Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity

2003 ◽  
Keyword(s):  
Primary Production ◽  
Sockeye Salmon ◽  
Secchi Depth ◽  
Zooplankton Biomass ◽  
Snake River ◽  
Forage Production ◽  
Meteorological Forcing ◽  
Kokanee Salmon ◽  
Compensation Depth ◽  
Large Populations

<em>Abstract.</em>—Snake River sockeye salmon <em>Oncorhynchus nerka </em>once inhabited five prealpine lakes in the Sawtooth Valley, Idaho, but are presently reduced to the Redfish Lake stock. Declining returns to Redfish Lake in the 1980s prompted the National Marine Fisheries Service to list Snake River sockeye salmon as endangered under the Endangered Species Act, and a multi-agency effort was initiated in 1991 to prevent their extinction. The recovery effort focused on the development of a captive broodstock coupled with evaluation and enhancement of nursery lake habitats. Large populations of nonendemic kokanee salmon <em>O. nerka </em>and the oligotrophic conditions of these lakes raised concerns about overstocking sockeye salmon and causing the collapse of macrozooplankton populations. To minimize these risks and to improve sockeye salmon forage production, the Shoshone- Bannock Tribes initiated a 4-year nutrient enrichment program in Redfish Lake. Liquid fertilizer (20:1, N:P by wt) was added weekly during the growing season from 1995 to 1998 to the surface of Redfish Lake with Stanley Lake (unfertilized) acting as a control. During the fertilization of Redfish Lake, Secchi depth decreased by 13% and compensation depth by 24%, while increases were observed for surface chlorophyll <em>a </em>(106%) and primary production (117%). Uniformity of phytoplankton communities throughout the experiment indicated that the Redfish Lake food web was efficient (without major carbon sinks) and improved forage conditions for macrozooplankton. Total macrozooplankton biomass increased 31%, and <em>Daphnia </em>spp<em>. </em>biomass increased by 225%, simultaneous to a 26% increase in <em>O. nerka </em>density. Also, during fertilization, overwinter survival of supplemented sockeye salmon increased 192% in Redfish Lake. However, meteorological conditions were partly responsible for these changes. In unfertilized Stanley Lake, during the same time periods, Secchi depth declined 27%, and compensation depth was reduced by 28%; chlorophyll <em>a </em>increased 16%, primary production increased 14%, and zooplankton biomass was stable. These changes highlight the importance of climate (meteorological forcing) and the need for a control when attempting to identify impacts from lake fertilization. Disproportionately larger increases in Redfish Lake chlorophyll <em>a</em>, primary productivity, and zooplankton biomass relative to observed changes in Stanley Lake provide evidence for the efficacy of nutrient supplementation in Redfish Lake.

Sounding Response of the Kokanee and Sockeye Salmon

1968 ◽  
Vol 25 (6) ◽  
pp. 1115-1131 ◽  
Author(s):  
H. H. Harvey ◽  
W. S. Hoar ◽  
C. R. Bothern
Keyword(s):  
Sockeye Salmon ◽  
Bladder Wall ◽  
Muscle Fibers ◽  
Circular Muscle ◽  
Adrenergic Blockade ◽  
Kokanee Salmon ◽  
Associated Gas ◽  
Treated Fish ◽  
Gas Loss ◽  
Adrenergic Blocking

When frightened, sockeye and kokanee salmon dive into deeper waters. This is termed the "sounding response."The sounding response in these fish is accompanied by the expulsion of gas from the swimbladder via the pneumatic duct. This gas loss is active and results from the contraction of the circular muscle fibers in the wall of the swimbladder.Gas loss on sounding is reduced or obviated after exposure to adrenergic blocking agents and enhanced in fish treated with sympathomimetics. Circular muscle fibers in intact and isolated strips of swimbladder contracted in response to sympathomimetics, but this response was prevented after adrenergic blockade. These results suggest the concentration of the swimbladder and associated gas expulsion is under adrenergic control.In untreated fish, an average pressure of 28.1 mm Hg was required to force gas out of the swimbladder through the pneumatic duct. In antropine-treated fish this duct-release pressure fell to an average of 0.2 mm Hg. This suggests constriction of the pneumatic duct is under cholinergic control.Histologically, the pneumatic duct was continuous with the oesophagus and extended as a convoluted duct to the anterior end of the swimbladder. Smooth muscle fibers surrounded the duct along its length and some striated fibers were present at the point where the duct joined the oesophagus. Occlusion of the pneumatic duct may be through the contraction of either of these types of fibers.The term "Gasspuckreflex" as originally used by Franz described the loss of gas from the swimbladder of physostomes in response to decompression. The authors suggest this term be reserved for this passive loss of gas, and not applied to fright-induced gas loss, resulting from active contraction of the bladder wall.

scholarly journals Large deep-sea zooplankton biomass mirrors primary production in the global ocean

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Hernández-León ◽  
R. Koppelmann ◽  
E. Fraile-Nuez ◽  
A. Bode ◽  
C. Mompeán ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Deep Sea ◽  
Large Scale ◽  
Net Primary Production ◽  
Deep Ocean ◽  
Zooplankton Biomass ◽  
Global Ocean ◽  
Global Coupling ◽  
Do So

AbstractThe biological pump transports organic carbon produced by photosynthesis to the meso- and bathypelagic zones, the latter removing carbon from exchanging with the atmosphere over centennial time scales. Organisms living in both zones are supported by a passive flux of particles, and carbon transported to the deep-sea through vertical zooplankton migrations. Here we report globally-coherent positive relationships between zooplankton biomass in the epi-, meso-, and bathypelagic layers and average net primary production (NPP). We do so based on a global assessment of available deep-sea zooplankton biomass data and large-scale estimates of average NPP. The relationships obtained imply that increased NPP leads to enhanced transference of organic carbon to the deep ocean. Estimated remineralization from respiration rates by deep-sea zooplankton requires a minimum supply of 0.44 Pg C y−1 transported into the bathypelagic ocean, comparable to the passive carbon sequestration. We suggest that the global coupling between NPP and bathypelagic zooplankton biomass must be also supported by an active transport mechanism associated to vertical zooplankton migration.

Proliferative kidney disease and Sphaerospora oncorhynchi in wild-caught salmonids from the Puntledge River system, Vancouver Island, British Columbia

1995 ◽  
Vol 52 (S1) ◽  
pp. 13-17 ◽  
Author(s):  
M.L. Kent ◽  
M. Higgins ◽  
D.J. Whitaker ◽  
H. Yokoyama
Keyword(s):  
British Columbia ◽  
Kidney Disease ◽  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Natural Infection ◽  
Vancouver Island ◽  
Renal Tubules ◽  
Kokanee Salmon ◽  
Proliferative Kidney Disease ◽  
Sexually Mature

Proliferative kidney disease (PKD), caused by the PKX myxosporean, was observed in kokanee salmon (non-anadromous sockeye salmon) (Oncorhynchus nerka) and chinook salmon (O. tshawytscha) collected from the Puntledge River, Vancouver Island, British Columbia in July 1993. This is the first report of a natural infection of PKX in either captive or wild sockeye salmon. All 14 underyearling kokanee salmon and the one underyearling chinook salmon exhibited numerous PKX organisms and associated chronic inflammation in the renal interstitium. Thirty-eight percent of sexually mature kokanee salmon collected in the autumn of 1993 from Comox Lake (which drains into the Puntledge River) were infected with Sphaerospora oncorhynchi, Kent, Whitaker and Margolis, 1993 in the renal tubules, while immature cutthroat trout (O. clarki) and coho salmon (O. kisutch) from the same collection did not exhibit myxosporean spores in the kidney. The kidneys of threespine stickleback (Gasterosteus aculeatus) and prickly sculpin (Cottus asper) collected from the Puntledge River during the summer were all infected with a Myxobilatus sp., but no organisms suggestive of PKX or Sphaerospora were observed. This study further supports the hypothesis that PKX is a developmental stage of S. oncorhynchi, which may sporulate only in sexually mature salmonids.

Salmon-mediated nutrient flux in Snake River sockeye salmon nursery lakes: the influence of depressed population size and hatchery supplementation

2019 ◽  
Vol 36 (1) ◽  
pp. 75-86
Author(s):  
Melissa L. Evans ◽  
Andre E. Kohler ◽  
Robert G. Griswold ◽  
Kurt A. Tardy ◽  
Kendra R. Eaton ◽  
...  
Keyword(s):  
Population Size ◽  
Sockeye Salmon ◽  
Nutrient Flux ◽  
Snake River ◽  
Hatchery Supplementation

scholarly journals Biogeochemical versus ecological consequences of modeled ocean physics

2017 ◽  
Vol 14 (11) ◽  
pp. 2877-2889 ◽  
Author(s):  
Sophie Clayton ◽  
Stephanie Dutkiewicz ◽  
Oliver Jahn ◽  
Christopher Hill ◽  
Patrick Heimbach ◽  
...  
Keyword(s):  
Primary Production ◽  
Ocean Circulation ◽  
Mixed Layer ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Resource Competition ◽  
Nutrient Supply ◽  
Zooplankton Biomass ◽  
Global Ocean ◽  
Competition Theory

Abstract. We present a systematic study of the differences generated by coupling the same ecological–biogeochemical model to a 1°, coarse-resolution, and 1∕6°, eddy-permitting, global ocean circulation model to (a) biogeochemistry (e.g., primary production) and (b) phytoplankton community structure. Surprisingly, we find that the modeled phytoplankton community is largely unchanged, with the same phenotypes dominating in both cases. Conversely, there are large regional and seasonal variations in primary production, phytoplankton and zooplankton biomass. In the subtropics, mixed layer depths (MLDs) are, on average, deeper in the eddy-permitting model, resulting in higher nutrient supply driving increases in primary production and phytoplankton biomass. In the higher latitudes, differences in winter mixed layer depths, the timing of the onset of the spring bloom and vertical nutrient supply result in lower primary production in the eddy-permitting model. Counterintuitively, this does not drive a decrease in phytoplankton biomass but results in lower zooplankton biomass. We explain these similarities and differences in the model using the framework of resource competition theory, and find that they are the consequence of changes in the regional and seasonal nutrient supply and light environment, mediated by differences in the modeled mixed layer depths. Although previous work has suggested that complex models may respond chaotically and unpredictably to changes in forcing, we find that our model responds in a predictable way to different ocean circulation forcing, despite its complexity. The use of frameworks, such as resource competition theory, provides a tractable way to explore the differences and similarities that occur. As this model has many similarities to other widely used biogeochemical models that also resolve multiple phytoplankton phenotypes, this study provides important insights into how the results of running these models under different physical conditions might be more easily understood.

Phytoplankton Succession and Primary Production in Babine Lake, British Columbia

1975 ◽  
Vol 32 (12) ◽  
pp. 2413-2427 ◽  
Author(s):  
John G. Stockner ◽  
K. R. S. Shortreed
Keyword(s):  
Primary Production ◽  
Sockeye Salmon ◽  
Mixed Layer Depth ◽  
Carbon Assimilation ◽  
Annual Production ◽  
Phosphate Limitation ◽  
The South ◽  
South Basin ◽  
The North ◽  
Principal Factors

Ten stations located in six zones (subbasins) were sampled biweekly from May to October 1973 to detect possible regional differences in production in this large, 155 km long, dystrophic lake. The spring bloom occurred in all zones while a fall bloom occurred only in Zones 5 and 6. Carbon assimilation showed two peaks in south basin zones, but only one (spring) at zones north of Topley Landing. Seasonal variation in phytoplankton numbers and volume, seston, and chlorophyll a followed a pattern similar to that noted for primary production. Mean production was 100 mg C∙m−2∙day−1 in Zones 1–4, but was 145 in Zones 5 and 6. Annual production was estimated at 25 g C∙m−2 in the north basin and 40 in the south basin. Reasons for the regional disparities are discussed, with greatest significance given to regional variations in mixed layer depth, surface inflows (loading), and basin mean depth. The development and sustainment of the autumnal bloom of Tabellaria fenestrata is thought to be one of the principal factors responsible for greater production in the south basin.An estimated 0.05 g TP∙m−2 enters the lake yearly. This can vary depending on the return of adult sockeye salmon (Oncorhynchus nerka), whose carcasses contribute up to 20% of the total. An estimated 30% is lost via the Babine River, and it is speculated that of the remaining 70%, most is lost to the sediments. Phosphate limitation is implied as a chief factor limiting primary production in the north basin stations, but not in the south basin. On the basis of total phosphorus load the lake is classed as oligotrophic, but in terms of annual production and its humic stained waters it is more correctly considered mixotrophic.

Temperature, flow, and the migration of adult sockeye salmon (Oncorhynchus nerka) in the Columbia River

1997 ◽  
Vol 54 (6) ◽  
pp. 1349-1360 ◽  
Author(s):  
Thomas P Quinn ◽  
Sayre Hodgson ◽  
Charles Peven
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Columbia River ◽  
Water Velocity ◽  
River Ice ◽  
Snake River ◽  
Arrival Date ◽  
Temperature Regimes ◽  
Arrival Timing ◽  
Travel Rate

We related the arrival timing of adult sockeye salmon (Oncorhynchus nerka) at a series of dams on the Columbia River (Bonneville, McNary, and Rock Island) and Snake River (Ice Harbor) to the changing flow and temperature regimes over the last several decades. The temperatures experienced by sockeye salmon have increased in the lower but not upper reaches of the system, and the flows experienced by the fish have decreased. The Bonneville-McNary travel rate increased from about 22 to 49 km/day, and sockeye salmon now pass McNary Dam about 11 days earlier than in 1954. Both travel rate and arrival date were correlated with temperature increases and flow decreases at McNary during that period. Sockeye salmon arrival at Rock Island Dam (14 days earlier from 1933 to 1994) was also correlated with temperature and flow there. However, the travel rate between McNary and Rock Island dams did not change from 1955 to 1994, despite a decrease in estimated water velocity from 85 to 23 km/day. Sockeye salmon arrival at Ice Harbor Dam has sometimes been bimodal; the first mode's date has not changed, but annual mean dates have been positively correlated with flow and negatively with temperature.

"Residual" and kokanee salmon in Cultus lake

1938 ◽  
Vol 4a (3) ◽  
pp. 192-218 ◽  
Author(s):  
W. E. Ricker
Keyword(s):  
Sockeye Salmon ◽  
Anadromous Fish ◽  
Kokanee Salmon ◽  
Rate Of Growth

The sockeye salmon in Cultus lake are of three kinds: (1) the normal anadromous stock, (2) a "residual" group, not anadromous, but largely or perhaps wholly the progeny of anadromous fish, and (3) a stock of non-anadromous kokanee, which have no known connection with the anadromous or residual fish at the present time. Morphological and physiological peculiarities distinguish the three kinds of sockeye at maturity. In the segregation of the progeny of a spawning of anadromous fish into migrant and residual groups, rate of growth and sex play a determining role.

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