Increased Juvenile Salmonid Growth by Whole-River Fertilization

1990 ◽  
Vol 47 (5) ◽  
pp. 862-872 ◽  
Author(s):  
N. T. Johnston ◽  
C J. Perrin ◽  
P. A. Slaney ◽  
B. R. Ward
Keyword(s):  
Primary Production ◽  
Standing Crop ◽  
Coho Salmon ◽  
Inorganic Phosphorus ◽  
Management Tool ◽  
Nutrient Concentrations ◽  
Steelhead Trout ◽  
Artificial Substrata ◽  
N:P Ratios ◽  
Coastal Streams

Nutrient concentrations, periphyton standing crop and size of steelhead trout (Oncorhynchus mykiss) and coho salmon (O, kisutch) fry increased after the fertilization of a nutrient-deficient stream with inorganic phosphorus (P) and nitrogen (N). Whole-river fertilization of the Keogh River, British Columbia, during 1983–86 to increase summer average nutrient concentrations from < 1 μg P∙L−1 and 25 μg N∙L−1 to 10–15 μg P∙L−1 and 30–100 μg N∙L−1 resulted in five- to 10-fold increases in periphyton standing crops on artificial substrata and 1.4- to 2.0-fold increases in late-September salmonid fry weights. Diatoms and chlorophytes dominated the algal periphyton on artificial substrata at fertilized sites. Cyanophytes were unimportant despite low N:P ratios in some cases. Juvenile salmonids fed primarily on benthic insects. These results suggest that autochthonous primary production can be an important energy source in forested, middle-order streams, and indicate that the manipulation of autochthonous primary production can be a useful management tool to increase salmonid growth in nutrient-poor coastal streams.

scholarly journals A Review of Nontraditional Biomanipulation

2008 ◽  
Vol 8 ◽  
pp. 1184-1196 ◽  
Author(s):  
Xia Zhang ◽  
Ping Xie ◽  
Xiaoping Huang
Keyword(s):  
Algal Blooms ◽  
Algal Species ◽  
Planktivorous Fish ◽  
Bighead Carp ◽  
Cyanobacterial Blooms ◽  
Management Tool ◽  
Nutrient Concentrations ◽  
Effective Management ◽  
Nuisance Algae ◽  
The Impact

The aim of this review is to identify problems, find general patterns, and extract recommendations for successful management using nontraditional biomanipulation to improve water quality. There are many obstacles that prevent traditional biomanipulation from achieving expectations: expending largely to remove planktivorous fish, reduction of external and internal phosphorus, and macrophyte re-establishment. Grazing pressure from large zooplankton is decoupled in hypereutrophic waters where cyanobacterial blooms flourish. The original idea of biomanipulation (increased zooplankton grazing rate as a tool for controlling nuisance algae) is not the only means of controlling nuisance algae via biotic manipulations. Stocking phytoplanktivorous fish may be considered to be a nontraditional method; however, it can be an effective management tool to control nuisance algal blooms in tropical lakes that are highly productive and unmanageable to reduce nutrient concentrations to low levels.Although small enclosures increase spatial overlap between predators and prey, leading to overestimates of the impact of predation, microcosm and whole-lake experiments have revealed similar community responses to major factors that regulate lake communities, such as nutrients and planktivorous fish. Both enclosure experiments and large-scale observations revealed that the initial phytoplankton community composition greatly impacted the success of biomanipulation. Long-term observations in Lake Donghu and Lake Qiandaohu have documented that silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) (two filter-feeding planktivorous species commonly used in management) can suppress Microcystis blooms efficiently. The introduction of silver and bighead carp could be an effective management technique in eutrophic systems that lack macrozooplankton. We confirmed that nontraditional biomanipulation is only appropriate if the primary aim is to reduce nuisance blooms of large algal species, which cannot be controlled effectively by large herbivorous zooplankton. Alternatively, this type of biomanipulation did not work efficiently in less eutrophic systems where nanophytoplankton dominated.

scholarly journals Hydrological and hydrochemical underpinnings of primary production and division of the Russian sector in the Gdansk basin of the Baltic sea

2019 ◽  
Vol 59 (1) ◽  
pp. 56-71
Author(s):  
E. A. Kudryavtseva ◽  
S. V. Aleksandrov
Keyword(s):  
Primary Production ◽  
Baltic Sea ◽  
Marine Environment ◽  
Bottom Topography ◽  
Water Area ◽  
Nutrient Concentrations ◽  
The Baltic Sea ◽  
Environment Temperature ◽  
Russian Sector ◽  
The Baltic

The distribution patterns of absolute and specific values of primary production in the upper 10-m layer depending on the physical and chemical condition of the marine environment (temperature, salinity, depth, bottom topography and configuration of the coastline, and nutrient concentrations) were distinguished in the Russian sector in the Gdansk Basin of the Baltic Sea based on long-term research data (2003–2015). Based on the results, the considered water area was divided into five regions: Cape Taran, the base of the Curonian Spit, the plateau of Rybachy, the open sea, and the Gdansk Bay (northeastern part). These regions are characterized by higher correlations of primary production and parameters of the marine environment compared to regression analysis for the regions distinguished by bathymetry. Primary production is the most closely correlated with temperature over the entire water area and with nutrients concentrations in seaward regions.

An analysis of primary production in the Daly River, a relatively unimpacted tropical river in northern Australia

2005 ◽  
Vol 56 (3) ◽  
pp. 303 ◽  
Author(s):  
I. T. Webster ◽  
N. Rea ◽  
A. V. Padovan ◽  
P. Dostine ◽  
S. A. Townsend ◽  
...  
Keyword(s):  
Primary Production ◽  
Plant Biomass ◽  
Net Primary Production ◽  
Low Flow ◽  
Nutrient Concentrations ◽  
Tight Coupling ◽  
Tropical River ◽  
Rate Of Photosynthesis ◽  
Curve Method ◽  
Tropical Australia

In this paper, the dynamics of primary production in the Daly River in tropical Australia are investigated. We used the diurnal-curve method for both oxygen and pH to calculate photosynthesis and respiration rates as indicators of whole-river productivity. The Daly River has maximum discharges during the summer, monsoonal season. Flow during the dry season is maintained by groundwater discharge via springs. The study investigated how primary production and respiration evolve during the period of low flow in the river (April–November). The relationship between primary production and the availability of light and nutrients enabled the role of these factors to be assessed in a clear, oligotrophic tropical river. The measured rate of photosynthesis was broadly consistent with the estimated mass of chlorophyll associated with the main primary producers in the river (phytoplankton, epibenthic algae, macroalgae, macrophytes). A significant result of the analysis is that during the time that plant biomass re-established after recession of the flows, net primary production proved to be ~4% of the rate of photosynthesis. This result and the observed low-nutrient concentrations in the river suggest a tight coupling between photosynthetic fixation of carbon and the microbial degradation of photosynthetic products comprising plant material and exudates.

Plasma thyroid hormones during smoltification of yearling and underyearling coho salmon and yearling chinook salmon and steelhead trout

Aquaculture ◽  
1982 ◽  
Vol 28 (1-2) ◽  
pp. 39-48 ◽  
Author(s):  
Walton W. Dickhoff ◽  
Leroy C. Folmar ◽  
James L. Mighell ◽  
Conrad V.W. Mahnken
Keyword(s):  
Thyroid Hormones ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Steelhead Trout

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.

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