Trophic position of Calanus finmarchicus (Copepoda, Calanoida) in the Trondheim Fjord

Saage, Andrea; Altin, Dag; Vadstein, Ôlav; Sommer, Ulrich

doi:10.1016/j.seares.2007.12.003

Cited by 8 publications

(3 citation statements)

References 42 publications

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“…Despite being opportunistic feeders, these large grazers prefer bigger phytoplankton cells such as diatoms (e.g., Nejstgaard et al 1995). If their preferred food source is unavailable or because of seasonal feeding behavior, they can switch their diets to carnivory or become detritivores (e.g., Euphausiacea, Hagen et al 2007; Calanoida, Saage et al 2008), or resort to using their stored lipid reserves (Lee and Hagen 2006). The nanophytoplankton were instead likely grazed by the smaller zooplankton that numerically dominated the archipelago (Fig.…”

Section: Discussionmentioning

confidence: 99%

Plankton community composition and productivity near the Subantarctic Prince Edward Islands archipelago in autumn

Stirnimann

Bornman

Verheye

et al. 2021

Limnology & Oceanography

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The Subantarctic Ocean is a sink for atmospheric CO2, largely due to its biological pump, which is enhanced by the influence of the Subantarctic islands on the plankton ecosystem (the so‐called “island mass effect”). The influence of the Prince Edward Islands archipelago in the Indian Subantarctic on the surrounding hydrography and benthos has been well studied; however, over the last two decades, little attention has been paid to the functioning and productivity of its plankton ecosystem. Here, we present the first measurements of primary production at the archipelago in over 20 years and the first‐ever rates of secondary production, interpreted in the context of hydrographic, biogeochemical, and plankton community composition data. In autumn 2017, after the late‐summer bloom, nanophytoplankton dominated the near‐island waters and regenerated nutrients fuelled 76% of phytoplankton growth. Primary production and carbon export potential (inferred from nitrate uptake) reached a local maximum in the inter‐island region, which we attribute to water‐mass retention and stratification over the inter‐island plateau (a manifestation of the island mass effect). We observed a diverse mesozooplankton community, likely a remnant of the late‐summer bloom rather than representing the consumers feeding on the in situ (nano)phytoplankton. We estimate that even after the decay of the late‐summer bloom, roughly a quarter of the planktonic carbon was potentially exportable. This finding implies that the archipelago's upper‐ocean ecosystem sequesters atmospheric CO2 at least through autumn despite high rates of recycling and inefficient trophic transfer, thereby contributing to the island mass effect‐associated strengthening of the Subantarctic Ocean's biological pump.

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Section: Discussionmentioning

confidence: 99%

Plankton community composition and productivity near the Subantarctic Prince Edward Islands archipelago in autumn

Stirnimann

Bornman

Verheye

et al. 2021

Limnology & Oceanography

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“…C. finmarchicus and Pseudocalanus spp. have trophic levels of about 2 (33). Thus, our TL sample is an estimate with uncertainty introduced by both the trophic enrichment factor (3.6‰) and the baseline value for TL2 (δ 15 N ) 8.01‰).…”

Section: Trophic Levelmentioning

confidence: 99%

Marine Natural Products, the Halogenated 1′-Methyl-1,2′-bipyrroles, Biomagnify in a Northwestern Atlantic Food Web

Pangallo

Reddy

2010

Environ. Sci. Technol.

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Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) are putative marine natural products that accumulate in marine mammal blubber in similar concentrations and patterns to biomagnifying organic pollutants. Here we measure concentrations of MBPs and 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) in 40 samples composed of eight fish species, two squid species, and six species of marine mammals. To determine their trophic positions and to further investigate influence of prey preference, we also measured the stable carbon and nitrogen isotopic compositions of all samples. Our results show that lipid-normalized MBP concentrations increase with increasing trophic level; therefore, MBPs qualify as another class of biomagnifying marine natural products. The presence of MBPs in pinniped prey and absence in pinniped blubber suggests that these mammals share dietary exposure to MBPs with odontocetes but have an enhanced ability to metabolize these natural products.

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“…However, δ 15 N and the TL of C. finmarchicus can vary throughout the year (Søreide et al 2006). Also, from Trondheimsfjorden farther south in Norway, Saage et al (2008) found that C. finmarchicus had an average TL of 2.4 and the highest δ 15 N in this copepod occurred in February before the spring bloom started. Thus, the assumption that our baseline organism, C. finmarchicus, is found strictly at TL 2.0 may be questionable.…”

Section: Trophic Level Calculationsmentioning

confidence: 88%

Ontogenetic niche changes in haddock Melanogrammus aeglefinus reflected by stable isotope signatures, δ13C and δ15N

Ramsvatn¹,

Pedersen²

2012

Mar. Ecol. Prog. Ser.

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We investigated stable nitrogen (δ 15 N) and carbon (δ 13 C) isotope signatures in haddock Melanogrammus aeglefinus in Ullsfjord, Norway, and found evidence of an ontogenetic shift as a result of growth but in the absence of other morphological changes. Stable isotope signatures and trophic level (TL) changed significantly from a pelagic signature and a low TL to a more benthic associated signature and higher TL when the fish were ca. 20 cm in length. The stable isotope signatures of haddock were compared with those of Atlantic cod Gadus morhua from the same system, other main demersal fish species in the fjord, and haddock from the adjacent fjord, Sør-fjord. Our results indicate that both haddock and cod are opportunistic feeders, feeding on the abundant crustaceans in the fjords. Several of the large demersal fish species in Ullsfjord had very similar stable isotope signatures, which reflected their predation on similar prey types.

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Trophic position of Calanus finmarchicus (Copepoda, Calanoida) in the Trondheim Fjord

Cited by 8 publications

References 42 publications

Plankton community composition and productivity near the Subantarctic Prince Edward Islands archipelago in autumn

Plankton community composition and productivity near the Subantarctic Prince Edward Islands archipelago in autumn

Marine Natural Products, the Halogenated 1′-Methyl-1,2′-bipyrroles, Biomagnify in a Northwestern Atlantic Food Web

Ontogenetic niche changes in haddock Melanogrammus aeglefinus reflected by stable isotope signatures, δ13C and δ15N

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