scholarly journals Environmental DNA for the enumeration and management of Pacific salmon

2018 ◽  
Author(s):  
Taal Levi ◽  
Jennifer M. Allen ◽  
Donovan Bell ◽  
John Joyce ◽  
Joshua R. Russell ◽  
...  

AbstractPacific salmon are a keystone resource in Alaska, generating annual revenues of well over ∼US$500 million/yr. Due to their anadromous life history, adult spawners distribute amongst thousands of streams, posing a huge management challenge. Currently, spawners are enumerated at just a few streams because of reliance on human counters and, rarely, sonar. The ability to detect organisms by shed tissue (environmental DNA, eDNA) promises a more efficient counting method. However, although eDNA correlates generally with local fish abundances, we do not know if eDNA can accurately enumerate salmon. Here we show that daily, and near-daily, flow-corrected eDNA rate closely tracks daily numbers of returning sockeye and coho spawners and outmigrating sockeye smolts. eDNA thus promises accurate and efficient enumeration, but to deliver the most robust numbers will need higher-resolution stream-flow data, at-least-daily sampling, and a focus on species with simple life histories, since shedding rate varies amongst jacks, juveniles, and adults.

2015 ◽  
Vol 76 (13) ◽  
Author(s):  
Siraj Muhammed Pandhiani ◽  
Ani Shabri

In this study, new hybrid model is developed by integrating two models, the discrete wavelet transform and least square support vector machine (WLSSVM) model. The hybrid model is then used to measure for monthly stream flow forecasting for two major rivers in Pakistan. The monthly stream flow forecasting results are obtained by applying this model individually to forecast the rivers flow data of the Indus River and Neelum Rivers. The root mean square error (RMSE), mean absolute error (MAE) and the correlation (R) statistics are used for evaluating the accuracy of the WLSSVM, the proposed model. The results are compared with the results obtained through LSSVM. The outcome of such comparison shows that WLSSVM model is more accurate and efficient than LSSVM.


1937 ◽  
Vol 18 (2) ◽  
pp. 419
Author(s):  
F. T. Mavis ◽  
Edward Soucek
Keyword(s):  

1998 ◽  
Vol 55 (S1) ◽  
pp. 104-118 ◽  
Author(s):  
L P Hansen ◽  
T P Quinn

Atlantic salmon (Salmo salar) are distributed over large areas in the north Atlantic Ocean. They usually move very quickly from freshwater to oceanic areas, whereas there is considerable variation among Pacific salmon in early marine movements. In some areas, Atlantic salmon of exploitable size are sufficiently abundant that commercial high seas fisheries have developed. Such areas are off west Greenland, where North American and European fish are harvested, and in the Norwegian Sea, north of the Faroe Islands, where mainly European fish are exploited. Atlantic salmon feed on a wide range of large crustaceans, pelagic fish, and squid in the marine environment, supporting the hypothesis that Atlantic salmon are opportunistic feeders. In the ocean the salmon grow relatively quickly and the sea age when they become sexually mature depends on both genetics and on growing conditions. Natural marine mortality of salmon is highest during the first few months at sea and the major mortality factor is probably predation. However, marine mortality of Atlantic salmon has increased in recent years, apparently correlated with a decline in sea surface temperatures. Similar relationships between environmental conditions and the growth and survival of Pacific salmon have been reported. Atlantic salmon life histories most closely mimic stream-type chinook salmon or steelhead trout among the Pacific species. Finally, Atlantic and Pacific salmon return to their home rivers with high precision and possible mechanisms controlling the oceanic homing migration are presented and discussed.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 579
Author(s):  
Thomas Papalaskaris ◽  
Theologos Panagiotidis

Only a few scientific research studies, especially dealing with extremely low flow conditions, have been compiled so far, in Greece. The present study, aiming to contribute in this specific area of hydrologic investigation, generates synthetic low stream flow time series of an entire calendar year considering the stream flow data recorded during a center interval period of the year 2015. We examined the goodness of fit tests of eleven theoretical probability distributions to daily low stream flow data acquired at a certain location of the absolutely channelized urban stream which crosses the roads junction formed by Iokastis road an Chrisostomou Smirnis road, Agios Loukas residential area, Kavala city, NE Greece, using a 3-inches conventional portable Parshall flume and calculated the corresponding probability distributions parameters. The Kolmogorov-Smirnov, Anderson-Darling and Chi-Squared, GOF tests were employed to show how well the probability distributions fitted the recorded data and the results were demonstrated through interactive tables providing us the ability to effectively decide which model best fits the observed data. Finally, the observed against the calculated low flow data are plotted, compiling a log-log scale chart and calculate statistics featuring the comparison between the recorded and the forecasted low flow data.


2019 ◽  
Vol 19 (3) ◽  
pp. 597-608 ◽  
Author(s):  
Taal Levi ◽  
Jennifer M. Allen ◽  
Donovan Bell ◽  
John Joyce ◽  
Joshua R. Russell ◽  
...  

FACETS ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 300-314 ◽  
Author(s):  
Nick Gayeski ◽  
Misty MacDuffee ◽  
Jack A. Stanford

The identification of sustainably managed fisheries is problematic for marketers and consumers of Pacific salmon food products owing to lack of well-defined and robust criteria that take into account current ecosystem science of salmon. We present the rationale for an alternative conceptual framework for salmon management that supports the development of sustainable sourcing criteria. Our approach contrasts with current large-scale fisheries certification programs such as that of the Marine Stewardship Council (MSC) and general consumer recommendation services such as Monterey Bay Aquarium’s Seafood Watch (SFW) program. Our framework is based on the “place-based” character of salmon populations and recognition of fundamental aspects of salmon ecology, particularly the evolution of population life histories that are locally adapted to freshwater spawning and rearing habitats. We describe how this framework underpins development of science-based sourcing criteria and how it differs in important respects from the industrial approach that historically and currently is the basis for most salmon management. We conclude with a discussion of how the framework and its application may provide a model for redirecting salmon management, in general, towards a more science- and place-based approach and why that is likely to be sustainable in the long term in a way that most contemporary salmon management is not.


<em>Abstract.—</em>We understand our environment through our senses and tend to interpret the behavior of other animals in the context of the world we understand. Butterflies and flowers sometimes show distinctive patterns in ultraviolet light that are important to them but invisible to us. Likewise, the senses of fish and their experience of the world are very different from ours. Many aspects of a salmon’s environment, such as olfactory stimuli, are completely invisible to us. Other factors, like certain aspects of habitat alteration, are visible but unnoticed because they occurred gradually or long ago. Like Poe’s purloined letter they are cryptic—there for us to see if we only knew what to look for. As we build salmon models we base them on what we understand is important to the fish. However, our anthropocentric bias may cause us to overlook or misinterpret factors of importance. In addition, our necessarily simplified models, when applied to management, may result in a pernicious simplification of the salmon populations we wish to preserve. For example, if we model and manage for a dominant (or highly visible or easily monitored) salmon life history we may inadvertently eliminate other life histories of equal importance, or reduce diversity in ways that affect population viability. We should actively seek to identify important factors missing from our models and be aware of critical assumptions. Recognizing that our models are tools used to understand and manage salmon, we should try to understand the broader implications of these models to the future of the salmon we hope to preserve. In this essay, I offer speculation about what we may be missing in freshwater habitat, life history diversity, metapopulation dynamics, ocean survival, and water chemistry. I also consider the question of scale, and the effect our philosophical viewpoint may have on the direction and application of our modeling efforts and the likelihood of successful outcomes.


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