scholarly journals Decline in Phytoplankton Biomass along Indian Coastal Waters due to COVID-19 Lockdown

2020 ◽  
Vol 12 (16) ◽  
pp. 2584 ◽  
Author(s):  
Deepak R. Mishra ◽  
Abhishek Kumar ◽  
Pradipta R. Muduli ◽  
Sk. Md. Equeenuddin ◽  
Gurdeep Rastogi ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Coastal Waters ◽  
Phytoplankton Biomass ◽  
Nutrient Loading ◽  
Early Stage ◽  
Indirect Evidence ◽  
Urban Centers ◽  
Ecosystem Responses ◽  
Business As Usual ◽  
The Relationship

The SARS-CoV-2 (or COVID-19) lockdown in India, which started at an early stage of its infection curve, has been one of the strictest in the world. Air quality has improved in all urban centers in India, a major emitter of greenhouse gases (GHG). This study is based on the hypothesis that an abrupt halt in all urban activities resulted in a massive decline in NO2 emissions and has also altered coastal nitrogen (N) inputs; in-turn, this affected the trophic status of coastal waters across the country. We present the first evidence of an overall decline in pre-monsoon chlorophyll-a, a proxy for phytoplankton biomass, in coastal waters off urban centers during the peak of the lockdown in April. The preliminary field data and indirect evidence suggests the reduction in coastal chlorophyll-a could be linked to a net decline in nutrient loading, particularly of bioavailable N through watershed fluxes and atmospheric deposition. The preliminary results stress the importance of a further understanding of the relationship between fluctuations in anthropogenic N, due to lockdown measures and coastal ecosystem responses, as countries open-up to a business-as-usual scenario.

scholarly journals Factors Regulating the Relationship Between Total and Size-Fractionated Chlorophyll-a in Coastal Waters of the Red Sea

2019 ◽  
Vol 10 ◽  
Author(s):  
Robert J. W. Brewin ◽  
Xosé Anxelu G. Morán ◽  
Dionysios E. Raitsos ◽  
John A. Gittings ◽  
Maria Ll. Calleja ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Red Sea ◽  
Coastal Waters ◽  
The Relationship

Bacterial abundance and production, and their relation to primary production in tropical coastal waters of Peninsular Malaysia

2008 ◽  
Vol 59 (1) ◽  
pp. 10 ◽  
Author(s):  
Choon Weng Lee ◽  
Chui Wei Bong
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Net Primary Production ◽  
Correlation Coefficients ◽  
Peninsular Malaysia ◽  
Chl A ◽  
The Relationship

In the present study, the relationship between bacteria and phytoplankton in tropical coastal waters was investigated. The bacterial abundance, bacterial production, chlorophyll a concentration and net primary production were measured at several locations in the coastal waters of Peninsular Malaysia. Chlorophyll a concentration ranged from 0.40 to 32.81 μg L–1, whereas bacterial abundance ranged from 0.1 to 97.5 × 106 cells mL–1. Net primary production ranged from 8.49 to 55.95 μg C L–1 h–1, whereas bacterial production ranged from 0.17 to 70.66 μg C L–1 h–1. In the present study, the carbon conversion factor used to convert bacterial production (cells mL–1 h–1) into carbon units ranged from 10 to 32.8 fg C cell–1, and was estimated from the bacterial size distribution measured at each location. Both phototrophic and heterotrophic biomass (bacteria–chlorophyll a) and activity (bacterial production–net primary production) were significantly correlated, although their correlation coefficients (r2) were relatively low (r2 = 0.188 and r2 = 0.218 respectively). Linear regression analyses provided the following equations to represent the relationship between: bacteria and chlorophyll a (Chl a), log Bacteria = 0.413 log Chl a + 6.057 (P = 0.003); and between bacterial production (BP) and net primary production (NPP), log BP = 0.896 log NPP – 0.394 (P = 0.004), which fitted with published results well. Comparison of annual carbon fluxes confirmed the prevalence of net heterotrophy in these coastal waters, and together with the low correlation coefficients, suggested the role of allochthonous organic matter in supporting heterotrophic activity.

Harmful algal blooms as a sink for inorganic nutrients in a eutrophic estuary

2021 ◽  
Vol 663 ◽  
pp. 63-76
Author(s):  
DA Lemley ◽  
JB Adams ◽  
JL Largier
Keyword(s):  
Coastal Waters ◽  
Harmful Algal Blooms ◽  
Phytoplankton Biomass ◽  
Algal Blooms ◽  
Nutrient Dynamics ◽  
Nutrient Loading ◽  
Positive Association ◽  
Inorganic Nutrient ◽  
Study Objective ◽  
Hydrological Variability

Phytoplankton-mediated nutrient fluxes typically provide only pulsed relief to adjacent coastal waters during the productive period, with nutrient export increasing in the absence of substantial phytoplankton biomass. On the warm temperate coastline of South Africa, the Sundays Estuary is characterised by highly regulated freshwater inflow patterns, nutrient-enriched conditions, and resident harmful algal blooms (HABs). Given these attributes, the study objective was to investigate the effect of these phytoplankton blooms on fluvial inorganic nutrient dynamics. To assess uptake, we analysed inorganic nutrient (phosphate, ammonium, NOx) and phytoplankton concentrations in relation to salinity using data from 17 surveys. Property-salinity mixing diagrams and statistical analyses indicated a positive association between increasing phytoplankton biomass and decreasing NOx flux (p < 0.001), and to a lesser degree phosphate flux (p = 0.22), along the gradient from low-salinity inner estuary to high salinity outer estuary. High biomass HAB accumulations of Heterosigma akashiwo (>100 µg chl a l-1) represent significant removal of available NOx (~100%) and phosphate (>75%) during warmer conditions (>20°C). These events, together with continuous inorganic nutrient uptake during less severe bloom conditions, remove a substantial portion of annual NOx and phosphate loads (36.5 and 36.4% flux, respectively). Although this buffers inorganic nutrient loading to adjacent coastal waters, it also represents an emerging legacy pollution issue in the form of a benthic accumulation of organic material in bottom waters subject to recurrent hypoxia. Future management efforts should adopt an ecosystem-based approach centred around simultaneous restoration of hydrological variability and dual nutrient reduction strategies (N and P).

scholarly journals Distribution of chlorophyll-a concentration with the catch of julung fish in Ternate Island city

2018 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
Aisyah Bafagih ◽  
Sahriar Hamzah ◽  
Umar Tangke
Keyword(s):  
Correlation Coefficient ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Gis Analysis ◽  
Chlorophyll A Concentration ◽  
Non Linear ◽  
The Relationship ◽  
Fishing Area

The study was conducted during March-May 2017 in the Coastal Waters of Ternate Island of North Maluku Province with the aim to study the relationship between the concentration of chlorophyll-a and the catch of Hemiramphus sp and its potential fishing area. Using experimental fishing method and non-linear regeneration analysis and GIS analysis. The result of this research shows that oceanographic factor that is chlorophyll-a concentration has significant effect on the catch of julung fish with correlation coefficient value of 0.729, with potential catch area located at three locations ie at coastal of Ngade to Kalumata on location 00o45'00"N - 127o21'03"E to 00o45'28.924"N - 127o22'08.893"E, coastal Keluarah Fitu at the location 00o44'39.490"N -127o19'51.083"E to 00o45'09.150"N - 127o20'52.263"E, and on the coast of Kelurahan Rua on location 00o45'51.169"N - 127o17'25.857"E to 00o46'42.457"N - 127o17'45.633"E.

scholarly journals Spatial-temporal Variability of the Chlorophyll “a” Concentration in the Krasnodar Reservoir According to the Satellite Images’ Data

2021 ◽  
pp. 67-84
Author(s):  
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Satellite Images ◽  
Nutrient Content ◽  
Water Area ◽  
Left Bank ◽  
Chl A ◽  
Delta Formation ◽  
Hydrodynamic Processes ◽  
The Relationship

The Krasnodar Reservoir has undergone significant transformations during its operation since 1973. As a result, of active delta formation of the Kuban and Belaya rivers, the reservoir was divided into two autonomous reservoirs, its area decreased by 35 %. The study is aimed at determining the significance of the eutrophication factor in the transformation of the Krasnodar Reservoir. Methods. Based on 51 Sentinel-2 satellite images for 2015–2020 the results of calculations of the concentration of chlorophyll «a» as an indicator of phytoplankton biomass in the reservoir are presented. The MSI sensor calculates the concentration of chlorophyll a (chl «a») based on the normalized chlorophyll difference index. Chl «a» estimates were obtained for a total area of 277 km2; the main bowl of the Krasnodar Reservoir and the Tshchik Reservoir, which was cut off from it. We have built maps reflecting the spatial and intra-annual variability of chl «a». Results The highest average concentrations of chl «a» are characteristic of the shallow upper part of the Krasnodar Reservoir, which is influenced by the runoff of the Kuban and Pshish rivers with an increased nutrient content. Locally high average values of chl «a» were recorded in the areas of the runoff current and in the estuaries of the left-bank tributaries. In the Tshchik water body with a low intensity of water exchange, the relationship between the concentration of chl «a» and hydrodynamic processes is not evident. We have revealed features of the annual cycle of phytoplankton biomass. It has been established that the trophic status of the reservoir is subject to seasonal variability: in spring, 2/3 of the water area correspond to eutrophic waters, 1/3 to mesotrophic waters; in autumn, the entire reservoir has a eutrophic status.

scholarly journals RELATIONS OF SEVERAL PHYSICOCHEMICAL PARAMETERS AND PHYTOPLANKTON IN COASTAL KUBU RAYA DISTRICT, WEST KALIMANTAN

2018 ◽  
Vol 9 (2) ◽  
pp. 727-737
Author(s):  
Sri Endah Purnamaningtyas ◽  
Dimas Angga Hedianto ◽  
. Riswanto
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Physicochemical Parameters ◽  
High Fertility ◽  
Chemical Parameters ◽  
Phytoplankton Abundance ◽  
High Concentration ◽  
West Kalimantan ◽  
The Relationship

This research was conducted in April, July and October 2013 at 8 (eight) stations: 1. Tj. Intan, 2. Tj. Tempurung, 3. Tj. Bunga Dalam, 4. Tj. Bunga dalam, 5. Tj. Burung, 6. P. Dabung, 7. Tasik Malaya, and 8. Tj. Harapan. This study aims to determine the relationship between several physic-chemical parameters and phytoplankton abundance. The results show the growth of phytoplankton biomass (chlorophyll a) was determined by high concentration of NH4 and NO3, while its growth is limited by turbidity (turbidity). Station that has high fertility in the Coastal District of Kubu Raya is Dabung Island. Keyword: water quality, chlorophyll a, coastal Kubu Raya district

Climate and Hydrological Factors Affecting Variation in Chlorophyll Concentration and Water Clarity in the Bahia Almirante, Panama

2012 ◽  
pp. 323-334
Author(s):  
Rachel Collin ◽  
Luis D'Croz ◽  
Plinio Gondola ◽  
Juan B. Del Rosario
Keyword(s):  
Wind Speed ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Nutrient Loading ◽  
Rapid Development ◽  
Chlorophyll Concentration ◽  
Water Clarity ◽  
Annual Rainfall ◽  
Bocas Del Toro ◽  
Factors Affecting

Water clarity and productivity are fundamentally important for the distribution of tropical marine organisms. In the Caribbean, changes in nutrient loading that result from rapid development are thought to have caused increased planktonic productivity, reduced water clarity, and reduced reef and seagrass health. Here we analyze chlorophyll a concentration and water clarity from eight years of environmental monitoring in Bocas del Toro, Panama. Chlorophyll a concentrations did not vary significantly among the six sampled sites and showed no significant temporal changes, despite the recent rapid development in the region, accompanied by scant wastewater treatment. In contrast, water clarity increased significantly during the study period. Because chlorophyll a does not vary closely with water clarity, Secchi depths are likely to reflect changes in suspended particulate matter rather than in phytoplankton biomass. Secchi depths decreased with rainfall and wind speed but increased with solar radiation, supporting the idea that clarity was not tightly linked to phytoplankton biomass. The decrease in annual rainfall, but not wind speed, over the past eight years suggests that the long-term trend in Secchi readings is the result of changes in rainfall patterns.

In Vivo Fluorescence of Chlorophyll A: Estimation of Phytoplankton Biomass and Activity in Římov Reservoir (Czech Republic)

1993 ◽  
Vol 28 (6) ◽  
pp. 29-33 ◽  
Author(s):  
V. Vyhnálek ◽  
Z. Fišar ◽  
A. Fišarová ◽  
J. Komárková
Keyword(s):  
Czech Republic ◽  
Chlorophyll Fluorescence ◽  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
In Vivo Fluorescence ◽  
Fluorescence Of Chlorophyll A ◽  
Římov Reservoir ◽  
Natural Phytoplankton

The in vivo fluorescence of chlorophyll a was measured in samples of natural phytoplankton taken from the Římov Reservoir (Czech Republic) during the years 1987 and 1988. The fluorescence intensities of samples either with or without addition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron, DCMU) were found reliable for calculating the concentration of chlorophyll a during periods when cyanobacteria were not abundant. The correction for background non-chlorophyll fluorescence appeared to be essential. No distinct correlation between a DCMU-induced increase of the fluorescence and primary production of phytoplankton was found.

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.

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