Search

Antarctic krill mainly inhabit the Antarctic Ocean, not far from Antarctica, especially the Weddell Sea, where krill is dense. Marine fisheries have reached new levels, but the topic of sustainable use of marine fishery resources is far from reaching the required levels. In order to study the sustainable development of the Antarctic krill environment, this paper studies the living environment and applicability of Antarctic krill based on system dynamics, and provides some references for the sustainable development of marine resources. Mentioned the use of case analysis method, literature analysis method and other methods to collect data, build a Model, and read and analyse a large number of related literatures through the literature survey method. The experimental results proved that the salinity has a significant effect on the survival rate of Antarctic krill (p < 0.05). When the salinity is 34, the molting frequency reaches its maximum value, which is 70 %. It is concluded that the ability of Antarctic krill to adapt to gradual changes in salinity is stronger than that of sudden changes in salinity, and the suitable salinity for survival is 30-42. With 34 as the basic salinity, when the salinity rises within a certain range, the molting rate of krill will increase, and as the salinity decreases, the molting rate will gradually decrease. This shows that improving the environmental resources of Antarctic krill is an effective method for improving salinity. [ABSTRACT FROM AUTHOR]

Intestinal bacterial communities are highly relevant to the digestion, nutrition, growth, reproduction, and a range of fitness in fish, but little is known about the gut microbial community in Antarctic fish. In this study, the composition of intestinal microbial community in four species of Antarctic fish was detected based on 16S rRNA gene sequencing. As a result, 1 004 639 sequences were obtained from 13 samples identified into 36 phyla and 804 genera, in which Proteobacteria, Actinobacteria, Firmicutes, Thermi, and Bacteroidetes were the dominant phyla, and Rhodococcus, Thermus, Acinetobacter, Propionibacterium, Streptococcus, and Mycoplasma were the dominant genera. The number of common OTUs (operational taxonomic units) varied from 346 to 768, while unique OTUs varied from 84 to 694 in the four species of Antarctic fish. Moreover, intestinal bacterial communities in individuals of each species were not really similar, and those in the four species were not absolutely different, suggesting that bacterial communities might influence the physiological characteristics of Antarctic fish, and the common bacterial communities might contribute to the fish survival ability in extreme Antarctic environment, while the different ones were related to the living habits. All of these results could offer certain information for the future study of Antarctic fish physiological characteristics. [ABSTRACT FROM AUTHOR]

The density of ice krill (Euphausia crystallorophias), a species of key ecological value, and related environmental factors were observed along two transects in the Amundsen Sea Coastal Polynya (ASCP) in Antarctica. The distribution of ice krill was processed using two-frequency acoustic backscatter data identification, and the target strength of ice krill was calculated via stochastic distorted-wave born approximation based on the ice krill sample. The ice krill density ranged from 0.96 to 11.01 g m−2 for each transect (mean value was 5.77 g m−2 for the entire survey). These results were of a lower order of magnitude than those of a previous study in the same waters, although the ice krill was still the dominant krill specie in this polynya. We contend that the extent of the phytoplankton bloom might be the factor behind this difference, while other hydrographic parameters such as surface temperature and salinity would have some effect on the spatial distribution of ice krill abundance. Meanwhile, the density and height of ice krill abundance suggested that the diurnal effect on the ice krill was almost negligible. According to the fitted results of regression model, the abundance of ice krill in ASCP in 2022 summer was estimated approximately 175,000 tons. • Ice krill density and related factors were observed in the Amundsen Polynya, Antarctica. • The ice krill density ranged from 0.96 to 11.01 g m−2 in two sampled transects. • Ice krill was still the dominant krill species considering previous findings. • The ice krill density, however, distinctly declined compared to the density in 2012. • The phenomenon of ice melting and eutrophication possibly influenced the density. [ABSTRACT FROM AUTHOR]