from his bathysphere in 1930. Marine snow has been a subject of intense study (e.g.
Alldredge 1998; Kiørboe 2000). Much of it is generated by phytoplankton that secrete
TEP, standing for transparent extracellular polysaccharides (Alldredge et al. 1993).
The polymers clump into mats. Mucus secreted by zooplankton (mostly by salps,
appendicularians, and pteropods) is also an important constituent.
Fig. 13.24 (a) Flux rates of sinking particulate organic matter measured as carbon
(POC) as a function of depth based on JGOFS studies using PARFLUX-type traps in
various sites: NABE, North Atlantic Bloom Experiment; EqPac, Equatorial Pacific;
AS, Arabian Sea; SO, Southern Ocean. (b) Organic-matter flux rates at 3000 m
relative to surface primary productivity measured as ^14 C-uptake rates.
(^) (After Berelson 2001.)
Fig. 13.25 Vertical profiles of POC flux rates estimated from vertical arrays of
PARFLUX-type sediment traps deployed in four JGOFS regional study areas. The
abscissas are logarithmic scales of POC flux compared to the euphotic-zone primary
production rate (the filled squares), both as mol C m−2 d−1. The curves are best-fit
Martin curves calculated with the b exponents to the right of each curve.
(^) (After Berelson 2001.)