Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Progress in Oceanography 165 (2018): 52-62, doi:10.1016/j.pocean.2018.04.014.
Description:
Small pelagic fishes represent a critical link between zooplankton and large predators. Yet, the
taxonomic resolution of the diets of these important fishes is often limited, especially in the Northwest
Atlantic. We examined the diets, along with stable isotope signatures, of five dominant small pelagic
species of the Northeast US continental shelf ecosystem (Atlantic mackerel Scomber scombrus, Atlantic
herring Clupea harengus, alewife Alosa pseudoharengus, blueback herring Alosa aestivalis, and Atlantic
butterfish Peprilus triacanthus). Diet analyses revealed strong seasonal differences in most species. Small
pelagic fishes predominantly consumed Calanus copepods, small copepod genera
(Pseudocalanus/Paracalanus/Clausocalanus), and Centropages copepods in the spring, with
appendicularians also important by number for most species. Krill, primarily Meganyctiphanes norvegica,
and hyperiid amphipods of the genera Hyperia and Parathemisto were common in the stomach contents
of four of the five species in the fall, with hyperiids common in the stomach contents of butterfish in both
seasons and krill common in the stomach contents of alewife in both seasons. Depth and region were also
found to be sources of variability in the diets of Atlantic mackerel, Atlantic herring, and alewife (region
but not depth) with krill being more often in the diet of alewife in more northerly locations, primarily the
Gulf of Maine. Stable isotope data corroborate the seasonal differences in diet but overlap of isotopic
niche space contrasts that of dietary overlap, highlighting the differences in the two methods. Overall, the
seasonal variability and consumer-specific diets of small pelagic fishes are important for understanding
how changes in the zooplankton community could influence higher trophic levels.
Description:
Funding for this work
was primarily through a US National Science Foundation (NSF) OCE-RIG grant (OCE 1325451) to JKL,
with additional support from NOAA through the Cooperative Institute for the North Atlantic Region
(CINAR) under Cooperative Agreement NA14OAR4320158 in the form a CINAR Fellow Award (JKL),
an NSF Long-term Ecological Research grant for the Northeast US Shelf Ecosystem (OCE 1655686;
JKL), a Hendrix College summer research award (ZRK), and an NSF REU-supported Woods Hole
Oceanographic Institution Summer Student Fellowship (SLH).
Keywords:
Forage fish
;
Zooplankton
;
Feeding
;
Copepods
;
Stable isotopes
;
Trophodynamics
;
Northeast US Shelf
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
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