The response of zooplankton in a whole-lake experiment on the effects of a cage aquaculture operation for rainbow trout (Oncorhynchus mykiss)

2010 ◽  
Vol 67 (11) ◽  
pp. 1852-1861 ◽  
Author(s):  
Michael J. Paterson ◽  
Cheryl L. Podemski ◽  
Wilhelmina J. Findlay ◽  
David L. Findlay ◽  
Alex G. Salki
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Egg Production ◽  
Crustacean Zooplankton ◽  
Zooplankton Community Structure ◽  
Ecosystem Impacts ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Freshwater Aquaculture ◽  
Multiple Variables ◽  
Cage Aquaculture

There is hope that increased development of aquaculture will help meet future global needs for protein. The growth of the freshwater aquaculture industry in Canada, however, has been hampered by insufficient information on environmental impacts. We examined the effects of an experimental cage aquaculture operation for rainbow trout ( Oncorhynchus mykiss ) on planktonic Crustacea and rotifers using 6 years of precage and 7 years of postcage data. Following the initiation of aquaculture, total crustacean and rotifer biomass, egg production, and depth distributions did not change significantly when compared with data from three nearby unimpacted lakes. We found statistically detectable increases in densities of Bosmina  cf.  longirostris and Diacyclops thomasi and an overall change in crustacean zooplankton community structure using correspondence analysis. The response of zooplankton was less than we expected because comparatively large changes were observed in phytoplankton biomass, hypolimnetic O2, and densities of invertebrate ( Mysis diluviana ) and fish predators. Our study emphasizes the need to monitor multiple variables when assessing the ecosystem impacts of potential stressors such as aquaculture.

Broodstock management, fecundity, egg quality and the timing of egg production in the rainbow trout (Oncorhynchus mykiss)

Aquaculture ◽  
1992 ◽  
Vol 100 (1-3) ◽  
pp. 141-166 ◽  
Author(s):  
Niall Bromage ◽  
John Jones ◽  
Clive Randall ◽  
Mark Thrush ◽  
Briony Davies ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Egg Production ◽  
Egg Quality ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Broodstock Management

Effects of an experimental rainbow trout (Oncorhynchus mykiss) farm on invertebrate community compositionThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 1949-1964 ◽  
Author(s):  
Rebecca C. Rooney ◽  
Cheryl L. Podemski
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Rank Correlation ◽  
Organic Loading ◽  
Experimental Lakes Area ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Northwestern Ontario ◽  
Freshwater Aquaculture ◽  
Invertebrate Abundance ◽  
Production Cycles

We examined the development of changes in the zoobenthos along a transect from an experimental rainbow trout ( Oncorhynchus mykiss ) farm in Lake 375, Experimental Lakes Area, northwestern Ontario, Canada. After 2 months, invertebrate abundance was reduced under the fish cage (2542 ± 569 individuals·m–2) compared with samples collected 45 m away (16 137 ± 2624 individuals·m–2). Taxa richness was also depressed, but changes in biomass were variable. Reductions in abundance and richness at high organic loading levels are consistent with earlier models developed for the marine environment of responses to organic loading in marine systems. After two production cycles, the significant principal components axis explaining 76% of total variance in abundance was correlated with distance from the cage (Spearman rank correlation, r = –0.775, p = 0.014) and with chemical variables recommended for freshwater aquaculture monitoring (Pearson’s correlation coefficient, r = 0.78, 0.76, and 0.75 with p = 0.013, 0.018, and 0.020 for pore-water ammonia and sediment Cu and Zn, respectively). The effects of farming were localized, dissipating within 15 m of the cage edge. Invertebrate abundance demonstrated the most potential for incorporation into monitoring schemes at new farms. At established farms, richness may be a valuable monitoring metric.

Morphological changes in rainbow trout (Oncorhynchus mykiss) gill epithelia following repeated intermittent exposure to chloramine-T

1995 ◽  
Vol 73 (1) ◽  
pp. 154-165 ◽  
Author(s):  
Mark D. Powell ◽  
David J. Speare ◽  
Glenda M. Wright
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Morphological Changes ◽  
Experimental Period ◽  
Chloride Cells ◽  
Compensatory Mechanism ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Freshwater Aquaculture ◽  
Intermittent Exposure ◽  
Chloramine T

Chloramine-T is a widely used prophylactic and therapeutic agent in freshwater aquaculture. This study examined the effects of repeated intermittent exposure of healthy rainbow trout (Oncorhynchus mykiss) fingerlings to sublethal concentrations of chloramine-T (0, 5, 10, or 20 mg/L) twice weekly in 1-h pulses at 11 °C for 4 weeks in a replicate-tank facility. Gills were excised from subsamples of fish prior to exposure and at the end of the 4-week experimental period. Tissue was fixed and processed for light microscopy and transmission and scanning electron microscopy. The gill epithelium from fish treated with 10 and 20 mg/L chloramine-T appeared swollen and vacuolated, with extensive intercellular edema. There was a significant reduction in the number of lamellar mucous cells and an apparent increase in the numbers of chloride cells. Chloride cells from both the base of the lamella and the lamellar surface of gills exposed to chloramine-T had a significant increase in the area of the apical plasmalemma after treatment with 10 and 20 mg/L, and a reduction in the thickness of the apical plasmalemma-associated glycocalyx. These morphological changes are consistent with a compensatory mechanism for the remedial uptake of ions, suggesting that chloramine-T increased epithelial ion permeability coincident with a possible influx of water leading to intercellular edema. Chloride cell proliferation and intercellular edema may also have affected gas exchange across the branchial epithelium.

Survival and behaviour of rainbow trout (Oncorhynchus mykiss) released from an experimental aquaculture operationThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 1976-1988 ◽  
Author(s):  
Paul J. Blanchfield ◽  
Lori S. Tate ◽  
Cheryl L. Podemski
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
High Growth ◽  
High Growth Rate ◽  
Normal Operation ◽  
Farmed Fish ◽  
Experimental Lakes Area ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Study Lake ◽  
Cage Aquaculture

The potential for farmed fish that have escaped from open-cage aquaculture operations to affect native populations will depend on their survival and behaviour in the wild. We used standard commercial practices to rear 10 tonnes of rainbow trout ( Oncorhynchus mykiss ) in a 23 ha lake at the Experimental Lakes Area (Ontario, Canada). Each fall (2003–2005), we released farmed rainbow trout (escapees) into the study lake and monitored their movements using automated positioning telemetry. Rainbow trout experienced high annual mortality (~50%), with none surviving beyond 3 years. Farmed fish had narrowly defined pelagic distributions that comprised the upper few metres of the water column, even when at the cage site. Although released rainbow trout dispersed throughout the study lake, most spent significant portions of time at the cage site, especially during normal operation when commercial feed was available. Core use areas (50% Kernel) included the farm for half of the released fish. Surviving rainbow trout showed continued reliance upon the cage site in their second year. However, wide dispersal, high growth rate, and lack of reliance on the cage site by some escaped fish warrant further research to assess potential effects of open-cage aquaculture in the water bodies where the industry occurs.

The essential oils of some medicinal plants on the immune system of rainbow trout (Oncorhynchus mykiss)

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
A Ghasemi Pirbalouti ◽  
E Pirali ◽  
G Pishkar ◽  
S Mohammadali Jalali ◽  
M Reyesi ◽  
...  
Keyword(s):  
Immune System ◽  
Rainbow Trout ◽  
Medicinal Plants ◽  
Oncorhynchus Mykiss ◽  
Essential Oils ◽  
Rainbow Trout Oncorhynchus Mykiss
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