scholarly journals Effects of warming on a Mediterranean phytoplankton community

Web Ecology ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 89-92 ◽  
Author(s):  
Silvia Pulina ◽  
Andreas Brutemark ◽  
Sanna Suikkanen ◽  
Bachisio M. Padedda ◽  
Lorena M. Grubisic ◽  
...  
Keyword(s):  
Global Warming ◽  
Water Temperature ◽  
Chlorophyll A ◽  
Phytoplankton Community ◽  
Total Biomass ◽  
Planktothrix Agardhii ◽  
Mediterranean Lagoon ◽  
Chlorella Sp ◽  
Phytoplankton Communities ◽  
Different Temperatures

Abstract. Predicting the responses of organisms is a complex challenge especially when water temperature is expected to increase over the coming decades, as a result of global warming. In this work the effects of warming on phytoplankton communities were investigated. An indoor experiment was performed, where water from a Mediterranean lagoon was incubated at different temperatures. Three treatments were applied in triplicate incubation units: the control (11 °C), 3 °C increase (14 °C), and 6 °C increase (17 °C). Our results showed significant effects by warming on phytoplankton. The abundance of relatively smaller taxa (Chlorella sp. and Planktothrix agardhii–rubescens group) increased at 17 °C, whereas the abundance of relatively larger species (Cyclotella sp. and Thalassiosira sp.) decreased, compared with the control. This shift towards smaller taxa resulted in a higher total biomass but lower chlorophyll a concentrations at the highest temperature.

Differences between Nearshore and Offshore Phytoplankton Communities in Lake Ontario

1987 ◽  
Vol 44 (12) ◽  
pp. 2155-2163 ◽  
Author(s):  
I. M. Gray
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Algal Biomass ◽  
Phytoplankton Community ◽  
Seasonal Pattern ◽  
Principal Component ◽  
Lake Ontario ◽  
Dominant Group ◽  
Phytoplankton Communities ◽  
Eutrophic Species

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.

A VARIABILIDADE AMBIENTAL INFLUENCIA A COMPOSIÇÃO E BIOMASSA FITOPLANCTÔNICA DE UM RESERVATÓRIO NEOTROPICAL

2021 ◽  
Vol 25 (01) ◽  
pp. 90-102
Author(s):  
Bárbara Marques dos Santos ◽  
◽  
Silvia Moreira dos Santos ◽  
Cláudia Alves de Souza ◽  
Carlos Roberto Alves dos Santos ◽  
...  
Keyword(s):  
Water Temperature ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Environmental Variability ◽  
Total Biomass ◽  
Dry Period ◽  
Rainy Period ◽  
Biomass Structure ◽  
Health Relevance ◽  
Spatio Temporal

Phytoplankton is an important model of the aquatic environments functioning, responding directly to environmental variability in space and time. Therefore, represents an excellent tool for the monitoring of reservoirs, which comprise highly heterogeneous ecosystems longitudinally, influencing the structure and distribution of phytoplankton species. The objective of this study was to investigate the variation in the composition and biomass of the phytoplankton in a reservoir in the Goiás state, Brazil, and how these organisms respond to environmental variability along the reservoir spatial extent in dry and rainy periods. The phytoplankton and environmental variables were collected during one dry period and other rainy, over seven sampling sites, distributed in the regions downstream of the dam, lacustrine, intermediate and lotic of the reservoir. The composition and biomass of the phytoplankton community were measured as a response to the spatial and temporal environmental variability. We recorded a spatio-temporal variation in water temperature, light, nutrients, and phytoplankton biomass. Cyanobacteria had the highest biomass in the lacustrine and intermediate regions, while diatoms in the lotic region, in both periods. The highest phytoplankton total biomass was recorded in rainy period. We recorded a clear relation between the phytoplankton biomass and the environmental variability, being that water temperature, turbidity and soluble iron the ones that showed the biggest influence on the biomass structure. Thus, the composition and biomass of the phytoplankton community can be important metrics of reservoirs functioning and, therefore, the phytoplankton study in these ecosystems it's of interest in their monitoring, since reservoirs have great ecological, economic or public health relevance

Effects of zooplankton grazing on phytoplankton communities in Mt Bold Reservoir, South Australia, using enclosures

1988 ◽  
Vol 39 (4) ◽  
pp. 503 ◽  
Author(s):  
CJ Merrick ◽  
GG Ganf
Keyword(s):  
Chlorophyll A ◽  
Selection Criteria ◽  
Phytoplankton Community ◽  
Food Selection ◽  
South Australia ◽  
Zooplankton Grazing ◽  
Multivariate Statistical ◽  
Phytoplankton Communities ◽  
Phytoplankton Size ◽  
Temporal Path

Enclosure experiments demonstrated that zooplankton grazing changed the composition of the phytoplankton community in Mt Bold Reservoir. Phytoplankton biomass as measured by chlorophyll a did not change within the enclosures but changed across the experiments in response to zooplankton grazing. The chlorophyll a : phaeophytin a ratio did not reflect zooplankton grazing activity. Phytoplankton species richness and diversity did not change but the frequencies of many individual phytoplankton taxa differed in response to zooplankton grazing. Neither taxonomic identity nor phytoplankton size as measured by greatest axial linear dimension and volume determined the susceptibility of a taxon to grazing. This suggests that other criteria are important in food selection, criteria which vary between experiments. Multivariate statistical techniques successfully differentiated the grazed and the ungrazed phytoplankton communities based on the different frequencies of the component taxa. There was an indication that, within the enclosures, zooplankton grazing advanced the phytoplankton community along a temporal path. Microzooplankton grazing was not examined in these experiments but there was evidence that it was significant.

scholarly journals Phytoplankton dynamics in contrasting early stage North Atlantic spring blooms: composition, succession, and potential drivers

2015 ◽  
Vol 12 (8) ◽  
pp. 2395-2409 ◽  
Author(s):  
C. J. Daniels ◽  
A. J. Poulton ◽  
M. Esposito ◽  
M. L. Paulsen ◽  
R. Bellerby ◽  
...  
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
North Atlantic ◽  
Phytoplankton Community ◽  
Spring Bloom ◽  
Early Stage ◽  
Biological Factors ◽  
Phytoplankton Composition ◽  
Bloom Formation ◽  
Phytoplankton Communities

Abstract. The spring bloom is a key annual event in the phenology of pelagic ecosystems, making a major contribution to the oceanic biological carbon pump through the production and export of organic carbon. However, there is little consensus as to the main drivers of spring bloom formation, exacerbated by a lack of in situ observations of the phytoplankton community composition and its evolution during this critical period. We investigated the dynamics of the phytoplankton community structure at two contrasting sites in the Iceland and Norwegian basins during the early stage (25 March–25 April) of the 2012 North Atlantic spring bloom. The plankton composition and characteristics of the initial stages of the bloom were markedly different between the two basins. The Iceland Basin (ICB) appeared well mixed down to >400 m, yet surface chlorophyll a (0.27–2.2 mg m−3) and primary production (0.06–0.66 mmol C m−3 d−1) were elevated in the upper 100 m. Although the Norwegian Basin (NWB) had a persistently shallower mixed layer (<100 m), chlorophyll a (0.58–0.93 mg m−3) and primary production (0.08–0.15 mmol C m−3 d−1) remained lower than in the ICB, with picoplankton (<2 μm) dominating chlorophyll a biomass. The ICB phytoplankton composition appeared primarily driven by the physicochemical environment, with periodic events of increased mixing restricting further increases in biomass. In contrast, the NWB phytoplankton community was potentially limited by physicochemical and/or biological factors such as grazing. Diatoms dominated the ICB, with the genus Chaetoceros (1–166 cells mL−1) being succeeded by Pseudo-nitzschia (0.2–210 cells mL−1). However, large diatoms (>10 μm) were virtually absent (<0.5 cells mL−1) from the NWB, with only small nano-sized (<5 μm) diatoms (i.e. Minidiscus spp.) present (101–600 cells mL−1). We suggest microzooplankton grazing, potentially coupled with the lack of a seed population of bloom-forming diatoms, was restricting diatom growth in the NWB, and that large diatoms may be absent in NWB spring blooms. Despite both phytoplankton communities being in the early stages of bloom formation, different physicochemical and biological factors controlled bloom formation at the two sites. If these differences in phytoplankton composition persist, the subsequent spring blooms are likely to be significantly different in terms of biogeochemistry and trophic interactions throughout the growth season, with important implications for carbon cycling and organic matter export.

scholarly journals Effect of silver nanoparticles on water quality and phytoplankton communities in fresh waterbody

2018 ◽  
Vol 9 (4) ◽  
pp. 185-190
Author(s):  
Thi Thu Huong Tran ◽  
Thi Thuy Duong ◽  
Trung Kien Nguyen ◽  
Thi Phuong Quynh Le ◽  
Duc Dien Nguyen ◽  
...  
Keyword(s):  
Water Quality ◽  
Silver Nanoparticles ◽  
Chlorophyll A ◽  
Environmental Variables ◽  
Phytoplankton Community ◽  
Chemical Reduction ◽  
Ammonium Phosphate ◽  
Uniform Size ◽  
Spherical Form ◽  
Phytoplankton Communities

This study aims to investigate the potential effects of environmental variables and the toxicity of nanosilver colloids synthesized by chemical reduction method on growth and development of phytoplankton community (the Microcystis genus dominance) in the eutrophication Tien lake water, Hanoi city, Vietnam. The variables analyzed including: physical (pH and Turbidity), chemical (content of NH4+, PO43- and silver metal), biological (content of Chlorophyll-a, cell density). The characteristic of nanomaterial was confirmed by using UV-visible spectrophotometer, TEM and HR-TEM methods. The obtained silver nanoparticles (AgNPs) showed that their spherical form and uniform size varied from 10 to 15 nm. The experimental results showed that the samples treated with AgNPs inhibition on growth against M. aeruginosa at concentration 1 mg/l after 8 days. The content of silver in aquarium water decreased from 1 mg/l (D0) to 0.8 mg/l (D8). The contents of chlorophyll-a of phytoplankton community, including Microcystis genus in samples exposed with AgNPs were declined from 11.27 ± 0.56g/L (D0) to 1.98 ± 0.37 g/L (D8) . The environmental variables such as: pH, temperature, dissolved oxygen, turbidity, ammonium, phosphate... in the experiment were below the limit of the Vietnam Standard 08:2015/MONRE for surface water quality. Mục đích của nghiên cứu này là khảo sát ảnh hưởng của vật liệu nano bạc tổng hợp bằng phương pháp khử hóa học đến sinh trưởng và phát triển của quần xã thực vật nổi (chủ yếu là chi Microcystis) trong nước hồ Tiền phú dưỡng, tại Hà Nội, Việt Nam. Các thông số phân tích bao gồm: thủy lý (pH và độ đục), hóa học (hàm lượng amoni, photphat và hàm lượng bạc kim loại), sinh học (hàm lượng chất diệp lục, mật độ tế bào). Đặc trưng của vật liệu được xác định bằng các phương pháp quang phổ UV-VIS, TEM và HR-TEM. Vật liệu nano bạc có dạng hình cầu, kích thước đồng nhất trong khoảng 10-15nm. Kết quả thử nghiệm sau 8 ngày cho thấy các mẫu có bổ sung vật liệu nano bạc ức chế sinh trưởng đối với vi khuẩn lam M. aeruginosa ở nồng độ 1mg/l. Hàm lượng bạc kim loại giảm từ 1 mg/l (ngày đầu tiên) xuống còn 0.8 mg/l (vào ngày cuối cùng). Sinh khối thực vật nổi trong đó có chi Microcystis trong mẫu xử lý với AgNPs đã giảm tương ứng từ 11.27 ± 0.56 g/L (ngày đầu tiên, D0) xuống 1.98 ± 0.37 g/L (ngày cuối cùng, D8). Các thông số môi trường của nước hồ đều nằm dưới giới hạn cho phép của QCVN 08:2015/BTNMT đối với chất lượng nước mặt.

scholarly journals Spring phytoplankton communities of the Labrador Sea (2005–2014): pigment signatures, photophysiology and elemental ratios

2017 ◽  
Vol 14 (5) ◽  
pp. 1235-1259 ◽  
Author(s):  
Glaucia M. Fragoso ◽  
Alex J. Poulton ◽  
Igor M. Yashayaev ◽  
Erica J. H. Head ◽  
Duncan A. Purdie
Keyword(s):  
Chlorophyll A ◽  
Community Composition ◽  
Phytoplankton Community ◽  
High Light ◽  
Labrador Sea ◽  
Total Chlorophyll ◽  
Phytoplankton Communities ◽  
Mixed Layers ◽  
Phytoplankton Group

Abstract. The Labrador Sea is an ideal region to study the biogeographical, physiological, and biogeochemical implications of phytoplankton community composition due to sharp transitions between distinct water masses across its shelves and central basin. We have investigated the multi-year (2005–2014) distributions of late spring and early summer (May to June) phytoplankton communities in the various hydrographic settings of the Labrador Sea. Our analysis is based on pigment markers (using CHEMTAX analysis), and photophysiological and biogeochemical characteristics associated with each phytoplankton community. Diatoms were the most abundant group, blooming first in shallow mixed layers of haline-stratified Arctic shelf waters. Along with diatoms, chlorophytes co-dominated at the western end of the section (particularly in the polar waters of the Labrador Current (LC)), whilst Phaeocystis co-dominated in the east (modified polar waters of the West Greenland Current (WGC)). Pre-bloom conditions occurred in deeper mixed layers of the central Labrador Sea in May, where a mixed assemblage of flagellates (dinoflagellates, prasinophytes, prymnesiophytes, particularly coccolithophores, and chrysophytes/pelagophytes) occurred in low-chlorophyll areas, succeeding to blooms of diatoms and dinoflagellates in thermally stratified Atlantic waters in June. Light-saturated photosynthetic rates and saturation irradiance levels were highest at stations where diatoms were the dominant phytoplankton group ( >  70 % of total chlorophyll a), as opposed to stations where flagellates were more abundant (from 40 up to 70 % of total chlorophyll a). Phytoplankton communities from the WGC (Phaeocystis and diatoms) had lower light-limited photosynthetic rates, with little evidence of photoinhibition, indicating greater tolerance to a high light environment. By contrast, communities from the central Labrador Sea (dinoflagellates and diatoms), which bloomed later in the season (June), appeared to be more sensitive to high light levels. Ratios of accessory pigments (AP) to total chlorophyll a (TChl a) varied according to phytoplankton community composition, with polar phytoplankton (cold-water related) having lower AP  :  TChl a. Polar waters (LC and WGC) also had higher and more variable particulate organic carbon (POC) to particulate organic nitrogen (PON) ratios, suggesting the influence of detritus from freshwater input, derived from riverine, glacial, and/or sea ice meltwater. Long-term observational shifts in phytoplankton communities were not assessed in this study due to the short temporal frame (May to June) of the data. Nevertheless, these results add to our current understanding of phytoplankton group distribution, as well as an evaluation of the biogeochemical role (in terms of C  :  N ratios) of spring phytoplankton communities in the Labrador Sea, which will assist our understanding of potential long-term responses of phytoplankton communities in high-latitude oceans to a changing climate.

scholarly journals Spatiotemporal Variation in Phytoplankton Community Driven by Environmental Factors in the Northern East China Sea

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2695
Author(s):  
Yejin Kim ◽  
Seok-Hyun Youn ◽  
Hyun Oh ◽  
Jae Kang ◽  
Jae Lee ◽  
...  
Keyword(s):  
Community Structure ◽  
Water Temperature ◽  
East China Sea ◽  
Phytoplankton Community ◽  
East China ◽  
Nutrient Concentrations ◽  
Nutrient Distribution ◽  
Pigment Analysis ◽  
China Sea ◽  
Phytoplankton Communities

The East China Sea (ECS) is the largest marginal sea in the northern western Pacific Ocean. In comparison to various physical studies, little information on the seasonal patterns in community structure of phytoplankton is currently available. Based on high performance liquid chromatography (HPLC) pigment analysis, spatiotemporal variations in phytoplankton community compositions were investigated in the northern ECS. Water temperature and salinity generally decreased toward the western part of the study area but warmer conditions in August led to strong vertical stratification of the water column. In general, major inorganic nutrient concentrations were considerably higher in the western part with a shallow water depth, and consistent with previous results, had no discernable vertical pattern during our observation period except in August. This study also revealed PO4-limited environmental conditions in May and August. The monthly averaged integral chlorophyll-a concentration varied seasonally, highest (35.2 ± 20.22 mg m−2) in May and lowest (5.2 ± 2.54 mg m−2) in February. No distinct vertical differences in phytoplankton community compositions were observed for all the sampling seasons except in August when cyanobacteria predominated in the nutrient-deficient surface layer and diatoms prevailed at deep layer. Canonical correlation analysis results revealed that nutrient distribution and the water temperature were the major drivers of the vertical distribution of phytoplankton communities in August. Spatially, a noticeable difference in phytoplankton community structure between the eastern and western parts was observed in November with diatom domination in the western part and cyanobacteria domination in the eastern part, which were significantly (p < 0.01) correlated with water temperature, salinity, light conditions, and nutrient concentrations. Overall, the two major phytoplankton groups were diatoms (32.0%) and cyanobacteria (20.6%) in the northern ECS and the two groups were negatively correlated, which holds a significant ecological meaning under expected warming ocean conditions.

scholarly journals Phytoplankton dynamics in contrasting early stage North Atlantic spring blooms: composition, succession, and potential drivers

2015 ◽  
Vol 12 (1) ◽  
pp. 93-133 ◽  
Author(s):  
C. J. Daniels ◽  
A. J. Poulton ◽  
M. Esposito ◽  
M. L. Paulsen ◽  
R. Bellerby ◽  
...  
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
North Atlantic ◽  
Phytoplankton Community ◽  
Spring Bloom ◽  
Early Stage ◽  
Biological Factors ◽  
Phytoplankton Composition ◽  
Bloom Formation ◽  
Phytoplankton Communities

Abstract. The spring bloom is a key annual event in the phenology of pelagic ecosystems, making a major contribution to the oceanic biological carbon pump through the production and export of organic carbon. However, there is little consensus as to the main drivers of spring bloom formation, exacerbated by a lack of in situ observations of the phytoplankton community composition and its evolution during this critical period. We investigated the dynamics of the phytoplankton community structure at two contrasting sites in the Iceland and Norwegian Basins during the early stage (25 March–25 April) of the 2012 North Atlantic spring bloom. The plankton composition and characteristics of the initial stages of the bloom were markedly different between the two basins. The Iceland Basin (ICB) appeared well mixed to > 400 m, yet surface chlorophyll a (0.27–2.2 mg m–3) and primary production (0.06–0.66 mmol C m–3 d–1) were elevated in the upper 100 m. Although the Norwegian Basin (NWB) had a persistently shallower mixed layer (< 100 m), chlorophyll a (0.58–0.93 mg m–3) and primary production (0.08–0.15 mmol C m–3 d–1) remained lower than in the ICB, with picoplankton (> 2 μm) dominating chlorophyll a biomass. The ICB phytoplankton composition appeared primarily driven by the physicochemical environment, with periodic events of increased mixing restricting further increases in biomass. In contrast, the NWB phytoplankton community was potentially limited by physicochemical and/or biological factors such as grazing. Diatoms dominated the ICB, with the genus Chaetoceros (1–166 cells mL–1) being succeeded by Pseudo-nitzschia (0.2–210 cells mL–1). However, large diatoms (> 10 μm) were virtually absent (< 0.5 cells mL–1) from the NWB, with only small nanno-sized (< 5 μm) diatoms present (101–600 cells mL–1). We suggest micro-zooplankton grazing, potentially coupled with the lack of a seed population of bloom forming diatoms, was restricting diatom growth in the NWB, and that large diatoms may be absent in NWB spring blooms. Despite both phytoplankton communities being in the early stages of bloom formation, different physicochemical and biological factors controlled bloom formation at the two sites. If these differences in phytoplankton composition persist, the subsequent spring blooms are likely to be significantly different in terms of biogeochemistry and trophic interactions throughout the growth season, with important implications for carbon cycling and organic matter export.

Development of a water temperature-ecological model to stimulate global warming effects on lake ecosystem

1996 ◽  
Vol 34 (7-8) ◽  
pp. 237-244 ◽  
Author(s):  
Masaaki Hosomi ◽  
Tetsu Saigusa ◽  
Kenichi Yabunaka ◽  
Takuya Okubo ◽  
Akihiko Murakami
Keyword(s):  
Global Warming ◽  
Water Temperature ◽  
Thermal Stratification ◽  
Ecological Model ◽  
Nutrient Release ◽  
Eddy Diffusion ◽  
Nutrient Concentrations ◽  
Lake Ecosystem ◽  
Phytoplankton Species ◽  
Freezing And Thawing

This paper describes a newly developed combined water temperature-ecological (WT-ECO) model which is employed to simulate the effects of global warming on lake and reservoir ecosystems. The WT model includes (i) variations in the eddy diffusion coefficient based on the degree of thermal stratification and the velocity of wind, and (ii) a sub-model for simulating the freezing and thawing processes of surface water, water temperatures, and the mixing rates between two adjacent layers of water. The ECO model then uses these results to calculate the resultant effect on a lake's ecological dynamics, e.g., composition of phytoplankton species, their respective concentrations, and nutrient concentrations. When the model was benchmarked against Lake Yunoko, a dimictic lake, fairly good agreement was obtained over a 4-yr period; thereby indicating it is suitably calibrated. In addition, to assess the effects of global warming on a lake ecosystem, changes in Lake Yunoko's water temperature/quality were simulated in response to an increase in air temperature of 2 - 4°C. Results indicate that such an increase will (i) increase thermal stratification in summer, which increases the nutrient concentrations in bottom water due to nutrient release from bottom sediment, (ii) increase the concentration of phytoplankton at the beginning of the autumn circulation period, and (iii) change the composition of phytoplankton species.

Sign in / Sign up

Export Citation Format

Share Document