Seasonal studies on the phytoplankton and primary production in the inner Firth of Clyde

1986 ◽  
Vol 90 ◽  
pp. 203-222
Author(s):  
A. D. Boney
Keyword(s):  
Primary Production ◽  
Seasonal Changes ◽  
Total Carbon ◽  
Zooplankton Grazing ◽  
Cell Numbers ◽  
Annual Basis ◽  
Factors Influencing ◽  
Dispersion Data ◽  
Net Phytoplankton

SynopsisAnalysis of the factors influencing the seasonal changes in biomass of the ‘net’ phytoplankton in 1972– 73 snowed that the dynamics of the spring waxing of the diatom populations were controlled by narrow ‘windows’ of climatic events, and that subsequent fluctuations in cell numbers were linked with the interplay between zooplankton grazing and wind induced dispersion. Data for 1976–77, set against a similar background of events with the ‘net’ plankton, showed that the nanophytoplankton constituted a less variable biomass through the seasons and, on an annual basis, contributed some 50% of the total carbon fixed.

scholarly journals Relative rates of photosynthesis and standing stock of the net phytoplankton and nannoplankton

1963 ◽  
Vol 13 (2) ◽  
pp. 53-60 ◽  
Author(s):  
C. Teixeira
Keyword(s):  
Primary Production ◽  
Water Samples ◽  
Sea Water ◽  
Standing Stock ◽  
Pronounced Difference ◽  
Cell Numbers ◽  
Total Phytoplankton ◽  
Net Phytoplankton

Some experiments on C-14 uptake and cell numbers were made with the purpose of comparing nannoplankton and net phytoplankton from surface sea-water samples collected at six stations in Equatorial waters (Fig. 1). The results of these experiments showed a pronounced difference between nanno and net phytoplankton in photosynthesis and in cell numbers (Table I). The net phytoplankton represents an average of as little as 9.93% of total photosynthesis and 22.20% in numbers of organisms of total phytoplankton. The results obtained in coastal and in oceanic waters show that the effect of the proximity of land on standing stock and upon primary production is well marked (Table II). The results obtained are discussed and compared with data of earlier papers.

Size-fractionated surface phytoplankton in the Kara and Laptev Seas: environmental control and spatial variability

2021 ◽  
Vol 664 ◽  
pp. 59-77
Author(s):  
AB Demidov ◽  
IN Sukhanova ◽  
TA Belevich ◽  
MV Flint ◽  
VI Gagarin ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Primary Production ◽  
Water Temperature ◽  
Environmental Control ◽  
Size Structure ◽  
Total Carbon ◽  
The Arctic ◽  
Size Groups ◽  
Phytoplankton Size ◽  
Phytoplankton Size Structure

Climate-induced variability of phytoplankton size structure influences primary productivity, marine food web dynamics, biosedimentation and exchange of CO2 between the atmosphere and ocean. Investigation of phytoplankton size structure in the Arctic Ocean is important due to rapid changes in its ecosystems related to increasing temperature and declining sea ice cover. We estimated the contribution of surface micro-, nano- and picophytoplankton to the total carbon biomass, chlorophyll a concentration and primary production in the Kara and Laptev Seas and investigated the relationships of these phytoplankton size groups with environmental factors which determine their spatial variability. Additionally, we compared chlorophyll specific carbon fixation rate, specific growth rate and carbon to chlorophyll ratios among different phytoplankton size groups. The investigation was carried out from August to September 2018. Generally, picophytoplankton was dominant in terms of chlorophyll a and primary production in the whole study area. The spatial variability of phytoplankton size classes was influenced by river discharge and relied mainly on water temperature, salinity and dissolved silicon concentration. Microphytoplankton prevailed across the river runoff region under conditions of low salinity and relatively high water temperature, while picophytoplankton was predominant under conditions of high salinity and low water temperature. Our study is the first to characterize size-fractionated phytoplankton abundance in the Kara and Laptev Seas, and provides a baseline for future assessment of the response of Kara and Laptev Sea ecosystems to climate-induced processes using phytoplankton size structure.

scholarly journals A stochastic, Lagrangian model of sinking biogenic aggregates in the ocean (SLAMS 1.0): model formulation, validation and sensitivity

2016 ◽  
Vol 9 (4) ◽  
pp. 1455-1476 ◽  
Author(s):  
Tinna Jokulsdottir ◽  
David Archer
Keyword(s):  
Primary Production ◽  
Degradation Kinetics ◽  
Mechanistic Model ◽  
Euphotic Zone ◽  
Lagrangian Model ◽  
Zooplankton Grazing ◽  
Aggregate Model ◽  
Size Spectra ◽  
Sea Floor ◽  
Individual Particles

Abstract. We present a new mechanistic model, stochastic, Lagrangian aggregate model of sinking particles (SLAMS) for the biological pump in the ocean, which tracks the evolution of individual particles as they aggregate, disaggregate, sink, and are altered by chemical and biological processes. SLAMS considers the impacts of ballasting by mineral phases, binding of aggregates by transparent exopolymer particles (TEP), zooplankton grazing and the fractal geometry (porosity) of the aggregates. Parameterizations for age-dependent organic carbon (orgC) degradation kinetics, and disaggregation driven by zooplankton grazing and TEP degradation, are motivated by observed particle fluxes and size spectra throughout the water column. The model is able to explain observed variations in orgC export efficiency and rain ratio from the euphotic zone and to the sea floor as driven by sea surface temperature and the primary production rate and seasonality of primary production. The model provides a new mechanistic framework with which to predict future changes on the flux attenuation of orgC in response to climate change forcing.

scholarly journals Characteristics of Different Size Phytoplankton for Primary Production and Biochemical Compositions in the Western East/Japan Sea

2020 ◽  
Vol 11 ◽  
Author(s):  
Jae Joong Kang ◽  
Hyo Keun Jang ◽  
Jae-Hyun Lim ◽  
Dabin Lee ◽  
Jae Hyung Lee ◽  
...  
Keyword(s):  
Primary Production ◽  
Uptake Rate ◽  
Phytoplankton Community ◽  
Japan Sea ◽  
Trophic Levels ◽  
Total Carbon ◽  
Carbon Uptake ◽  
Uptake Rates ◽  
Small Phytoplankton ◽  
Biochemical Compositions

The current phytoplankton community structure is expected to change, with small phytoplankton becoming dominant under ongoing warming conditions. To understand and evaluate the ecological roles of small phytoplankton in terms of food quantity and quality, the carbon uptake rates and intracellular biochemical compositions (i.e., carbohydrates, CHO; proteins, PRT; and lipids, LIP) of phytoplankton of different sizes were analyzed and compared in two different regions of the western East/Japan Sea (EJS): the Ulleung Basin (UB) and northwestern East/Japan Sea (NES). The average carbon uptake rate by the whole phytoplankton community in the UB (79.0 ± 12.2 mg C m–2 h–1) was approximately two times higher than that in the NES (40.7 ± 2.2 mg C m–2 h–1), although the average chlorophyll a (chl a) concentration was similar between the UB (31.0 ± 8.4 mg chl a m–2) and NES (28.4 ± 7.9 mg chl a m–2). The main reasons for the large difference in the carbon uptake rates are believed to be water temperature, which affects metabolic activity and growth rate, and the difference in euphotic depths. The contributions of small phytoplankton to the total carbon uptake rate were not significantly different between the regions studied. However, the rate of decrease in the total carbon uptake with increasing contributions from small phytoplankton was substantially higher in the UB than in the NES. This result suggests that compared to other regions in the EJS, the primary production in the UB could decrease rapidly under ongoing climate change. The calorific contents calculated based on biochemical compositions were similar between the small (1.01 ± 0.33 Kcal m–3) and large (1.14 ± 0.36 Kcal m–3) phytoplankton in the UB, whereas the biochemical contents were higher in the large phytoplankton (1.88 ± 0.54 Kcal m–3) than in the small phytoplankton (1.06 ± 0.18 Kcal m–3) in the NES. The calorific values per unit of chl a were higher for the large phytoplankton than for the small phytoplankton in both regions, which suggests that large phytoplankton could provide a more energy efficient food source to organisms in higher trophic levels in the western EJS.

Variable littoral-pelagic coupling as a food-web response to seasonal changes in pelagic primary production

2017 ◽  
Vol 62 (12) ◽  
pp. 2008-2025 ◽  
Author(s):  
Simon D. Stewart ◽  
David P. Hamilton ◽  
W. Troy Baisden ◽  
Michel Dedual ◽  
Piet Verburg ◽  
...  
Keyword(s):  
Primary Production ◽  
Food Web ◽  
Seasonal Changes

Variability in carbon exchange and light utilization among boreal forest stands: implications for remote sensing of net primary production

1998 ◽  
Vol 28 (3) ◽  
pp. 375-389 ◽  
Author(s):  
Scott J Goetz ◽  
Stephen D Prince
Keyword(s):  
Remote Sensing ◽  
Primary Production ◽  
Boreal Forest ◽  
Populus Tremuloides ◽  
Net Primary Production ◽  
Gross Primary Production ◽  
Total Carbon ◽  
Simple Relationship ◽  
Carbon Exchange ◽  
Forest Stands

Variability in carbon exchange, net primary production (NPP), and light-use efficiency were explored for 63 boreal forest stands in northeastern Minnesota using an ecophysiological model. The model was initialized with extensive field measurements of Populus tremuloides Michx. and Picea mariana (Mill.) BSP stand properties. The results showed that the proportion of total carbon assimilation expended in autotrophic respiration (i.e., the respiration to assimilation ratio, R/A) was significantly different for the two tree species and this explained much of the variability in the amount of net production per unit absorbed photosynthetically active radiation (APAR), referred to as PAR utilization ( epsilonn). This is the first known study to directly link variability in respiratory costs to epsilonn. Total assimilation per unit APAR ( epsilong) was much less variable than epsilonn and was not significantly different between species. Greater stomatal control on some moisture stressed sites accounted for most of the variability in epsilong. The lack of a simple relationship between light harvesting and net carbon gain indicates that estimation of net primary production with satellite remote sensing requires additional information on respiration costs; however, evidence for convergence in epsilong can be used to simplify the remote sensing of gross primary production over large areas.

Sign in / Sign up

Export Citation Format

Share Document