Advances in Fisheries Bioengineering

2008 ◽  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Spatial Scales ◽  
Habitat Type ◽  
Strain Rates ◽  
Habitat Types ◽  
Drift Feeding ◽  
Velocity Gradients ◽  
The Difference ◽  
Lateral Scale

Abstract<em>.</em>—Focal positions of drift-feeding salmonids are often proximate to higher velocities and may be characterized by velocity gradients. Velocity gradients result in distortion of the flow field through linear deformation and angular deformation, which are summarized as the normal and shear strain rates, respectively. The objective of our study was to use a metric termed the exposure strain rate to quantify velocity gradients used by juvenile spring Chinook salmon <em>Oncorhynchus tshawytscha </em>across habitat type, seasons, and spatial scales. Within a habitat type, focal and mean water column velocities were measured at the position of each fish. In addition, mean column velocities were measured 0.6 and 1.2 m laterally toward the center of the channel. Three exposure strain rates were calculated as the difference between focal and mean column velocity in the vertical scale and at 0.6 and 1.2 m lateral scale divided by the length of the smallest fish (0.4 cm) length scale for all seasons and habitat types. This allowed direct comparison of exposure strain rates for all sizes of fish. The data revealed that for Chinook salmon larger than 4 cm, the distribution of vertical exposure strain rates was similar across all habitat types by season. Exposure strain rates began to vary between habitat types for the lateral scale, reflecting hydraulic differences between reach-scale habitat features. We concluded that juvenile Chinook occupied a specific shear environment independent of reach-scale habitat. Exposure strain rates described microhabitat use in a manner reflecting the habitat occupancy model for drift-feeding salmonids. For this reason, exposure strain rates provide more specific information on habitat use than focal velocities alone.

scholarly journals Geomagnetic field influences upward movement of young Chinook salmon emerging from nests

2018 ◽  
Vol 14 (2) ◽  
pp. 20170752 ◽  
Author(s):  
Nathan F. Putman ◽  
Michelle M. Scanlan ◽  
Amanda M. Pollock ◽  
Joseph P. O'Neil ◽  
Ryan B. Couture ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Chinook Salmon ◽  
Geomagnetic Field ◽  
Oncorhynchus Tshawytscha ◽  
Dimensional Space ◽  
Spatial Scales ◽  
Vertical Component ◽  
Life Cycles ◽  
Upward Movement ◽  
The Magnetic Field

Organisms use a variety of environmental cues to orient their movements in three-dimensional space. Here, we show that the upward movement of young Chinook salmon ( Oncorhynchus tshawytscha ) emerging from gravel nests is influenced by the geomagnetic field. Fish in the ambient geomagnetic field travelled farther upwards through substrate than did fish tested in a field with the vertical component inverted. This suggests that the magnetic field is one of several factors that influences emergence from the gravel, possibly by serving as an orientation cue that helps fish determine which way is up. Moreover, our work indicates that the Oncorhynchus species are sensitive to the magnetic field throughout their life cycles, and that it guides their movements across a range of spatial scales and habitats.

scholarly journals Evidence of a ‘dinner bell’ effect from acoustic transmitters in adult Chinook salmon

2020 ◽  
Vol 641 ◽  
pp. 1-11
Author(s):  
AM Wargo Rub ◽  
BP Sandford
Keyword(s):  
Chinook Salmon ◽  
Marine Mammals ◽  
Oncorhynchus Tshawytscha ◽  
Spatial Scales ◽  
California Sea Lions ◽  
Sea Lions ◽  
Acoustic Transmitter ◽  
Archival Tags ◽  
Significant Difference ◽  
Survival Differences

The ‘dinner bell’ hypothesis posits that marine mammals hear or otherwise sense soundwaves produced by acoustic transmitters and use the signal to selectively prey on fish carrying them. A dual tagging study conducted during 2010 and 2011 supports this hypothesis. Results from this study revealed a significant difference in the survival of fish marked with passive integrated transponder (PIT) tags and those marked with active acoustic transmitters. Our objective had been to use both types of tags to study behavior and survival of migrating adult spring Chinook salmon Oncorhynchus tshawytscha at 2 different spatial scales. We tagged fish as they entered the Columbia River, USA, and monitored their survival and progress over a 193 km reach to Bonneville Dam (river km 234), its lowest impoundment. In 2010, estimated survival was 0.74 (95% CI, 0.62-0.86) for PIT-tagged fish but only 0.30 (0.15-0.45) for acoustic-tagged fish. Therefore, in 2011, we included archival tags and a sham acoustic transmitter group to help identify causes of the survival discrepancy. Survival was 0.75 (0.54-0.97) for sham transmitter fish and 0.73 (0.60-0.86) for PIT fish, but only 0.10 (0.00-0.24) for active acoustic transmitter fish. Our study area was replete with harbor seals Phoca vitulina, California sea lions Zalophus californianus, and Steller sea lions Eumetopias jubatus during both years. We suspect the most likely cause of survival differences between tag treatment groups was pinniped predation. Using temperature data from archival tags, we found evidence of such predation and support for a ‘dinner bell’ effect from acoustic transmitter tags.

Early experience and reproductive morph both affect brain morphology in adult male Chinook salmon (Oncorhynchus tshawytscha)

2014 ◽  
Vol 71 (9) ◽  
pp. 1430-1436 ◽  
Author(s):  
Mallory L. Wiper ◽  
Stephanie Britton ◽  
Dennis M. Higgs
Keyword(s):  
Chinook Salmon ◽  
Habitat Complexity ◽  
Oncorhynchus Tshawytscha ◽  
Driving Forces ◽  
Brain Size ◽  
Brain Regions ◽  
Brain Morphology ◽  
Short Term ◽  
Trade Offs ◽  
The Difference

It is clear that brain size and structure can be greatly influenced by the environment, and in fish, factors such as habitat complexity, rearing environment, and reproductive status have been shown to affect brain morphology and behaviour, but it is unclear how long these effects last. The objective of the current study was to investigate variability in overall brain size and particular brain regions of male Chinook salmon (Oncorhynchus tshawytscha) through the evaluation of potential driving forces — environment and reproductive morph. By comparing fish from different rearing environments and different male reproductive morphs (hooknose versus jack), the current research assessed the influence of each of these factors on overall brain size and on select brain regions. Male hooknose salmon had relatively smaller brains, once corrected for body size, than male jack salmon, suggesting possible trade-offs between somatic and brain development. Fish reared in hatchery environments but released into the wild as presmolts still had relatively larger brains than their wild counterparts, despite sharing wild habitats for over 3 years, suggesting persistent effects of hatchery rearing. Taken together, these results show that the difference in reproductive morphs can substantially impact brain morphology and that short-term environmental influences can have persistent effects throughout ontogeny.

Habitat use by sympatric female mallards and American black ducks breeding in a forested environment

1994 ◽  
Vol 72 (9) ◽  
pp. 1538-1542 ◽  
Author(s):  
Chris P. Dwyer ◽  
Guy A. Baldassarre
Keyword(s):  
New York ◽  
Habitat Use ◽  
Habitat Type ◽  
Home Ranges ◽  
Habitat Types ◽  
Black Duck ◽  
Disturbed Areas ◽  
Forested Areas ◽  
American Black ◽  
The Difference

There has been much speculation regarding whether breeding mallards (Anas platyrhynchos) and American black ducks (A. rubripes) use similar habitat types in forested areas, which could lead to increased interspecific contact. To study this issue, we used radiotelemetry during 1990–1991 on sympatric female mallards and black ducks breeding in the western Adirondack Mountains of New York. Mallard and black duck pairs occupied the general area at a density of 0.7 and 0.6/km2, respectively. Black duck home ranges tended to be larger than those of mallards, although the difference was not significant. Habitat composition within the home ranges of mallards and black ducks was similar, upland forest being the dominant habitat type, followed by wetlands, disturbed areas, and active residential sites. Within home ranges, mallards and black ducks were similar in their use of four major wetland habitat types. Our data suggest that undisturbed forest and habitat use within such areas may not serve as an isolating mechanism between breeding mallards and black ducks.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
River Basin ◽  
Chinook Salmon ◽  
Spatial Scales ◽  
Stream Temperature ◽  
Growth Potential ◽  
Main Stem ◽  
Field Observations ◽  
Habitat Types ◽  
Yukon River Basin ◽  
Freshwater Habitats

<i>Abstract.</i>—Climatic variation is a key driver of freshwater physical processes that in turn control stream fish growth and population dynamics at fine spatial scales and species distributions across broad landscapes. A recent downturn in Chinook Salmon <i>Oncorhynchus tshawytscha </i>returns across the Yukon River basin, Alaska, USA and Yukon Territories, Canada has led to hardship among user groups and increased interest in understanding how freshwater processes affect population persistence within this important commercial, recreational, and subsistence fishery. Here, we present results for the Chena River basin, interior Alaska, where we used field observations and riverscape-scale spatially explicit models to assess the influence of stream temperature on juvenile Chinook Salmon growth potential among years (2003–2015) and across 438 stream kilometers. We ran bioenergetic simulations for warm and cool year scenarios and contrasted temperature model precision and growth among different habitat types (small and large tributaries, main stem, and side channels) based on field estimates of growth, size, diet, and measured stream temperatures. Stream temperature regimes predicted from remotely sensed land surface temperatures were precise during the open water season (<I>R</I><sup>2</sup> > 0.87; root-mean-squared error < 1.1°C), although the relationship was weakest in groundwater-mediated tributary habitats. Field observations revealed salmon were 67% larger by mass (g) in September during a warm year versus a cool year from main-stem sites. Bioenergetic simulations predicted that, on average, growth potential was 42% higher in warm years, although growth potential varied across the riverscape as much as 60% between cool upstream and warm downstream habitats. Climate variability is clearly an important driver of freshwater habitat conditions and has a large role in controlling freshwater growth of juvenile salmon. A better understanding of how climate influences growth conditions in different habitat types and across broad landscapes will be critical for conservation and management of Alaskan Chinook Salmon stocks under an expected warmer and more variable climate.

scholarly journals Vegetation biomass and habitat selection by a newly introduced population of muskoxen in northern Quebec

Rangifer ◽  
1993 ◽  
Vol 13 (2) ◽  
pp. 71 ◽  
Author(s):  
René Nault ◽  
Carole Mathieu ◽  
Michel Crête
Keyword(s):  
Plant Species ◽  
Extreme Values ◽  
Habitat Type ◽  
Ground Cover ◽  
Aerial Photographs ◽  
Herbaceous Plant ◽  
Habitat Types ◽  
Wet Meadow ◽  
Similar Range ◽  
The Difference

Ground coverage by woody and herbaceous plant species and standing biomass of vegetation susceptible to being grazed upon were estimated in a 156 km2 area where 190 muskoxen were censused during the preceding autumn. Habitat use was estimated with droppings census. Six terrestrial habitat types were delineated on 1:32 000 aerial photographs and randomly sampled: low shrub on xeric sites (LSX; 64 km2), low shrub on mesic sites (LSM; 45 km2), bare ground (BG; 27 km2), forest-tundra (FT; 12 km2), wet meadow (WM; 2 km2) and riparian willows (RW; 1 km2). Dominant plant species varied greatly between habitat types, and only a few such as Betula glandulosa, Salix arctophila, and Polygonum viviparum were common. Tall shrubs were present only in RW where they covered most of the ground, and in FT. Low shrubs were uniformly distributed and covered 18-32% of the ground, with the exception of RW (5%). Ground cover by herbs had a similar range (i.e. 20-37%), except in RW where the mean exceeded 50%. Mosses and lichens occupied about half of the ground everywhere. Phytomass exhibited great variation within and between habitat types; extreme values averaged 892 kg*ha-1 in LSX, and 1965 kg*ha-1 in LSM. However the difference was not significant due to limited sample size and within habitat variance. Nevertheless the mass of herbaceous dicots was greater in RW than in any other habitat type. Total phytomass was 2-20 times greater in northern Qu&eacute;bec than in Greenland. Based on droppings density, muskoxen preferred RW over BG and FT, and LSX over BG. Although the density of muskoxen in the study area was high relative to other muskox ranges, habitat quality and quantity should allow continued population growth.

scholarly journals Otolith shape as a classification tool for Chinook salmon (Oncorhynchus tshawytscha) discrimination in native and introduced systems

2020 ◽  
Vol 77 (7) ◽  
pp. 1172-1188
Author(s):  
Alexander L. Koeberle ◽  
Ivan Arismendi ◽  
Whitney Crittenden ◽  
Cecilia Di Prinzio ◽  
Daniel Gomez-Uchida ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Spatial Scales ◽  
North Pacific Ocean ◽  
Classification Tree ◽  
Shape Variation ◽  
Tree Model ◽  
Otolith Shape ◽  
Stock Discrimination ◽  
Classification Tree Model

Chinook salmon (Oncorhynchus tshawytscha) are widely distributed across the globe, with native stocks in the North Pacific Ocean and self-sustained populations in both the Northern and Southern hemispheres. In their native range, Chinook salmon face many conservation and management challenges, including depleted stocks, loss of genetic diversity, and hatchery influences, whereas naturalized range expansion poses a threat to novel ecosystems. Therefore, ways to improve stock discrimination would be a useful tool for fishery managers. Here, we evaluated otolith shape variation in Chinook salmon as a potential tool for stock discrimination using wavelet coefficients and Fourier harmonics in three case studies at multiple spatial scales. We adopted a simple Classification Tree model that used otolith shape variation to separate Chinook salmon groups. We found best performance of the model occurring between hemispheres, followed by Oregon basins, within-watershed Elk River, Oregon, and lastly among South American basins. Otolith shape analysis is a promising tool for stock discrimination if used in conjunction with other methods to better understand plasticity of anadromous species that use pan-environmental systems.

Systematic hexamitid (Protozoa: Diplomonadida) Infection in seawater pen-reared Chinook salmon Oncorhynchus tshawytscha

1992 ◽  
Vol 14 ◽  
pp. 81-89 ◽  
Author(s):  
ML Kent ◽  
J Ellis ◽  
JW Fournie ◽  
SC Dawe ◽  
JW Bagshaw ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha

scholarly journals Do the assemblages of benthic macroinvertebrates in nearshore waters of Western Australia vary among habitat types, zones and seasons?

2005 ◽  
Vol 85 (2) ◽  
pp. 217-232 ◽  
Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell
Keyword(s):  
Species Composition ◽  
Benthic Macroinvertebrates ◽  
Habitat Type ◽  
Abundant Species ◽  
Subtidal Zone ◽  
Habitat Types ◽  
Environmental Characteristics ◽  
Deposit Feeding ◽  
Number Of Individuals

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.

scholarly journals Responses of Vertebrate Wildlife to Oil and Natural Gas Development: Patterns and Frontiers

2021 ◽  
Author(s):  
A. D. Chalfoun
Keyword(s):  
Natural Gas ◽  
Anthropogenic Activities ◽  
Spatial Scales ◽  
Habitat Type ◽  
Population Level ◽  
Low Frequencies ◽  
Natural Gas Development ◽  
The Usa ◽  
Oil And Natural Gas

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.

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