Landscape-scale spatial heterogeneity in phytodetrital cover and megafauna biomass in the abyss links to modest topographic variation

Morris, Kirsty J, Bett, Brian J, Durden, Jennifer M, Benoist, Noelie MA, Huvenne, Veerle AI, Jones, Daniel OB, Robert, Katleen, Ichino, Matteo C, Wolff, George A ORCID: 0000-0002-9380-1039 and Ruhl, Henry A (2016) Landscape-scale spatial heterogeneity in phytodetrital cover and megafauna biomass in the abyss links to modest topographic variation. SCIENTIFIC REPORTS, 6 (1). 34080-.

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Abstract

Sinking particulate organic matter (POM, phytodetritus) is the principal limiting resource for deep-sea life. However, little is known about spatial variation in POM supply to the abyssal seafloor, which is frequently assumed to be homogenous. In reality, the abyss has a highly complex landscape with millions of hills and mountains. Here, we show a significant increase in seabed POM % cover (by ~1.05 times), and a large significant increase in megafauna biomass (by ~2.5 times), on abyssal hill terrain in comparison to the surrounding plain. These differences are substantially greater than predicted by current models linking water depth to POM supply or benthic biomass. Our observed variations in POM % cover (phytodetritus), megafauna biomass, sediment total organic carbon and total nitrogen, sedimentology, and benthic boundary layer turbidity, all appear to be consistent with topographically enhanced current speeds driving these enhancements. The effects are detectable with bathymetric elevations of only 10 s of metres above the surrounding plain. These results imply considerable unquantified heterogeneity in global ecology.

Item Type:	Article
Depositing User:	Symplectic Admin
Date Deposited:	03 Oct 2016 10:39
Last Modified:	19 Jan 2023 07:30
DOI:	10.1038/srep34080
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3003319