In:
Biogeosciences, Copernicus GmbH, Vol. 17, No. 13 ( 2020-07-05), p. 3385-3407
Abstract:
Abstract. Zooplankton play an important role in global biogeochemistry, and their
secondary production supports valuable fisheries of the world's oceans.
Currently, zooplankton standing stocks cannot be estimated using remote
sensing techniques. Hence, coupled physical–biogeochemical models (PBMs)
provide an important tool for studying zooplankton on regional and global
scales. However, evaluating the accuracy of zooplankton biomass estimates
from PBMs has been a major challenge due to sparse observations. In this
study, we configure a PBM for the Gulf of Mexico (GoM) from 1993 to 2012 and
validate the model against an extensive combination of biomass and rate
measurements. Spatial variability in a multidecadal database of
mesozooplankton biomass for the northern GoM is well resolved by the model
with a statistically significant (p 〈 0.01) correlation of 0.90.
Mesozooplankton secondary production for the region averaged 66±8×109 kg C yr−1, equivalent to ∼10 % of
net primary production (NPP), and ranged from 51 to 82×109 kg C yr−1, with higher secondary production inside cyclonic eddies and
substantially reduced secondary production in anticyclonic eddies. Model
results from the shelf regions suggest that herbivory is the dominant
feeding mode for small mesozooplankton (〈 1 mm), whereas larger mesozooplankton are primarily carnivorous. In open-ocean oligotrophic
waters, however, both mesozooplankton groups show proportionally greater
reliance on heterotrophic protists as a food source. This highlights an
important role of microbial and protistan food webs in sustaining
mesozooplankton biomass in the GoM, which serves as the primary food source
for early life stages of many commercially important fish species, including
tuna.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-17-3385-2020
DOI:
10.5194/bg-17-3385-2020-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2020
detail.hit.zdb_id:
2158181-2
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