Zooplankton biomass estimation from digitized images: a comparison between subtropical and Antarctic organisms

Lehette, Pascal; Hernández‐León, Santiago

doi:10.4319/lom.2009.7.304

Cited by 70 publications

(60 citation statements)

References 16 publications

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“…Then the carbon requirement of zooplankton (Z Creq ), could be expressed in mgC m −2 d −1 as (Nival et al, 1975), Z Creq = Ration · B zoo , where B zoo is the biomass of zooplankton in mgC m −3 , calculated using size-carbon weight relationships from Lehette and Hernández-León (2009) and Mauchline (1998) applied on samples of the WP2 (that quantitatively samples zooplankton in the size range [0.4:2.8] mm ESD). The Ration is defined following Nival et al (1975) as a function of growth rate g z , respiration r and assimilation efficiency A.…”

Section: Primary Production and Zooplankton Carbon Requirementmentioning

confidence: 99%

Inter-annual fluctuations of zooplankton communities in the Bay of Villefranche-sur-mer from 1995 to 2005 (Northern Ligurian Sea, France)

et al. 2011

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Abstract. An integrated analysis of the pelagic ecosystems of the Ligurian Sea is performed combining time series (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005) of several zooplankton groups (one group for copepods smaller than 0.724 mm 3 and nine groups for individuals larger than 0.724 mm 3 , i.e. large copepods, decapod larvae, other crustaceans, chaetognaths, appendicularians, pteropods, thaliaceans, gelatinous predators and other zooplankton), chlorophyll-a, nutrients, salinity, temperature, density, and local weather at Point B coastal station (Northern Ligurian Sea). From 1995 to 2000 winters were wet and mild resulting in lower winter sea surface density. These years showed lower than average nutrients and zooplankton concentrations while chlorophyll-a biomass was high. After 2000, winters were colder and dryer resulting in higher sea surface density. Nutrients and zooplankton showed higher concentrations while chlorophyll-a was lower than average. The ca. 2000 change was observed for most zooplankton groups with a one-year delay for some groups. Inter-annual variability within each period was also observed. The observed patterns suggest that the pelagic ecosystem trophic state at the studied point is mostly set by the winter forcing on the vertical mixing that upwells nutrients to the surface sustaining primary production. Surprisingly, low chlorophyll-a biomass in high nitrate and zooplankton conditions during the well mixed years suggest that phytoplankton biomass is Correspondence to: P. Vandromme (vandromme.pieter@gmail.com) controlled by grazers. The proposed mechanisms of stronger winter vertical mixing hold for most of the time series, but specific years with contradicting patterns suggest also the possible influence of the summer climate. A review of recent literature suggests that changes in the pelagic ecosystem are not limited to the studied site but concern also the central Ligurian Sea.

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Section: Primary Production and Zooplankton Carbon Requirementmentioning

confidence: 99%

Inter-annual fluctuations of zooplankton communities in the Bay of Villefranche-sur-mer from 1995 to 2005 (Northern Ligurian Sea, France)

et al. 2011

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“…Zooplankton estimated dry weight of each vignette was calculated from its area using the regression equation obtained for 30 mesozooplankton by Lehette and Hernández-León (2009 Below, the terms -ZOOSCAN abundance‖ and -ZOOSCAN biomass‖ will indicate values derived from the laboratory ZOOSCAN processing. The abundance and biomass of organisms were first calculated for four size fractions (< 500, 500-1000, 1000-2000 and > 2000 μm) based on their ECD, and then summed to deliver the total average abundance and biomass per sample over the upper 200 m. 5…”

Section: Abundance Biomass and Size Structure Using The Zooscanmentioning

confidence: 99%

Mesozooplankton structure and functioning in the western tropical South Pacific along the 20° parallel south during the OUTPACE survey (February–April 2015)

Carlotti¹,

Pagano²,

Guilloux³

et al. 2018

Preprint

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Abstract.This paper presents new results on spatial and temporal distribution patterns of mesozooplankton in the western 20 tropical South Pacific along the 20°S south visited during austral summer (February -April 2015). By contributing to the interdisciplinary OUTPACE (Oligotrophy to UlTra-oligotrophy PACific Experiment) project (Moutin et al., 2017), the specific aims of this study dedicated to mesozooplankton observations were (1) to document zooplankton density, species diversity, and biomass along the transect, and (2) to characterize the trophic pathways from primary production to mesozooplankton . Along a West-East transect of 4000 km from New Caledonia to the French Polynesia, 15 short-duration 25 stations (SD-1 to SD-15, 8hours each) dedicated to a large-scale description, and three long-duration stations (LD-A to LD-C, 5days each), respectively positioned (1) in offshore northern waters of New Caledonia, (2) near Niue Island, and (3) in the subtropical Pacific gyre near the Cook Islands, were sampled with a Bongo Net with 120 μm mesh size net for quantifying mesozooplankton abundance, biomass, community taxonomy and size structure, and size fractionated content of δ Daily grazing pressure on phytoplankton stocks and daily regeneration by zooplankton were as well estimated for the different regions showing contrasted impacts between MA and GY regions. For the 3 LD stations, it was not possible to find any relationship between the abundance and biomass in the water column and swimmers found in sediment traps. Diel vertical migration of zooplankton, which obviously occurs from observed differences in day and night samples, might 25 strongly influence the community of swimmers in traps.Biogeosciences Discuss., https://doi

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“…The carbon weight is calculated from the ESD of each object (both for the LOPC and the WP2/Zs) following ESD-to-dry weight (Lehette and Hernández-León, 2009) and dry weight-to-carbon (Mauchline, 1998) conversion equations:…”

Section: Size Spectra Calculationmentioning

confidence: 99%

Springtime zooplankton size structure over the continental shelf of the Bay of Biscay

Vandromme

Nogueira²,

Huret

et al. 2014

Ocean Sci.

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Abstract. Linking lower and higher trophic levels requires special focus on the essential role played by mid-trophic levels, i.e., the zooplankton. One of the most relevant pieces of information regarding zooplankton in terms of flux of energy lies in its size structure. In this study, an extensive data set of size measurements is presented, covering parts of the western European continental shelf and slope, from the Galician coast to the Ushant front, during the springs from 2005 to 2012. Zooplankton size spectra were estimated using measurements carried out in situ with the Laser Optical Plankton Counter (LOPC) and with an image analysis of WP2 net samples (200 µm mesh size) performed following the ZooScan methodology. The LOPC counts and sizes particles within 100-2000 µm of spherical equivalent diameter (ESD), whereas the WP2/ZooScan allows for counting, sizing and identification of zooplankton from ∼ 400 µm ESD. The difference between the LOPC (all particles) and the WP2/ZooScan (zooplankton only) was assumed to provide the size distribution of non-living particles, whose descriptors were related to a set of explanatory variables (including physical, biological and geographic descriptors). A statistical correction based on these explanatory variables was further applied to the LOPC size distribution in order to remove the non-living particles part, and therefore estimate the size distribution of zooplankton. This extensive data set provides relevant information about the zooplankton size distribution variability, productivity and trophic transfer efficiency in the pelagic ecosystem of the Bay of Biscay at a regional and interannual scale.

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Zooplankton biomass estimation from digitized images: a comparison between subtropical and Antarctic organisms

Cited by 70 publications

References 16 publications

Inter-annual fluctuations of zooplankton communities in the Bay of Villefranche-sur-mer from 1995 to 2005 (Northern Ligurian Sea, France)

Inter-annual fluctuations of zooplankton communities in the Bay of Villefranche-sur-mer from 1995 to 2005 (Northern Ligurian Sea, France)

Mesozooplankton structure and functioning in the western tropical South Pacific along the 20° parallel south during the OUTPACE survey (February–April 2015)

Springtime zooplankton size structure over the continental shelf of the Bay of Biscay

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