scholarly journals Nitrogen and Phosphorus Eutrophication in Marine Ecosystems

2019 ◽  
Author(s):  
Lucy Ngatia ◽  
Johnny M. Grace III ◽  
Daniel Moriasi ◽  
Robert Taylor
Keyword(s):  
Marine Ecosystems ◽  
Nitrogen And Phosphorus

Nutrient and Energy Transport between Estuaries and Coastal Marine Ecosystems by Fish Migration

1993 ◽  
Vol 50 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Linda A. Deegan
Keyword(s):  
Energy Transport ◽  
Biomass Accumulation ◽  
Marine Ecosystems ◽  
Fish Migration ◽  
Nitrogen And Phosphorus ◽  
Coastal Marine ◽  
Marine System ◽  
Coastal Marine Ecosystems ◽  
Brevoortia Patronus ◽  
Body Energy

Biomass accumulation and changes in body energy and nutrient (carbon, nitrogen, and phosphorus) composition were evaluated relative to the migration pattern of gulf menhaden (Brevoortia patronus) to determine if biotic transport by fish is an important source of energy and nutrients to coastal marine ecosystems. Gulf menhaden transported significant quantities of energy, C, N, and P from a Louisiana estuary to the nearshore Gulf of Mexico. Transport was always out of the estuary to the marine system, although the magnitude depended on the balance between growth and mortality rates and abundance of fish. Average export per year was 38 g biomass, 930 kJ, 22.5 g C, 3.1 g N, and 0.9 g P∙m−2 out of estuaries. This is roughly 5–10% of the total primary production of these estuarine areas. N and P export by fish is of the same magnitude as passive waterborne export; however it is higher quality. This indicates that fish migration can play an important role in exporting the productivity of estuaries to coastal marine ecosystems.

Marine Ecosystems

2015 ◽  
Author(s):  
Tasman P. Crowe ◽  
Christopher L. J. Frid
Keyword(s):  
Marine Ecosystems

Influence of increased nutrient supply on Microcystis aeruginosa at cellular and proteomic levels

2020 ◽  
Vol 85 ◽  
pp. 47-58
Author(s):  
Y Jiang ◽  
Y Liu
Keyword(s):  
Microcystis Aeruginosa ◽  
Regulatory Protein ◽  
Acid Synthesis ◽  
Nutrient Supply ◽  
Nitrogen Supply ◽  
Nitrogen And Phosphorus ◽  
Comprehensive Description ◽  
Amino Acid Synthesis ◽  
High Nutrient ◽  
Proteomic Responses

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

Method application of optimal multi-parameter analysis to assess the distribution of water masses as an example of CTD data of the Barents Sea in summer 2017

2019 ◽  
pp. 38-51
Author(s):  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Field Measurements ◽  
Structural Similarity ◽  
Water Masses ◽  
Parameter Analysis ◽  
Water Dynamics ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
The Barents Sea ◽  
Expert Assessments

Identification of water masses in areas with complex water dynamics is a complex task, which is usually solved by the method of expert assessments. In this paper, it is proposed to use a formal procedure based on the application of the method of optimal multiparametric analysis (OMP analysis). The data of field measurements obtained in the 68th cruise of the R/V “Academician Mstislav Keldysh” in the summer of 2017 in the Barents Sea on the distribution of temperature, salinity, oxygen, silicates, nitrogen, and phosphorus concentration are used as a data for research. A comparison of the results with data on the distribution of water masses in literature based on expert assessments (Oziel et al., 2017), allows us to conclude about their close structural similarity. Some differences are related to spatial and temporal shifts of measurements. This indicates the feasibility of using the OMP analysis technique in oceanological studies to obtain quantitative data on the spatial distribution of different water masses.

Phytoplankton Production and Decomposition Characteristics in Water Bodies Differing in the Degree of Their Contamination by Inorganic Compounds of Nitrogen and Phosphorus

2019 ◽  
Vol 55 (3) ◽  
pp. 29-43 ◽  
Author(s):  
P. D. Klochenko ◽  
T. F. Shevchenko ◽  
I. N. Nezbrytskaya ◽  
Ye. P. Belous ◽  
Z. N. Gorbunova ◽  
...  
Keyword(s):  
Inorganic Compounds ◽  
Water Bodies ◽  
Phytoplankton Production ◽  
Nitrogen And Phosphorus
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