scholarly journals Planktivores and Plankton Dynamics: Effects of Fish Biomass and Planktivore Type

1992 ◽  
Vol 49 (7) ◽  
pp. 1466-1473 ◽  
Author(s):  
Xavier Lazzaro ◽  
Ray W. Drenner ◽  
Roy A. Stein ◽  
J. Durward Smith
Keyword(s):  
Water Quality ◽  
Green Algae ◽  
Primary Productivity ◽  
Trophic Cascade ◽  
Gizzard Shad ◽  
Particulate Phosphorus ◽  
Fish Biomass ◽  
Dorosoma Cepedianum ◽  
Pennate Diatoms ◽  
Plankton Communities

We quantified the effects of planktivore biomass and planktivore type in an experimental mesocosm study of factorial design in which five levels of fish biomass (0–75 g/m3) were cross-classified with two plantivore types: filter-feeding gizzard shad (Dorosoma cepedianum) and visual-feeding bluegill (Lepomis macrochims). As fish biomass increased, cladocerans, cyclopoids, particulate phosphorus (PP) > 200 μm, and chironomids declined; conversely, rotifers, primary productivity, chlorophyll a, turbidity, unicellular flagellates, colonial and unicellular green algae, pennate diatoms, total phosphorus, and 20–200 and 12–20 μm PP were enhanced. In the presence of gizzard shad, as compared with bluegill, cyclopoids, turbidity, unicellular green algae, pennate diatoms, > 200 μm PP, and chironomid tubes were higher whereas colonial green algae and < 0.2 μm PP were lower. Fish biomass operated independently of planktivore type for most variables, except copepods, colonial green algae, turbidity, and 20–200 μm PP. Although gizzard shad and bluegill have different trophic cascade pathways, fish biomass was more important than planktivore type as a regulator of plankton communities and water quality.

Improvements in water quality following biomanipulation of gizzard shad (Dorosoma cepedianum) in Lake Denham, Florida

2011 ◽  
Vol 27 (4) ◽  
pp. 287-297 ◽  
Author(s):  
Walt Godwin ◽  
Michael Coveney ◽  
Edgar Lowe ◽  
Lawrence Battoe
Keyword(s):  
Water Quality ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum

Particulate Organic Carbon Supply and Trophic Dynamics in a Mississippi Flood-Control Reservoir Dominated by Gizzard Shad (Dorosoma cepedianum)

1992 ◽  
Vol 49 (8) ◽  
pp. 1722-1733 ◽  
Author(s):  
Nicholas G. Aumen ◽  
Cindy L. Crist ◽  
Dawn E. Miller ◽  
Keith O. Meals
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Fish Community ◽  
Flood Control ◽  
Gizzard Shad ◽  
Forage Fish ◽  
Fish Biomass ◽  
Dorosoma Cepedianum ◽  
Fish Community Structure ◽  
Phytoplankton Primary Production

Sources of particulate organic carbon (POC) and trophic–dynamic relationships were studied in a reservoir with low sportfish populations. Fish community structure and POC input from tributaries, phytoplankton primary production, and vascular vegetation on mudflats were estimated. Gizzard shad (Dorosoma cepedianum) averaged 39.8% of the total fish biomass in 1988, and as much as 94% of the total forage fish biomass was too large to serve as prey for most predators. Phytoplankton primary productivity averaged 1182 mg C∙m−2∙d−1 in 1987 and 1988, contributed 33.57 Gg POC∙yr−1 to the reservoir, and apparently was phosphate limited. POC inflow from tributaries contributed 60.00 Gg∙yr−1with 79% of POC <75 μm in size. Winter and spring stormflow was responsible for 92% of the total POC transported. Considering POC size fractions available to gizzard shad, POC input from tributaries, phytoplankton, and mudflats contributed 21, 54, and 25% of the total POC input, respectively. The trophic–dynamic analysis indicated that phytoplankton POC was adequate to support the reservoir fish community. A more efficient transfer of carbon in the food web might be accomplished by stocking with a smaller forage fish, such as threadfin shad (Dorosoma petenense), which are not common in the reservoir.

Balancing Fisheries Management and Water Uses for Impounded River Systems

2008 ◽  
Keyword(s):  
Trophic State ◽  
Supply And Demand ◽  
Gizzard Shad ◽  
Fish Biomass ◽  
Dorosoma Cepedianum ◽  
Fish Prey ◽  
Watershed Area ◽  
Reservoir Volume ◽  
Poor Recruitment ◽  
Acoustic Surveys

<em>Abstract</em>.—In Ohio reservoirs, a perceived excess of available gizzard shad <em>Dorosoma cepedianum </em>prey and poor recruitment of stocked walleyes <em>Sander vitreus </em>during the 1970s resulted in research to develop and expand a program to stock saugeyes (walleye × sauger <em>S. canadensis</em>), a hybrid better suited for shallow, productive, and turbid reservoirs with short water-residence times. Development of successful production techniques increased saugeye stocking from fewer than 1.2 million to 6–10 million fingerlings (28–42 mm) per year during 1980 through 1990, presenting the challenge of determining stocking rates suited to available prey. To improve <em>Sander </em>spp. stocking practices, we assessed prey supply by quantifying fish biomass in Ohio reservoirs using acoustic technology. Fish biomass varied from 10 to 897 kg/ha as estimated by 53 acoustic surveys conducted on 16 reservoirs during 1999–2006. Among 15 variables associated with reservoir productivity, 84% of the variability in fish biomass was explained by watershed area, trophic state, reservoir area, and reservoir volume; watershed area plus trophic state explained 77% of this variability. Dominance of fish prey smaller than 150 mm, which represented more than 80% of fishes sampled in acoustic surveys, revealed that reservoir fish biomass largely reflected the upper limit of prey fish biomass morphologically available to age-1 and older <em>Sander </em>spp. Gizzard shad represented more than 50% of the fishes captured in 92% of gill-netting surveys conducted in conjunction with acoustic surveys. Unexpectedly, reservoirs with extensive prey biomass occasionally had poor recruitment for <em>Sander </em>spp., and these reservoirs often were stocked at lower rates than ones with better recruitment. Fisheries managers in Ohio can improve stocking practices by using acoustic surveys to predict reservoir capacity for stocked sport fish based on reservoir attributes, then applying these results to details of reservoir-specific recruitment of stocked fishes and their consumptive demand. Refining this supply and demand approach will require continual progress in understanding reservoir ecosystems and their watersheds.

scholarly journals Food-web regulation by a planktivore: exploring the generality of the trophic cascade hypothesis

1995 ◽  
Vol 52 (11) ◽  
pp. 2518-2526 ◽  
Author(s):  
Roy A. Stein ◽  
Dennis R. DeVries ◽  
John M. Dettmers
Keyword(s):  
Trophic Cascade ◽  
Spatial Scales ◽  
Micropterus Salmoides ◽  
Lepomis Macrochirus ◽  
Open Water ◽  
Gizzard Shad ◽  
Lower Latitude ◽  
Dorosoma Cepedianum ◽  
High Fecundity ◽  
Fish Predators

The trophic cascade hypothesis currently being tested in north temperate systems may not apply to open-water communities in lower latitude U.S. reservoirs. These reservoir communities differ dramatically from northern lakes in that an open-water omnivore, gizzard shad (Dorosoma cepedianum), often occurs in abundance. Neither controlled by fish predators (owing to high fecundity and low vulnerability) nor by their zooplankton prey (following the midsummer zooplankton decline, gizzard shad consume detritus and phytoplankton), gizzard shad regulate community composition rather than being regulated by top-down or bottom-up forces. In experiments across a range of spatial scales (enclosures, 1–9 m2; ponds, 4–5 ha; and reservoirs, 50–100 ha), we evaluated the generality of the trophic cascade hypothesis by assessing its conceptual strength in reservoir food webs. We reviewed the role of gizzard shad in controlling zooplankton populations and hence recruitment of bluegill, Lepomis macrochirus (via exploitative competition for zooplankton), and largemouth bass, Micropterus salmoides (by reducing their bluegill prey). Reservoir fish communities, owing to the presence of gizzard shad, appear to be regulated more by complex weblike interactions among species than by the more chainlike interactions characteristic of the trophic cascade.

Toxicity of a Mixture of Metals on Freshwater Algae

1978 ◽  
Vol 35 (4) ◽  
pp. 479-481 ◽  
Author(s):  
P. T. S. Wong ◽  
Y. K. Chau ◽  
P. L. Luxon
Keyword(s):  
Water Quality ◽  
Great Lakes ◽  
Key Words ◽  
Green Algae ◽  
Primary Productivity ◽  
Lake Water ◽  
Metal Toxicity ◽  
Culture Medium ◽  
Freshwater Algae ◽  
Water Quality Objectives

Recommended levels of a number of metals for Great Lakes Water Quality Objectives were found to be very toxic to freshwater algae when these metals were present simultaneously in lake water and culture medium. The diatom tested was more sensitive to metal toxicity than the blue-green and green algae. Key words: metals, Water Quality Objectives, toxicity, algae, diatom, primary productivity

scholarly journals Mitigasi Beban Fosfor dari Kegiatan Budidaya dengan Penebaran Ikan Bandeng (Chanos chanos) Di Waduk Cirata, Jawa Barat

2018 ◽  
Vol 19 (2) ◽  
pp. 259
Author(s):  
Andri Warsa ◽  
Joni Haryadi ◽  
Lismining Pujiyani Astuti
Keyword(s):  
Water Quality ◽  
Primary Productivity ◽  
Carrying Capacity ◽  
Aquatic Environment ◽  
Aquatic Ecology ◽  
Planktivorous Fish ◽  
Phosphorus Loading ◽  
Fish Biomass ◽  
Chanos Chanos ◽  
Net Cages

ABSTRACTThe phosphorus loading from aquaculture activity as a product of floating net cages (KJA) in Cirata Reservoir have exceeded the carrying capacity of the aquatic ecology. This results in a decrease in water quality which is characterized by uncontrolled phytoplankton growth. The stocking of fish is one of the ways used in the improvement of the aquatic environment resulting eutrophication. Phosphorus which is wasted from cultivation activity will be utilized by phytoplankton for its growth. The phytoplankton can be utilized by planktivorous fish as its natural feed. One type of fish that can be used for stocking is a planktivora fish as milkfish (Chanos chanos). The purpose of this study was to estimate the load of phosphorus and calculate the number of milkfish seeds which are planktivorous fish that can be stocked with the aim of reducing phosphorus waste from aquaculture activities in Cirata Reservoir, West Java. The result showed that P load from cultivation activity at Cirata Reservoir was 1,206 tons/year. The concentration of chlorophyll-a and the primary productivity produced by the P load from the cultivation activities were 28.6 mg/m3 and 364.6 gC/m2/year respectively. The number of milkfish seeds that can be stocked as an effort to utilize the load of phosphorus as much as 1.8 million/year. The P load can be reduced based on estimation of harvested fish biomass and phosphor requirement for milkfish of 11.52 ton/year.Keywords: Cirata Reservoir, phosphorus loading, stocking, milkfishABSTRAKBeban masukkan fosfor (P) dari kegiatan budidaya ikan dalam keramba jaring (KJA) dari pakan yang terbuang dan sisa metabolisme ikan di Waduk Cirata telah melebihi daya dukung ekologi perairan. Hal ini berdampak pada penurunan kualitas perairan yang ditandai oleh pertumbuhan fitoplankton yang tidak terkendali. Penebaran ikan merupakan salah satu cara yang digunakan dalam perbaikan lingkungan perairan akibat dari eutrofikasi. Fosfor di perairan dimanfaatkan oleh fitoplankton untuk pertumbuhannya. Fitoplankton tersebut dapat dimanfaatkan oleh ikan planktivora sebagai pakan alaminya.Salah satu jenis ikan yang dapat ditebar (stocking) adalah ikan planktivora yaitu ikan bandeng (Chanos chanos). Tujuan penelitian ini adalah untuk mengestimasi beban masukkan fosfor serta menghitung jumlah benih ikan bandeng yang dapat ditebar dengan tujuan pengurangan limbah fosfor dari kegiatan budidaya di Waduk Cirata, Jawa Barat. Hasil penelitian menunjukkan beban P yang berasal dari kegiatan budidaya di Waduk Cirata sebesar 1.206 ton/tahun. Konsentrasi klorofil-a dan produktivitas primer yang dihasilkan oleh beban P dari kegiatan budidaya masing-masing sebesar 28,6 mg/m3 dan 364,6 gC/m2/tahun. Jumlah benih ikan bandeng yang dapat ditebar sebagai upaya pemanfaatan beban masukkan fosfor sebanyak 1,8 juta ekor/tahun. Beban P yang mampu dikurangi berdasarkan estimasi biomassa ikan yang dipanen dan kebutuhan fosfor untuk ikan bandeng sebesar ton 11,52 ton/tahun.Kata kunci: Waduk Cirata, beban fosfor, penebaran, bandeng

The relationship between musty-odor-causing organisms and water quality in Lake Biwa

1995 ◽  
Vol 31 (11) ◽  
pp. 153-158 ◽  
Author(s):  
M. Kajino ◽  
K. Sakamoto
Keyword(s):  
Water Quality ◽  
Data Analysis ◽  
Green Algae ◽  
Analytical Methods ◽  
Lake Biwa ◽  
Blue Green Algae ◽  
Odor Compounds ◽  
Musty Odor ◽  
The Relationship

Musty odor has occurred annually in Lake Biwa since 1969. Osaka municipal waterworks, which is located downstream of Lake Biwa, has made many efforts to treat musty-odor compounds produced in Lake Biwa from spring through autumn. With the development of analytical methods for the determination of musty-odor compounds, we have been able to confirm that planktonic blue-green algae are the major causes of the musty-odor occurrences. The relationship between the growth of blue-green algae and the water quality was not so apparent. However, through our data analysis focusing on the relationship between musty-odor occurrences due to Phormidium tenue or Oscillatoria tenuis and some nutrients in Lake Biwa, we found that the concentration of nitrate in water may be an important parameter for the estimation of growth of the algae and the musty-odor behavior.

Reflecting materials in the eyes of three teleosts, Orthopristes chrysopterus, Dorosoma cepedianum and Anchoa mitchilli

1973 ◽  
Vol 184 (1074) ◽  
pp. 15-27 ◽  
Keyword(s):  
Body Length ◽  
Pigment Epithelium ◽  
Total Body Length ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum ◽  
Anchoa Mitchilli ◽  
First Report ◽  
Total Body ◽  
Bay Anchovy

The tapeta lucida of three species of teleosts were examined to determine the composition of the reflecting material. The fishes were bay anchovy Anchoa mitchilli (Engraulidae), gizzard shad Dorosoma cepedianum (Clupeidae) and pigfish Orthopristes chrysopterus (Haemulidae). The tapetum of each species was situated in the pigment epithelium of the eye. That of the pigfish contained triglycerides identified as chiefly glyceryl tridocosahexaenoate. A reduced pteridine, 7, 8-dihydroxanthopterin, occurred in the tapetum of the gizzard shad. Guanine occurred in the tapetum of the bay anchovy. The tapetum of the shad contained brightly reflecting particles about 0.5 μm in diameter There were 10.8 mg of dihydroxanthopterin in the tapetum of a shad (total body length 23 cm) and 0.46 mg of guanine in the tapetum of an anchovy (total body length 9 cm). This is the first report of a pteridine acting as a retinal reflector in vertebrates. Various aspects of retinal reflectors of teleosts are discussed and their variety and common characteristics commented upon.

scholarly journals Hyperspectral Data and Machine Learning for Estimating CDOM, Chlorophyll a, Diatoms, Green Algae and Turbidity

2018 ◽  
Vol 15 (9) ◽  
pp. 1881 ◽  
Author(s):  
Sina Keller ◽  
Philipp Maier ◽  
Felix Riese ◽  
Stefan Norra ◽  
Andreas Holbach ◽  
...  
Keyword(s):  
Machine Learning ◽  
Water Quality ◽  
Chlorophyll A ◽  
Green Algae ◽  
Hyperspectral Data ◽  
Coefficient Of Determination ◽  
Inland Waters ◽  
Learning Approaches ◽  
River Elbe ◽  
Regression Framework

Inland waters are of great importance for scientists as well as authorities since they are essential ecosystems and well known for their biodiversity. When monitoring their respective water quality, in situ measurements of water quality parameters are spatially limited, costly and time-consuming. In this paper, we propose a combination of hyperspectral data and machine learning methods to estimate and therefore to monitor different parameters for water quality. In contrast to commonly-applied techniques such as band ratios, this approach is data-driven and does not rely on any domain knowledge. We focus on CDOM, chlorophyll a and turbidity as well as the concentrations of the two algae types, diatoms and green algae. In order to investigate the potential of our proposal, we rely on measured data, which we sampled with three different sensors on the river Elbe in Germany from 24 June–12 July 2017. The measurement setup with two probe sensors and a hyperspectral sensor is described in detail. To estimate the five mentioned variables, we present an appropriate regression framework involving ten machine learning models and two preprocessing methods. This allows the regression performance of each model and variable to be evaluated. The best performing model for each variable results in a coefficient of determination R 2 in the range of 89.9% to 94.6%. That clearly reveals the potential of the machine learning approaches with hyperspectral data. In further investigations, we focus on the generalization of the regression framework to prepare its application to different types of inland waters.

scholarly journals Sediment Remediation for Ecosystem in Eutrophic Lakes

2002 ◽  
Vol 2 ◽  
pp. 885-891 ◽  
Author(s):  
Y. Amano ◽  
K. Taki ◽  
K. Murakami ◽  
T. Ishii ◽  
H. Matsushima
Keyword(s):  
Water Quality ◽  
Green Algae ◽  
Hybrid System ◽  
Size Reduction ◽  
Control Effect ◽  
Sediment Remediation ◽  
Eutrophic Lakes

The remediation method — namely, a hybrid system combined with DAF and CRM — is studied in this paper for the size reduction of aqua-ecological circulation and for the elution control in lakes. Results show that two effects on water quality purification, the sediment washout effect and the elution control effect, can be induced by this system, and the biota inhabiting the lake is therefore shifted into an oligotrophic aspect, from blue algae to green algae and/or diatoms.

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