Fluxes of particulate organic carbon, nitrogen and mass from the Station M abyssal time series in the northeast Pacific, (1989-2022)

Overview:

This dataset provides particulate fluxes to Station M in the NE Pacific, from 1989 to 2022.  Samples were collected with McLane Parflux sequencing sediment traps deployed on moorings. Data are provided for traps 50 m above bottom and 600 m above bottom, with deployment bottom depths ranging from approximately 3900 m to 4500 m.  Gaps reflect lapses in funding, weather disruptions, clogs in sediment traps, or the occasional spilled sample.  Where available, GPS coordinates and ship-recorded bottom depth at deployment location are given. Where these are not available, approximate location and depth are given and noted.

Methods:

This program used McLane Parflux sequencing sediment traps. Attempts to avoid sediment trap clogs, which increasingly became an issue, included replacing manufacture-supplied plastic funnels with Teflon-coated fiberglass funnels (October 2014), doubling the size of sediment trap collection cups (from 250 ML to 500 ML starting in October 2014), and adding a function that periodically agitated material in the funnel constriction (starting in June 2015).

Before deployment, sediment trap cups were acid-washed and filled with a preservative (mercuric chloride from 1989 to 2009, 3%–5% buffered formalin from 2009 to 2022). Formalin brine recipe followed that recommended by McLane. Following sample recovery, zooplankton that many have swum into the traps were identified visually and manually removed (KLS). Samples were returned to the lab, freeze-dried, and weighed to calculate mass flux. The freeze-dried sample was analyzed for inorganic carbon content using a coulometer (UIC), and total carbon, hydrogen, and nitrogen using an elemental analyzer (Perkin-Elmer or Exeter Analytical, University of California Santa Barbara Marine Science Institute Analytical Laboratory). Dry mass was corrected for salt content using a AgNO3 titration (Strickland and Parsons, 1972). Data [mass flux, particulate organic carbon flux, and total nitrogen flux] from the 600 mab trap were used. Gaps in this data set were infilled using the linear relationship between data from the 600 mab and 50 mab traps. Full details of these methods can be found in Baldwin et al. (1998).

Data provided have been quality-controlled, and only usable data are included here.

References:

Baldwin, R. J., Glatts, R. C., & Smith Jr, K. L. (1998). Particulate matter fluxes into the benthic boundary layer at a long time-series station in the abyssal NE Pacific: composition and fluxes. Deep Sea Research Part II: Topical Studies in Oceanography, 45(4-5), 643-665.

Strickland, J.D.H., Parsons, T.R. (1972) A Practical Handbook of Seawater Analysis. Fisheries Research Board of Canada, Ottawa