scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Predicting marine phytoplankton community size structure from empirical relationships with remotely sensed variables

TL;DR: In this article, the authors describe relationships between the environment and the size composition of phytoplankton communities, using a collation of empirical measurements of size composition from sites that include polar, tropical and upwelling environments.
Abstract: The size composition of primary producers has a potential influence on the length of marine food chains and carbon sinking rates, thus on the proportion of primary production (PP) that is removed from the upper layers and available to higher trophic levels. While total rates of PP are widely reported, it is also necessary to account for the size composition of primary producers when developing food web models that predict consumer biomass and production. Empirical measurement of size composition over large space and time scales is not feasible, so one approach is to predict size composition from environmental variables that are measured and reported on relevant scales. Here, we describe relationships between the environment and the size composition of phytoplankton communities, using a collation of empirical measurements of size composition from sites that include polar, tropical and upwelling environments. The size composition of the phytoplankton communities can be predicted using two remotely sensed variables, chlorophyll-a concentration and sea surface temperature. Applying such relationships in combination allows prediction of the slope and location of phytoplankton size spectra and estimation of the percentage of different sized phytoplankton groups in communities.

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
TL;DR: When applied in combination, these 3 techniques have the potential to reveal pathways of energy flux across marine ecosystems and to provide new insight into marine ecosystem dynamics.
Abstract: Understanding seabird marine habitat affinities, at-sea behavior, variability in repro- ductive success, migratory patterns, phenology, and other life history traits depends primarily on knowledge of the prey that they consume. Traditionally, estimating diets has been done through classification and enumeration of prey remains found in stomach contents of seabirds collected at sea, as well as chick meals, pellets, and feces collected at breeding colonies. These techniques have the advantage of high taxonomic resolution of prey, but suffer from biases due to the under - estimation of soft-bodied or small prey that are digested completely and overestimation of prey with durable parts that are retained for long periods of time. Recent innovations in 2 biochemical assays of seabird tissues—stable isotope and fatty acid analyses—have greatly expanded knowledge of seabird diets and have advanced our understanding of the ways in which seabirds can indicate in- ter-seasonal, annual, decadal, and longer shifts in oceanographic conditions over varying spatial scales. Advances in statistical approaches to these data have provided new ways in which prey can be identified and quantified. When applied in combination, these 3 techniques (traditional diet sampling, and stable isotope and fatty acid analyses) have the potential to reveal pathways of energy flux across marine ecosystems and to provide new insight into marine ecosystem dynamics. We review the basic principles of these approaches to determining seabird diet and emphasize the need for more formal conceptual and statistical integration of methods to advance this field.

94 citations


Cites background from "Predicting marine phytoplankton com..."

  • ...As our understanding of key mechanisms controlling the isotopic composition of primary productivity increases, our ability to construct marine isoscapes relevant to seabird studies will increase (Graham et al. 2010, Barnes et al. 2011)....

    [...]

Dissertation
30 May 2011
TL;DR: In this article, the general patterns of seasonal dynamics in four areas of Estonian operational phytoplankton monitoring have been demonstrated, and the results are discussed in relation to present and future environmental challenges to the Baltic Sea.
Abstract: Muutused futoplanktoni kui mere okosusteemi uhe aluskomponendi koosseisus kutsuvad esile nii struktuurseid kui funktsionaalseid nihkeid toiduahela jargmistes lulides. Toos on analuusitud Eesti rannikumere erinevatest osadest kogutud seireandmeid 1990-ndate algusest kuni praeguseni. Saadud tulemused fikseerivad futoplanktoni sesoonse dunaamika pohijooned. Futoplanktoni liigilise koosseisu aastatevahelist ja sesoonisisest varieeruvust seletatavad uhelt poolt ilmastikutingimusted ning teiselt poolt vee toitainetesisaldus. Temperatuur ja soolsus on peamised tegurid, mis kujundavad Laanemere, sealhulgas Soome lahe futoplanktoni koosluste struktuuri ja levikut. Luhikesel ajaskaalal on looduslike ja inimtekkeliste protsesside osakaalu maaramine futoplanktoni dunaamikas keeruline, sest pusivama iseloomuga muutused leiavad aset jark-jargult ning isegi moodukas toitainetesisalduse kasv peegeldub liigilises koosseisus vahemargatavalt. Futoplanktoni ajalis-ruumiline varieeruvus tingib, et sesoonseid muutusi tuleb jalgida voimalikult vaikese ajasammuga, ent samas vaatluste ja analuusikulusid moistlikul tasemel hoides. Traditsiooniliste meetodite korval saab seiret tohustada kommertsalustele paigaldatud jarelvalveta mootmis- ja proovikogumissusteemide abil. Teadmised futoplanktoni koosluste suktsessiooni ja uksikute liikide ajalis-ruumilist dunaamika kohta voimaldavad anda soovitusi seiresageduse optimeerimiseks, arvestades vetikaoitsengute esinemise ajalisi mustreid ja oitsenguvaheliste perioodide suuremat stabiilsust koosluse struktuuris. Pakutakse valja potentsiaalsed uued keskkonnaseisundi indikaatorid Laanemere pohjaosa jaoks.; Changes in phytoplankton composition may reflect structural and functional ecosystem shifts. In this thesis, the general patterns of seasonal dynamics in four areas of Estonian operational phytoplankton monitoring have been demonstrated. All data are linked to spatial distributions of abiotic parameters and the results are discussed in relation to present and future environmental challenges to the Baltic Sea. Temperature and salinity are the main factors shaping the phytoplankton communities in the Gulf of Finland. Most of the statistically significant changes over the study period (1993–2010) have been related to increases in the mean seasonal or monthly biomass values at different taxo¬nomic levels. Measuring seasonal changes and inter-annual variability requires extensive sampling efforts. The optimal sampling frequency for the northern parts of the Baltic Sea has been discussed and alternative methods of phytoplankton monitoring introduced. Although phytoplankton biomass and species composition are influenced by different mechanisms, the impact of climate change may be overwhelming in the future and induce changes at higher trophic levels. Therefore it is important to maintain long-term biological monitoring programs to assess the biological response to both relatively slow processes and short-term events in water environment. Phytoplankton is also determined as one of the biological quality…

88 citations

Journal ArticleDOI
30 Jul 2015-PLOS ONE
TL;DR: A size-based macroecological model is developed and used to assess the effects of parameter uncertainty on predicted consumer biomass, production and distribution and shows that models with minimal parameter demands that are based on a few established ecological principles can support equitable analysis and comparison of diverse ecosystems.
Abstract: Existing estimates of fish and consumer biomass in the world’s oceans are disparate. This creates uncertainty about the roles of fish and other consumers in biogeochemical cycles and ecosystem processes, the extent of human and environmental impacts and fishery potential. We develop and use a size-based macroecological model to assess the effects of parameter uncertainty on predicted consumer biomass, production and distribution. Resulting uncertainty is large (e.g. median global biomass 4.9 billion tonnes for consumers weighing 1 g to 1000 kg; 50% uncertainty intervals of 2 to 10.4 billion tonnes; 90% uncertainty intervals of 0.3 to 26.1 billion tonnes) and driven primarily by uncertainty in trophic transfer efficiency and its relationship with predator-prey body mass ratios. Even the upper uncertainty intervals for global predictions of consumer biomass demonstrate the remarkable scarcity of marine consumers, with less than one part in 30 million by volume of the global oceans comprising tissue of macroscopic animals. Thus the apparently high densities of marine life seen in surface and coastal waters and frequently visited abundance hotspots will likely give many in society a false impression of the abundance of marine animals. Unexploited baseline biomass predictions from the simple macroecological model were used to calibrate a more complex size- and trait-based model to estimate fisheries yield and impacts. Yields are highly dependent on baseline biomass and fisheries selectivity. Predicted global sustainable fisheries yield increases ≈4 fold when smaller individuals (< 20 cm from species of maximum mass < 1kg) are targeted in all oceans, but the predicted yields would rarely be accessible in practice and this fishing strategy leads to the collapse of larger species if fishing mortality rates on different size classes cannot be decoupled. Our analyses show that models with minimal parameter demands that are based on a few established ecological principles can support equitable analysis and comparison of diverse ecosystems. The analyses provide insights into the effects of parameter uncertainty on global biomass and production estimates, which have yet to be achieved with complex models, and will therefore help to highlight priorities for future research and data collection. However, the focus on simple model structures and global processes means that non-phytoplankton primary production and several groups, structures and processes of ecological and conservation interest are not represented. Consequently, our simple models become increasingly less useful than more complex alternatives when addressing questions about food web structure and function, biodiversity, resilience and human impacts at smaller scales and for areas closer to coasts.

86 citations


Cites background or methods from "Predicting marine phytoplankton com..."

  • ...M at the lower and upper extremes of the phytoplankton size distribution,MP0 and MP100, as needed to determine the proportion of cells in different mass ranges, were calculated fromMP50 andMP1090 owing to the variable tails of the real distributions [43]....

    [...]

  • ...Slopes bP and intercepts aP of the phytoplankton size spectra were estimated from empirical relationships with primary production PP using the approach and data of Barnes et al [43] bP 1⁄4 aþ b1 log10PP ð1Þ...

    [...]

  • ...While these simple models do not include some structures or processes that can be important predictors of biomass distributions, especially on smaller scales, the underlying justifications for the structures of both models are founded in empirical and theoretical study of size-based processes in marine systems that show how body size, energy acquisition and transfer and the effects of temperature account for much of the variation in the structure and function of many types of communities [21, 26, 28, 29, 43, 48, 63, 64]....

    [...]

  • ...Size composition of the phytoplankton community was estimated from primary production and temperature (T) using empirical relationships [43] and, in turn, size composition was used to estimate particle export ratios [44]....

    [...]

  • ...Means and standard deviations of the α, β1 and β2 coefficients used to predict the size structure of the phytoplankton community as a function of primary production and temperature [43]....

    [...]

Journal ArticleDOI
TL;DR: It is shown that phytoplankton average cell sizes tend to become smaller in warmer waters, although temperature is not necessarily the proximate environmental factor driving size shifts, and the implications of the temperature‐related size trends in a global‐warming context are discussed.
Abstract: Global warming has revitalized interest in the relationship between body size and temperature, proposed by Bergmann's rule 150 years ago, one of the oldest manifestations of a ‘biogeography of traits’. We review biogeographic evidence, results from clonal cultures and recent micro- and mesocosm experiments with naturally mixed phytoplankton communities regarding the response of phytoplankton body size to temperature, either as a single factor or in combination with other factors such as grazing, nutrient limitation, and ocean acidification. Where possible, we also focus on the comparison between intraspecific size shifts and size shifts resulting from changes in species composition. Taken together, biogeographic evidence, community-level experiments and single-species experiments indicate that phytoplankton average cell sizes tend to become smaller in warmer waters, although temperature is not necessarily the proximate environmental factor driving size shifts. Indirect effects via nutrient supply and grazing are important and often dominate. In a substantial proportion of field studies, resource availability is seen as the only factor of relevance. Interspecific size effects are greater than intraspecific effects. Direct temperature effects tend to be exacerbated by indirect ones, if warming leads to intensified nutrient limitation or copepod grazing while ocean acidification tends to counteract the temperature effect on cell size in non-calcifying phytoplankton. We discuss the implications of the temperature-related size trends in a global-warming context, based on known functional traits associated with phytoplankton size. These are a higher affinity for nutrients of smaller cells, highest maximal growth rates of moderately small phytoplankton (ca. 102 µm3), size-related sensitivities for different types of grazers, and impacts on sinking rates. For a phytoplankton community increasingly dominated by smaller algae we predict that: (i) a higher proportion of primary production will be respired within the microbial food web; (ii) a smaller share of primary production will be channeled to the classic phytoplankton – crustacean zooplankton – fish food chain, thus leading to decreased ecological efficiency from a fish-production point of view; (iii) a smaller share of primary production will be exported through sedimentation, thus leading to decreased efficiency of the biological carbon pump.

83 citations


Cites background from "Predicting marine phytoplankton com..."

  • ...…ranged from approximately −1.3 to −0.7; more negative slopes characterizing open-ocean oligotrophic stations while less negative slopes characterized more eutrophic coastal and upwelling stations (Reul et al., 2005; Marañón et al., 2007; Barnes et al., 2011; Huete-Ortega et al., 2012, 2014)....

    [...]

  • ...7; more negative slopes characterizing open-ocean oligotrophic stations while less negative slopes characterized more eutrophic coastal and upwelling stations (Reul et al., 2005; Marañón et al., 2007; Barnes et al., 2011; Huete-Ortega et al., 2012, 2014)....

    [...]

  • ...Barnes et al. (2011) analysed size spectra from 362 samples from open Atlantic Ocean transects (50◦S to 48◦N) and coastal stations from the Benguela Upwelling to the Irminger Sea....

    [...]

Journal ArticleDOI
TL;DR: This work presents the first global biogeography of key traits (body size, feeding mode, relative offspring size and myelination) for pelagic copepods, the major group of marine zooplankton, and identifies strong patterns with latitude, season and between ocean basins that are partially explained by key environmental drivers.
Abstract: Functional traits, rather than taxonomic identity, determine the fitness of individuals in their environment: traits of marine organisms are therefore expected to vary across the global ocean as a function of the environment. Here, we quantify such spatial and seasonal variations based on extensive empirical data and present the first global biogeography of key traits (body size, feeding mode, relative offspring size and myelination) for pelagic copepods, the major group of marine zooplankton. We identify strong patterns with latitude, season and between ocean basins that are partially (c. 50%) explained by key environmental drivers. Body size, for example decreases with temperature, confirming the temperature-size rule, but surprisingly also with productivity, possibly driven by food-chain length and size-selective predation. Patterns unrelated to environmental predictors may originate from phylogenetic clustering. Our maps can be used as a test-bed for trait-based mechanistic models and to inspire next-generation biogeochemical models.

75 citations


Cites background or methods from "Predicting marine phytoplankton com..."

  • ...Active diverCHL & medianPhyto 521.52 519.13 0.03 0 Feeding_mode....

    [...]

  • ...Communities with high body-size diversity 326 were most common in environments with low NPP, CHL seasonality and phytoplankton cell 327 size (Figure 4e,f,h)....

    [...]

  • ...Although not all 171 copepods feed solely on phytoplankton, phytoplankton cell size has a strong impact on the 172 entire food web (Barnes et al. 2011)....

    [...]

  • ...769 SST a ZSD b NPP c CHL seasonality d MD50 e SST 1 0.47 -0.06 -0.52 -0.86 1 0.48 -0.15 -0.49 -0.58 ZSD 0.47 1 -0.78 -0.92 -0.82 0.48 1 -061 -0.6 -0.79 NPP -0.06 -0.78 1 0.77 0.5 -0.15 -0.61 1 0.37 0.4 CHL seasonality -0.52 -0.92 0.77 1 0.86 -0.49 -0.6 0.37 1 0.59 MD50 -0.86 -0.82 0.5 0.86 1 -0.58 -0.79 0.42 0.59 1 a Sea surface temperature; b Secchi Depth; c net primary productivity; d seasonality in chlorophyll a concentrations; 770 e median diameter of phytoplankton cells 771 772 Appendix C: Spatial and temporal meshes for INLA 773 North Atlantic 774 Models for the North Atlantic were constructed including both, a spatial and a 775 seasonal mesh....

    [...]

  • ...Active meanNPP & diverCHL 502.49 500.07 0.13 1 Feeding_mode....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: If the organisms are randomly distributed, a single count is sufficient to obtain an estimate of their abundance and confidence limits for this estimate, even if pipetting, dilution or concentration are involved.
Abstract: Various methods for the estimation of populations of algae and other small freshwater organisms are described. A method of counting is described in detail. It is basically that of Utermohl and uses an inverted microscope. If the organisms are randomly distributed, a single count is sufficient to obtain an estimate of their abundance and confidence limits for this estimate, even if pipetting, dilution or concentration are involved. The errors in the actual counting and in converting colony counts to cell numbers are considered and found to be small relative to the random sampling error. Data are also given for a variant of Utermohl's method using a normal microscope and for a method of using a haemocytometer for the larger plankton algae.

2,572 citations


"Predicting marine phytoplankton com..." refers background or methods in this paper

  • ...Sub-samples (100 ml) were settled (Utermıhl technique (Lund et al. 1958)) and individuals counted at the species level with an inverted microscope....

    [...]

  • ...technique (Lund et al. 1958)) and individuals counted at the species level with an inverted...

    [...]

Journal ArticleDOI
TL;DR: Cellular carbon and nitrogen content and cell volume of nutritionally and morphologically diverse dinoflagellate species were measured to determine carbon to volume and nitrogen to volume relationships.
Abstract: Cellular carbon and nitrogen content and cell volume of nutritionally and morphologically diverse dinoflagellate species were measured to determine carbon to volume (C : vol) and nitrogen to volume (N : vol) relationships. Cellular C and N content ranged from 48 to 3.0 3 10 4 pgC cell 21 21 5

2,137 citations


"Predicting marine phytoplankton com..." refers background in this paper

  • ...0 −− = µvolumeyearCpg Equation 5 reported for taxonomically diverse protist plankton (Menden-Deuer and Lessard 2000)....

    [...]

  • ...reported for taxonomically diverse protist plankton (Menden-Deuer and Lessard 2000)....

    [...]

Journal ArticleDOI
TL;DR: In this paper, an estimate of global net primary production in the ocean has been computed from the monthly mean near-surface chlorophyll fields for 1979-1986 obtained by the Nimbus 7 CZCS radiometer.
Abstract: An estimate of global net primary production in the ocean has been computed from the monthly mean near-surface chlorophyll fields for 1979-1986 obtained by the Nimbus 7 CZCS radiometer. Our model required information about the subsurface distribution of chlorophyll, the parameters of the photosynthesis-light relationship, the sun angle and cloudiness. The computations were partitioned among 57 biogeochemical provinces that were specified from regional oceanography and by examination of the chlorophyll fields. Making different assumptions about the overestimation of chlorophyll by the CZCS in turbid coastal areas, the global net primary production from phytoplankton is given as 45-50 Gt C year"1. This may be compared with current published estimates for land plants of 45-68 Gt C year"' and for coastal vegetation of 1.9 Gt C year"1.

1,381 citations


"Predicting marine phytoplankton com..." refers background or methods in this paper

  • ...All changes from the implementation of Longhurst et al. (Longhurst et al. 1995) are detailed in Mélin (Mélin 2003)....

    [...]

  • ...ocean area (Longhurst et al. 1995), and to regional differences in phytoplankton community...

    [...]

  • ...PP was computed from a wavelength- and depthresolved model (Mélin 2003), building on the approach of Longhurst et al. (Longhurst et al. 1995)....

    [...]

  • ...This is due to variations in absolute productivity among regions, with 50% of production estimated to come from 27% of ocean area (Longhurst et al. 1995), and to regional differences in phytoplankton community structure....

    [...]

  • ...(Longhurst et al. 1995) are detailed in Mélin (Mélin 2003)....

    [...]

Journal ArticleDOI
TL;DR: This study provides evidence that reduced body size is the third universal ecological response to global warming in aquatic systems besides the shift of species ranges toward higher altitudes and latitudes and the seasonal shifts in life cycle events.
Abstract: Understanding the ecological impacts of climate change is a crucial challenge of the twenty-first century. There is a clear lack of general rules regarding the impacts of global warming on biota. Here, we present a metaanalysis of the effect of climate change on body size of ectothermic aquatic organisms (bacteria, phyto- and zooplankton, and fish) from the community to the individual level. Using long-term surveys, experimental data and published results, we show a significant increase in the proportion of small-sized species and young age classes and a decrease in size-at-age. These results are in accordance with the ecological rules dealing with the temperature–size relationships (i.e., Bergmann's rule, James' rule and Temperature–Size Rule). Our study provides evidence that reduced body size is the third universal ecological response to global warming in aquatic systems besides the shift of species ranges toward higher altitudes and latitudes and the seasonal shifts in life cycle events.

1,292 citations


"Predicting marine phytoplankton com..." refers background in this paper

  • ...There is evidence that reduced body size is the third universal ecological response to global warming besides the shift of species ranges toward higher altitudes and latitudes and the seasonal shifts in life-cycle events (Daufresne et al. 2009)....

    [...]

  • ...higher altitudes and latitudes and the seasonal shifts in life-cycle events (Daufresne et al. 2009)....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the frequency distributions of particIe size between sizes of about I and 100 p are given for both surface and deep water of the Atlantic and Pacific Oceans.
Abstract: Frequency distributions of particIe size between sizes of about I and 100 p are given for both surface and deep water of the Atlantic and Pacific Oceans. The form of the size spectra varies predictably both geographically and with depth. A hypothesis is presented to show that, to a first approximation, roughly equal concentrations of material occur at all particle sizes within the range from 1 p to about 10” p, i.e. from bacteria to whales.

1,116 citations