Carbon and nitrogen content of copepod faecal pellets: effect of food concentration and feeding behavior

Morales, CE

doi:10.3354/meps036107

Cited by 48 publications

(24 citation statements)

References 25 publications

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“…Therefore an important fraction of phytoplankton biomass increases observed by satellite may not contribute to export fluxes. Notably, the POC : PON ratio measured in our trap material is close to values reported for marine diatoms (7.3 ± 1.2; Sarthou et al, 2005) compared to the C : N ratio of zooplankton faecal pellets, which is typically higher (7.3 to > 15, Gerber and Gerber, 1979;Checkley and Entzeroth, 1985;Morales, 1987). Simple mass balance would therefore suggest a significant contribution of phytoplanktonic cells to the POC export, which is indeed corroborated by detailed microscopic analysis (Rembauville et al, 2015).…”

Section: Seasonal Dynamics Of Poc Exportsupporting

confidence: 66%

Export fluxes in a naturally iron-fertilized area of the Southern Ocean – Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap

et al. 2015

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Abstract.A sediment trap moored in the naturally ironfertilized Kerguelen Plateau in the Southern Ocean provided an annual record of particulate organic carbon and nitrogen fluxes at 289 m. At the trap deployment depth, current speeds were typically low ( ∼ 10 cm s −1 ) and primarily tidaldriven (M2 tidal component). Although advection was weak, the sediment trap may have been subject to hydrodynamical and biological (swimmer feeding on trap funnel) biases. Particulate organic carbon (POC) flux was generally low (< 0.5 mmol m −2 d −1 ), although two episodic export events (< 14 days) of 1.5 mmol m −2 d −1 were recorded. These increases in flux occurred with a 1-month time lag from peaks in surface chlorophyll and together accounted for approximately 40 % of the annual flux budget. The annual POC flux of 98.2 ± 4.4 mmol m −2 yr −1 was low considering the shallow deployment depth but comparable to independent estimates made at similar depths (∼ 300 m) over the plateau, and to deep-ocean (> 2 km) fluxes measured from similarly productive iron-fertilized blooms. Although undertrapping cannot be excluded in shallow moored sediment trap deployment, we hypothesize that grazing pressure, including mesozooplankton and mesopelagic fishes, may be responsible for the low POC flux beneath the base of the winter mixed layer. The importance of plankton community structure in controlling the temporal variability of export fluxes is addressed in a companion paper.

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Section: Seasonal Dynamics Of Poc Exportsupporting

confidence: 66%

Export fluxes in a naturally iron-fertilized area of the Southern Ocean – Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap

et al. 2015

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“…Moreover, the produced pellets were highly enriched with phaeophytine and were quite low in organic N compared to the ingested food, which suggests high assimilation rates for Chl. a (Bathmann and Liebezeit 1986) and proteins (Morales 1987). The former can be supported by the data on the food spectra of these species reported above.…”

Section: Discussionsupporting

confidence: 76%

Seasonal abundance and feeding patterns of copepods Temora longicornis, Centropages hamatus and Acartia spp. in the White Sea (66°N)

et al. 2011

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We have studied the seasonal dynamics of abundance and feeding characteristics of three species of calanoid copepods (Acartia spp., Centropages hamatus and Temora longicornis) in the White Sea from the surface water layer (0-10 m), in order to assess their role in the pelagic food web and to determine the major factors governing their population dynamics during the productive season. These species dominated in the upper water layer (0-10 m) from June through September, producing up to 3 generations per year. Data on the food spectra revealed all species to be omnivorous; but some inter-and intraspecific differences were observed. Generally, copepods consumed diatoms, dinoflagellates and microzooplankton. The omnivory index 'UC' (i.e., fatty acid unsaturation coefficient) varied from 0.2 to 0.6, which implied ingestion of phytoplankton. The different degree of selectivity on the same food items by the studied species was observed, and therefore, successful surviving strategy with minimal overlapping could be assumed. In total, the populations of the three studied copepod species grazed up to 2.15 g C m -2 day -1 and released up to 0.68 g C m -2 day -1 in faecal pellets. They consumed up to 50% of particulate organic carbon, or up to 85% of phytoplankton standing stock (in terms of Chl. a), and thus played a significant role in the transformation of particulate organic matter. Seasonal changes in abundance of the studied species depended mostly on water temperature in the early summer, but were also affected by food availability (Chl. a concentration) during the productive season.

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“…Although in some cases pellet density varies with food concentration within a food (Feinberg & Dam 1988), this is a small effect (< 5% change), which is ignored here. DW was assumed to be 30% of the wet weight of the pellet (V × D) and CW was assumed to be 25% of DW (Morales 1987 fecal pellet production, pellet volume and total pellet volume were done with 2-level nested ANOVA (Sokal & Rohlf 1981 ), where a is the asymptotic maximum value of Y (the dependent variable), and b represents the rate of increase of Y with respect to X (the independent variable). Analysis of covariance (ANCOVA) was employed for comparisons of slopes of linear regressions.…”

Section: Methodsmentioning

confidence: 99%

Coupling of ingestion and defecation as a function of diet in the calanoid copepod Acartia tonsa

Beşiktepe¹,

Dam

2002

Mar. Ecol. Prog. Ser.

157

129

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ABSTRACT:The relationship between the rates of ingestion and defecation of the calanoid copepod Acartia tonsa was examined in laboratory experiments with different diets: the diatom Thalassiosira weissflogii, the autotrophic dinoflagellate Prorocentrum minimum, the heterotrophic dinoflagellate Oxyrrhis sp., the flagellate Dunaliella tertiolecta, and the bacterivorous scuticociliate Uronema sp. Experiments were run typically using between 6 and 8 concentrations ranging from 10 to 1150 µg C l -1. Both diet and food concentration had significant effects on ingestion rate, pellet production rates and pellet volume. Ingestion and pellet production rates increased curvilinearly with food concentration. Copepods achieved the highest pellet production rates, the largest pellets and the shortest estimated gut passage times with the diatom diet. For all diets, gut passage time decreased with food concentration in the range 0 to ca. 250 µg C l -1 , but little thereafter. In addition, for all diets, but most obviously in the case of the diatom, pellet volume increased curvilinearly with food concentration. Maximum pellet volume was achieved at food concentrations ranging from 50 to 150 µg C l -1. The defecation and ingestion rates were best correlated when the copepods fed on the diatom and the autotrophic dinoflagellate. Likewise, a decrease in estimated assimilation efficiency with increasing food concentration was apparent only for these 2 diets. This latter pattern is primarily due to an increase in pellet production rate, instead of pellet volume, relative to ingestion rate at the high food concentrations. We conclude that a diatom diet is the most likely one to result in attributes that enhance zooplankton-mediated export flux: high fecal pellet production rates, large pellet size and relatively low assimilation efficiency.

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Carbon and nitrogen content of copepod faecal pellets: effect of food concentration and feeding behavior

Cited by 48 publications

References 25 publications

Export fluxes in a naturally iron-fertilized area of the Southern Ocean – Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap

Export fluxes in a naturally iron-fertilized area of the Southern Ocean – Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap

Seasonal abundance and feeding patterns of copepods Temora longicornis, Centropages hamatus and Acartia spp. in the White Sea (66°N)

Coupling of ingestion and defecation as a function of diet in the calanoid copepod Acartia tonsa

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