Feeding selectivity of Calanus finmarchicus in the Trondheimsfjord

Leiknes, Øystein; Striberny, Anja; Tokle, Nils; Ôlsen, Yngvar; Vadstein, Ôlav; Sommer, Ulrich

doi:10.1016/j.seares.2013.05.012

Cited by 17 publications

(7 citation statements)

References 45 publications

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“…Zooplankton engage in a range of selective feeding behaviors, but what may be a universal aspect of zooplankton feeding is the relationship between ingestion rate and food density (Gamble, 1978;Isari et al, 2013;Leiknes et al, 2014). Demonstrative differences in phytoplankton biomass or particle density will likely result in differences in ingestion rate and accumulated zooplankton biovolume.…”

Section: Discussionmentioning

confidence: 99%

Spring bloom dynamics and zooplankton biomass response on the US Northeast Continental Shelf

Friedland

Leaf

Kane

et al. 2015

Continental Shelf Research

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a b s t r a c tThe spring phytoplankton bloom on the US Northeast Continental Shelf is a feature of the ecosystem production cycle that varies annually in timing, spatial extent, and magnitude. To quantify this variability, we analyzed remotely-sensed ocean color data at two spatial scales, one based on ecologically defined sub-units of the ecosystem (production units) and the other on a regular grid (0.5°). Five units were defined: Gulf of Maine East and West, Georges Bank, and Middle Atlantic Bight North and South. The units averaged 47 Â 10 3 km 2 in size. The initiation and termination of the spring bloom were determined using change-point analysis with constraints on what was identified as a bloom based on climatological bloom patterns. A discrete spring bloom was detected in most years over much of the western Gulf of Maine production unit. However, bloom frequency declined in the eastern Gulf of Maine and transitioned to frequencies as low as 50% along the southern flank of the Georges Bank production unit. Detectable spring blooms were episodic in the Middle Atlantic Bight production units. In the western Gulf of Maine, bloom duration was inversely related to bloom start day; thus, early blooms tended to be longer lasting and larger magnitude blooms. We view this as a phenological mismatch between bloom timing and the "top-down" grazing pressure that terminates a bloom. Estimates of secondary production were available from plankton surveys that provided spring indices of zooplankton biovolume. Winter chlorophyll biomass had little effect on spring zooplankton biovolume, whereas spring chlorophyll biomass had mixed effects on biovolume. There was evidence of a "bottom up" response seen on Georges Bank where spring zooplankton biovolume was positively correlated with the concentration of chlorophyll. However, in the western Gulf of Maine, biovolume was uncorrelated with chlorophyll concentration, but was positively correlated with bloom start and negatively correlated with magnitude. This observation is consistent with both a "top-down" mechanism of control of the bloom and a "bottom-up" effect of bloom timing on zooplankton grazing. Our inability to form a consistent model of these relationships across adjacent systems underscores the need for further research.Published by Elsevier Ltd.

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Section: Discussionmentioning

confidence: 99%

Spring bloom dynamics and zooplankton biomass response on the US Northeast Continental Shelf

Friedland

Leaf

Kane

et al. 2015

Continental Shelf Research

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“…Diatoms selected or omnivorous (Irigoien et al, 2000;Fileman et al, 2007, Leiknes et al, 2014, but some records of selection for large motile prey (Fileman et al, 2010).…”

Section: Feeding Mode Preymentioning

confidence: 99%

High prey-predator size ratios and unselective feeding in copepods: A seasonal comparison of five species with contrasting feeding modes

Djeghri¹,

Atkinson²,

Fileman³

et al. 2018

Progress in Oceanography

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There has been an upsurge of interest in trait-based approaches to zooplankton, modelling the seasonal changes in the feeding modes of zooplankton in relation to phytoplankton traits such as size or motility. We examined this link at two English Channel plankton monitoring sites south of Plymouth (L4 and E1). At L4 there was a general transition from diatoms in spring to motile microplankton in summer and autumn, but this was not mirrored in the succession of copepod feeding traits; for example the ambushing Oithona similis dominated during the spring diatom bloom. At nearby E1 we measured seasonality of food and grazers, finding strong variation between 2014 and 2015 but overall low mesozooplankton biomass (median 4.5 mg C m-3). We also made a seasonal grazing study of five copepods with contrasting feeding modes (Calanus helgolandicus, Centropages typicus, Acartia clausi, Pseudocalanus elongatus and Oithona similis), counting the larger prey items from the natural seston. All species of copepod fed on all food types and differences between their diets were only subtle; the overriding driver of diet was the composition of the prey field. Even the smaller copepods fed on copepod nauplii at significant rates, supporting previous suggestions of the importance of intra-guild predation. All copepods, including O. similis, were capable of tackling extremely long (>500 µm) diatom chains at clearance rates comparable to those on ciliates. Maximum observed prey:predator length ratios ranged from 0.12 (C. helgolandicus) up to 0.52 (O. similis). Unselective feeding behaviour and the ability to remove highly elongated cells have implications for how copepod feeding is represented in ecological and biogeochemical models.

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“…Whether active detection and capturing of individual particles is a relevant grazing strategy for the observed filtration of oil particles is not known. It is suggested that larger particles are detected via sensors responding to hydrodynamic cues given off by moving prey (Kiørboe, 2011), but also nutritional value is indicated to be of significance for selective grazing (Leiknes et al, 2014). If selective grazing by copepods is purely based on size it may be expected that larger oil droplets ascending in the water column will transmit similar hydrodynamic cues as large feed particles, and hence be grazed upon in the same manner.…”

Section: Resultsmentioning

confidence: 99%

Modeling filtration of dispersed crude oil droplets by the copepod Calanus finmarchicus

Nepstad

Størdal

Brönner

et al. 2015

Marine Environmental Research

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Feeding selectivity of Calanus finmarchicus in the Trondheimsfjord

Cited by 17 publications

References 45 publications

Spring bloom dynamics and zooplankton biomass response on the US Northeast Continental Shelf

Spring bloom dynamics and zooplankton biomass response on the US Northeast Continental Shelf

High prey-predator size ratios and unselective feeding in copepods: A seasonal comparison of five species with contrasting feeding modes

Modeling filtration of dispersed crude oil droplets by the copepod Calanus finmarchicus

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