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.

scholarly journals ESTIMASI PRODUKTIVITAS PRIMER PERAIRAN BERDASARKAN KONSENTRASI KLOROFIL-A YANG DIEKSTRAK DARI CITRA SATELIT LANDSAT-8 DI PERAIRAN KEPULAUAN KARIMUN JAWA

2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Mulkan Nuzapril ◽  
Setyo Budi Susilo ◽  
James Parlindungan Panjaitan
Keyword(s):  
Chlorophyll A ◽  
Attenuation Coefficient ◽  
Primary Productivity ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Landsat 8 ◽  
Secchi Disk ◽  
Estimation Model ◽  
Chlorophyll A Concentration ◽  
Average Value

Sea primary productivity is an important factor in monitoring the quality of sea waters due to his role in the carbon cycle and the food chain for heterotrophic organisms. Estimation of sea primary productivity may be suspected through the values of chlorophyll-a concentration, but surface chlorophyll-a concentration was only able to explain 30% of the primary productivity of the sea. This research aims to build primary productivity estimation model based on chlorophyll-a concentration value of a surface layer of depth until depth compensation. Primary productivity model of relationships with chlorophyll concentration were extracted from Landsat-8 imagery then it could be used to calculated of sea primary productivity. The determination of the depth classification were done by measuring the attenuation coefficient values using the luxmeter underwater datalogger 2000 and secchi disk. The attenuation coefficient values by the luxmeter underwater, ranges between of 0.13-0.21 m-1 and secchi disk ranged, of 0.12 – 0.21 m-1. The penetration of light that through into the water column where  primary productivity is still in progress or where the depth of compensation ranged from 28.75 – 30.67 m. The simple linier regression model between average value of chlorophyll- concentration in all euphotic zone with sea primary productivity has high correlation, it greater than of surface chlorophyll-a concentration (R2 = 0.65). Model validation of sea primary productivity has high accuracy with the RMSD value of 0.09 and satellite-derived sea primary productivity were not significantly different. The satellite derived of chlorophyll-a could be calculated into sea primary productivity.Abstrak Produktivitas primer perairan merupakan faktor penting dalam pemantauan kualitas perairan laut karena berperan dalam siklus karbon dan rantai makanan bagi organisme heterotrof. Estimasi produktivitas primer perairan dapat diduga melalui nilai konsentrasi klorofil-a, namun konsentrasi klorofil-a permukaan laut hanya mampu menjelaskan 30% produktivitas primer laut. Penelitian ini bertujuan untuk membangun model estimasi produktivitas primer berdasarkan nilai konsentrasi klorofil-a dari lapisan kedalaman permukaan sampai kedalaman kompensasi. Model hubungan produktivitas primer dengan konsentrasi klorofil-a yang diekstrak dari citra satelit Landsat-8 kemudian dapat digunakan untuk mengestimasi produktivitas primer satelit. Penentuan klasifikasi kedalaman dilakukan dengan mengukur nilai koefisien atenuasi menggunakan luxmeter underwater datalogger 2000  dan secchi disk. Nilai koefisien atenuasi dengan menggunakan luxmeter underwater berkisar antara 0,13 -0,21m-1 dan secchi disk berkisar antara 0,12 – 0,21 m-1. Penetrasi cahaya yang masuk ke kolom perairan dimana produksi primer masih berlangsung atau kedalaman kompensasi berkisar antara 28,75 – 30,67 m. Model regresi linier sederhana antara konsentrasi klorofil-a rata-rata seluruh zona eufotik dengan produktivitas primer perairan memiliki korelasi yang lebih tinggi dibandingkan konsentrasi klorofil-a permukaan dengan R2= 0,65. Validasi model produktivitas primer memiliki keakuratan yang tinggi dengan RMSD sebesar 0,09 dan produktivitas primer satelit secara signifikan tidak berbeda nyata dengan produktivitas primer data insitu. Sehingga  nilai konsentrasi klorofil-a satelit dapat ditransformasi menjadi produktivitas primer satelit.

Seasonal Dynamics of the Deep-Chlorophyll Maximum in Castle Lake, California

1983 ◽  
Vol 40 (2) ◽  
pp. 208-214 ◽  
Author(s):  
John C. Priscu ◽  
Charles R. Goldman
Keyword(s):  
Primary Productivity ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Deep Chlorophyll Maximum ◽  
Deep Basin ◽  
Photoautotrophic Growth ◽  
Chlorophyll Maximum ◽  
Early Portion ◽  
Castle Lake ◽  
Do So

Vertical profiles of chlorophyll concentration measured during 1980 in Castle Lake showed that a deep maximum developed immediately after ice thaw and persisted in the deep basin of the lake until autumn overturn. In the early portion of the ice-free season, low epilimnetic turbidity allows enough light to reach this deep-chlorophyll layer to produce a deep-primary productivity maximum. Photoautotrophic growth appears to maintain the deep-chlorophyll maximum early in the season whereas the accumulation of sinking organisms appears to do so later in the season. Although the deep-water phytoplankton have reduced rates of photosynthesis late in the season, they maintain their ability to photosynthesize immediately upon exposure to light. Consequently, the redistribution of deepwater chlorophyll at fall overturn can increase the chlorophyll concentration of the euphotic zone (0–15 m) by 58% which can potentially increase primary productivity in this zone by 81%.Key words: deep-chlorophyll maximum, primary productivity, aphotic viability

Light, Nutrients, and Water Temperature as Determinants of Phytoplankton Production in Two Saline, Prairie Lakes with High Sulphate Concentrations

1992 ◽  
Vol 49 (11) ◽  
pp. 2281-2290 ◽  
Author(s):  
Richard D. Robarts ◽  
Marlene S. Evans ◽  
Michael T. Arts
Keyword(s):  
Water Temperature ◽  
Photosynthetic Capacity ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Dominant Factor ◽  
Phytoplankton Production ◽  
Dissolved Phosphorus ◽  
Prairie Lakes ◽  
The Mean ◽  
Algal Productivity

Our data support empirical models indicating that algal productivity is low relative to total phosphorus (TP) levels in prairie lakes with high sulphate concentrations. Mean chlorophyll accounted for 91.1% of the variance in euphotic zone primary production (ΣA) in Humboldt Lake (total dissolved solids (TDS) = 3.3 g∙L−1; Zmax = 6 m), while TP, total dissolved phosphorus, and water temperature accounted for 82.7% of ΣA variance in Redberry Lake (TDS = 20.9 g∙L−1; Zmax = 17 m). The relative importance of these variables to ΣA resulted from biological, chemical, and physical differences of these lakes. Light usually penetrated to the bottom of Redberry Lake due to a mean euphotic zone (Zeu) chlorophyll of 1.7 mg∙m−3, while Humboldt Lake's mean Zeu was 3.4 m with a mean chlorophyll concentration of 62.6 mg∙m−3. Chlorophyll was the dominant factor correlated with light penetration in Humboldt Lake (r2 = 0.65) but not in Redberry Lake. Photosynthetic capacity was correlated (r2 = 0.72) with water temperature only in Redberry Lake. The mean ΣA was 57.1 and 230.2 mg C∙m−2∙h−1 for Redberry and Humboldt lakes, respectively.

scholarly journals Short‐term variability in euphotic zone biogeochemistry and primary productivity at Station ALOHA: A case study of summer 2012

2015 ◽  
Vol 29 (8) ◽  
pp. 1145-1164 ◽  
Author(s):  
Samuel T. Wilson ◽  
Benedetto Barone ◽  
Francois Ascani ◽  
Robert R. Bidigare ◽  
Matthew J. Church ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Euphotic Zone ◽  
Short Term ◽  
Station Aloha ◽  
Short Term Variability

scholarly journals Spatiotemporal variations of nitrogen isotopic records in the Arabian Sea

2015 ◽  
Vol 12 (1) ◽  
pp. 1-14 ◽  
Author(s):  
S.-J. Kao ◽  
B.-Y. Wang ◽  
L.-W. Zheng ◽  
K. Selvaraj ◽  
S.-C. Hsu ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Arabian Sea ◽  
Euphotic Zone ◽  
Southeastern Part ◽  
Data Set ◽  
Global Coherence ◽  
One Step ◽  
Isotopic Records ◽  
Bottom Depth ◽  
Reported Data

Abstract. Available reports of dissolved oxygen, δ15N of nitrate (δ 15NNO3) and δ15N of total nitrogen (δ15Nbulk) for trap material and surface/downcore sediments from the Arabian Sea (AS) were synthesized to explore the AS' past nitrogen dynamics. Based on 25 μmol kg−1 dissolved oxygen isopleth at a depth of 150 m, we classified all reported data into northern and southern groups. By using δ15Nbulk of the sediments, we obtained geographically distinctive bottom-depth effects for the northern and southern AS at different climate stages. After eliminating the bias caused by bottom depth, the modern-day sedimentary δ15Nbulk values largely reflect the δ15NNO3 supply from the bottom of the euphotic zone. Additionally to the data set, nitrogen and carbon contents vs. their isotopic compositions of a sediment core (SK177/11) collected from the most southeastern part of the AS were measured for comparison. We found a one-step increase in δ15Nbulk starting at the deglaciation with a corresponding decrease in δ13CTOC similar to reports elsewhere revealing a global coherence. By synthesizing and reanalyzing all reported down core δ15Nbulk, we derived bottom-depth correction factors at different climate stages, respectively, for the northern and southern AS. The diffusive sedimentary δ15Nbulk values in compiled cores became confined after bias correction revealing a more consistent pattern except recent 6 ka. Such high similarity to the global temporal pattern indicates that the nitrogen cycle in the entire AS had responded to open-ocean changes until 6 ka BP. Since 6 ka BP, further enhanced denitrification (i.e., increase in δ15Nbulk) in the northern AS had occurred and was likely driven by monsoon, while, in the southern AS, we observed a synchronous reduction in δ15Nbulk, implying that nitrogen fixation was promoted correspondingly as the intensification of local denitrification at the northern AS basin.

No simple relationship between above-ground tree growth and fine-litter production in tropical forests

2008 ◽  
Vol 24 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Luke P. Shoo ◽  
Jeremy VanDerWal
Keyword(s):  
Missing Data ◽  
Primary Productivity ◽  
Net Primary Productivity ◽  
Woody Debris ◽  
Litter Production ◽  
Simple Relationship ◽  
Above Ground Biomass ◽  
Data Set ◽  
Geographic Coverage ◽  
Incremental Growth

An important deficiency of the tropical forest data set on above-ground net primary productivity (ANPP) is the paucity of studies where requisite components of forest productivity have been measured at the same location. Missing data on above-ground biomass increment (ABI, which refers to the incremental growth of trees) and fine-litter production (leaves, fruit, flowers, small twigs, but excluding coarse woody debris) is particularly problematic as these are the two major components of ANPP. The fragmentary nature of the data is reflected by the fact that only 13 of 39 (33%) plots reviewed by Clark et al. (2001) and 8 of 104 (8%) plots reviewed by Malhi et al. (2004) had data on both major components of productivity. In an attempt to retain the geographic coverage and replication of data in analyses, researchers have proposed ways to infer missing data. Typically ratios or (more recently) fitted relationships between ABI and litter production have been used for this purpose (Bray & Gorham 1964, Clark et al. 2001, Murphy 1975).

scholarly journals Mesoscale variability in intact and ghost colonies of Phaeocystis antarctica in the Ross Sea: Distribution and abundance

2017 ◽  
Vol 166 ◽  
pp. 97-107 ◽  
Author(s):  
Walker O. Smith ◽  
Dennis J. McGillicuddy ◽  
Elise B. Olson ◽  
Valery Kosnyrev ◽  
Emily E. Peacock ◽  
...  
Keyword(s):  
Ross Sea ◽  
Mesoscale Variability ◽  
Phaeocystis Antarctica

Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. V. Chlorophyll Distribution

1959 ◽  
Vol 10 (3) ◽  
pp. 316
Author(s):  
PS Davis
Keyword(s):  
Surface Waters ◽  
Vertical Profile ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Early Summer ◽  
Late Winter ◽  
Light Penetration ◽  
Chlorophyll Distribution ◽  
The Mean ◽  
Made In

The chlorophyll a in samples from five stations in Lake Macquarie was determined over the period July 1955 to November 1956. The mean surface value for the four stations within the lake proper was 1.26 mg/m³. The vertical profile at one station was studied and the mean of these profile values was 1.23 mg/m³. Throughout the period of the survey chlorophyll concentrations in the lake varied from 0.1 to 4.0 mg/m³. The lowest values were found in the late winter and early summer (November) and the peaks during spring and autumn. The chlorophyll concentration in the surface waters of Lake Macquarie was shown to be significantly higher than that of the marine water entering the lake, but lower than that of a comparison station in the Hawkesbury River. One series of light penetration measurements made in December 1956 showed that all the water in the lake, and all but one section of Dora Creek, lay within the euphotic zone.

Sign in / Sign up

Export Citation Format

Share Document