Inferring sockeye salmon (Oncorhynchus nerka) population dynamics and water quality changes in a stained nursery lake over the past ∼500 years

2004 ◽  
Vol 61 (7) ◽  
pp. 1235-1246 ◽  
Author(s):  
Irene Gregory-Eaves ◽  
Bruce P Finney ◽  
Marianne SV Douglas ◽  
John P Smol
Keyword(s):  
Population Dynamics ◽  
Sockeye Salmon ◽  
Environmental Changes ◽  
Oncorhynchus Nerka ◽  
The Past ◽  
The North ◽  
Salmon Population ◽  
High Concentrations ◽  
The North Pacific ◽  
Multiproxy Approach

Historical and paleolimnological studies have demonstrated that environmental changes in the North Pacific can strongly affect sockeye salmon (Oncorhynchus nerka) abundances. Whether these marine shifts would be influential on sockeye salmon from all lake types, however, has not yet been studied. This study represents the first paleolimnological analysis of past sockeye salmon population dynamics in a stained nursery lake (Packers Lake, Alaska). We adopted a multiproxy approach to determine whether salmon-derived nutrients (inferred from δ15N) would be available for algal uptake (inferred from the diatom species responses) in this stained lake, as high concentrations of humics and iron are known to sequester phosphorus. The strong degree of coherency between δ15N and diatoms, however, suggests that salmon-derived nutrients were bioavailable and enhanced productivity. Overall, our indicators responded to changes in sockeye salmon abundances and volcanic ashfalls over the past ∼500 years. In a section of the core unaffected by tephras (AD ∼1770–1882), our record suggests that the number of sockeye salmon spawners fluctuated widely. Comparison of temporal shifts in inferred sockeye salmon abundances from Packers Lake with other clearwater nursery lakes reveals a broadly consistent pattern, likely influenced by past climatic changes.

scholarly journals Sockeye salmon population dynamics over the past 4000 years in Upper Russian Lake, south-central Alaska

2018 ◽  
Vol 60 (1) ◽  
pp. 67-75
Author(s):  
Molly D. McCarthy ◽  
Daniel J. Rinella ◽  
Bruce P. Finney
Keyword(s):  
Population Dynamics ◽  
Sockeye Salmon ◽  
The Past ◽  
South Central ◽  
Salmon Population

Density-dependent predation by brown bears (Ursus arctos) on sockeye salmon (Oncorhynchus nerka)

2003 ◽  
Vol 60 (5) ◽  
pp. 553-562 ◽  
Author(s):  
T P Quinn ◽  
S M Gende ◽  
G T Ruggerone ◽  
D E Rogers
Keyword(s):  
Population Dynamics ◽  
Sockeye Salmon ◽  
Ursus Arctos ◽  
Oncorhynchus Nerka ◽  
Brown Bears ◽  
Density Dependent ◽  
Salmon Population ◽  
Average Proportion ◽  
Stream Size ◽  
Salmon Carcasses

The number of sockeye salmon (Oncorhynchus nerka) killed by brown bears (Ursus arctos) in 13 streams over more than a decade in southwestern Alaska was best explained by an asymptotic increase to about 3000 salmon killed per stream per year as salmon density increased to 10 000 fish·ha–1 of stream. Divergence from this pattern at some streams probably reflected variation in the number of bears using the stream (which we did not determine) and variation in salmon biomass consumed per fish killed. Daily surveys at one creek over 11 years revealed about 100–130 salmon killed per day, ranging from a few to over 600. Higher proportions of the available salmon were killed early and late in the season, when densities were low. Thus the number of salmon killed within and among years increased with salmon abundance but at a declining rate, and the proportion killed generally decreased. Our previous work indicated that the average proportion of salmon killed among streams was controlled mostly by stream size, affecting the ability of bears to catch salmon. These findings are important for understanding the effects of bears on salmon population dynamics and their role in the transport of nutrients from salmon carcasses.

scholarly journals Response Characteristics of Chinese Pine (Pinus tabulaeformis Carr.) Radial Growth to Climate and Drought Variability Reconstruction in Western Liaoning, Northeast China

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 752
Author(s):  
Liu ◽  
Bao ◽  
Bao
Keyword(s):  
Northeast China ◽  
Radial Growth ◽  
Pinus Tabulaeformis ◽  
Western Liaoning ◽  
Chinese Pine ◽  
The Past ◽  
The North ◽  
Pinus Tabulaeformis Carr ◽  
The North Pacific

Chinese pine (Pinus tabulaeformis Carr.) plays an important role in maintaining ecosystem health and stability in western Liaoning Province and the southern Horqin sand land, Northeast China, with benefits including sand fixation and soil erosion. In the context of climate change, developing a better understanding of the relationship between climate factors and growth rates of this species will be extremely valuable in guiding management activities and meeting regional conservation objectives. Here, the results based on two groups of tree-ring samples show that the radial growth of Chinese pine is controlled primarily by water conditions. The longer chronology had the highest correlation coefficient with the January–September mean self-calibrating Palmer Drought Severity Index (scPDSI); therefore, drought variability was reconstructed for the period 1859–2014. Statistical analysis showed that our model explained 41.9% of the variance in radial growth during the 1951–2014 calibration period. Extreme dry and wet events, defined as the criteria of one standard deviation less or greater than the mean value, accounted for 19.9% and 18.6% of the 156-year climate record, respectively. During the past century, the regional hydroclimate experienced significant long-term fluctuations. The dry periods occurred from the early-1900s–1930s and 1980s–2000s, and the wet periods occurred from the 1940s–1970s. The drought reconstruction was consistent with the decreasing trend of the East Asian summer monsoon since the late 1970s. The reconstructed temporal patterns in hydroclimate in western Liaoning were closely related to the large-scale climate drivers in the North Pacific and the tropical equatorial Pacific. The teleconnections were confirmed by spatial correlations between the reconstructed sequence and sea surface temperature (SST) in the North Pacific, as well as the correlations with the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) indices. Aerosols played an important role in affecting drought variations over the past several decades. Moisture stress caused by global warming and interdecadal changes in the PDO will have long-term effects on the growth of pines in the study area in the future.

A widespread decrease in productivity of sockeye salmon (Oncorhynchus nerka) populations in western North America

2012 ◽  
Vol 69 (8) ◽  
pp. 1255-1260 ◽  
Author(s):  
Randall M. Peterman ◽  
Brigitte Dorner
Keyword(s):  
Sockeye Salmon ◽  
Spatial Scales ◽  
Oncorhynchus Nerka ◽  
Geographic Area ◽  
Fraser River ◽  
Western North America ◽  
Southeast Alaska ◽  
The Past ◽  
Large Geographic Area ◽  
Marine Areas

We used data on 64 stocks of sockeye salmon ( Oncorhynchus nerka ) from British Columbia (B.C.), Washington, and Alaska to determine whether recent decreases in abundance and productivity observed for Fraser River, B.C., sockeye have occurred more widely. We found that decreasing time trends in productivity have occurred across a large geographic area ranging from Washington, B.C., southeast Alaska, and up through the Yakutat peninsula, Alaska, but not in central and western Alaska. Furthermore, a pattern of predominantly shared trends across southern stocks and opposite trends between them and stocks from western Alaska was present in the past (1950–1985), but correlations have intensified since then. The spatial extent of declining productivity of sockeye salmon has important implications for management as well as research into potential causes of the declines. Further research should focus on mechanisms that operate at large, multiregional spatial scales, and (or) in marine areas where numerous correlated sockeye stocks overlap.

scholarly journals High concentrations of black carbon over middle latitudes in the North Pacific Ocean

2000 ◽  
Vol 105 (D15) ◽  
pp. 19881-19890 ◽  
Author(s):  
Naoki Kaneyasu ◽  
Shohei Murayama
Keyword(s):  
Pacific Ocean ◽  
Black Carbon ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Middle Latitudes ◽  
The North ◽  
High Concentrations ◽  
The North Pacific

scholarly journals Using stable isotopes to infer stock‐specific high‐seas distribution of maturing sockeye salmon in the North Pacific

2020 ◽  
Vol 10 (23) ◽  
pp. 13555-13570
Author(s):  
Boris Espinasse ◽  
Brian P. V. Hunt ◽  
Bruce P. Finney ◽  
Jeffrey K. Fryer ◽  
Alexander V. Bugaev ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
North Pacific ◽  
Sockeye Salmon ◽  
The North ◽  
The North Pacific ◽  
High Seas

Did a Beringian ice sheet once exist?

2020 ◽  
Author(s):  
Zhongshi Zhang ◽  
Qing Yan ◽  
Ran Zhang ◽  
Florence Colleoni ◽  
Gilles Ramstein ◽  
...  
Keyword(s):  
North Pacific ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Climate Modelling ◽  
Mountain Glaciers ◽  
The Past ◽  
The North ◽  
Paleoclimate Records ◽  
Glacial Landforms ◽  
The North Pacific

<p>Did a Beringian ice sheet once exist? This question was hotly debated decades ago until compelling evidence for an ice-free Wrangel Island excluded the possibility of an ice sheet forming over NE Siberia-Beringia during the Last Glacial Maximum (LGM). Today, it is widely believed that during most Northern Hemisphere glaciations only the Laurentide-Eurasian ice sheets across North America and Northwest Eurasia became expansive, while Northeast Siberia-Beringia remained ice-sheet-free. However, recent recognition of glacial landforms and deposits on Northeast Siberia-Beringia and off the Siberian continental shelf has triggered a new round of debate.These local glacial features, though often interpreted as local activities of ice domes on continental shelves and mountain glaciers on continents,   could be explained as an ice sheet over NE Siberia-Beringia. Only based on the direct glacial evidence, the debate can not be resolved. Here, we combine climate and ice sheet modelling with well-dated paleoclimate records from the mid-to-high latitude North Pacific to readdress the debate. Our simulations show that the paleoclimate records are not reconcilable with the established concept of Laurentide-Eurasia-only ice sheets. On the contrary, a Beringian ice sheet over Northeast Siberia-Beringia causes feedbacks between atmosphere and ocean, the result of which well explains the climate records from around the North Pacific during the past four glacial-interglacial cycles. Our ice-climate modelling and synthesis of paleoclimate records from around the North Pacific argue that the Beringian ice sheet waxed and waned rapidly in the past four glacial-interglacial cycles and accounted for ~10-25 m ice-equivalent sea-level change during its peak glacials. The simulated Beringian ice sheet agrees reasonably with the direct glacial and climate evidence from Northeast Siberia-Beringia, and reconciles the paleoclimate records from around the North Pacific. With the Beringian ice sheet involved, the pattern of past NH ice sheet evolution is more complex than previously thought, in particular prior to the LGM.</p>

SOCKEYE SALMON ONCORHYNCHUS NERKA (WALBAUM) FROM THE NORTH-EASTERN CONTINENTAL COAST OF THE OKHOTSK SEA

2019 ◽  
pp. 49-58
Author(s):  
V.V. Volobuev ◽  
◽  
M.N. Gorokhov ◽  
I.S. Golovanov ◽  
L.L. Khovanskaya ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Okhotsk Sea ◽  
The North ◽  
Continental Coast ◽  
North Eastern
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