Meiofauna abundance and community patterns along a transatlantic transect in the Vema Fracture Zone and in the hadal zone of the Puerto Rico trench

• Published in: Deep Sea Research Part II: Topical Studies in Oceanography
• Main Authors: Schmidt, Christina, Escobar Wolf, Kaibil, Lins Pereira, Lidia, Martínez Arbizu, Pedro, Brandt, Angelika
• Other Authors: Kaiser, Stefanie, Riehl, Torben
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Biology and Life Sciences; Earth and Environmental Sciences; North Atlantic; Deep sea; Abyssal; Transform fault; Mid-Oceanic Ridge; Metazoan; Benthos; DEEP-SEA MEIOFAUNA; MID-ATLANTIC RIDGE; WESTERN IBERIAN MARGIN; SOUTH-PACIFIC OCEAN; NE ATLANTIC; NEMATODE ASSEMBLAGES; ORGANIC-MATTER; NORTH-ATLANTIC; HARPACTICOID COPEPODS; BATHYMETRIC PATTERNS; Pacific; Mid-Atlantic Ridge; Western Basin; Northwest Atlantic; Copepods
• Online Access: https://biblio.ugent.be/publication/8560825; http://hdl.handle.net/1854/LU-8560825; https://doi.org/10.1016/j.dsr2.2017.12.021; https://biblio.ugent.be/publication/8560825/file/8609224

Despite the increasing sampling effort that occurred in the deep-sea environment during the last decades, knowledge about meiofauna ecology in trenches and Fracture Zones is still scarce. Based on the lack of this information, a longitudinal transect across the Verna Fracture Zone in the North Atlantic was sampled to test whether meiofauna abundances differ between Northeast and Northwest Atlantic basins, separated by the MidAtlantic Ridge. Also, for examination of meiofauna depth pattern, the Puerto Rico trench floor, its upper trench slope and the Western North Atlantic abyssal were investigated. In this study, meiofauna communities were dominated by Nematoda (93%) and Copepoda (4%). The highest total abundance of meiofauna was found in the Puerto Rico trench and the lowest in the Western basin. We found significant differences between the Eastern and Western Atlantic basins, which were potentially caused by differences in current regimes. Stronger currents observed in the Western basin possibly led to the coarser sediment grain size observed in this region, and consequently to the lower abundances of the major groups found there. Besides grain size, the total abundance of meiofauna was significantly correlated with total nitrogen, total organic carbon, and water depth. Moreover, our study reveals a trend of increasing abundance of total meiofauna with increasing water depth in the Puerto Rico trench. Also, significant differences between the Western abyssal and the Puerto Rico trench were discovered. Generally, the meiofauna abundance in the investigated area decreased from East to West but increased with increasing water depth in the Puerto Rico trench. Due to funnelling of organic sediments increased food availability towards deeper regions in trenches could occur and promote higher abundance.