The swarm dynamics of northern krill (Meganyctiphanes norvegica) and pteropods (Cavolinia inflexa) during vertical migration in the Ligurian Sea observed by an acoustic Doppler current profiler

Tarling, Geraint A.; Matthews, J. B. L.; David, P. M.; Guerin, O.; Búchholz, Friedrich

doi:10.1016/s0967-0637(00)00105-9

Cited by 50 publications

(45 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The maximum hourly mean vertical migration speeds estimated from the measured vertical component of ADCP velocity ( À15 to 16 mm s À 1 ) were on average lower than those estimated from the slope of the scattering layer ( À 34 to 31 mm s À 1 ). This discrepancy is consistent with that found by other studies made by Plueddemann and Pinkel (1989), Heywood (1996), Luo et al (2000) and Tarling et al (2001). These discrepancies arise from the two different estimation methods.…”

Section: Discussionsupporting

confidence: 91%

Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica

Cisewski

Strass

Rhein

et al. 2010

Deep Sea Research Part I: Oceanographic Research Papers

104

View full text Add to dashboard Cite

a b s t r a c tTen-month time series of mean volume backscattering strength (MVBS) and vertical velocity obtained from three moored acoustic Doppler current profilers (ADCPs) deployed from February until December 2005 at 641S, 66.51S and 691S along the Greenwich Meridian were used to analyse the diel vertical zooplankton migration (DVM) and its seasonality and regional variability in the Lazarev Sea. The estimated MVBS exhibited distinct patterns of DVM at all three mooring sites. Between February and October, the timing of the DVM and the residence time of zooplankton at depth were clearly governed by the day-night rhythm. Mean daily cycles of the ADCP-derived vertical velocity were calculated for successive months and showed maximum ascent and descent velocities of 16 and -15 mm sHowever, a change of the MVBS pattern occurred in late spring/early austral summer (October/ November), when the zooplankton communities ceased their synchronous vertical migration at all three mooring sites. Elevated MVBS values were then concentrated in the uppermost layers ( o 50 m) at 66.51S. This period coincided with the decay of sea ice coverage at 641S and 66.51S between early November and mid-December. Elevated chlorophyll concentrations, which were measured at the end of the deployment, extended from 671S to 651S and indicated a phytoplankton bloom in the upper 50 m. Thus, we propose that the increased food supply associated with an ice edge bloom caused the zooplankton communities to cease their DVM in favour of feeding.

show abstract

Section: Discussionsupporting

confidence: 91%

Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica

Cisewski

Strass

Rhein

et al. 2010

Deep Sea Research Part I: Oceanographic Research Papers

104

View full text Add to dashboard Cite

show abstract

“…11. In the deeper layers, upward movement is often rapid (active) to reduce transit time through food-poor regions (Andersen and Nival 1991;Tarling et al 2001), whereas downward movement is slow (passive) because predation risk is less (Fiksen and Carlotti 1998) and energy can be conserved (Minkina 1981). Assuming the flux of individuals in and out of this layer is equal, this would produce a net upward movement.…”

Section: Discussionmentioning

confidence: 99%

“…Some studies in temperate regions have examined the gut contents of individuals caught in the deeper layers to determine whether they contain surfaceliving prey items (Pearre 1973), but this demands specialized taxonomic knowledge and a level of net sampling resolution difficult to achieve in extreme environments such as the arctic. The acoustic Doppler current profiler (ADCP) is becoming increasingly used to obtain behavioral information on zooplankton that can help interpret the movements of individuals in populations (Tarling et al 2001). The ADCP has the capacity to measure the velocity of zooplankton in the vertical plane through measuring Doppler shift (Plueddemann and Pinkel 1989).…”

mentioning

confidence: 99%

Unsynchronised and synchronised vertical migration of zooplankton in a high Arctic fjord

Cottier

Tarling

Wold

et al. 2006

Limnology & Oceanography

116

View full text Add to dashboard Cite

We measured vertical migration of zooplankton in an arctic fjord at 79uN between June and September 2002 and transcending a period of continuous illumination to one of true day and night to investigate the changing influence of light cues on behavior. Observations made with a moored 300 kHz acoustic Doppler current profiler indicated that two modes of vertical migration occurred during the study period. During the weeks of continuous illumination, backscatter data indicated that there was no net vertical displacement of the population at any time during the 24-h period, but vertical velocity showed a continuous net downward movement in the surface layers and a net upward movement at depth. We interpreted this as unsynchronized vertical migrations by individuals with upward trajectories that slowed closer to the surface and downward trajectories that were most rapid in their initial phases. Synchronized migrations, seen as an upward and downward movement of scattering layers at dusk and dawn respectively, began once true nighttime resumed toward autumn. It is likely that the relative rate of change in light was used as the proximal cue for synchronized migrations. Concurrent net samples identified Calanus finmarchicus and C. glacialis as the most likely contributors to the unsynchronized migration patterns. The high backscatter of the synchronized scattering layers suggests that they included additional taxa such as the euphausiid Thysanoessa spp., the pteropod Limacina helicina, or the hyperiid amphipod Themisto spp.

show abstract

“…M. norvegica covers a wide distributional area from the Mediterranean to sub-polar waters but is not an explicit Arctic species (Mauchline & Fischer 1969, Mauchline 1980. Northern krill is able to perform extended diel vertical migrations of more than 800 m as shown in the Mediterranean by Tarling et al (2001). At night the animals enter the productive surface layers, where they feed on phytoplankton and small zooplankton (Sameoto 1976, Lass et al 2001), while they descend to deeper layers during daytime.…”

Section: Introductionmentioning

confidence: 99%

Food utilization of two pelagic crustaceans in the Greenland Sea: Meganyctiphanes norvegica (Euphausiacea) and Hymenodora glacialis (Decapoda, Caridea)

Kreibich¹,

Hagen²,

Saborowski³

2010

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Large pelagic crustaceans from Greenland Sea waters, the northern krill Meganyctiphanes norvegica (Euphausiacea) and the decapod shrimp Hymenodora glacialis (Caridea), were captured in depths down to 1500 m and studied with respect to their physiological food utilization abilities. Both species showed distinct differences in the amount of total lipids (TLs), lipid class and fatty acid (FA) compositions as well as proteolytic enzyme activities. In M. norvegica, the overall amount of TLs and storage lipids was much lower than in H. glacialis, and triacylglycerols formed the major lipid fraction with a mean of 48% TLs. Major FAs comprised the trophic markers 20:1(n-9) and 22:1(n-11), indicating the ingestion of calanid copepods. Additionally, the FAs 22:6(n-3), 18:1(n-9) and 16:0 prevailed. In H. glacialis, TLs (mean = 44% dry mass) were about twice as high as in krill, with wax esters comprising up to 89% TLs. H. glacialis seems to accumulate these lipids as energy reserves to survive periods of food limitation. Moreover, high lipid levels, particularly wax esters, also help to maintain neutral buoyancy. The major FA in H. glacialis was 18:1(n-9); other dominant FAs were 20:1(n-9) and 22:1(n-11), typical of calanid copepods, as well as the diatom trophic marker 16:1(n-7). Both species showed omnivorous feeding behaviour with a strong tendency towards carnivory. Total proteolytic activities in midgut gland tissue were higher in M. norvegica than in H. glacialis. In M. norvegica, proteinases were dominated by serine proteinases, whereas cysteine proteinases formed the major group in H. glacialis. High proteolytic activity in M. norvegica indicates a high digestive potential for proteins and efficient utilization of prey. The presence of different proteinase classes in both species may be due to different group-specific enzyme expression patterns between euphausiids and caridean decapods. Both species follow highly deviating life strategies, as reflected by their specific lipid and enzymatic characteristics.

show abstract

The swarm dynamics of northern krill (Meganyctiphanes norvegica) and pteropods (Cavolinia inflexa) during vertical migration in the Ligurian Sea observed by an acoustic Doppler current profiler

Cited by 50 publications

References 28 publications

Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica

Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica

Unsynchronised and synchronised vertical migration of zooplankton in a high Arctic fjord

Food utilization of two pelagic crustaceans in the Greenland Sea: Meganyctiphanes norvegica (Euphausiacea) and Hymenodora glacialis (Decapoda, Caridea)

Contact Info

Product

Resources

About