scholarly journals The Connectivity of Nutrient Ratios on The Abundance of Phytoplankton Population In Jakarta Bay

2020 ◽  
Vol 147 ◽  
pp. 02012 ◽  
Author(s):  
Tumpak Sidabutar ◽  
Endang S. Srimariana
Keyword(s):  
Community Structure ◽  
Strong Correlation ◽  
Rainy Season ◽  
Mesh Size ◽  
Nutrient Ratios ◽  
Phytoplankton Abundance ◽  
Phytoplankton Population ◽  
Very High

The frequency of algal bloom’s event has been increased in Jakarta Bay, recently. Most of the bloom events were tend to be reoccurred after the rainy season. The research was conducted from 2008 until 2015 to study the linkage of nutrients and the ratios on the growth of the phytoplankton population. Collecting samples were conducted using a canonical plankton net of 20 µm mesh size, 125 cm length and 30 cm diameter of the opening mouth. The results of the study showed that the concentration of phosphate in the waters ranged from 0.01-12.5 µg/l (average 4.58 µg/l) and nitrate ranged from 0.01-15.89 µg/l (average 0.72 µg/l). The N/P ratio during the study ranging from 0.2 up to 45.4. High ratios of nutrients were mostly recorded in 2010 where the overall abundance of phytoplankton is very high. There is a strong correlation of N/P ratio with the community structure or composition of the phytoplankton population. The variability of phytoplankton abundance appears to be related to nutrient ratios of nitrate and phosphate.

scholarly journals Nutrient ratios driven by vertical stratification regulate phytoplankton community structure in the oligotrophic western Pacific Ocean

Ocean Science ◽  
2021 ◽  
Vol 17 (6) ◽  
pp. 1775-1789
Author(s):  
Zhuo Chen ◽  
Jun Sun ◽  
Ting Gu ◽  
Guicheng Zhang ◽  
Yuqiu Wei
Keyword(s):  
Spatial Distribution ◽  
Community Structure ◽  
Pacific Ocean ◽  
Phytoplankton Community ◽  
Western Pacific ◽  
Vertical Stratification ◽  
Nutrient Ratios ◽  
Western Pacific Ocean ◽  
Phytoplankton Community Structure ◽  
Phytoplankton Abundance

Abstract. The stratification of the upper oligotrophic ocean has a direct impact on biogeochemistry by regulating the components of the upper-ocean environment that are critical to biological productivity, such as light availability for photosynthesis and nutrient supply from the deep ocean. We investigated the spatial distribution pattern and diversity of phytoplankton communities in the western Pacific Ocean (WPO) in the autumn of 2016, 2017, and 2018. Our results showed the phytoplankton community structure mainly consisted of cyanobacteria, diatoms, and dinoflagellates, while the abundance of Chrysophyceae was negligible. Phytoplankton abundance was high from the equatorial region to 10∘ N and decreased with increasing latitude in spatial distribution. Phytoplankton also showed a strong variation in the vertical distribution. The potential influences of physicochemical parameters on phytoplankton abundance were analyzed by a structural equation model (SEM) to determine nutrient ratios driven by vertical stratification to regulate phytoplankton community structure in the typical oligotrophic ocean. Regions with strong vertical stratification were more favorable for cyanobacteria, whereas weak vertical stratification was more conducive to diatoms and dinoflagellates. Our study shows that stratification is a major determinant of phytoplankton community structure and highlights that physical processes in the ocean control phytoplankton community structure by driving the balance of chemical elements, providing a database to better predict models of changes in phytoplankton community structure under future ocean scenarios.

scholarly journals Community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters, Indonesia

2019 ◽  
Vol 9 (2) ◽  
Author(s):  
LADY A. SRIWIJAYANTI ◽  
DJUMANTO ◽  
RIZA Y. SETIAWAN ◽  
MOCHAMAD R. FIRDAUS ◽  
NURUL FITRIYA ◽  
...  
Keyword(s):  
Surface Layer ◽  
Community Structure ◽  
Morphological Character ◽  
Mesh Size ◽  
Environmental Parameter ◽  
Phytoplankton Species ◽  
Phytoplankton Abundance ◽  
Phytoplankton Diversity ◽  
Species Dominance ◽  
Counting Cell

Abstract. Sriwijayanti LA, Djumanto, Setiawan RY, Firdaus MR, Fitriya N, Sugeha HY. 2019. Community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters, Indonesia. Bonorowo Wetlands 9: 51-58. The aim of this study was to determine the species dominance and distribution, and community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters Indonesia. Phytoplankton samples were collected at the Sangihe-Talaud waters in October 2018 at 14 research stations. Water samples were collected at 5 m (surface) and thermoclines layers using rosette sampler equipped with Conductivity, Temperature, and Depth (CTD) recorder. Samples were concentrated to 40 ml using hand plankton net (mesh size 20 µm), then preserved with 4% formaldehyde. Phytoplankton species were identified using a guidebook based on morphological character traits. The cell count of each species of plankton was calculated using a Sedgwick rafter counting cell chamber. The result showed that there were 4 classes of phytoplankton (Bacillariophyceae, Dinophyceae, Cyanophyceae, and Raphydophyceae) which consisted of 59 species in the surface and 56 species in the thermocline, respectively. The abundance of phytoplankton at surface ranged from 77,333-4,024,000 cell m-3, meanwhile in the thermocline layer 8,000-542,222 cell m-3. The average of phytoplankton diversity of the surface was 0.82 and the thermocline was 1.71. The surface layer was dominated by Leptocylindrus danicus (8.92 x 106 cell m-3), Trichodesmium erythareum (5.83 x 106 cell m-3), and Detonula converfacea (0.62 x 106 cell m-3). The thermocline layer was dominated by Chaetoceros affinis (2.74 x 105 cell m-3), Thalassionema nitzchioides (2.21 x 105 cell m-3), and Chaertoceros dichaeta (1.38 x 105 cell m-3). The low phytoplankton abundance was found at the stations 12 and 13 caused by higher salinity concentration. The highest phytoplankton abundance was found in the stations with warmer temperatures, both in the surface and in the thermocline. The shallow depth thermocline layer (75-100 m) has a higher abundance than the deeper thermocline layer (110-150 m). Temperature was the environmental parameter that has the greatest influence on the abundance and species of phytoplankton, the phytoplankton in the surface layer reached 10 times more abundant than the thermocline layer.

scholarly journals Phytoplankton abundance, dominance and coexistence in an eutrophic reservoir in the state of Pernambuco, Northeast Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1313-1326 ◽  
Author(s):  
Giulliari A. S. T. Lira ◽  
Elcida L. Araújo ◽  
Maria Do Carmo Bittencourt-Oliveira ◽  
Ariadne N. Moura
Keyword(s):  
Rainy Season ◽  
Phytoplankton Community ◽  
Dry Season ◽  
Cylindrospermopsis Raciborskii ◽  
Phytoplankton Abundance ◽  
Vertical Variation ◽  
Total Phytoplankton ◽  
Physical And Chemical Variables ◽  
Different Depths ◽  
Physical And Chemical

The present study reports the phytoplankton abundance, dominance and co-existence relationships in the eutrophic Carpina reservoir, Pernambuco, Brazil. Sampling was carried out at six different depths bimonthly at a single reservoir spanning two climatic periods: dry season (January, September, and November 2006) and rainy season (March, May, and July 2006). Density, abundance, dominance, specific diversity and equitability of the community were determined, along with chlorophyll a, and physical and chemical variables of the environment. Eight species were considered abundant, and their densities corresponded to more than 90% of the total phytoplankton community quantified. Cyanobacteria represented more than 80% of this density. Cylindrospermopsis raciborskii was the only dominant taxon in the dry season, and was co-dominant in the rainy season. C. raciborskii, Planktothrix agardhii and Geitlerinema amphibium had the greatest densities and lowest vertical variation coefficients. The statistical analysis indicated relationships with vertical and seasonal variations in the phytoplankton community and the following variables: total dissolved solids, water temperature, electrical conductivity and pH. The changes in the environmental variables were discrete and regulated by the establishment of precipitation however, they were able to promote vertical and seasonal instability in the structure of the phytoplankton community.

scholarly journals The peril of adjusting for baseline when using change as a predictor

2019 ◽  
Author(s):  
Kimmo Sorjonen ◽  
Daniel Falkstedt ◽  
Bo Melin ◽  
Michael Ingre
Keyword(s):  
High Risk ◽  
Sample Size ◽  
Simulation Study ◽  
Strong Correlation ◽  
High Reliability ◽  
Large Sample Size ◽  
Present Simulation ◽  
Very High ◽  
Time Point

Some studies have analyzed the effect of a predictor measured at a later time point (X1), or of the X1-X0 difference, while adjusting for the predictor measured at baseline (X0), on some outcome Y of interest. The present simulation study shows that, if used to analyze the effect of change in X on Y, there is a high risk for this analysis to produce type 1-errors, especially with a strong correlation between true X and Y, when X0 and X1 are not measured with very high reliability, and with a large sample size. These problems are not encountered if analyzing the unadjusted effect of the X1-X0 difference on Y instead, and as this effect exhibits power on par with the adjusted effect it seems as the preferable method when using change between two measurement points as a predictor.

hr KETERSEDIAAN FOSFOR PADA LAHAN PADI SAWAH BERDASARKAN INTENSITAS PENGGUNAANNYA DI KECAMATAN GERUNG KABUPATEN LOMBOK BARAT

2019 ◽  
Vol 12 (01) ◽  
pp. 90
Author(s):  
Habiburrahman Habiburrahman Habiburrahman
Keyword(s):  
Land Use ◽  
Strong Correlation ◽  
Positive Relationship ◽  
Rice Field ◽  
Phosphorus Availability ◽  
Rice Fields ◽  
Land Area ◽  
High Accumulation ◽  
Descriptive Method ◽  
Very High

This research was aimed to know the phosphorus availability in rice fields based on use intensity in Sub District of Gerung West Lombok Regency. The research conducted from February 2018 until April 2018 with 3 location criteria (Less Intensive, Intensive, Very Intensive). Method which used is descriptive method with survey technical. The results showed, the phosphorus availability on intensive rice field in all criteria location is range from high to very high containing. The land use with very intensive  (3 times plant) indicate very high accumulation of nutrient P with the range 85% of the land area was researched. Correlation of using SP36/TSP with  availability of P in each location criteria have a positive relationship and which have a very strong correlation ( r = 0.994) that is in Less Intensive location. Keywords : Phosphorus Availability, Intensive Rice Fields

Macrobenthic community structure in tropical estuaries: the effect of sieve mesh-size and sampling depth on estimated abundance, biomass and composition

2013 ◽  
Vol 93 (6) ◽  
pp. 1441-1456 ◽  
Author(s):  
Ana Paula Maria Cavalcanti Valença ◽  
Paulo Jorge Parreira dos Santos
Keyword(s):  
Community Structure ◽  
Mesh Size ◽  
Environmental Parameters ◽  
Total Biomass ◽  
Sampling Depth ◽  
Total N ◽  
The Status ◽  
Sieve Mesh Size ◽  
The Difference ◽  
Sampling Procedures

Macrobenthic data from estuaries along the Pernambuco coast in north-eastern Brazil were analysed to evaluate the effect of sieve mesh size (1.0 mm × 0.5 mm) and sampling depth (0–10 cm × 0–20 cm) on the description of infaunal communities, in an attempt to discuss standardized sampling procedures for different ecological studies objectives in these ecosystems. In general, the difference in sieve retention was less evident for biomass but was important for abundance: the 1.0 mm sieve retained only 27% of total individuals but 77% of total biomass. Regarding sampling depth, the 0–10 cm layer contained most individuals (94%) but contributed just 64% of the overall biomass. Although no strong differences in community structure were observed at most sites with the use of different sieves, the correlations among community dissimilarity using different meshes with environmental parameters (organic matter, total-N and microphytobenthos) indicated that the use of the 0.5 mm sieve will allow a better evaluation of the status of these estuaries. The results also highlight the importance of taking the vertical distribution of tropical macrofauna into account for quantitative estimates: for taxa composition and abundance the top layer is clearly essential, whereas for biomass the deeper layers should also be considered.

How does mesh-size selection reshape the description of zooplankton community structure in coastal lakes?

2014 ◽  
Vol 151 ◽  
pp. 221-235 ◽  
Author(s):  
Marco Pansera ◽  
Antonia Granata ◽  
Letterio Guglielmo ◽  
Roberta Minutoli ◽  
Giacomo Zagami ◽  
...  
Keyword(s):  
Community Structure ◽  
Zooplankton Community ◽  
Mesh Size ◽  
Zooplankton Community Structure ◽  
Coastal Lakes ◽  
Size Selection

scholarly journals Phytoplankton Composition and Abundance Assessment in the Nador Lagoon (Mediterranean Coast of Morocco)

2011 ◽  
Vol 70 (2) ◽  
pp. 269-288 ◽  
Author(s):  
Faid Elmadani ◽  
Abderrahim Chiaar ◽  
Abdelhafid Chafi
Keyword(s):  
Trophic State ◽  
Mesh Size ◽  
Mediterranean Coast ◽  
Phytoplankton Composition ◽  
Phytoplankton Abundance

Phytoplankton Composition and Abundance Assessment in the Nador Lagoon (Mediterranean Coast of Morocco)We evaluated phytoplankton abundance, composition and trophic state of the Nador lagoon (Morocco) on the basis of data taken in the period November 2007 to August 2008. Sampling was performed at 11 stations (bottle samples at 0.5 m depth and horizontal plankton net tows with mesh size of 20 μm). Among seven identified phytoplankton classes, diatoms and dinoflagellates dominated with 133 and 169 species, respectively. Frequent phyto-plankton blooms were contributed by one to three species in the lagoon. Abundance and seasonality of phytoplankton characterized the Nador lagoon as a highly eutrophicated environment.

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