scholarly journals Synoptic relationships quantified between surface Chlorophyll-<i>a</i> and diagnostic pigments specific to phytoplankton functional types

2010 ◽  
Vol 7 (5) ◽  
pp. 6675-6704
Author(s):  
T. Hirata ◽  
N. J. Hardman-Mountford ◽  
R. J. W. Brewin ◽  
J. Aiken ◽  
R. Barlow ◽  
...  
Keyword(s):  
Green Algae ◽  
Phytoplankton Community ◽  
Marine Ecosystem ◽  
Global Scale ◽  
Least Square ◽  
Surface Distribution ◽  
Functional Types ◽  
Background Population ◽  
Marine Ecosystem Models ◽  
Global Surface

Abstract. Error-quantified, synoptic-scale relationships between chlorophyll-a (Chla) and phytoplankton pigment groups at the sea surface are presented. A total of nine pigment groups were considered to represent nine phytoplankton functional types (PFTs) including microplankton, nanoplankton, picoplankton, diatoms, dinoflagellates, green algae, picoeukaryotes, prokaryotes and Prochlorococcus sp. The observed relationships between Chla and pigment groups were well-defined at the global scale to show that Chla can be used as an index of not only phytoplankton abundance but also community structure; large (micro) phytoplankton monotonically increase as Chla increases, whereas the small (pico) phytoplankton community generally decreases. Within these relationships, we also found non-monotonic variations with Chla for certain pico-plankton (pico-eukaryotes, Prokaryotes and Prochlorococcus sp.) and for Green Algae and nano-sized phytoplankton. The relationships were quantified with a least-square fitting approach in order to estimate the PFTs from Chla alone. The estimated uncertainty of the relationships quantified depends on both phytoplankton types and Chla concentration. Maximum uncertainty over all groups (34.7% Chla) was found from diatom at approximately Chla = 1.07 mg m−3. However, the mean uncertainty of the relationships over all groups was 5.8 [% Chla] over the entire Chla range observed (0.02 < Chla < 6.84 mg m−3). The relationships were applied to SeaWiFS satellite Chla data from 1998 to 2009 to show the global climatological fields of the surface distribution of PFTs. Results show that microplankton are present in the mid and high latitudes, constituting ~9.0 [% Chla] of the phytoplankton community at the global surface, in which diatoms explain ~6.0 [% Chla]. Nanoplankton are ubiquious throught much of the global surface oceans except subtropical gyres, acting as a background population, constituting ~44.2 [% Chla]. Picoplankton are mostly limited in subtropical gyres, constituting ~46.8 [% Chla] globally, in which prokaryotes are the major species explaining 32.3 [% Chla] (prochlorococcus sp. explaining 21.5 [% Chla]), while pico-eukaryotes are notably abundant in the Southern Pacific explaining ~14.5 [% Chla]. These results may be used to constrain or validate global marine ecosystem models.

scholarly journals Synoptic relationships between surface Chlorophyll-<i>a</i> and diagnostic pigments specific to phytoplankton functional types

2011 ◽  
Vol 8 (2) ◽  
pp. 311-327 ◽  
Author(s):  
T. Hirata ◽  
N. J. Hardman-Mountford ◽  
R. J. W. Brewin ◽  
J. Aiken ◽  
R. Barlow ◽  
...  
Keyword(s):  
Green Algae ◽  
Marine Ecosystem ◽  
Global Scale ◽  
Least Square ◽  
Major Group ◽  
Surface Distribution ◽  
Chl A ◽  
Functional Types ◽  
Total Community ◽  
The Mean

Abstract. Error-quantified, synoptic-scale relationships between chlorophyll-a (Chl-a) and phytoplankton pigment groups at the sea surface are presented. A total of ten pigment groups were considered to represent three Phytoplankton Size Classes (PSCs, micro-, nano- and picoplankton) and seven Phytoplankton Functional Types (PFTs, i.e. diatoms, dinoflagellates, green algae, prymnesiophytes (haptophytes), pico-eukaryotes, prokaryotes and Prochlorococcus sp.). The observed relationships between Chl-a and PSCs/PFTs were well-defined at the global scale to show that a community shift of phytoplankton at the basin and global scales is reflected by a change in Chl-a of the total community. Thus, Chl-a of the total community can be used as an index of not only phytoplankton biomass but also of their community structure. Within these relationships, we also found non-monotonic variations with Chl-a for certain pico-sized phytoplankton (pico-eukaryotes, Prokaryotes and Prochlorococcus sp.) and nano-sized phytoplankton (Green algae, prymnesiophytes). The relationships were quantified with a least-square fitting approach in order to enable an estimation of the PFTs from Chl-a where PFTs are expressed as a percentage of the total Chl-a. The estimated uncertainty of the relationships depends on both PFT and Chl-a concentration. Maximum uncertainty of 31.8% was found for diatoms at Chl-a = 0.49 mg m−3. However, the mean uncertainty of the relationships over all PFTs was 5.9% over the entire Chl-a range observed in situ (0.02 < Chl-a < 4.26 mg m−3). The relationships were applied to SeaWiFS satellite Chl-a data from 1998 to 2009 to show the global climatological fields of the surface distribution of PFTs. Results show that microplankton are present in the mid and high latitudes, constituting only ~10.9% of the entire phytoplankton community in the mean field for 1998–2009, in which diatoms explain ~7.5%. Nanoplankton are ubiquitous throughout the global surface oceans, except the subtropical gyres, constituting ~45.5%, of which prymnesiophytes (haptophytes) are the major group explaining ~31.7% while green algae contribute ~13.9%. Picoplankton are dominant in the subtropical gyres, but constitute ~43.6% globally, of which prokaryotes are the major group explaining ~26.5% (Prochlorococcus sp. explaining 22.8%), while pico-eukaryotes explain ~17.2% and are relatively abundant in the South Pacific. These results may be of use to evaluate global marine ecosystem models.

scholarly journals Disentangling diverse responses to climate change among global marine ecosystem models

2021 ◽  
pp. 102659
Author(s):  
Ryan F. Heneghan ◽  
Eric Galbraith ◽  
Julia L. Blanchard ◽  
Cheryl Harrison ◽  
Nicolas Barrier ◽  
...  
Keyword(s):  
Climate Change ◽  
Marine Ecosystem ◽  
Ecosystem Models ◽  
Marine Ecosystem Models

scholarly journals Whole-Ecosystem Experiments Reveal Varying Responses of Phytoplankton Functional Groups to Epilimnetic Mixing in a Eutrophic Reservoir

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 222 ◽  
Author(s):  
Mary Lofton ◽  
Ryan McClure ◽  
Shengyang Chen ◽  
John Little ◽  
Cayelan Carey
Keyword(s):  
Community Composition ◽  
Green Algae ◽  
Phytoplankton Community ◽  
Water Reservoir ◽  
Ecosystem Dynamics ◽  
Bubble Plume ◽  
Community Responses ◽  
Drinking Water Reservoir ◽  
Biological Variables ◽  
Lakes And Reservoirs

Water column mixing can influence community composition of pelagic phytoplankton in lakes and reservoirs. Previous studies suggest that low mixing favors cyanobacteria, while increased mixing favors green algae and diatoms. However, this shift in community dominance is not consistently achieved when epilimnetic mixers are activated at the whole-ecosystem scale, possibly because phytoplankton community responses are mediated by mixing effects on other ecosystem processes. We conducted two epilimnetic mixing experiments in a small drinking water reservoir using a bubble-plume diffuser system. We measured physical, chemical, and biological variables before, during, and after mixing and compared the results to an unmixed reference reservoir. We observed significant increases in the biomass of cyanobacteria (from 0.8 ± 0.2 to 2.4 ± 1.1 μg L−1, p = 0.008), cryptophytes (from 0.7 ± 0.1 to 1.9 ± 0.6 μg L−1, p = 0.003), and green algae (from 3.8 to 4.4 μg L−1, p = 0.15) after our first mixing event, likely due to increased total phosphorus from entrainment of upstream sediments. After the second mixing event, phytoplankton biomass did not change but phytoplankton community composition shifted from taxa with filamentous morphology to smaller, rounder taxa. Our results suggest that whole-ecosystem dynamics and phytoplankton morphological traits should be considered when predicting phytoplankton community responses to epilimnetic mixing.

Pre-treating algae-laden raw water by silver carp during Microcystis-dominated and non-Microcystis-dominated periods

2012 ◽  
Vol 65 (8) ◽  
pp. 1448-1453 ◽  
Author(s):  
Hua Ma ◽  
Fuyi Cui ◽  
Zhiquan Liu ◽  
Zhiwei Zhao
Keyword(s):  
Chlorophyll A ◽  
Green Algae ◽  
Total Phosphorus ◽  
Phytoplankton Community ◽  
Phosphorus Content ◽  
Silver Carp ◽  
Nutrient Level ◽  
Species Structure ◽  
Raw Water ◽  
Filter Feeding

Performance of pre-treating algae-laden raw water by silver carp during a non-Microcystis-dominated period (period I) and a Microcystis-dominated period (period II) was investigated in terms of algae cell concentration, total phosphorus content, chlorophyll a and phytoplankton species structure. During period I the ineffective filter-feeding for small green algae resulted in the increase of small single algae, which led to the negative removal of chlorophyll a, and when the biomass was higher, the negative was more significant. However, due to the effective filter-feeding of silver carp for Microcystis flos-aquae, the average removal efficiency exceeded 50% at all stocking biomass levels (20–120 g/m3) used in experiments during period II. Total phosphorus removal efficiencies could exceed 50% at silver carp biomass stocking levels of 60–80 g/m3 during both period I and period II. The experimental results indicated that silver carp stocking contributed to the removal of colony-forming cyanobacteria, but led to the increase of single-cell algae (mainly green algae and diatoms) during both period I and period II. The initial phytoplankton community structure and the control of nutrient level were important factors in the choice of silver carp stocking biomass when used to purify algae-loaded water.

scholarly journals Distribution of mesozooplankton biomass in the global ocean

2012 ◽  
Vol 5 (2) ◽  
pp. 893-919
Author(s):  
R. Moriarty ◽  
T. D. O'Brien
Keyword(s):  
Marine Ecosystem ◽  
Original Data ◽  
Dry Mass ◽  
Global Ocean ◽  
Ecosystem Models ◽  
Mesozooplankton Biomass ◽  
Carbon Biomass ◽  
Community Effort ◽  
Marine Ecosystem Models ◽  
The Tropics

Abstract. Mesozooplankton are cosmopolitan within the sunlit layers of the global ocean. They are important in the classical food web, having a significant feedback to primary production through their consumption of phytoplankton and microzooplankton. They are also the primary contributor to vertical particle flux in the oceans. Through both they affect the biogeochemical cycling of carbon and other nutrients in the oceans. Little, however, is known about their global distribution and biomass. While global maps of mesozooplankton biomass do exist in the literature they are usually in the form of hand-drawn maps and the original data associated with these maps are not readily available. The dataset presented in this synthesis has been in development since the late 1990's, is an integral part of the Coastal &amp; Oceanic Plankton Ecology, Production, &amp; Observation Database (COPEPOD), and is now also part of a wider community effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. A total of 153 163 biomass values were collected, from a variety of sources, for mesozooplankton. Of those 2% were originally recorded as dry mass, 26% as wet mass, 5% as settled volume, and 68% as displacement volume. Using a variety of non-linear biomass conversions from the literature, the data have been converted from their original units to carbon biomass. Depth-integrated values were then used to calculate mesozooplankton global biomass. Global mesozooplankton biomass, to a depth of 200 m, had a mean of 5.9 μg C l−1, median of 2.7 μg C l−1 and a standard deviation of 10.6 μg C l−1. The global annual average estimate of mesozooplankton, based on the median value, was 0.19 Pg C. Biomass was highest in the Northern Hemisphere, but the general trend shows a slight decrease from polar oceans to temperate regions with values increasing again in the tropics. Gridded dataset http://doi.pangaea.de/10.1594/PANGAEA.785501x.

Estimation of the Parameters in a Dynamical Marine Ecosystem Model Based on the Adjoint Assimilation

2013 ◽  
Vol 321-324 ◽  
pp. 2419-2423
Author(s):  
Xiao Yan Li ◽  
Chun Hui Wang ◽  
Xian Qing Lv
Keyword(s):  
Marine Ecosystem ◽  
Absolute Error ◽  
Ecosystem Model ◽  
Global Scale ◽  
Time Step ◽  
Marine Ecosystem Model ◽  
Maximum Uptake Rate ◽  
Influence Radius ◽  
Adjoint Assimilation ◽  
Spatially Varying

By utilizing spatial biological parameterizations, the adjoint variational method was applied to a 3D marine ecosystem model (NPZD-type) and its adjoint model which were built on global scale based on climatological environment and data. When the spatially varying Vm (maximum uptake rate of nutrient by phytoplankton) was estimated alone, we discussed how would the distribution schemes of spatial parameterization and influence radius affected the results. The reduced cost function (RCF), the mean absolute error (MAE) of phytoplankton in the surface layer, and the relative error (RE) of Vm between given and simulated values decreased obviously. The influence of time step was studied then and we found that the assimilation recovery would not be more successful with a smaller time step of 3 hours compared with 6 hours.

scholarly journals An underwater light attenuation scheme for marine ecosystem models

2008 ◽  
Vol 16 (21) ◽  
pp. 16581 ◽  
Author(s):  
Bradley Penta ◽  
Zhongping Lee ◽  
Raphael M. Kudela ◽  
Sherry L. Palacios ◽  
Deric J. Gray ◽  
...  
Keyword(s):  
Marine Ecosystem ◽  
Light Attenuation ◽  
Ecosystem Models ◽  
Underwater Light ◽  
Marine Ecosystem Models

Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. VI. Plant Communities and their Significance

1959 ◽  
Vol 10 (3) ◽  
pp. 322 ◽  
Author(s):  
EJF Wood
Keyword(s):  
Green Algae ◽  
Plant Communities ◽  
Brown Algae ◽  
Phytoplankton Community ◽  
Bottom Community ◽  
Blue Green Algae ◽  
Reef Community ◽  
Photosynthetic Organisms ◽  
Sea Grass

There are four plant communities in Lake Macquarie: the see-grass community, the reef community, the mud bottom community, and the phytoplankton community. Biologically, the sea-grass community is regarded as being the most important. The epiphytes on the sea-grasses are largely used as food by phytophagous fish and other animals. The reef community consists of larger brown algae which are not of themselves of great importance, and of felts of blue-green algae such as Ectocarpus, and other filamentous forms which are important. Photosynthetic organisms are sparse in the mud bottoms, except for the tapetic organisms in the sea. Phytoplankton is relatively abundant.

scholarly journals Influences of Nutrient Sources on the Alternation of Nutrient Limitations and Phytoplankton Community in Jiaozhou Bay, Southern Yellow Sea of China

2020 ◽  
Vol 12 (6) ◽  
pp. 2224
Author(s):  
Jie Shi ◽  
Qian Leng ◽  
Junying Zhu ◽  
Huiwang Gao ◽  
Xinyu Guo ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Phytoplankton Community ◽  
Inorganic Nitrogen ◽  
Marine Ecosystem ◽  
Jiaozhou Bay ◽  
Nutrient Concentrations ◽  
River Input ◽  
Aquaculture Wastewater ◽  
The 1960S ◽  
Yellow Sea Of China

A marine ecosystem box model was developed to reproduce the seasonal variations nutrient concentrations and phytoplankton biomasses in Jiaozhou Bay (JZB) of China. Then, by removing each of the external sources of nutrients (river input, aquaculture, wastewater discharge, and atmospheric deposition) in the model calculation, we quantitatively estimated its influences on nutrient structure and the phytoplankton community. Removing the river input of nutrients enhanced silicate (SIL) limitation to diatoms (DIA) and decreased the ratio of DIA to flagellates (FLA); removing the aquaculture input of nutrients decreased FLA biomass because it provided less dissolved inorganic nitrogen (DIN) but more dissolved inorganic phosphate (DIP) as compared to the Redfield ratio; removing the wastewater input of nutrients changed the DIN concentration dramatically, but had a relatively weaker impact on the phytoplankton community than removing the aquaculture input; removing atmospheric deposition had a negligible influence on the model results. Based on these results, we suppose that the change in the external nutrients sources in the past several decades can explain the long-term variations in nutrient structure and phytoplankton community. Actually, the simulations for the 1960s, 1980s, and 2000s in JZB demonstrated the shift of limiting nutrients from DIP to SIL. A reasonable scenario for this is the decrease in riverine SIL and increase in DIP from aquaculture that has reduced DIA biomass, promoted the growth of FLA, and led to the miniaturization of the phytoplankton.

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