Dear All, My coauthors and I are pleased to announce the publication of our paper titled “Linking mesopelagic prey abundance and distribution to the foraging behavior of a deep-diving predator, the northern elephant seal” published in Deep Sea Research Part II. Saijo, D., Mitani, Y., Abe, T., Sasaki, H., Goetsch, C., Costa, D. P., & Miyashita, K. (2016). Linking mesopelagic prey abundance and distribution to the foraging behavior of a deep-diving predator, the northern elephant seal. Deep Sea Research Part II: Topical Studies in Oceanography. Abstract: The Transition Zone in the eastern North Pacific is important foraging habitat for many marine predators. Further, the mesopelagic depths (200–1000 m) host an abundant prey resource known as the deep scattering layer that supports deep diving predators, such as northern elephant seals, beaked whales, and sperm whales. Female northern elephant seals (Mirounga angustirostris) undertake biannual foraging migrations to this region where they feed on mesopelagic fish and squid; however, in situ measurements of prey distribution and abundance, as well as the subsurface oceanographic features in the mesopelagic Transition Zone are limited. While concurrently tracking female elephant seals during their post-molt migration, we conducted a ship-based oceanographic and hydroacoustic survey and used mesopelagic mid-water trawls to sample the deep scattering layer. We found that the abundance of mesopelagic fish at 400–600 m depth zone was the highest in the 43 °N zone, the primary foraging area of female seals. We identified twenty-nine families of fishes from the mid-water trawls, with energy-rich myctophid fishes dominating by species number, individual number, and wet weight. Biomass of mesopelagic fishes is positively correlated to annual net primary productivity; however, at the temporal and spatial scale of our study, we found no relationship between satellite derived surface primary production and prey density. Instead, we found that the subsurface chlorophyll maximum correlated with the primary elephant seal foraging regions, indicating a stronger linkage between mesopelagic ecosystem dynamics and subsurface features rather than the surface features measured with satellites. Our study not only provides insights on prey distribution in a little-studied deep ocean ecosystem, but shows that northern elephant seals are targeting the dense, species-diverse mesopelagic ecosystem at the gyre-gyre boundary that was previously inferred from their diving behavior. http://www.sciencedirect.com/science/article/pii/S0967064516303307 Yoko Mitani -- Yoko MITANI Laboratory of Marine Ecosystem Change Analysis Hakodate Marine Station, Field Science Center for Northern Biosphere, Hokkaido University Hakodate Research Center for Fisheries and Oceans 20-5 Benten-cho, Hakodate, Hokkaido 040-0051, JAPAN TEL: +81-138-85-6558; FAX: +81-138-85-6625 E-mail: yo_mitani@fsc.hokudai.ac.jp