关键词: 全氮, 水溶性有机氮, 微生物生物量氮, 铵态氮, 硝态氮, N₂O

Abstract: We measured the morphological parameters and growth characteristics of 39 dead finless porpoises (Neophocaena asiaeorientalis sunameri) collected along Liaoning coastal waters from 2007 to 2018, and identified the age of 27 finless porpoises collected from 2014 to 2018 by observing teeth growth layer. The results showed that ages of the dead animals ranged from 0 to 4 years, with 21 male and 18 female. There was no significant difference in length and weight between male and female with the same ages (P>0.05). Both weight (Y=137e^-2.475exp(-0.205t)) and length (Y=232(1-0.680e^-0.161t) were significantly correlated with age (P<0.01). Moreover, the growth rates of weight and length showed decreasing trends with the increases of age. The discovery times of dead finless porpoises varied among different areas of Liaoning coastal waters. They were always discovered in the northern Yellow Sea during March to June, and mainly distributed on the coast of Xinghai Bay to Laohutan Beach, while in Liaodong Bay of Bohai Sea they were usually discovered during the period from October to November, mainly distributed in the northern waters of Changxing Island. The death of finless porpoise in Liaodong Bay occurred mostly in fishery period, which may be closely related to fishing. The distribution period of finless porpoise death was alternated with that of spotted seals in Liaodong Bay. Whether it was related to the adaptation capacities of both species to the sea water temperature, their food competition and seasonal migration needs further study.

Key words: total nitrogen, water soluble organic nitrogen, soil microbial biomass nitrogen, NH₄⁺-N, NO₃^--N, N₂O.