Zooplankton fecal pellet flux in the abyssal northeast Pacific: A 15 year time‐series study

Abstract

Sinking particulate material collected in sequencing sediment traps moored at 3500 m depth (600 m above bottom) from 1993 to 2008 at the abyssal time-series Sta. M in the northeast Pacific was analyzed via microscopy and digital imaging. Intact zooplankton fecal pellets were quantified and size, shape, and carbon content were measured. The most common identifiable fecal pellets were from larvaceans, which feed on small particles. Other abundant fecal pellets were likely produced by large copepods and euphausiids. The proportion of identifiable fecal pellet carbon to total particulate organic carbon (POC) flux varied and ranged from 3.3% to 47.7%. Fecal pellet flux and fecal pellet-derived carbon flux was lowest in February, and highest in May, August, and November samples. The proportion of total POC in identifiable fecal pellets was negatively correlated to overall POC flux and to indicators of climate variability. The North Pacific Gyre Oscillation and Northern Oscillation Index climate indices were negatively correlated to the dominance of fecal pellets in POC flux, with changes in fecal pellet fluxes temporally lagging climate-related changes by about 3 and 5 months, respectively. Variations in zooplankton distribution and abundance affect biogeochemical cycling to abyssal depths, further demonstrating how a changing climate may affect deep-sea ecology. The dominance of zooplankton fecal pellets can shift proportionally, providing new insight into the processes controlling marine carbon sequestration in the deep sea.

Downward particle flux and carbon export in the Beaufort Sea, Arctic Ocean; the role of zooplankton

“…The example in Fig. 7d matches well the description given by Wilson et al (2013): "The ellipsoid pellets. .…”

The contribution of zooplankton faecal pellets to deep-carbon transport in the Scotia Sea (Southern Ocean)

“…It is known that zooplankton residing within the deeper layers of the ocean consume FPs, break them apart and repackage them several times over the course of their descent (Conte et al, 2001). The important role of deep-dwelling zooplankton in the re- cycling and reprocessing of FPs at the P2 site is in line with a number of others studies that have considered the role of the bathypelagic zooplankton community in the downward flux of material (Pilskaln and Honjo, 1987;Gonzalez et al, 2000;Wilson et al, 2013). Despite the likelihood that the largest part of deep-dwelling zooplankton might not have been "captured" by sediment traps, a relatively high number of swimmers were observed at P2, while at P3 their abundance was extremely low (fewer than organisms per sample).…”

Near seafloor bioluminescence, macrozooplankton and macroparticles at the Mid-Atlantic Ridge

“…These findings are in agreement with the results of the present study, which show an increase in appendicularian density towards the seafloor, but no increase in the remaining macrozooplankton density when the appendicularian count is excluded. Appendicularians are often encountered in benthic boundary regimes, based on in situ observations and sediment trap data , Robison et al, 2010, Wilson et al, 2013, and the occurrence of these detritivores is indicative of rich populations of microbial organisms. The presence of recognisable houses also suggests local populations as houses usually deform shortly after being discarded.…”