Pacific herring, Clupea pallasii, a keystone species with significant ecological and commercial importance, is declining globally throughout much of its range. While traditional fishing equipment methods remain limited, new sensitive and rapid detection methods should be developed to monitor fisheries resources. To monitor the presence and quantity of C. pallasii from environmental DNA (eDNA) extracted from seawater samples, a pair of primers and a TaqMan® probe specific to this fish based on mitochondrial cytochrome b (COB) sequences were designed for the real-time PCR (qPCR) assay. The combination of our molecular markers showed high specificity in the qPCR assay, which affirmed the success of presenting a positive signal only in the C. pallasii specimens. The markers also showed a high sensitivity for detecting C. pallasii genomic DNA in the range of 1 pg~100 ng rxn-1 and its DNA plasmid containing COB amplicon in the range of 1~100,000 copies rxn-1, which produced linear standard calibration curves (r2=0.99). We performed a qPCR assay for environmental water samples obtained from 29 sampling stations in the southeastern coastal regions of South Korea using molecular markers. The assay successfully detected the C. pallasii eDNA from 14 stations (48.2%), with the highest mean concentration in Jinhae Bay with a value of 76.09±18.39 pg L-1 (246.20±58.58 copies L-1). Our preliminary application of molecular monitoring of C. pallasii will provide essential information for efficient ecological control and management of this valuable fisheries resource.

Abstract
INTRODUCTION
MATERIALS AND METHODS
    1. Sampling of fish specimens and sequencing
    2. Design of primers and probe
    3. Seawater sampling and eDNA extraction
    4. qPCR analysis
RESULTS
    1. Design of oligonucleotide primers and probeand qPCR analysis
    2. Application to field environmental samples
DISCUSSION
REFERENCES

• Keun-Yong Kim(Department of Genetic Analysis, AquaGenTech, Co., Ltd)
• Jung Soo Heo(Department of Genetic Analysis, AquaGenTech, Co., Ltd)
• Seong Yong Moon(South Sea Fisheries Research Institute, National Institute of Fisheries Science)
• Keun-Sik Kim(Fishes/Amphibians & Reptile Team, Research Center for Endangered Species, National Institute of Ecology)
• Jung-Hwa Choi(Jeju Fisheries Research Institute, National Institute of Fisheries Science)
• Joon-Taek Yoo(Cetacean Research Institute, National Institute of Fisheries Science) Corresponding author