Phytoplankton Productivity Changes in a Small, Double-Basin Lake in Response to Termination of Experimental Fertilization

1987 ◽  
Vol 44 (S1) ◽  
pp. s47-s54 ◽  
Author(s):  
J. A. Shearer ◽  
E. J. Fee ◽  
E. R. DeBruyn ◽  
D. R. DeClercq
Keyword(s):  
Numerical Model ◽  
Primary Production ◽  
The Other ◽  
Production Rates ◽  
Nitrogen And Phosphorus ◽  
Phytoplankton Productivity ◽  
Phytoplankton Primary Production ◽  
Carbon And Nitrogen ◽  
Model Technique ◽  
Reference Lakes

One basin of a small, double-basin lake was fertilized with carbon, nitrogen, and phosphorus for eight years, and then fertilization was stopped. The other basin was fertilized simultaneously with equivalent amounts of carbon and nitrogen only. Phytoplankton primary production was monitored using an incubator–numerical model technique. Production increased dramatically in the basin receiving artificial additions of C, N, and P. The increase was particularly large in the epilimnion where Cyanophyte blooms occurred during each year of fertilization and production rates averaged 2 to 10 times higher than in nearby, unfertilized reference lakes. Phosphorus, not nitrogen or carbon, was the critical nutrient. The productivity of the other basin also increased, but to a lesser degree and no Cyanophyte blooms were observed in this basin. When all fertilization was terminated, production in both basins immediately decreased. No more surface blooms were observed in either basin. Within 3 yr, the production had dropped to levels typical of reference lakes.

Phytoplankton Productivity

2017 ◽  
Author(s):  
John Raven
Keyword(s):  
Primary Production ◽  
Organic Compounds ◽  
Inorganic Carbon ◽  
Chemical Elements ◽  
Inorganic Compounds ◽  
Initial Energy ◽  
The Other ◽  
Phytoplankton Productivity ◽  
Cell Components ◽  
Nitrogen Phosphorus

This chapter describes the productivity of phytoplankton, from the initial energy and chemical requirements for photosynthesis to the rate of production of heterotrophic organisms. Phytoplankton are the planktonic organisms which account for most of the primary production in the ocean. Their characteristic trophic mode is the production of organic compounds using energy from light and chemical elements from inorganic compounds, known as phototrophy, or more strictly photolithotrophy. This process uses water as the electron donor and the reduction of inorganic carbon producing sugars, from which all other cell components are made using inorganic forms of nitrogen, phosphorus, and all the other chemical elements needed to produce cells.

Seasonal Variability and Estimation of Annual East Siberian Sea Phytoplankton Primary Production and Comparison with the Other Siberian Seas

Oceanology ◽  
2020 ◽  
Vol 60 (5) ◽  
pp. 603-616
Author(s):  
A. B. Demidov ◽  
V. I. Gagarin ◽  
S. V. Sheberstov
Keyword(s):  
Primary Production ◽  
Seasonal Variability ◽  
The Other ◽  
Phytoplankton Primary Production ◽  
East Siberian Sea

Experimental Lakes Area: Whole-Lake Experiments in Eutrophication

1974 ◽  
Vol 31 (5) ◽  
pp. 937-953 ◽  
Author(s):  
D. W. Schindler ◽  
E. J. Fee
Keyword(s):  
Algal Blooms ◽  
Large Scale ◽  
The Other ◽  
Phosphorus Fertilization ◽  
Low Carbon ◽  
Nitrogen And Phosphorus ◽  
Experimental Lakes Area ◽  
Carbon And Nitrogen ◽  
Small Phytoplankton ◽  
Carbon Concentrations

The following whole-lake experiments are described:Lake 227, fertilized for 5 yr with phosphate and nitrate, has shown an enormous increase in phytoplankton, in spite of low carbon concentrations. The carbon necessary for production of algal blooms was found to invade from the atmosphere.Lake 304, eutrophied by fertilization with phosphorus, nitrogen, and carbon in 1971 and 1972, recovered rapidly when phosphorus fertilization was terminated.Lake 226 was split in half with a curtain. One half was fertilized with carbon and nitrogen and the other was fertilized with phosphorus, carbon, and nitrogen. The half of the lake receiving phosphorus developed an algal bloom and the other half did not.Lake 302, which had carbon, nitrogen, and phosphorus added to the hypolimnion, did not develop algal blooms in summer. Small phytoplankton blooms were found under ice in early December, but all nutrients were efficiently sedimented and unavailable the following year.The above studies illustrate clearly that phosphorus control is an efficient primary step in preventing or checking eutrophication problems.A review of other published and ongoing studies in the Experimental Lakes Area is given, illustrating the role which large-scale experiments can play in interpreting environmental problems.

Primary Production and Nutrient Assimilation by Natural Phytoplankton Populations of the Eastern Canadian Arctic

1982 ◽  
Vol 39 (2) ◽  
pp. 335-345 ◽  
Author(s):  
W. G. Harrison ◽  
Trevor Platt ◽  
Brian Irwin
Keyword(s):  
Solar Radiation ◽  
Primary Production ◽  
Mixed Layer ◽  
Growth Rates ◽  
Euphotic Zone ◽  
Open Water ◽  
Production Rates ◽  
Phytoplankton Primary Production ◽  
Baffin Bay ◽  
Ambient Temperatures

Phytoplankton biomass (chlorophyll a) and primary production rates in Baffin Bay during summer 1978 were comparable to levels reported for other open water arctic and subarctic regions. Values were moderately high ([Formula: see text] mg Chl∙m−2; 227 mg C-fixed∙m−2∙d−1) considering the low mixed-layer nutrient (nitrogen) concentrations, low ambient temperatures ([Formula: see text] euphotic zone = −0.2 °C), and variable and moderately low daily solar radiation ([Formula: see text] MW∙m−2). Biomass maxima were consistently found at or near the bottom of the euphotic zone, and were 6 times higher than surface values on the average. Nitrate and ammonium were assimilated in approximately equal proportions despite the relatively greater abundance of nitrate in the euphotic zone, particularly below the mixed layer. Average C:N assimilation ratios were slightly lower (5:1) than the chemical composition ratio of the particulate matter (7:1). High phosphate assimilation rates reflected the abundance of this nutrient in the euphotic zone and resulted in low C:P (22:1) and N:P (6:1) assimilation ratios. Growth rates computed from carbon and nitrogen (NO3− + NH4+) assimilation rates averaged 0.31 and 0.35 doublings∙d−1, respectively, for the euphotic zone, and were half the maximum expected growth rates for prevailing water temperatures and optimal conditions of light and nutrients. Baffin Bay phytoplankton populations exhibited no obvious signs of severe nitrogen limitation despite low euphotic zone concentrations of the nutrient. Furthermore, the strong correspondence between: (1) normalized primary production rates (photosynthetic index) and incident solar radiation and (2) growth rates and incubation temperatures suggests that nutrients may play a relatively less important role in controlling arctic primary production than previously considered.Key words: phytoplankton, primary production, nutrients, arctic, light, and temperature

Phytoplankton Community Responses to Nutrient Addition in Lake 226, Experimental Lakes Area, Northwestern Ontario

1987 ◽  
Vol 44 (S1) ◽  
pp. s35-s46 ◽  
Author(s):  
D. L. Findlay ◽  
S. E. M. Kasian
Keyword(s):  
Species Composition ◽  
Water Exchange ◽  
Phytoplankton Community ◽  
Late Summer ◽  
Nitrogen And Phosphorus ◽  
Experimental Lakes Area ◽  
Carbon And Nitrogen ◽  
Northwestern Ontario ◽  
Average Biomass ◽  
Reference Lakes

Inclusion of phosphorus in fertilizer added to one of two basins of a small lake, between which water exchange was greatly reduced by a vinyl sea-curtain, significantly increased epilimnetic phytoplankton biomass, and altered species composition. Over an 8-yr period, the average biomass of phytoplankton in the basin receiving carbon, nitrogen, and phosphorus (in ratios of 10:5:1) increased 4 to 8 times and the biomass in the basin receiving only carbon and nitrogen (in ratios of 10:5) increased 2 to 4 times over non-fertilized years. The basin receiving all three nutrients consistently had blooms in late summer which were dominated by nitrogen fixing species of cyanophytes. In comparison with unfertilized reference lakes, the proportion of phytoplankton in fertilized basins which was available to zooplankton as food was 10 times greater in the basin receiving all three nutrients, and two times greater in the basin receiving only nitrogen and carbon. When fertilization of both basins was stopped, species composition and levels of biomass reverted within a year to the composition and biomass levels of phytoplankton observed in the reference lakes and remained at those levels for 2 further years of study.

Spatial and Temporal Dynamics of Phytoplankton Primary Production in the Teterev River

2008 ◽  
Vol 44 (1) ◽  
pp. 3-15
Author(s):  
V. I. Shcherbak ◽  
Yu. S. Kuzminchuk
Keyword(s):  
Primary Production ◽  
Temporal Dynamics ◽  
Phytoplankton Primary Production ◽  
Spatial And Temporal Dynamics

ENERGY TRANSFER EFFICIENCIES ON LOWER TROPHIC LEVELS WITH INTENSIVE OYSTER FARMING IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Akira Umehara ◽  
Akira Umehara ◽  
Satoshi Asaoka ◽  
Satoshi Asaoka ◽  
Naoki Fujii ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Primary Production ◽  
Skeletonema Costatum ◽  
Warm Season ◽  
Nutrient Supply ◽  
Trophic Levels ◽  
Phytoplankton Primary Production ◽  
Mean Values ◽  
Hiroshima Prefecture ◽  
Study Species

In enclosed water areas, organic matters are actively produced by phytoplankton due to abundant nutrient supply from the rivers. In our study area of the semi-enclosed Hiroshima Bay, oyster farming consuming high primary production has been developed since the 1950s, and the oyster production of Hiroshima prefecture have had the largest market share (ca. 60%) in Japan. In this study, species composition of phytoplankton, primary production, and secondary production of net zooplanktons and oysters were determined seasonally at seven stations in the bay between November 2014 and August 2015. In the bay, diatoms including Skeletonema costatum dominated during the period of the study. The primary productions markedly increased during summer (August), and its mean values in the northern part of the bay (NB) and the southern part (SB) were 530 and 313 mgC/m2/d, respectively. The productions of net zooplankton and oyster increased during the warm season, and its mean values in the NB were 14 and 1.2 mgC/m2/d, and in SB were 28 and 0.9 mgC/m2/d, respectively. The energy transfer efficiencies from the primary producers to the secondary producers in the NB and SB were 2.8% and 9.1%, respectively. However, the transfer efficiency to the oysters was approximately 0.3% in the bay. This study clearly showed the spatial difference of the productions and transfer efficiencies, and the low contribution of the production of oysters in secondary productions in Hiroshima Bay.

Modelling waste output from trout farms

1995 ◽  
Vol 31 (10) ◽  
pp. 103-121
Author(s):  
J.-O. Frier ◽  
J. From ◽  
T. Larsen ◽  
G. Rasmussen
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Numerical Model ◽  
Organic Compounds ◽  
Waste Treatment ◽  
Waste Water Treatment ◽  
Nitrogen And Phosphorus ◽  
Waste Discharge ◽  
Scientific Background ◽  
Trout Farms

The aim of waste modelling in aquaculture is to provide tools for simulating input, transformation, output and subsidiary degradation in recipients of organic compounds, nitrogen, and phosphorus. The direct purpose of this modelling is to make it possible for caretakers and water authorities to calculate waste discharge from existing and planned aquaculture activities. A special purpose is simulating outcome of waste water treatment and altered feeding programmes. Different submodels must be applied for P, N, and organics, as well as for the different phases of food and waste treatment. Altogether this calls for an array of co-operating submodels for a sufficient coverage of the options. In all the required fields there is some scientific background for numerical model approaches, and some submodels have been proposed. Because of its multidisciplinary character a synthesized approach is still lacking. Within trout farming this work attempts to establish the different submodels and outlines future possibilities for synthesizing the knowledge to a numerical model.

The Influence of Phytoplankton Primary Production on the Cycle of Biogenic Elements in the Coastal Waters off Sevastopol, Black Sea

2018 ◽  
Vol 44 (3) ◽  
pp. 240-247 ◽  
Author(s):  
V. N. Egorov ◽  
V. N. Popovichev ◽  
S. B. Gulin ◽  
N. I. Bobko ◽  
N. Yu. Rodionova ◽  
...  
Keyword(s):  
Primary Production ◽  
Black Sea ◽  
Coastal Waters ◽  
Biogenic Elements ◽  
Phytoplankton Primary Production

Phytoplankton primary production in Lake Grevelingen (II)

1979 ◽  
Vol 13 (2-3) ◽  
pp. 77-78
Author(s):  
F. Vegter
Keyword(s):  
Primary Production ◽  
Phytoplankton Primary Production ◽  
Lake Grevelingen
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