noun which may take the genitive case particle 'no', noun
pelagic
Technical term used in marine biology and oceanography to describe organisms or environments of the open ocean, away from the coast or the sea floor.
外洋性の魚は沿岸性の魚より回遊範囲が広い。
Pelagic fish have a wider migratory range than coastal fish.
この海域には外洋性のプランクトンが多く見られる。
Many pelagic plankton are found in this sea area.
Compound of 外洋 (open ocean) + 性 (nature, -ity). A straightforward Sino-Japanese technical term.