scholarly journals Spatial and seasonal variation in growth rate and secondary production of Yoldia notabilis in Otsuchi Bay, Japan, with reference to the influence of food supply from the water column

1992 ◽  
Vol 88 ◽  
pp. 215-223 ◽  
Author(s):  
M Nakaoka
Keyword(s):  
Growth Rate ◽  
Seasonal Variation ◽  
Water Column ◽  
Food Supply ◽  
Secondary Production ◽  
Otsuchi Bay ◽  
Spatial And Seasonal Variation ◽  
Influence Of Food

Seasonal variation of water-column light utilization efficiency for primary production in Saroma-ko Lagoon

2021 ◽  
pp. 1-9
Author(s):  
Akihiro Shiomoto ◽  
Yushi Kamuro
Keyword(s):  
Seasonal Variation ◽  
Primary Production ◽  
Water Column ◽  
Fresh Water ◽  
Utilization Efficiency ◽  
Commercial Activity ◽  
The Sustainable Development ◽  
Light Utilization Efficiency ◽  
Light Utilization ◽  
Sunlight Intensity

Abstract In Saroma-ko Lagoon, where scallop aquaculture is a thriving commercial activity, monitoring primary production is essential for determining the amount of scallops that can be farmed. Using the primary production data obtained so far, we calculated Ψ, an index of water-column light utilization efficiency, and clarified its seasonal variation. Ψ tended to be lower in the spring bloom season (February–April), and higher in the late autumn to winter (October–December). Low chlorophyll-normalized production, an index of growth rate, resulted in lower values, while low daily irradiance resulted in higher values. The values of Ψ from our study had a range of 0.05–1.42 gC gChl-a−1 mol photons−1 m2 (N = 56). These values were within the previously reported range of 0.07–1.92 (gC gChl-a−1 mol photons−1 m2) for seawater and fresh water worldwide. Therefore, it is likely that Ψ varies from 0.05–2 gC gChl-a−1 mol photons−1 m2, being affected by conditions of phytoplankton growth and sunlight intensity, regardless of whether samples are collected from seawater or fresh water. Using the median Ψ value of 0.45 gC gChl-a−1 mol photons−1 m2 obtained in this study, primary production was 0.3–3.5 times the actual production at Saroma-ko Lagoon. Using this method, primary production can be easily and constantly monitored, facilitating the sustainable development of scallop aquaculture.

scholarly journals Spatio-temporal variation in number and production of neustonic and planktonic bacteria inhabiting polluted estuarine harbour channel

2021 ◽  
Vol 203 (9) ◽  
pp. 5547-5559
Author(s):  
Piotr Perliński ◽  
Zbigniew J. Mudryk ◽  
Marta Zdanowicz ◽  
Łukasz Kubera
Keyword(s):  
Seasonal Variation ◽  
Secondary Production ◽  
Seasonal Cycle ◽  
Subsurface Water ◽  
Surface Microlayer ◽  
Water Basin ◽  
Planktonic Bacteria ◽  
Microbiological Parameters ◽  
Spatio Temporal ◽  
Number Of Bacteria

AbstractThe aim of this paper was to determine the abundance and secondary production by bacteria inhabiting the surface microlayer and subsurface water in a specific water basin, i.e., polluted estuarine harbour channel. In a 3-year seasonal cycle, the total number of bacteria and their biomass were higher in the surface microlayer (SML) 7.57 × 108cells dm−3 and 15.86 µg C dm−3 than in the subsurface water (SSW) 4.25 × 108cells dm−3 and 9.11 µg C dm−3 of the studied channel. The opposite relationship was noted in the level of the secondary production (SML—37.16 μg C dm−3 h−1, SSW—60.26 μg C dm−3 h−1) in this water basin. According to the analysed microbiological parameters, the total number of bacteria and secondary production varied along the horizontal profile in the water of the studied channel. The total number of bacteria and their secondary production showed the seasonal variation as well.

scholarly journals (A343) Rebuilding Post Conflict Food Security in Liberia

2011 ◽  
Vol 26 (S1) ◽  
pp. s96-s97
Author(s):  
T.W. Graham
Keyword(s):  
Growth Rate ◽  
Food Security ◽  
Food Supply ◽  
Food Production ◽  
Potable Water ◽  
Food Storage ◽  
Unequal Distribution ◽  
Post Conflict ◽  
Safe Food ◽  
Domestic Food

Liberia's 14 year civil war destroyed domestic agricultural production, veterinary and agricultural education, extension services and domestic food security. These losses severely limited domestic food production, and basic hygiene and sanitation: potable water, abattoirs, cold chain and food storage were greatly diminished. The average Liberian life expectancy fell from 45.8 in 1990 to 41.8 years presently. The population birth and death rate are two of the highest globally with a resulting population growth rate, of 2.7% per annum; this growth rate requires an immediate and concerted focus on domestic food production to alleviate nutritional inadequacy and hunger, trade imbalances and loss of foreign exchange credits. Food supply nationally is presumed adequate because of importation, though domestic production is inadequate. Unequal distribution precludes food security for all Liberians. Value chain augmentation, enhancing food availability across all sectors of Liberian society and ensuring distribution of a safe food supply needs critical development. Infant mortality remains one of the highest in the world (approximately 160/1000 births), much of which is attributed to food insecurity, food contamination and lack of uniformly available potable water. Recreation of Liberia's public health and food security requires redevelopment of disease monitoring and laboratory diagnostic capability to re-establish safe food production and handling practices across all sectors. This will allow determination of endemic disease burden for the principal livestock species: poultry, sheep, goats, cattle and swine. Creation of a national disease surveillance/monitoring system allows for targeted disease intervention, ensuring vaccination for correct serotypes and most critically prevalent diseases. Creation of community level training and support will target intervention of local diseases, but also allow for national prioritization of diseases. Targeting which are most prevalent or most likely to cause production limiting effects will require periodic surveillance, targeted vaccination, and chemotherapeutic intervention and evaluation of therapeutic success.

Spatial and seasonal variation in littoral fish assemblages of four estuarine lagoons on the Mexican Pacific coast

2021 ◽  
pp. 102000
Author(s):  
Yureidy Cabrera-Páez ◽  
Consuelo M. Aguilar-Betancourt ◽  
Gaspar González-Sansón ◽  
Angel Hinojosa-Larios
Keyword(s):  
Seasonal Variation ◽  
Pacific Coast ◽  
Fish Assemblages ◽  
Mexican Pacific ◽  
Littoral Fish ◽  
Spatial And Seasonal Variation

scholarly journals Biogeochemical processes and buffering capacity concurrently affect acidification in a seasonally hypoxic coastal marine basin

2015 ◽  
Vol 12 (5) ◽  
pp. 1561-1583 ◽  
Author(s):  
M. Hagens ◽  
C. P. Slomp ◽  
F. J. R. Meysman ◽  
D. Seitaj ◽  
J. Harlay ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Primary Production ◽  
Water Column ◽  
Bottom Water ◽  
Substantial Reduction ◽  
Buffering Capacity ◽  
Total Alkalinity ◽  
Acid Base ◽  
Data Set ◽  
Ph Fluctuations

Abstract. Coastal areas are impacted by multiple natural and anthropogenic processes and experience stronger pH fluctuations than the open ocean. These variations can weaken or intensify the ocean acidification signal induced by increasing atmospheric pCO2. The development of eutrophication-induced hypoxia intensifies coastal acidification, since the CO2 produced during respiration decreases the buffering capacity in any hypoxic bottom water. To assess the combined ecosystem impacts of acidification and hypoxia, we quantified the seasonal variation in pH and oxygen dynamics in the water column of a seasonally stratified coastal basin (Lake Grevelingen, the Netherlands). Monthly water-column chemistry measurements were complemented with estimates of primary production and respiration using O2 light–dark incubations, in addition to sediment–water fluxes of dissolved inorganic carbon (DIC) and total alkalinity (TA). The resulting data set was used to set up a proton budget on a seasonal scale. Temperature-induced seasonal stratification combined with a high community respiration was responsible for the depletion of oxygen in the bottom water in summer. The surface water showed strong seasonal variation in process rates (primary production, CO2 air–sea exchange), but relatively small seasonal pH fluctuations (0.46 units on the total hydrogen ion scale). In contrast, the bottom water showed less seasonality in biogeochemical rates (respiration, sediment–water exchange), but stronger pH fluctuations (0.60 units). This marked difference in pH dynamics could be attributed to a substantial reduction in the acid–base buffering capacity of the hypoxic bottom water in the summer period. Our results highlight the importance of acid–base buffering in the pH dynamics of coastal systems and illustrate the increasing vulnerability of hypoxic, CO2-rich waters to any acidifying process.

scholarly journals SECONDARY PRODUCTION OF Scolelepis goodbodyi (POLYCHAETA: SPIONIDAE) IN A TROPICAL SANDY BEACH IN THE SOUTHWESTERN ATLANTIC, BRAZIL

2020 ◽  
Vol 24 (04) ◽  
pp. 819-833
Author(s):  
Luciana Sanches Dourado Leão ◽  
◽  
Abílio Soares-Gomes ◽  
José Roberto Botelho de Souza ◽  
Cinthya Simone Gomes Santos ◽  
...  
Keyword(s):  
Growth Rate ◽  
Secondary Production ◽  
Environmental Variability ◽  
Trophic Levels ◽  
Southwestern Atlantic ◽  
Web Studies ◽  
Marine Habitats ◽  
Production Values ◽  
Annual Biomass ◽  
Density And Biomass

The secondary production is the result of the functional response of populations subject to various environmental factors. Marine habitats vary in terms of quantity and quality of food supply, and the use of secondary production values, as well as renewal rates (P/B), may be used as estimates for understanding the incorporation of organic matter and energy per unit, population or community in each area. This estimative was performed for the population of Scolelepis goodbodyi in a tropical beach in the Southwestern Atlantic, located in an upwelling area. A comparison of Spionidae and non-spionid populations from different latitudes was also done. The Mass Specific Growth Rate method (MSGR) and the Production/Biomass ratio (P/B) were used to estimate the somatic annual production and average annual biomass. The mean density and biomass were 16.38 ind. m-2 and 2.78 g AFDW m-2,respectively. The secondary production and P/B were 8.3 g AFDW m-2 y-1 and 2.98 y1, respectively. The growth rate in weight was greater for the small size than the large size classes. The largest individuals (W3C = 1.0 mm) showed the lowest biomass and secondary production values. The observed high rates of secondary production and P/B suggest that this S. goodbodyi population can transfer large amounts of biomass to higher trophic levels of the local food web. Studies of the secondary production of spionidae populations in different latitudes, including the population of S. goodbodyi in the beach of Manguinhos, showed variability in their rates probably due to the differences of several factors such as life history and environmental variability

Sign in / Sign up

Export Citation Format

Share Document