Meiofauna community structure of deep-sea habitats at the northeastern margin of the Antarctic Peninsula

Aramayo V.; Quipúzcoa L.; Marquina R.; Romero D. · Polar Science (2026) · DOI: 10.1016/j.polar.2026.101387

Resumen

Meiofaunal organisms in Antarctic deep-sea sediments play a pivotal role in benthic ecosystem processes, yet their community structure and drivers remain poorly understood. During the Peruvian ANTAR XXV campaign (January 2017, austral summer), sediment cores were collected at three stations along the northeastern margin of the Antarctic Peninsula (mid-slope: 325.2 and 357.1 m; deep-slope: 492.7 m). Cores were sectioned at 1 cm intervals down to 5 cm depth, and meiofauna were identified morphologically. Mid-slopes were observed with the highest taxonomic richness (76 and 72 taxa) and lowest at the deep-slope site (37 taxa). Meiofaunal abundances ranged from 537 to 1013 Ind. 10 cm−2, with free-living nematodes accounting for over 70 % of all individuals, followed by arthropods and annelids. Vertical profiles revealed higher abundances in subsurface sediment layers, whereas arthropods (ostracods, harpacticoid copepods), kinorhynchs, and mollusks contributed notably in deeper layers, although these did not drive the overall community turnover. Nematode feeding mode analysis demonstrated the coexistence of selective and non-selective deposit feeders, predatory, and epistrate feeders throughout the sediment column and across stations, indicating effective microhabitat partitioning and trophic versatility. The pronounced dominance and functional diversity of Nematoda underline their ecological adaptability under variable oxygen conditions. This study establishes a quantitative baseline for meiofaunal biodiversity on the Antarctic Peninsula's continental slope and provides a framework for future investigations into the environmental drivers of benthic community dynamics.

Instituciones: Universidad Nacional Mayor de San Marcos