Chehalis River Research Articles

The signal crayfish is not a single species: cryptic diversity and invasions in the Pacific Northwest range of Pacifastacus leniusculus

Summary1. We used historical sources, morphology‐based taxonomy and mtDNA sequence data to address questions about the signal crayfish Pacifastacus leniusculus. These included evaluating unrecognised cryptic diversity and investigating the extent to which P. leniusculus may have been introduced within its presumed native range in the Pacific Northwest region of North America. Our study builds and expands on Pacific Northwest phylogeographic knowledge, particularly related to patterns of glacial refugia for freshwater species.2. Extensive collections (824 specimens) from British Columbia (Canada), Idaho, Nevada, Oregon and Washington (United States) were used to characterise P. leniusculus at the mitochondrial 16S rRNA gene. Genetic groups within the species were elucidated by phylogenetics and amova; evolutionary relationships within the most common and diverse group were investigated using a statistical parsimony haplotype network, a nested amova, and tests of isolation by distance. Morphological measurements were used to relate findings of molecular analyses to three historically recognised P. leniusculus subspecies and characterise cryptic diversity by morphology.3. We found substantial cryptic diversity, with three groups highly distinct from P. leniusculus in discrete geographic regions: the Chehalis River glacial refugium, Central Oregon and the Okanagan Plateau. Disjunct distributions of P. leniusculus relative to these cryptic groups and known patterns of Pleistocene glaciation and landscape evolution cast doubt on whether P. leniusculus is native to some areas such as coastal drainages of northern Washington and southern British Columbia. Morphological traits previously used to characterise P. leniusculus subspecies still persist but may be incapable of distinguishing P. leniusculus from newly discovered cryptic groups.4. Cryptic diversity found within P. leniusculus highlights the pressing need for a thorough investigation of the genus Pacifastacus using data based on more extensive gene and taxon sampling. It also warrants conservation attention, as introductions of P. leniusculus within the Pacific Northwest may carry risks of hybridisation and introgression for cryptic groups. Owing to high genetic diversity and limited dispersal capacity relative to more vagile organisms like freshwater fish, crayfish of the genus Pacifastacus offer powerful potential insights into the geological history and phylogeography of the Pacific Northwest region. Finally, by shedding light on the long‐neglected native range of P. leniusculus, our results should also better inform our understanding of potential source populations for, and the ecology of, this important invasive species in regions including Europe, Japan and elsewhere in North America.

Genetic versus Rearing-Environment Effects on Phenotype: Hatchery and Natural Rearing Effects on Hatchery- and Wild-Born Coho Salmon

With the current trends in climate and fisheries, well-designed mitigative strategies for conserving fish stocks may become increasingly necessary. The poor post-release survival of hatchery-reared Pacific salmon indicates that salmon enhancement programs require assessment. The objective of this study was to determine the relative roles that genotype and rearing environment play in the phenotypic expression of young salmon, including their survival, growth, physiology, swimming endurance, predator avoidance and migratory behaviour. Wild- and hatchery-born coho salmon adults (Oncorhynchus kisutch) returning to the Chehalis River in British Columbia, Canada, were crossed to create pure hatchery, pure wild, and hybrid offspring. A proportion of the progeny from each cross was reared in a traditional hatchery environment, whereas the remaining fry were reared naturally in a contained side channel. The resulting phenotypic differences between replicates, between rearing environments, and between cross types were compared. While there were few phenotypic differences noted between genetic groups reared in the same habitat, rearing environment played a significant role in smolt size, survival, swimming endurance, predator avoidance and migratory behaviour. The lack of any observed genetic differences between wild- and hatchery-born salmon may be due to the long-term mixing of these genotypes from hatchery introgression into wild populations, or conversely, due to strong selection in nature—capable of maintaining highly fit genotypes whether or not fish have experienced part of their life history under cultured conditions.

Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non‐estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three‐spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi. Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non‐game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.

Biology of the introduced copepod Pseudodiaptomus inopinus in a northeast Pacific estuary

Compared to other regions, estuaries and coastal bays along the west coast of North America have experienced the largest number of invasions by nonindigenous planktonic copepods. Eight species of copepods from Asia, including 2 species of the genus Pseudodiaptomus, have been reported in coastal bays of northern California, and a third species of Asian Pseudodiaptomus (P. inopinus) has become established in the Columbia River estuary and many smaller estuaries in the northeast Pacific Ocean. It can dominate the plankton in fresh and oligohaline tidal waters of estuar- ies that are utilized as rearing grounds for a variety of larger invertebrates and fishes. In July 1998 we initiated a 16 mo study of P. inopinus in the Chehalis River estuary, Washington State, USA, to docu- ment its biology, ecological relationships with other holoplankton, and importance as prey for fish and invertebrate planktivores. In 1998 P. inopinus reached peak densities in the late summer/early autumn period of low river flow but a similar peak was not seen in the same period in 1999, when densities of the copepod were significantly lower. These interannual density differences did not appear to be caused by between-year differences in predation or river flooding, but could have resulted from cooler temperatures and higher river flows that occurred in the Chehalis River in 1999. Other abundant planktonic copepods were separated from P. inopinus either temporally (Eurytemora affinis) or spatially (Acartia spp., Eurytemora americana) within the estuary, over a relatively short segment of the estuary spanning salinities of 0 to 10 psu. This separation may imply that P. inopinus experienced little competition when it was introduced; alternatively, it may have altered the distrib- ution of other copepods in the estuary. P. inopinus was rare in the diets of estuarine fishes, but com- prised an important and sometimes dominant prey for mysid shrimp Neomysis mercedis and juvenile caridean shrimp Crangon franciscorum. In turn, N. mercedis was an important prey item for estuar- ine fishes, and thus the main impact of P. inopinus on the estuarine food web was via this pathway.

Juvenile Salmonid Use of Freshwater Emergent Wetlands in the Floodplain and Its Implications for Conservation Management

AbstractA recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington, and to determine the fate of the salmon using them. Enhanced emergent wetlands contained water control structures that provided an outlet for fish emigration and a longer hydroperiod for rearing than unenhanced wetlands. Age‐0 and age‐1 coho salmon O. kisutch were the most common salmonid at all sites, enhanced wetlands having significantly higher age‐1 abundance than unenhanced wetlands that were a similar distance from the main‐stem river. Yearling coho salmon benefited from rearing in two enhanced wetland habitats, where their specific growth rate and minimum estimates of survival (1.43%/d by weight and 30%; 1.37%/d and 57%) were comparable to those in other side‐channel rearing studies. Dissolved oxygen concentrations decreased in emergent wetlands throughout the season and approached the limits lethal to juvenile salmon by May or June each year. Emigration patterns suggested that age‐0 and age‐1 coho salmon emigrated as habitat conditions declined. This observation was further supported by the results of an experimental release of coho salmon. Survival of fish utilizing emergent wetlands was dependent on movement to the river before water quality decreased or stranding occurred from wetland desiccation. Thus, our results suggest that enhancing freshwater wetlands via water control structures can benefit juvenile salmonids, at least in the short term, by providing conditions for greater growth, survival, and emigration.

Control of Knotweed and other invasive species and experiences restoring native species in the Pacific Northwest US

Invasive knotweed (Polygonum L. [Polygonaceae]) species are a significant threat to native ecological communities that occur in riparian areas and other vulnerable habitats. This project applied practical methods to control Bohemian knotweed (Polygonum x bohemicum).This species was controlled for 2 y prior to restoring appropriate native species for the Chehalis River Surge Plain Natural Area Preserve in Washington State (US). The invasive species Himalayan blackberry (Rubus discolor Weihe & Nees [Rosaceae]), scotsbroom (Cytisus scoparius (L.) Link [Fabaceae]), and reed canarygrass (Phalaris arundinacea L. Raeush [Poaceae]) were also controlled.

AMPHIBIAN USE OF CHEHALIS RIVER FLOODPLAIN WETLANDS

Abstract The use of isolated emergent wetlands by amphibians has been well documented. However, amphibian habitats such as emergent wetlands in floodplains may differ from isolated wetlands because of their high disturbance (water fluctuation) related to riverine flooding, presence of fish species, and increased connectivity among aquatic habitats. We compared the amphibian assemblages at 6 freshwater wetland habitats in the Chehalis River floodplain and examined the effect of wetland restoration on amphibians. We sampled 6 wetlands during the breeding season in 2003 and 2004 and captured over 15,000 adults, tadpoles, and larvae from 6 species. The red-legged frog (Rana aurora) was the most abundant species captured. The rough skinned newt (Taricha granulose) was the only amphibian captured at all sampled sites. Although it is more desirable to prevent wetland degradation from occurring, restored and enhanced wetlands in floodplains do provide breeding habitat for amphibians. Amphibian species captured in...

Control of knotweed and other invasive species and experiences restoring native species in the Pacific Northwest US

Abstract Invasive knotweed (Polygonum L. [Polygonaceae]) species are a significant threat to native ecological communities that occur in riparian areas and other vulnerable habitats. This project applied practical methods to control Bohemian knotweed (Polygonum x bohemicum). This species was controlled for 2 y prior to restoring appropriate native species for the Chehalis River Surge Plain Natural Area Preserve in Washington State (US). The invasive species Himalayan blackberry (Rubus discolor Weihe & Nees [Rosaceae]), scotsbroom (Cytisus scoparius (L.) Link [Fabaceae]), and reed canarygrass (Phalaris arundinacea L. Raeush [Poaceae]) were also controlled.

Discharge Rating Curve Extension – A New Approach

It is often necessary to have stage discharge curve extended (extrapolated) beyond the highest (and sometimes lowest) measured discharges, for river forecasting, flood control and water supply for agricultural/industrial uses. During the floods or high stages, the river may become inaccessible for discharge measurement. Rating curves are usually extended using log–log axes, which are reported to have a number of problems. This paper suggests the use of Support Vector Machine (SVM) in the extrapolation of rating curves, which works on the principle of linear regression on a higher dimensional feature space. SVM is applied to extend the rating curves developed at three gauging stations in Washington, namely Chehalis River at Dryad and Morse Creek at Four Seasons Ranch (for extension of high stages) and Bear Branch near Naselle (for extension of low stages). The results obtained are significantly better as compared with widely used logarithmic method and higher order polynomial fitting method. A comparison of SVM results with ANN (Artificial Neural Network) indicates that SVM is better suited for extrapolation.

Late Pleistocene stratigraphy and chronology of lower Chehalis River valley, southwestern British Columbia: evidence for a restricted Coquitlam Stade

Sediments in lower Chehalis valley span middle Wisconsin (Olympia nonglacial interval) to Holocene time. Sediments are divided into six units with chronological control provided by 14 new radiocarbon ages. Fluvial gravel spans the transition from the late Olympia nonglacial interval to the early Fraser Glaciation. Glaciolacustrine sedimentation represents the first definitive glacial activity in the valley and indicates that Vashon ice in the Fraser Lowland blocked the mouth of the Chehalis valley at ca. 18–17 ka BP. Ice then flowed down the Chehalis valley. The Chehalis valley deglaciated while ice persisted in the Fraser Lowland, forming another lake. After this lake drained, terraces and fans formed. This style of glaciation–deglaciation is typical of many watersheds peripheral to the Fraser Lowland in that local valley ice was slightly out of phase with ice in the lowland. This resulted in glacial lakes forming during both advance and retreat phases. However, in contrast to watersheds in the northwestern Fraser Lowland, no definitive evidence of a Coquitlam ice advance was found within the Chehalis valley. Although glaciers in the area were likely active and advancing, data from the Chehalis valley indicates that they were not as extensive as previously thought. Since ice source areas in the northeastern Fraser Lowland are in the leeward area of the Coast Mountains, it is suggested that lower precipitation resulted in limited glacier activity there during the Coquitlam Stade.

Predation by Northern Pikeminnow on Hatchery and Wild Coho Salmon Smolts in the Chehalis River, Washington

Abstract One explanation for the low smolt-to-adult survival rates of hatchery and wild coho salmon Oncorhynchus kisutch originating from the Chehalis River, Washington, is predation by northern pikeminnow Ptychocheilus oregonensis. To evaluate this hypothesis, we studied predation by northern pikeminnow on emigrating coho salmon smolts in the undammed, lower main-stem Chehalis River (river kilometers (rkm) 27-82) during Apr and May of 1988 and 1989. Where only wild coho salmon smolts were available, we estimated that northern pikeminnow ate 0.2% of the 1,100,000 wild coho salmon smolts migrating through this reach in 1989. In the reach where both hatchery and wild fish were present, northern pikeminnow ate about 0.9% of the hatchery and wild coho salmon available in this area in 1989. Thus, the total estimated loss of coho salmon smolts due to northern pikeminnow predation in the lower main-stem Chehalis River in 1989 was approximately 18,200 fish. This was about two orders of magnitude less than the los...

Landscape allometry: from tidal channel hydraulic geometry to benthic ecology

The use of hydraulic geometry and other geomorphic indices has been recommended for habitat restoration and creation of estuarine tidal channels. Although such an approach provides design guidance for tidal channel form, it does not provide guidance for the ecological consequences of channel form. This study investigates the potential linkage of the scaling of tidal channel form with ecological patterns and processes in estuarine tidal channels of the lower Chehalis River, Washington, U.S.A. Ebb tide surface velocity was related to channel size, as was exit time and export probability of tiny drogues, which mimic floating allochthonous detritus. Consequently, the amount of organic material in channel sediments scaled negatively with channel size as did the abundance of benthic surface deposit feeders. These observations suggest that the highest concentrations of fish feeding in estuarine tidal channels may be in smaller channels or in the smaller and more distal portions of large channels. Scaling of ecological patterns and processes with tidal channel size may be an example of a more general ecological scaling with landscape form, i.e., landscape allometry.

Sensory drive and nuptial colour loss in the three‐spined stickleback

Three‐spined sticklebacks Gasterosteus aculeatus, from the Chehalis River drainage. Washington, U.S.A., that have lost the mosaic nuptial signal were more likely to be found in tannin stained sub‐drainages whereas those expressing the mosaic nuptial signal were more likely to be found in sub‐drainages that were not tannin stained. This result is consistent with the sensory drive model.

Field data do not support a textbook example of convergent character displacement.

Experimental evidence supporting convergent character displacement is rare; only one example exists and it is in the form of orientation and territory competition experiments performed in the laboratory. However, outcomes of laboratory experiments involving behaviour or competition can be artefacts of unnatural conditions and, therefore, the results of the previous experiments supporting convergent character displacement are equivocal. In this study, we re-examine the evolution of melanic nuptial coloration in male three-spined stickleback (Gasterosteus aculeatus) inhabiting the Chehalis River drainage in Washington State. This novel nuptial coloration has been thought to have evolved in response to competition for nesting territories with the co-distributed Olympic mudminnow (Norzumbra hubbsi), which is also melanic and breeds at the same time. I found that melanic stickleback males did not have an advantage over their red counterparts from typical populations when competing for nesting territories with Olympic mudminnows. Additionally competitive interactions between sticklebacks and mudminnows were rare in both cage experiments and naturally breeding sticklebacks. Finally, melanic coloration in the Chehalis populations did not develop until males were parental, well after the hypothesized territory establishment period. These results refute the only experimental support for convergent character displacement and emphasize the importance of conducting behavioural experiments and observations under natural conditions.

A Comparative Assessment of a Natural and Created Estuarine Slough as Rearing Habitat for Juvenile Chinook and Coho Salmon

Short-term otolith growth rates, residence times, and forage of two species of juvenile salmon (Oncorhynchus spp.) were compared in a created and natural estuarine slough on the Chehalis River in Washington to assess the functional equivalency of the created slough in providing suitable rearing habitat. Otolith microstructure, mark-recapture data, and forage of sub-yearling chinook, O. tshawytscha, and coho, O. kisutch, residing in both sloughs during the spring of 1991 and 1992 served as indicators of rearing habitat quality. No significant differences in the number or width of coho daily otolith increments were detected between the sloughs. Juvenile chinook residence and emigration times were also comparable. Aquatic and terrestrial insects composed the majority of all chinook and coho diets; however, the order of importance of main prey items did differ between sloughs, and salmon in the created slough had emptier stomachs, possibly because of reduced prey availability and/or foraging efficiency.

Response of Juvenile Coho Salmon and Steelhead to Placement of Large Woody Debris in a Coastal Washington Stream

Abstract Many fish habitats have been altered in Pacific Northwest streams and rivers over the past century by a variety of land use practices, including forestry, urbanization, agriculture, and channelization. There are research and management needs for evaluation of the effectiveness of rehabilitation projects intended to enhance stream fish habitat recovery. The response of populations of juvenile coho salmon Oncorhynchus kisutch and steelhead O. mykiss to addition of large woody debris (LWD) was tested in North Fork Porter Creek (NFPC), a small coastal tributary of the Chehalis River, Washington. The NFPC was divided into three 500-m study sections; two sections were altered with two approaches (engineered and logger's choice) to adding LWD, and the third was kept as a reference site. Immediately after LWD addition, the abundance of LWD pieces was 7.9 times greater than the pretreatment level in the engineered site and 2.7 times greater in the logger's choice site; abundance was unchanged in the refer...

POLLUTANT LOADING CAPACITY FOR THE BLACK RWER, CHEHALIS RWER SYSTEM, WASHINGTON1

ABSTRACT: The Black River, a tributary of the Chehalis River in western Washington State, has a history of widespread low dissolved oxygen (DO), anoxia in some locations, and fish kills. As part of a Total Maximum Daily Load (TMDL) study, environmental data were collected during two summer dry seasons and simulations were conducted with the WASP5 model to assess the effect of biochemical oxygen demand (BOD), ammonia, and nutrient loads on DO in the Black River. DO levels were below the State water quality regulatory criterion of 8.0 mg/L in almost all locations during the study. The slow middle reach of the river showed stratified conditions, with anoxia in some of the deepest pools. Based on model simulations, DO was found to still fall below the 8.0 mg/L criterion in the entire mainstem under “natural” conditions, and eutrophication was identified as a potential problem in the middle reach. A TMDL was proposed for BOD and ammonia that would prevent significant degradation of DO in the Black River. To prevent eutrophic conditions in the Black River, a TMDL for total phosphorus was proposed that establishes a protective criterion of 0.05 mg/L for the middle river during the dry low‐flow season.

Behavioral responses of juvenile coho salmon (Oncorhynchus kisutch) exposed to pulp mill effluents.

Coho salmon (Oncorhynchus kisutch) smolts from the Chehalis River may encounter large discharges (>1.7x108 L/d) of pulp mill effluent during their downstream migration through Grays Harbor, Washington. Smolt survival is believed to be reduced by the impaired water quality resulting from effluent releases (Seiler 1989), and it is possible that the orientation behavior of young salmon could be disrupted by exposure to sublethal concentrations of these effluents (Sutterlin 1974).

Chehalis River Disease: A Unique Gill Disease of Salmonids

Epidemic mortalities of chinook salmon alevins (Oncorhynchus tshawytscha) have occurred annually at a freshwater hatchery at the Chehalis River, British Columbia, Canada, since 1982. Previous work has identified branchial epithelial hyperplasia as the predominant pathological change. Our initial work lead us to test the hypothesis that Chehalis River disease (CRD) was actually a novel form of bacterial gill disease (BGD). Histological and ultrastructural observations indicated that CRD-affected gills harboured a bacterial biofilm apparently complexed with particulate iron prior to and during clinical CRD. In one instance, extracellular viruslike particles were observed. Large numbers of a mixed bacterial population were recovered from diseased gills. Flavobacterium sp. and Pseudomonas fluorescens were considered the predominant isolates from the 1990–91 outbreak. However, indirect immunofluorescence of gills with anti-Flavobacterium branchophila serum failed to detect antigenically similar bacteria on the gills of CRD-affected fish. Chemotherapeutic treatment of both naturally and experimentally infected fish was successful, thereby confirming the infectious nature of the disease. We conclude that CRD is a form of BGD, but the significance of the branchial viruslike particles and the presence of particulate iron has not yet been established.

Riverine and Estuarine Migratory Behavior of Coho Salmon (Oncorhynchus kisutch) Smolts

Using radio and ultrasonic transmitters, we tracked coho salmon (Oncorhynchus kisutch) smolts in the Chehalis River and Grays Harbor estuary, Washington, to document patterns of seaward migration. In spite of dramatic differences in the two habitats, the fish behaved similarly in both systems. Migratory progress was saltatory, characterized by movement in the direction of the current and extended periods of holding in areas of low current velocity. Consequently, smolts were displaced rapidly downstream by swift, unidirectional river currents but were retained in the estuary by relatively low-velocity, reversing tidal currents. Smolts did not use tidal currents to move seaward and appeared to swim most rapidly against strong ebbing currents. Estimated mean total metabolic cost incurred by migrating smolts was 0.027 cal∙s−1∙smolt−1 (1 cal = 4.184 J). Estimated daily caloric expenditure by smolts in 1988 was twice that of smolts tracked in 1989, apparently due to faster water velocities in 1988. The observation that coho salmon migration through estuaries is slower than riverine migration suggests that a period of estuarine residence may be necessary for them to adjust their osmoregulatory capability, orient for their return migration, feed, or reduce their vulnerability to predators.