Longitudinal distribution of Trichoptera in the Loire River (France): simple ordination methods and community structure

Hydrobiologia ◽  
1996 ◽  
Vol 317 (3) ◽  
pp. 231-245 ◽  
Author(s):  
Bruno Guinand ◽  
Jeanne-Marie Ivol ◽  
Henri Tachet
Keyword(s):  
Community Structure ◽  
Longitudinal Distribution ◽  
Ordination Methods ◽  
Loire River

scholarly journals Eutrophication mitigation in rivers: 30 years of trends in spatial and seasonal patterns of biogeochemistry of the Loire River (1980–2012)

2015 ◽  
Vol 12 (8) ◽  
pp. 2549-2563 ◽  
Author(s):  
C. Minaudo ◽  
M. Meybeck ◽  
F. Moatar ◽  
N. Gassama ◽  
F. Curie
Keyword(s):  
Dissolved Oxygen ◽  
Chlorophyll A ◽  
Seasonal Variations ◽  
River System ◽  
Longitudinal Distribution ◽  
Seasonal Patterns ◽  
Nutrient Load ◽  
Main River ◽  
Loire River ◽  
Monthly Survey

Abstract. Trends and seasonality analysis from 1980 onward and longitudinal distribution, from headwaters to estuary, of chlorophyll a, nitrate and phosphate were investigated in the eutrophic Loire River. The continuous decline of phosphate concentrations which has been recorded since 1991 both in the main river and in the tributaries has led to the conclusion that it was responsible for the significant reduction in phytoplanktonic biomass across the whole river system, although Corbicula spp. clams invaded the river during the same period and probably played a significant role in the phytoplankton decline. While eutrophication remained lower in the main tributaries than in the Loire itself, they were found to contribute up to ≈ 35% to the total nutrient load of the main river. The seasonality analysis revealed significant seasonal variations for the different eutrophication metrics and calls into question the classical monthly survey recommended by national or international authorities. Reducing P inputs impacted these seasonal variations: the decline of seasonal amplitudes of chlorophyll a reduced the seasonal amplitude of orthophosphate and of daily variations of dissolved oxygen and pH but did not significantly affect the seasonal amplitude of nitrate. Thus, the influence of phytoplankton on seasonal variations of nitrate was minor throughout the period of study.

scholarly journals Eutrophication mitigation in rivers: 30 years of trends and seasonality changes in biogeochemistry of the Loire River (1980–2012)

2014 ◽  
Vol 11 (12) ◽  
pp. 17299-17337 ◽  
Author(s):  
C. Minaudo ◽  
M. Meybeck ◽  
F. Moatar ◽  
N. Gassama ◽  
F. Curie
Keyword(s):  
Aquatic Vegetation ◽  
River System ◽  
Longitudinal Distribution ◽  
Terrestrial Vegetation ◽  
Exact Role ◽  
P Limitation ◽  
Main River ◽  
Algal Pigment ◽  
Loire Basin ◽  
Loire River

Abstract. Trends and seasonality analysis since 1980 and longitudinal distribution from headwaters to estuary of algal pigment, nitrate and phosphate were investigated in the eutrophic Loire River. The continuous decline of phosphate concentrations recorded since 1991 both in the main river and in the tributaries led to a significant reduction in algal biomass across the whole river system. While eutrophication remained lower in the main tributaries than in the Loire itself, they were found to contribute up to 45% to the total nutrient load of the main river. The seasonality analysis revealed that the river has always been under P limitation, explaining why reducing P inputs led to decreasing eutrophication in the whole Loire basin. The decline of seasonal amplitudes of algal pigments reduced the seasonal amplitude of phosphate and of daily variations of dissolved oxygen and pH but did not significantly affect the seasonal amplitude of nitrate. Thus, algal uptake responsibility on the summer nitrate loss seemed to be declining, questioning the exact role played by denitrification, terrestrial vegetation and fixed aquatic vegetation on the nitrogen cycle.

STRUKTUR KOMUNITAS MAKRO ALGA DI PESISIR PULAU KECAMATAN BULANG

SIMBIOSA ◽  
2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Notowinarto Notowinarto ◽  
Ramses Ramses ◽  
Mulhairi Mulhairi
Keyword(s):  
Community Structure ◽  
Diversity Index ◽  
Algal Species ◽  
Algal Communities ◽  
Marine Life ◽  
Ph Values ◽  
Abundance Patterns ◽  
Coastal Marine ◽  
Temperature Parameter ◽  
Important Value Index

Bulang districts Batam Islands of  Riau province (Riau Islands), its consists of many islands with as well as having the potential diversity of coastal marine life in particular kinds of macro algae or seaweed. Conducted research aimed to determine the structure of macro- algal communities in the intertidal zone islands. The results of the identification of algal species found 16 species are: the Order of Chlorophyceae as 6 spesies; Order Phaeophyceae as 2 spesies; and Order Rhodophyceae as 8 spesies. The community structure at the five stations showed the highest values were found in the island of dominance Cicir (D ' = 0.79) , uniformity index values on Tengah Island (E ' = 0.99) , while the island Balak had the highest diversity index (H ' = 0.88) , with the abundance patterns of population structure on the island is pretty good Central . Results of correlation analysis of regression between IVI types of algae with the conditions of environmental quality suggests that there is a significance (Fhit ˃ F table and the value of r = > 90 %) between IVI algae Halimeda sp and Cryptarachne polyglandulosa at each station with a temperature parameter surface (⁰C) , depth temperature (⁰C) and pH values. Keywords : Algae, Community Structure, Important Value Index.

Seasonal changes in phytoplankton community structure in a bioluminescent lagoon, St. Croix, US Virgin Islands

2018 ◽  
Vol 81 (2) ◽  
pp. 109-124 ◽  
Author(s):  
JL Pinckney ◽  
C Tomas ◽  
DI Greenfield ◽  
K Reale-Munroe ◽  
B Castillo ◽  
...  
Keyword(s):  
Community Structure ◽  
Seasonal Changes ◽  
Phytoplankton Community ◽  
Virgin Islands ◽  
Phytoplankton Community Structure ◽  
Us Virgin Islands

A comparison of bacterial community structure, activity and microcystins associated with formation and breakdown of a cyanobacterial scum

2017 ◽  
Vol 80 (3) ◽  
pp. 243-256 ◽  
Author(s):  
K Steiner ◽  
SA Wood ◽  
J Puddick ◽  
I Hawes ◽  
DR Dietrich ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Structure Activity

Temporally invariable bacterial community structure in the Arabian Sea oxygen minimum zone

2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Arabian Sea ◽  
Oxygen Minimum Zone ◽  
Minimum Zone ◽  
Oxygen Minimum

Microbial community structure and dynamics in restored subtropical seagrass sediments

2015 ◽  
Vol 74 (1) ◽  
pp. 43-57 ◽  
Author(s):  
AS Bourque ◽  
R Vega-Thurber ◽  
JW Fourqurean
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
Structure And Dynamics

Effects of resuspension of eastern oyster Crassostrea virginica biodeposits on phytoplankton community structure

2020 ◽  
Vol 640 ◽  
pp. 79-105
Author(s):  
ET Porter ◽  
E Robins ◽  
S Davis ◽  
R Lacouture ◽  
JC Cornwell
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Crassostrea Virginica ◽  
Skeletonema Costatum ◽  
Eastern Oyster ◽  
Energy Dissipation Rate ◽  
Negative Effects ◽  
Cell Densities ◽  
Sediment Bottom ◽  
Nitrite Nitrate

Anthropogenic disturbances in the Chesapeake Bay (USA) have depleted eastern oyster Crassostrea virginica abundance and altered the estuary’s environment and water quality. Efforts to rehabilitate oyster populations are underway; however, the effect of oyster biodeposits on water quality and plankton community structure are not clear. In July 2017, we used 6 shear turbulence resuspension mesocosms (STURMs) to determine differences in plankton composition with and without the daily addition of oyster biodeposits to a muddy sediment bottom. STURM systems had a volume-weighted root mean square turbulent velocity of 1.08 cm s-1, energy dissipation rate of ~0.08 cm2 s-3, and bottom shear stress of ~0.36-0.51 Pa during mixing-on periods during 4 wk of tidal resuspension. Phytoplankton increased their chlorophyll a content in their cells in response to low light in tanks with biodeposits. The diatom Skeletonema costatum bloomed and had significantly longer chains in tanks without biodeposits. These tanks also had significantly lower concentrations of total suspended solids, zooplankton carbon, and nitrite +nitrate, and higher phytoplankton carbon concentrations. Results suggest that the absence of biodeposit resuspension initiates nitrogen uptake for diatom reproduction, increasing the cell densities of S. costatum. The low abundance of the zooplankton population in non-biodeposit tanks suggests an inability of zooplankton to graze on S. costatum and negative effects of S. costatum on zooplankton. A high abundance of the copepod Acartia tonsa in biodeposit tanks may have reduced S. costatum chain length. Oyster biodeposit addition and resuspension efficiently transferred phytoplankton carbon to zooplankton carbon, thus supporting the food web in the estuary.

Fish community structure, habitat complexity, and soundscape characteristics of patch reefs in a tropical, back-reef system

2019 ◽  
Vol 609 ◽  
pp. 33-48 ◽  
Author(s):  
RP Lyon ◽  
DB Eggleston ◽  
DR Bohnenstiehl ◽  
CA Layman ◽  
SW Ricci ◽  
...  
Keyword(s):  
Community Structure ◽  
Habitat Complexity ◽  
Fish Community ◽  
Back Reef ◽  
Fish Community Structure ◽  
Patch Reefs ◽  
Reef System
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