Archive for new technology

Lasers shed light on giant larvacean filtration impact on the ocean’s biological pump

Posted by mmaheigan 
· Thursday, January 4th, 2018 

To accurately assess the impacts of climate change, we need to understand how atmospheric carbon is transported from surface waters to the deep sea. Grazers and filter feeders drive the ocean’s biological pump as they remove and sequester carbon at various rates. This pump extends down into the midwater realm, the largest habitat on earth. Giant larvaceans are fascinating and enigmatic occupants of the upper 400 m of the water column, where they build complex filtering structures out of mucus that can reach diameters greater than 1 m in longest dimension (Figure 1A). Because of the fragility of these structures, direct measurements of filtration rates require us to study them in situ. We developed DeepPIV, an ROV-deployable instrument (Figure 1B) to directly measure fluid motion and filtration rates in situ (Figure 1C).

Figure 1. (A) Traditional view of a giant larvacean illuminated by white ROV lights. (B) DeepPIV instrument is seen attached to Monterey Bay Aquarium Research Institute’s (MBARI) MiniROV. (C) DeepPIV-illuminated interior view of a giant larvacean house, where particle motion in ambient seawater serves as a proxy for fluid motion. White arrows in (A) and (C) indicate larvacean head/trunk; white arrow in (B) indicates DeepPIV.

The filtration rates we measured for giant larvaceans are far greater than for any other zooplankton filter feeder. When combined with abundance data from a 22-year time series, the grazing impact of giant larvaceans indicates that within 13 days, they can filter the total volume of water within their habitable depth range (~100-300 m; based on maximum abundance and measured filtration rates). Our results reveal that the contribution of giant larvaceans to vertical carbon flux is much greater than previously thought. Small larvaceans, which are present in the water column in even larger quantities than giant larvaceans, may also have a measurable impact on carbon fluxes. New technologies such as DeepPIV are yielding more quantitative observations of midwater filter feeders, which is improving our understanding of the roles that deep-water biota play in the long-term removal of carbon from the atmosphere.

Read the full journal article: http://advances.sciencemag.org/content/3/5/e1602374.full

Authors: (All at MBARI)
Kakani Katija
Rob E. Sherlock
Alana D. Sherman
Bruce H. Robison

Filter by Keyword

acidification air-sea interactions allometry AMOC Antarctica anthropogenic carbon aragonite saturation aragonite saturation state arctic argo Atlantic Atlantic modeling atmospheric CO2 atmospheric nitrogen deposition autonomous observing autonomous platforms BATS bcg-argo biogeochemical cycles biogeochemical models biological pump biological uptake biophysics bloom blooms blue carbon bottom water CaCO3 calcification calcite carbon-climate feedback carbon cycle Caribbean CCS changing marine ecosystems changing ocean chemistry chl a chlorophyll circulation climate change CO2 coastal and estuarine coastal carbon fluxes coastal ocean coastal oceans cobalt community composition conservation cooling effect copepod coral reefs DCM deep convection deep ocean deep sea coral diatoms DIC dimethylsulfide DOC domoic acid dust earth system models eddy Education Ekman transport emissions ENSO enzyme equatorial regions estuarine and coastal carbon fluxes estuary EXPORTS filter feeders filtration rates fish Fish carbon fisheries floats fluid dynamics fluorescence food web food webs forams freshening geochemistry geoengineering GEOTRACES glaciers gliders global carbon budget global warming go-ship greenhouse gas Greenland Gulf of Maine Gulf of Mexico Gulf Stream gyre harmful algal bloom human impact hydrothermal hypoxia ice age ice ages ice cores ice cover industrial onset iron iron fertilization isotopes katabatic winds kelvin waves kuroshio larvaceans lateral transport lidar ligands mangroves marine boundary layer marine snowfall marshes meltwater mesopelagic mesoscale metagenome metals methane microbes microlayer microorganisms microscale microzooplankton midwater mixed layer mixotrophy modeling mode water formation molecular diffusion MPT multi-decade NASA net community production new technology nitrogen nitrogen fixation nitrous oxide north atlantic north pacific nutricline nutrient budget nutrient cycling nutrient flux nutrient limitation nutrients OA ocean-atmosphere ocean acidification ocean carbon uptake and storage ocean color ocean observatories ODZ oligotrophic OMZ open ocean organic particles overturning circulation oxygen pacific ocean paleoceanography particle flux particulate organic carbon pCO2 PDO pH phosphorus photosynthesis physical processes physiology phytoplankton plankton polar regions pollutants prediction primary production primary productivity pteropods radioisotopes remineralization remote sensing residence time respiration rivers Rossby waves Ross Sea ROV salinity salt marsh satellite scale seagrass sea ice sea level rise seasonal patterns sediments sensors shelf system ship-based observations sinking particles SOCCOM southern ocean south pacific speciation species oscillations subduction submesoscale subpolar subtropical subtropical gyres subtropical mode water surface ocean teleconnections temperature thermohaline thorium tidal time-series time of emergence top predators trace element trace elements trace metals trait-based transfer efficiency transient features trophic transfer tropical turbulence twilight zone upper ocean upper water column upwelling US CLIVAR validation velocity gradient ventilation vertical flux vertical migration vertical transport western boundary currents wetlands winter mixing zooplankton

Copyright © 2019 - OCB Project Office, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, MS #25, Woods Hole, MA 02543 USA Phone: 508-289-2838  •  Fax: 508-457-2193  •  Email: ocb_news@us-ocb.org

link to nsflink to noaalink to WHOI

Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). The OCB Project Office is housed at the Woods Hole Oceanographic Institution.