Abstract: We measured the abundance of carbon and nitrogen stable isotopes in the dominant fishery species in the coast of the Daling and Yalu rivers in spring with stable isotope technique, calculated the trophic levels, and established the continuous nutritional spectrum of the majorbiological groups. The results showed that the δ¹⁵N and δ¹³C of the dominant species ranged from8.2‰ to 14.1‰ and from -22.9‰ to -16.6‰, respectively in Daling River, while ranged from 7.9‰ to 13.2‰ and from -20.6‰ to -16.1‰ in Yalu River, respectively. The trophic level of the major biological groups in Daling River was between 2.8 and 3.9, with the crustacean, gastropod, bivalve and fish ranging 2.9-3.5, 2.8-3.1, 2.9-3.4 and 3.4-3.9, respectively. The trophic level of the major biological groups in Yalu River was between 2.8 and 3.7, with the crustacean, cephalopod, gastropod, bivalve and fish ranging 3.0-3.6, 3.4-3.5, 2.8-3.0, 2.9-3.2 and 3.1-3.7, respectively. The continuous trophic spectrum demonstrated thatBullacta exarataand Mactra veneriformis were the primary consumers in both rivers. Crustacean was the secondary consumer, and fishes were the senior consumers. This study established the continuous trophic spectrum of the major fishery species in the coast in Daling and Yalu rivers, and thus provided basic data for the conservation and development of fisheries resources.

Key words: seed rain, Changbai Mountains, mixed broadleaf-conifer forest, interannual variation, spatial variation.