Frist observation and effect of fishery of seabed litter on sea bed by trawl survey Korea waters.

Fisheries activities for supplying marine productions were excessively overwhelming. Furthermore in the competitive industrialization, the impact on marine ecosystems and fisheries resources are severe due to the increase of various seabed litter such as plastic materials, styrofoam and plastic bottles and the deterioration of the marine environment. Despite these seriously situation, very few studies of some sea of Korea have been carried out on sedimentary waste fishing. Also some fisheries and there are few reports on plastics present on the seabed of around Korea. This study investigated the distribution of seabed litter collected from the seabed and characteristics of each area by using the trawl gear of the survey vessel from February to November 2018. The weight of all seabed litter collected during the investigation was 62,541.5 kg km-2, with a range of 0.2-15,019.7 kg km-2. The most amount of seabed litter was collected from sea block 106 in the South Sea, followed by sea blocks 76 and 82 in the East Sea. Through this study, which was conducted for the first time in all sea in around Korea, it can be used as basic data to understand the current status of seabed litter in the seabed and to establish effective policies at the led by the government.

The phylogenetic study on Thelohanellus species (Myxosporea) in relation to host specificity and infection site tropism.

Thelohanellus kitauei (Myxobolidae) infects cyprinid fish. The evolution of species derived from common ancestors results in the sharing of biological features. To reveal the origin of T. kitauei biological features, the correlation between phylogeny and biological features of Myxobolidae was investigated by Bayesian inference tree and Bayesian tip association significance testing. The results demonstrated that host specificity and infection site tropism were correlated with the phylogeny of Myxobolidae, and that the biological features of T. kitauei originated from the ancient Myxobolidae as exhibited by the non-specific infection site tropism and the ability to infect cyprinids.