A comparison of four methods for integrating14C-primary productivity measurements per unit area

1980 ◽  
Vol 36 (5) ◽  
pp. 259-262 ◽  
Author(s):  
Shun-ei Ichimura ◽  
Timothy R. Parsons ◽  
Masayuki Takahashi ◽  
Humitake Seki
Keyword(s):  
Primary Productivity ◽  
Unit Area ◽  
Productivity Measurements

scholarly journals PENGARUH KEDALAMAN TERHADAP NILAI PRODUKTIVITAS PRIMER DI WADUK JATIBARANG SEMARANG

2016 ◽  
Vol 5 (3) ◽  
pp. 150-156
Author(s):  
Wiwi Siti Rohmah ◽  
Suryanti Suryanti ◽  
Max Rudolf Muskananfola
Keyword(s):  
Chlorophyll A ◽  
Primary Productivity ◽  
Chemical Parameters ◽  
Average Value ◽  
Depth Difference ◽  
Sampling Locations ◽  
Regression Test ◽  
Productivity Measurements ◽  
Descriptive Method ◽  
Simple Regression

ABSTRAK Waduk Jatibarang merupakan salah satu waduk yang tergolong baru di Kota Semarang. Untuk mencegah terjadinya penurunan kualitas perairan pada waduk dimasa mendatang, penting dilakukan pengukuran tingkat kesuburan perairan waduk secara berkala. Salah satu cara untuk mengetahui tingkat kesuburan perairan waduk yaitu dengan melakukan pengukuran produktivitas primer perairan dan kandungan klorofil-a serta parameter fisika-kimia perairan. Penelitian ini dilakukan pada bulan Februari-Maret 2016 di Waduk Jatibarang Semarang. Tujuan dari Penelitian ini adalah untuk mengetahui nilai produktivitas primer perairan berdasarkan perbedaan kedalaman serta untuk mengetahui pengaruh kedalaman terhadap nilai produktivitas primer perairan di Waduk Jatibarang, Semarang. Metode yang digunakan dalam penelitian ini adalah Deskriptif lokasi sampling, yaitu Stasiun I; Inlet, Stasiun II perairan tengah waduk dan Stasiun III Outlet dalam tiga kali pengulangan dengan rentang waktu satu minggu. Hasil pengukuran produktivitas primer pada ketiga stasiun per kedalaman adalah; kedalaman 0 m berkisar 54,750-90,000 mgC/m3/hari, kedalaman 5 m berkisar 91,500-102,750 mgC/m3/hari, kedalaman 10 m berkisar 39,750-64,500 mgC/m3/hari dan kedalaman 15 m berkisar 20,250-45,5000 mgC/m3/hari. Berdasarkan nilai tersebut maka perairan waduk Jatibarang tergolong sebagai perairan Mesotrofik-Eutrofik. Rata-rata nilai kandungan klorofil-a minggu ke-1 0,6913 mg/m3, minggu ke-2 0,6665mg/m3, dan minggu ke-3 0,4409 mg/m3. Hasil uji regresi sederhana menunjukan terdapat pengaruh variabel kedalaman dan kandungan klorofil-a terhadap produktivitas primer sebesar 51,3%. Kata Kunci : Produktivitas Primer; Klorofil-a; Waduk Jatibarang Semarang  ABSTRACT Jatibarang Reservoir is one of the new reservoirs in Semarang. To prevent the degradation of reservoirs water quality in the future, it is important to measure the dam water fertilization periodically. Like one of the ways to determine the level of fertility of the dam water is by measuring the primary productivity of the water and chlorophyll-a and physic-chemical parameters of the waters. This study was conducted from February to March 2016 in Semarang Jatibarang Reservoir. The aim of this study is to determine the primary productivity of waters based on depth difference and the depth effects on primary productivity of the waters of the Jatibarang reservoir, Semarang. The method used in this study is descriptive method. Sampling locations are station I; Inlet, Station II: middle of reservoir and stations III: Outlet with three repetitions for the period of one week. The results of primary productivity measurements at each stations per depth is; at the depth of 0 m the results ranges from 54.750 to 90.000 mgC/m3/day, at the depth of 5 m from 91.500 to 102.750 mgC/m3/day, at the depth of 10 m from 39.750 to 64.500 mgC/m3/day and at the depth of 15 m from 20.250 to 45.5000 mgC/m3/day. Based on these results, it is concluded that the water of Jatibarang Reservoir is classified as Mesotrofik-eutrophic waters. The average value of chlorophyll-a in the first week is 0.6913 mg/m3, in the 2nd week is 0.6665 mg/m3, and the 3rd week is 0.4409 mg/m3. The results of simple regression test reveals that there is a significant effect of water depth and chlorophyll-a on primary productivity is  51.3%. Keywords: Primary Productivity, Chlorophyll-a, Jatibarang Reservoir Semarang

scholarly journals A Promising Development for Detecting Ocean Productivity

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Terri Cook
Keyword(s):  
Primary Productivity ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Marine Food Web ◽  
The North ◽  
Ocean Productivity ◽  
Marine Food ◽  
Promising Development ◽  
Productivity Measurements ◽  
The North Pacific

A comparison of primary productivity measurements across the North Pacific Ocean demonstrates the potential for using autonomous instruments to discern effects of climate change on the marine food web.

scholarly journals Primary productivity measurements in the Ross Sea, Antarctica: A regional synthesis

2021 ◽  
Author(s):  
Walker O. Smith Jr.
Keyword(s):  
Primary Productivity ◽  
Ross Sea ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Data Set ◽  
Phaeocystis Antarctica ◽  
Ecological Importance ◽  
Global Biogeochemical Cycles ◽  
Critical Components ◽  
Productivity Measurements

Abstract. Polar systems are undersampled due to the difficulty of sampling remote and challenging environments; however, these systems are critical components of global biogeochemical cycles. Measurements on primary productivity in specific areas can quantify the input of organic matter to food webs, and so are of critical ecological importance as well. However, long-term measurements using the same methodology are available only for a few polar systems. Primary productivity measurements using 14C-uptake incubations from the Ross Sea, Antarctica, are synthesized, along with chlorophyll concentrations at the same depths and locations. A total of 19 independent cruises were completed, and 449 stations occupied where measurements of primary productivity (each with 7 depths) were completed. The incubations used the same basic simulated in situ methodology for all. Integrated water column productivity for all stations averaged 1.10 ± 1.20 g C m−2 d−1, and the maximum was 13.1 g C m−2 d−1. Annual productivity calculated from the means throughout the growing season equalled 146 g C m−2 yr−1. Mean chlorophyll concentration in the euphotic zone (the 1 % irradiance level) was 2.85 ± 2.68 mg m−3 (maximum concentration was 19.1 mg m−3). Maximum photosynthetic rates at the surface (normalized to chlorophyll) averaged 0.94 ± 0.71 mg C (mg chl)−1 h−1, similar to the maximum rate found in photosynthesis/irradiance measurements. Productivity measurements are consistent with the temporal patterns of biomass found previously, with biomass and productivity peaking in late December; mixed layers were at a minimum at this time as well. Estimates of plankton composition also suggest that pre-January productivity was largely driven by the haptophyte Phaeocystis antarctica, and summer productivity by diatoms. The data set will be useful for a comparison to other Antarctic regions and provide a basis for refined bio-optical models of regional primary productivity.

The acid-bubbling method for primary productivity measurements modified and tested

1975 ◽  
Vol 20 (6) ◽  
pp. 1018-1019 ◽  
Author(s):  
Pall Theodorsson ◽  
Jon Orn Bjarnason
Keyword(s):  
Primary Productivity ◽  
Productivity Measurements
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