater characteristics on the density surfaces, the DSW in the sub-bottom layers can also be exported along the isopycnals, manifested as thermohaline intrusion patches. These thermohaline intrusion patches have significantly colder, fresher, and oxygen-rich characteristics, which may contribute to the enhancement of sub-bottom ventilation. In addition, VBBW can reach the bottom of the Australia-Antarctic basin at depths deeper than
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |