Author: Dalton J. Hance Publisher: ISBN: Category : Coho salmon Languages : en Pages : 77
Book Description
From the summer dry season to the winter wet season. Such movement that connects summer and winter habitats may be particularly important for coho salmon, O. kisutch, because availability of overwintering habitat can limit freshwater survival for this species. Here, I describe basin-scale variability in the spatial pattern of fall movement for juvenile coho salmon between mainstem and tributary streams during the fall of 2002, 2003, 2004, and 2005. Juvenile coho salmon were tagged with a passive integrated transponder (PIT) and could be detected at five stationary detection sites, two located in perennial tributaries, two in intermittent tributaries, and one in the upper mainstem of the West Fork Smith River, Oregon. For each detection site, I compare the likelihood of detection during the fall by juvenile coho salmon from tagging locations over a multi-kilometer range of distances in each direction away from the tributary confluence. I developed logistic regression models with data from each detection site to estimate: 1) the relative likelihood of immigration into a tributary as compared to emigration out of the tributary, and 2) the relative likelihood of immigration into a tributary from the mainstem downstream of the tributary confluence as compared to immigration from the mainstem upstream of the confluence. For each pair of directions at each detection site, I also compare the change in the likelihood of detection with increasing distance for each direction. Overall, at the two upper-river detection sites, juvenile coho salmon were more likely to emigrate than to immigrate. At the remaining detection sites, juvenile coho salmon were no more likely to emigrate than immigrate. Of these detection sites, fish that immigrated into the mid-river perennial stream were more likely to come from the mainstem downstream of the confluence, whereas fish that immigrated into the two lower-river intermittent tributaries were more likely to come from the mainstem upstream of the confluence. Fall movement of juvenile coho salmon between tributary and mainstem habitat can occur over relatively long distances. This case study demonstrates variation among tributaries in the overall likelihood of emigration and immigration and in the source of immigrants from the mainstem, which may be related to spatial context that combines the physical characteristics and network position of tributary streams. The demonstrated variation in fall movement that connects summer and winter habitat within a stream network is a first step in exploring how complexity in movement interacts with the spatial arrangement and quality of seasonal habitats. More research on the causes of variation in the expression of fall movement will improve our understanding of how the spatial arrangement of habitat within a stream network influences the survival of juvenile coho salmon over the whole freshwater life cycle.
Author: Ge Sun Publisher: MDPI ISBN: 3039288237 Category : Science Languages : en Pages : 198
Book Description
Forests cover 30% of the Earth’s land area, or nearly four billion hectares. Enhancing the benefits and ecosystem services of forests has been increasingly recognized as an essential part of nature-based solutions for solving many emerging global environmental problems today. A core science supporting forest management is understanding the interactions of forests, water, and people. These interactions have become increasingly complex under climate change and its associated impacts, such as the increases in the intensity and frequency of drought and floods, increasing population and deforestation, and a rise in global demands for multiple ecosystem services including clean water supply and carbon sequestration. Forest watershed managers have recognized that water management is an essential component of forest management. Global environmental change is posing more challenges for managing forests and water toward sustainable development. New science on forest and water is critically needed across the globe. The International Forests and Water Conference 2018, Valdivia, Chile (http://forestsandwater2018.cl/), a joint effort of the 5th IUFRO International Conference on Forests and Water in a Changing Environment and the Second Latin American Conference on Forests and Water provided a unique forum to examine forest and water issues in Latin America under a global context. This book represents a collection of some of the peer-reviewed papers presented at the conference that were published in a Special Issue of Forests.
Author: Rebecca L. Flitcroft Publisher: ISBN: Category : Coho salmon Languages : en Pages : 378
Book Description
Aquatic ecological investigation is expanding to encompass considerations of multiple scales across large landscapes. Much of the analysis included in this work focuses specifically on coho salmon (Oncorhynchus kisutch) in multiple subbasins on the Oregon coast. Coho salmon were chosen for an investigation of spatial scales, network connections, and life history stages due to their broad distribution on the Oregon coast, and abundant data describing their distribution, habitat needs, behavior, and survival. Chapter 2 introduces dynamic network topology (DNT) as a framework for analysis and interpretation of aquatic obligate species. DNT is based on the premise that in-stream habitats change in form and organization over time, and native aquatic species are adapted to those changes through movement and life history diversity. Chapter 3 analyzes juvenile coho salmon density and stream network occupancy at three spatial scales (site, patch, and subbasin). The site scale analysis indicated that combining network and traditional in-stream habitat metrics (i.e., substrate and habitat juxtaposition variables) are most effective at describing juvenile coho salmon density. Patch sizes of juvenile coho salmon were defined using variograms. Variogram shape indicated that a nested spatial structure may be present in larger subbasins, indicating overlapping patterns of juvenile stream use. At the subbasin scale, stream network occupancy by juvenile coho salmon was shown to vary over time within subbasins, and appeared to increase or decrease similarly to the size of the adult spawning run. In chapter 3, two-tier Bayesian hierarchical models were applied to adult (subbasin and basin scales) and juvenile (site and subbasin scales) coho salmon in an attempt to combine spatial scales that might be influential at each life history stage. The best fitting adult model included the percent of large trees in the riparian zone at the subbasin scale with mean annual precipitation at the basin scale. The best fitting juvenile model included three variables, percent sand, stream order, and network distance to spawning habitat which mirrors the result of modeling efforts in Chapter 3. Multiple spatial scales and the framework of a stream network were informative at detecting patterns and interactions among scales and life history stages of coho salmon.
Author: Adam D. Weybright Publisher: ISBN: Category : Coho salmon Languages : en Pages : 110
Book Description
Juvenile salmonids display highly variable spatial and temporal movement patterns that are influenced by density dependent (e.g., competition, predation) and density independent (e.g., genetics, stream discharge, physical habitat conditions) factors. The effects of these factors differ with fish life history stage, but will ultimately affect how salmonids utilize freshwater nursery habitats and influence their size at smolting. Although juvenile coho salmon (Oncorhynchus kisutch) (Walbaum 1792) movement patterns and their relationships with body mass have been previously examined, the temporal scale considered in most studies has been within individual seasonal periods. In this study, we monitored the movement of PIT tagged juvenile coho salmon throughout the period of freshwater residence in an entire southern Oregon coastal basin to identify the prevalent sedentary and mobile strategies these fish may adopt and to examine possible relationships between those strategies and fish body mass, growth and survival. Specific objectives include: 1) to describe juvenile coho salmon movement strategies and patterns during the freshwater residence period; 2) to determine the relative proportions of juvenile coho salmon that exhibit each movement strategy; 3) to establish whether juvenile coho salmon body mass and growth rates are related with a set of habitat variables recorded during this study; 4) to determine whether coho salmon body mass or growth rates are related to movement strategy; and 5) to evaluate whether winter survival of juvenile coho salmon is associated with movement strategy. Results revealed seasonally and spatially variable movement. More than half of coho salmon tracked throughout the period of freshwater residence exhibited movement behavior that differed between summer and winter seasons. Within seasonal periods, coho salmon in tidally affected reaches exhibited greater prevalence of mobile behavior relative to those in riverine reaches. Regression analysis indicated coho biomass density, habitat unit structural complexity and size at tagging were important in predicting summer growth of coho salmon. Juvenile coho salmon that were mobile during summer were either larger or no different in body mass in early summer relative to fish that exhibited sedentary behavior. Similarly, no consistent differences were observed between sedentary and mobile coho salmon in regards to summer growth. Coho salmon that were sedentary in summer and winter experienced higher apparent winter survival than mobile fish in each season, though the reach in which an individual resided at the start of winter appeared to also affect survival. Coho salmon residing in the tide gate reservoir reach and mainstem headwater reaches experienced greatest apparent winter survival. These results indicate that juvenile coho salmon movement within a stream basin is spatially and temporally variable and that mobility does not necessarily indicate inferior competitive ability. In a broader context, variable movement patterns reflect the capacity for plastic behavior in salmonids and this research demonstrates the importance of maintaining seasonally diverse freshwater and estuarine nursery habitats for juvenile fish.
Author: Anthony O. Olegario Publisher: ISBN: Category : Coho salmon Languages : en Pages : 114
Book Description
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition were greatest in spring. Growth rate varied through winter and was highest in Crane Creek, a small intermittent stream (4.3km2 basin area) and lowest in Beaver Creek (7.5 km2), a perennial stream. Prey availability and growth rate decreased in January and February as temperatures dropped, however stomach fullness was highly variable and not correlated to growth rate. The stomach contents of 477 juvenile coho (age-0), were quantitatively examined using an index of relative importance. Juvenile coho fed primarily on benthic invertebrates; rarely consumed non-insectan food included coho fry, salmon eggs, aquatic snails (Juga silicula), salamanders (Dicamptodon tenebrosus), and terrestrial invertebrates. The major portions of their diets, in order of relative importance, were aquatic chironomid larvae (Diptera), baetid mayfly larvae (Ephemeroptera), limnephilid caddisfly larvae (Trichoptera), and winter stonefly larvae (primarily Capniid Stonefly). Similarities in Relatively Important prey distinguished the two intermittent streams from the two perennial streams. In the WFSR tributaries, juvenile coho appear to rely on a variety of food sources to sustain growth and condition during winter. Small intermittent headwater streams may be disproportionately more important to stream fish with greater availability of prey than larger perennial streams highlighting the need to conserve and restore these habitats.
Author: Publisher: ISBN: Category : Coho salmon Languages : en Pages : 124
Book Description
Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may growth and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations.
Author: Jeffrey D. Rodgers Publisher: ISBN: Category : Coho salmon Languages : en Pages : 122
Book Description
The abundance of the 1982 brood of juvenile coho salmon (Oncorhynchus kisutch) was determined in August 1983, and January and April 1984 at 20 study sites spread throughout Knowles Creek, an Oregon coastal watershed. The timing of emigration of juvenile coho from the watershed was monitored from October 1983 through June 1984. Condition factor, fork length, and gill (Na+K)-ATPase activity were measured in migrants, a captive group of Knowles Creek juvenile coho held in the laboratory, and nonmigrant fish periodically sampled from the stream. Skin guanine levels were also measured in migrant and nonmigrant groups. Juvenile coho abundance in January was significantly correlated with abundance in August. Wood volume and amount of undercut streambank were the pair of physical variables that best explained variation in the number of fish per square meter or per cubic meter in January. Two debris torrent ponds in the middle of the watershed contained large amounts of woody debris and were the most heavily used overwintering habitats for juvenile coho in the Knowles Creek. Few juvenile coho overwintered in the lower half of watershed, an area lacking woody debris. Peaks in outmigration occurred in November and May. Approximately 24% of the total number of migrants emigrated in November. Fish that reared in two of three third-order areas in summer, together with fish from the lower (fifth-order) half of the mainstem, were the first to leave the watershed. While lack of winter habitat may have been the cause of migration from the lower mainstem, low summer streamflows may have caused early migration from the low order sites. Gill (Na+K)-ATPase activity of migrants rose gradually from a low in January to a peak at the end of the study in June. Mean gill (Na+K)-ATPase activity of nonmigrants was only significantly lower than that of migrant fish during April. Gill (Na+K)-ATPase of captives was similar to that of nonmigrants until it peaked during the last two weeks in April, after which the activity fell below that of migrants or nonmigrants. Condition factor of nonmigrant fish was higher than either migrants or captives throughout the study. Migrant skin guanine levels rose sharply during the first two weeks in April and continued to rise until the end of the study in June. Approximately 8,300 juvenile coho, 44% of the estimated number of juvenile coho present in Knowles Creek in August, migrated from the watershed by the following June. An estimated 9% of the August population migrated as smolts after April 1.
Author: Rachel LovellFord Publisher: ISBN: Category : Coho salmon Languages : en Pages : 146
Book Description
Coho salmon (Oncorhynchus kisutch) migration and spawning are unique components of the salmon life cycle because they require synchrony of behavior with other individuals as well as with acceptable fluvial conditions. As with other organisms that exhibit group mating behavior, it is likely that environmental cues trigger coho salmon movement to spawning grounds. These cues may also provide usable habitat for migration and spawning. River discharge, temperature, and length of day have long been assumed to be the environmental cues which trigger migration and spawning of coho salmon as coho return within the same season each year to spawn. Hatchery studies have also shown that the timing of reproductive behavior is heritable. If this heritability is determined by the fluvial conditions of the spawning grounds, then a predictable relationship should exist between reproductive behavior and the hydrologic and thermal regimes. Surprisingly, no defensible correlations between discharge thresholds and spawning or migrating activity have been identified for naturally reproducing coho salmon. Thermal, velocity, and depth limitations have been identified for coho salmon, but these values have not been examined in combination or within the context of a hydrologic and thermal regime. This study compares interannual patterns in the timing of coho mid-river migration in the North Umqua (180 km up river from the estuary) and the initiation of spawn timing in the Smith River basins (Oregon) with river discharge and water temperature data to ascertain whether these behaviors are driven by fluvial conditions. Additionally, we used this data to identify the window over which most migration and spawning takes place in our test systems. On the North Umpqua, coho salmon mid-river migration initiated (first 5% of migrants) after summer peak temperatures and following a threshold average daily temperature of 18° C, but before fall storm events occurred. In most years, approximately 75% of the migrating coho salmon have moved past the Winchester Dam before fall storms initiated and when discharge remained less than the 11 year average for the month of November, more similar to summer than winter flow levels. Additionally, characteristic lengths and numbers of peaks within the distribution of annual migrations were attributable to the generational cohort that the migration belonged to despite the similarity in population size across all years. These patterns in the distribution of generational cohorts suggest an inherited timing response as well as highlight cohorts which may contain diminished sub-populations. The initiation of coho salmon spawning appears limited both by a thermal threshold of 12° C in all basins, as well as by a minimal discharge threshold, which is unique to each stream. Continued spawning activity occurs as discharge remains elevated from fall levels. It is also notable that there was no statistical difference in the date of the initiation of spawning within each basin in a given year or across years at a given site. Together, these studies highlight the important role that the coho salmon genome plays in reproductive timing as well as the ways that fluvial thresholds limit reproductive behavior in time. Coho have survived because of their genome has been resilient when faced with environmental change. Future work should consider variability in fluvial conditions relative to coho salmon phenotypic plasticity over time. Coho salmon phenotypic plasticity will determine whether the rate of change of the hydrologic and thermal regimes important to coho salmon survival outpaces the coho's ability to adapt. This study contributed to this future work by establishing baseline relationships between the behavior of a threatened species and measurable environmental thresholds.
Author: John D. Deibner-Hanson Publisher: ISBN: Category : Coho salmon Languages : en Pages : 96
Book Description
Some studies suggest that Coho Salmon populations are limited by overwinter survival as a result of insufficient winter habitat. While many small-scale projects aim to define reach and basin-level habitat requirements for Coho Salmon, large-scale studies that assess multiple independent populations remain few. For my research, I quantified large woody debris (LWD) by volume and low-velocity rearing habitat (LVH) as percent area in three coastal watersheds of similar size in northern California to untangle the relationships between Coho Salmon overwinter survival, emigration timing and specific winter habitats. I used mark-recapture techniques with PIT tags to formulate Cormack-Jolly-Seber models for each of three years (2013-2015) to (1) estimate apparent overwinter survival of juvenile Coho Salmon populations, (2) determine to what extent outmigration timing varies among basins, and (3) evaluate the relationships between reach-specific survival, movement and winter habitat. LWD volume ranged from 47.8 to 109.9 cubic meters per kilometer among stream reaches while LVH area spanned from 9.3% to 23.6% of total stream area per reach. Effects of LWD on apparent overwinter survival and early emigration were absent during all three years of the study. Effects of LVH were not observed during 2013 and 2014. In 2015, LVH correlated positively with apparent overwinter survival and negatively with emigration. Larger Coho Salmon had higher apparent overwinter survival rates than small fish, whereas smaller fish had greater emigrations rates before spring. Mean apparent overwinter survival varied by basin from 0.052 to 0.567 but basins maintained consistency across years. Early emigration rates ranged even further by basin (0.023-0.773). Variation in both apparent overwinter survival and early emigration was much greater among basins than within basins. A lot remains to be learned regarding how habitat affects the migratory behavior of Coho Salmon in California and these results suggest the effects may vary significantly by stream. The drastic life history differences observed in neighboring Coho Salmon populations demonstrate the plasticity in a species once thought to be relatively inflexible. Moving forward, incorporating multi-basin approaches should be considered when evaluating freshwater survival and movement to inform large-scale restoration and conservation.
Author: Dalton J. Hance
Author: Ge Sun
Author: Rebecca L. Flitcroft
Author: Adam D. Weybright
Author: Anthony O. Olegario
Author: Brian Jonasson
Author: 
Author: Jeffrey D. Rodgers
Author: Rachel LovellFord
Author: John D. Deibner-Hanson