Relationships of Fish Yield to Lake Phytoplankton Standing Crop, Production, and Morphoedaphic Factors

1977 ◽  
Vol 34 (12) ◽  
pp. 2271-2279 ◽  
Author(s):  
Ray T. Oglesby
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Crop Production ◽  
Fishery Management ◽  
Cold Water ◽  
Phytoplankton Production ◽  
Fish Yield ◽  
Morphoedaphic Index ◽  
Intensively Managed ◽  
Predicted Values

Fish yield is related to annual primary production, summer phytoplankton standing crop, and the morphoedaphic index for lakes representing a wide variety of typologies by a series of models in the form of log-log regressions. Tentative boundary conditions are established by which lakes inappropriate to the models can be excluded. Confidence intervals for predicted values about the mean are given for the fish yield–phytoplankton standing crop regression. From this relation, potential yields for the lakes studied are reduced from a range of 10,000 to one of 25-fold. Efficiencies with which carbon is transferred from primary production to fish yield vary by 2 to 3 orders of magnitude and are highest for small, intensively managed ponds and lowest for large, deep, cold-water lakes. Models based upon fish yield as a function of phytoplankton production or standing crop are inherently more accurate and subject to fewer exceptions than are those related to morphoedaphic factors. The former appear to be capable of substantial refinement but even in their present state might be employed to make useful predictions for groups of lakes. A suggested supplement to existing approaches in fishery management involves the following sequence: (1) use of expectation-variability diagrams to obtain an overview of the problem, (2) selection of an appropriate model or models to predict yield, (3) prediction of a range of yields, and (4) implementation of regulations proved successful for other lakes in the same yield category. Key words: fish, lakes, phytoplankton, morphoedaphic index, fishery management

Primary Production and Phytoplankton in the Experimental Lakes Area, Northwestern Ontario, and other Low-Carbonate Waters, and a Liquid Scintillation Method for Determining 14C Activity in Photosynthesis

1971 ◽  
Vol 28 (2) ◽  
pp. 189-201 ◽  
Author(s):  
D. W. Schindler ◽  
S. K. Holmgren
Keyword(s):  
Primary Production ◽  
Liquid Scintillation ◽  
Species Abundance ◽  
Euphotic Zone ◽  
Phytoplankton Production ◽  
Phytoplankton Species ◽  
Experimental Lakes Area ◽  
Phytoplankton Species Composition ◽  
Northwestern Ontario ◽  
Filtration Error

A modified 14C method is described for measuring phytoplankton production in low-carbonate waters. The procedure includes the use of the Arthur and Rigler (Limnol. Oceanogr. 12: 121–124, 1967) technique for determining filtration error, liquid scintillation counting for determining the radioactivity of membrane filters and stock 14C solutions, and gas chromatography for measuring total CO2.Primary production, chlorophyll a, and total CO2 were measured for two dates in midsummer from each of several lakes in the Experimental Lakes Area (ELA), ranging from 1 to 1000 ha in area and from 2 to 117 m in maximum depth. Phytoplankton species abundance and biomass were determined for the same dates. Production ranged from 0.02 to 2.12 gC/m3∙day and from 0.179 to 1.103 g C/m2∙day. Chlorophyll ranged from 0.4 to 44 mg/m3 and from 5 to 98 mg/m2 in the euphotic zone. The corresponding ranges for live phytoplankton biomass were 120–5400 mg/m3 and 2100–13,400 mg/m2. Chrysophyceae dominated the phytoplankton of most of the lakes.A system for classifying the lakes in terms of phytoplankton species composition and production–depth curves is developed.

scholarly journals Biophysical interactions in the Cabo Frio upwelling system, southeastern Brazil

2012 ◽  
Vol 60 (3) ◽  
pp. 353-365 ◽  
Author(s):  
Sergio Augusto Coelho-Souza ◽  
Maria Soledad López ◽  
Jean Remy Davee Guimarães ◽  
Ricardo Coutinho ◽  
Rogério Nader Candella
Keyword(s):  
Cold Water ◽  
Basic Knowledge ◽  
Predatory Fish ◽  
Southeastern Brazil ◽  
Fish Stock ◽  
Phytoplankton Production ◽  
Brazilian Coast ◽  
Upwelled Water ◽  
Biophysical Interactions ◽  
Cabo Frio

The rising of cold water from deeper levels characterizes coastal upwelling systems. This flow makes nutrients available in the euphotic layer, which enhances phytoplankton production and growth. On the Brazilian coast, upwelling is most intense in the Cabo Frio region (RJ). The basic knowledge of this system was reviewed in accordance with concepts of biophysical interactions. The high frequency and amplitude of the prevailing winds are the main factor promoting the rise of South Atlantic Central Water, but meanders and eddies in the Brazil Current as well as local topography and coast line are also important. Upwelling events are common during spring/summer seasons. Primary biomass is exported by virtue of the water circulation and is also controlled by rapid zooplankton predation. Small pelagic fish regulate plankton growth and in their turn are preyed on by predatory fish. Sardine furnishes an important regional fish stock. Shoreline irregularities define the embayment formation of the Marine Extractive Reserve of Arraial do Cabo making it an area with evident different intensities of upwelled water that harbors high species diversity. Consequently, on a small spatial scale there are environments with tropical and subtropical features, a point to be explored as a particularity of this ecosystem.

scholarly journals Modeling Posidonia oceanica shoot density and rhizome primary production

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elena Catucci ◽  
Michele Scardi
Keyword(s):  
Random Forest ◽  
Primary Production ◽  
Large Scale ◽  
Posidonia Oceanica ◽  
Shoot Density ◽  
Large Scale Assessment ◽  
Goods And Services ◽  
Predictive Variables ◽  
Management Perspective ◽  
Predicted Values

Abstract Posidonia oceanica meadows rank among the most important and most productive ecosystems in the Mediterranean basin, due to their ecological role and to the goods and services they provide. Estimations of crucial ecological process such as meadows productivity could play a major role in an environmental management perspective and in the assessment of P. oceanica ecosystem services. In this study, a Machine Learning approach, i.e. Random Forest, was aimed at modeling P. oceanica shoot density and rhizome primary production using as predictive variables only environmental factors retrieved from indirect measurements, such as maps. Our predictive models showed a good level of accuracy in modeling both shoot density and rhizome productivity (R2 = 0.761 and R2 = 0.736, respectively). Furthermore, as shoot density is an essential parameter in the estimation of P. oceanica productivity, we proposed a cascaded approach aimed at estimating the latter using predicted values of shoot density rather than observed measurements. In spite of the complexity of the problem, the cascaded Random Forest performed quite well (R2 = 0.637). While direct measurements will always play a fundamental role, our estimates could support large scale assessment of the expected condition of P. oceanica meadows, providing valuable information about the way this crucial ecosystem works.

scholarly journals Satellite-measured seasonal variations in primary production in the scallop-farming region of the Okhotsk Sea

2009 ◽  
Vol 66 (7) ◽  
pp. 1557-1569 ◽  
Author(s):  
M. A. Mustapha ◽  
S. Sei-Ichi ◽  
T. Lihan
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Seasonal Variations ◽  
Cold Water ◽  
Late Spring ◽  
Frontal Area ◽  
Okhotsk Sea ◽  
Physical Processes ◽  
Soya Warm Current ◽  
Chl A

Abstract Mustapha, M. A., Sei-Ichi, S., and Lihan, T. 2009. Satellite-measured seasonal variations in primary production in the scallop-farming region of the Okhotsk Sea. – ICES Journal of Marine Science, 66: 1557–1569. Seasonal variation in primary production after a retreat of the sea ice in the scallop-farming region along the Hokkaido coast of the Okhotsk Sea (1998–2004) was determined using satellite images. Annual variability in primary production was caused by variability in the physical processes associated with retreat of the sea ice, advection of the Sōya Warm Current (SWC), and intrusion of the East Sakhalin Current (ESC). Variability in primary production resulted in variability in the Chl a concentration, which was also demonstrated with an empirical orthogonal function (EOF) analysis. Enhancement of Chl a concentration in the frontal area in late spring was demonstrated by the second EOF mode of Chl a concentration (14.2% of variance), in parallel with the generation of a well-developed frontal area resulting from the advection of warm waters of the SWC along the coast in late spring, as indicated by the second EOF mode of sea surface temperature (SST; 1.8% of variance). Elevated Chl a concentration and the presence of cold water of the ESC in late autumn were also highlighted by the third EOF mode of Chl a concentration (9.0% of variance) and SST (1.5% of variance). Prolonged high primary production within the scallop-farming region after spring is supported by the development of a frontal area in summer and strengthening of the ESC in autumn.

Primary Productivity of Southern Indian Lake before, during, and after Impoundment and Churchill River Diversion

1984 ◽  
Vol 41 (4) ◽  
pp. 591-604 ◽  
Author(s):  
R. E. Hecky ◽  
S. J. Guildford
Keyword(s):  
Light Intensity ◽  
Primary Production ◽  
Water Column ◽  
Primary Productivity ◽  
Phosphorus Deficiency ◽  
Light Environment ◽  
Phytoplankton Production ◽  
Light Penetration ◽  
The Mean ◽  
Chlorophyll Concentrations

The primary productivity of seven regions of Southern Indian Lake and neighboring Wood Lake was measured during open-water seasons from 1974 to 1978. The lake had regional differences in chlorophyll concentrations and daily rates of integral primary production in 1974 and 1975 prior to impoundment of the lake. Regions receiving Churchill River flow tended to have higher chlorophyll concentrations and production rates than those regions marginal to the flow. Impoundment of the lake resulted in higher efficiencies of primary production in all regions, as indicated by higher light-saturated rates of carbon uptake per unit chlorophyll and by higher initial slopes of the hyperbolic light response relation of the phytoplankton. Many large basins of the lake had light penetration reduced by high concentrations of suspended sediment from eroding shorelines, while other areas had relatively unchanged light penetration. The increased efficiency of carbon fixation per unit chlorophyll resulted in higher rates of integral production in those regions where light penetration was not greatly affected. Daily rates of integral primary production in lake regions where light penetration had decreased markedly were not significantly different after impoundment because efficiencies of light utilization were higher. Comparison of the mean water column light intensities for those turbid regions with the values of Ik (light intensity at the onset of light saturation) for phytoplankton indicated that these turbid regions are now light deficient on average. Phosphorus deficiency, as indicated by alkaline phosphatase activity per unit ATP, which was present before impoundment, has been eliminated as the mean water column light intensity declined below 5 mEinsteins∙m−2∙min−1. The light environment of a new reservoir can be a significant determinant of integral production, and predicting the consequences of impoundment on phytoplankton production requires accurate prediction of the light environment.

scholarly journals On the accuracy of official Chinese crop production data: Evidence from biophysical indexes of net primary production

2020 ◽  
Vol 117 (41) ◽  
pp. 25434-25444 ◽  
Author(s):  
Gengyuan Liu ◽  
Xueqi Wang ◽  
Giovanni Baiocchi ◽  
Marco Casazza ◽  
Fanxin Meng ◽  
...  
Keyword(s):  
Primary Production ◽  
Data Quality ◽  
Crop Production ◽  
Net Primary Production ◽  
Production Data ◽  
Physical Factors ◽  
National Statistics ◽  
Rapid Economic Growth ◽  
Self Sufficiency ◽  
Economic Statistics

With rapid economic growth and urbanization, self-sufficiency in crop production has become central to China’s agriculture policy. Accurate crop production statistics are essential for research, monitoring, and planning. Although researchers agree that China’s statistical authority has considerably modernized over time, China’s economic statistics have still been viewed as unreliable and often overstated to meet growth targets at different administrative levels. Recent increases in crop production reported by national statistics have also come under increasing scrutiny. This paper investigates crop production data quality from a planetary boundary perspective—comparing net primary production (NPP) harvested obtained from national statistics with satellite-driven NPP estimates that are supported by detailed observation of land cover, combined with observations on physical factors that limit plant growth. This approach provides a powerful means to check the plausibility of China’s grain production statistics at different administrative levels that can generate insights about their discrepancies and can contribute to improved crop production measurements. We find some evidence of potential misreporting problems from the lower administration level where the risk of manipulation of statistics is higher. We also find problems from provincial-level major grain producers. These values can also affect the national totals. Although the numbers are affected by large uncertainties, we find that improving the spatial resolution of key agricultural parameters can greatly improve the reliability of the indicator that in turn can help improve data quality. More reliable production data will be vital for relevant research and provide better insights into food security problems, the carbon cycle, and sustainable development.

scholarly journals Terrestrial trophic dynamics in the Canadian Arctic

2003 ◽  
Vol 81 (5) ◽  
pp. 827-843 ◽  
Author(s):  
Charles J Krebs ◽  
Kjell Danell ◽  
Anders Angerbjörn ◽  
Jep Agrell ◽  
Dominique Berteaux ◽  
...  
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Net Primary Production ◽  
Canadian Arctic ◽  
Faecal Pellet ◽  
Trophic Dynamics ◽  
Balance Model ◽  
Arctic Ecosystems ◽  
Large Herbivore ◽  
Tundra Ecosystems

The Swedish Tundra Northwest Expedition of 1999 visited 17 sites throughout the Canadian Arctic. At 12 sites that were intensively sampled we estimated the standing crop of plants and the densities of herbivores and predators with an array of trapping, visual surveys, and faecal-pellet transects. We developed a trophic-balance model using ECOPATH to integrate these observations and determine the fate of primary and secondary production in these tundra ecosystems, which spanned an 8-fold range of standing crop of plants. We estimated that about 13% of net primary production was consumed by herbivores, while over 70% of small-herbivore production was estimated to flow to predators. Only 9% of large-herbivore production was consumed by predators. Organization of Canadian Arctic ecosystems appears to be more top-down than bottom-up. Net primary production does not seem to be herbivore-limited at any site. This is the first attempt to integrate trophic dynamics over the entire Canadian Arctic.

Optimizing models for remotely estimating primary production in Antarctic coastal waters

2000 ◽  
Vol 12 (1) ◽  
pp. 20-32 ◽  
Author(s):  
H.M. Dierssen ◽  
M. Vernet ◽  
R.C. Smith
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Coastal Waters ◽  
Time Series Data ◽  
Cold Water ◽  
Water System ◽  
Environmental Parameters ◽  
Day Length ◽  
Series Data ◽  
Phytoplankton Productivity

Primary productivity and associated biogeochemical fluxes within the Southern Ocean are globally significant, sensitive to change and poorly known compared to temperate marine ecosystems. We present seasonal time series data of chlorophyll a, primary productivity and in-water irradiance measured in the coastal waters of the Western Antarctica Peninsula and build upon existing models to provide a more optimum parameterization for the estimation of primary productivity in Antarctic coastal waters. These and other data provide strong evidence that bio-optical characteristics and phytoplankton productivity in Antarctic waters are different from temperate waters. For these waters we show that over 60% of the variability in primary production can be explained by the surface chlorophyll a concentration alone, a characteristic, which lends itself to remote sensing models. If chlorophyll a concentrations are accurately determined, then the largest source of error (13–18%) results from estimates of the photoadaptive variable (PBopt). Further, the overall magnitude of PBopt is low (median 1.09 mg C mg chl−1 h−1) for these data compared to other regions and generally fits that expected for a cold water system. However, the variability of PBopt over the course of a season (0.4 to 3 mg C mg chl−1 h−1) is not consistently correlated with other possible environmental parameters, such as chlorophyll, sea surface temperature, incident irradiance, day length, salinity, or taxonomic composition. Nonetheless, by tuning a standard depth-integrated primary productivity model to fit representative PBopt values and the relatively uniform chlorophyll-normalized production profile found in these waters, we can improve the model to account for approximately 72–73% variability in primary production both for our data as well as for independent historic Antarctic data.

Emergence of Chironomidae (Diptera) in Fertilized and Natural Lakes at Saqvaqjuac, N.W.T.

1988 ◽  
Vol 45 (4) ◽  
pp. 731-737 ◽  
Author(s):  
Harold E. Welch ◽  
John K. Jorgenson ◽  
Martin F. Curtis
Keyword(s):  
Primary Production ◽  
Phytoplankton Production ◽  
Experimental Lakes Area ◽  
Natural Lakes ◽  
Before And After ◽  
Mean Size ◽  
Apparent Reason ◽  
Total Primary Production ◽  
Latitudinal Range ◽  
Lake Fertilization

Chironomid emergence was quantified in four small lakes at Saqvaqjuac, N.W.T. (63°39′N), before and after lake fertilization. Emerging biomass responded immediately to increased phytoplankton production, reaching equilibrium the following year. Emergence from the reference lake was extremely variable, for no apparent reason. The emergence – phytoplankton production relationships found by Davies for the Experimental Lakes Area (~49°N) were generally valid for Saqvaqjuac lakes and Char Lake (74°42′), except that (1) biomass was better correlated than numbers because of increased mean size with increasing latitude and (2) total primary production was a better predictor than phytoplankton production alone because benthic photosynthesis increases with increasing latitude. Chironomid production seems to be a predictable function of total primary production throughout the latitudinal range of the small Canadian lakes examined.

Sign in / Sign up

Export Citation Format

Share Document