Washington Lakes Research Articles

Largemouth bass consumption demand on hatchery rainbow trout in two Washington lakes

High mortality (84–89%) of stocked rainbow trout (Oncorhynchus mykiss) in Twin Lakes, Washington, has been partially blamed on predation from non-native largemouth bass (Micropterus salmoides). We examined the gut-content of 434 largemouth bass and applied a bioenergetics model to determine the consumption demand on hatchery-released rainbow trout and other prey species in the Twin Lakes. Largemouth bass consumed approximately 4915 (95% CI; 2393–13,452) fall stocked rainbow trout in South Twin. No rainbow trout consumption was observed in North Twin, despite a similar stocking regime. Approximately 6.3% (95% CI; 3–17%) of total fall stocked rainbow trout in South Twin were consumed by largemouth bass. Rainbow trout stocked in the fall ranged from 100 to 160 mm total length and were all subject to predation by large largemouth bass ⩾300 mm. Large largemouth bass consumed rainbow trout that reached up to 210 mm in length and 58% of bass body length. No predation was observed on larger rainbow trout (215–370 mm) stocked during the spring. Smaller largemouth bass ⩽299 mm consumed primarily invertebrates, including crayfish, and did not consume rainbow trout in either lake. During spring and summer in South Twin Lake, large largemouth bass consumed principally golden shiner (Notemigonus crysoleucas) and crayfish. In North Twin Lake, golden shiner constituted most of the larger bass diet for the entire year. Differences in macrophyte distribution, bathymetry, temperature and/or predator-prey demographics likely influenced variability in largemouth bass predation between lakes. Largemouth bass predation did not account for overall rainbow trout mortality.

Widespread Distribution of the Non-Native Northern Crayfish (Orconectes virilis) in the Columbia River Basin

Abstract We report here the first records of the non-native northern crayfish (Orconectes virilis) in the Columbia River basin within Washington State. Confirmed occurrences include the reservoirs Lake Rufus Woods and Lake Roosevelt on the Columbia River, North Twin Lake in the upper Columbia River basin, Lake Patterson in the Methow River basin, Wapato Lake in the Lake Chelan basin, and Moses Lake in central Washington. Uncertainty remains as to the source, extent of current distribution, and potential impacts of these O. virilis populations. Release of live bait by anglers is a common pathway for crayfish introductions, although stocking for harvest or aquaculture and releases of pets or laboratory animals is equally likely for the introduction of O. virilis to the region. Evaluating potential impacts of O. virilis on native crayfish, fish, and other species in the Columbia River basin will require additional study. These newly discovered O. virilis populations are likely to naturally disperse further t...

Shelter Occupancy by Mixed-Species Pairs of Native Signal Crayfish and Non-Native Red Swamp Crayfish Held in Enclosures

ABSTRACT Sheltering ability does not appear to confer an advantage to non-native red swamp crayfish (Procambarus clarkil) in a small, western Washington lake where the invader outnumbers the native signal crayfish (Pacifastacus leniusculus.) When paired with similar-sized non-native P. clarkii, P. leniusculus was adept at monopolizing limited artificial shelter inside enclosures placed on the bottom of Pine Lake. In these contests, the dominant crayfish or winner was typically the one with longer chelae, or, in the case of P. clarkii, the one that was sexually mature. Female crayfishes of both species also were adept at monopolizing the artificial shelter. Furthermore, irrespective of species and sex, when paired with smaller heterospecifics, large crayfish readily monopolized the artificial shelter. These results suggest that additional mechanisms besides shelter competition are contributing to the possible displacement of P. leniusculus in Pine Lake.

Short-term effects of a buffered alum treatment on Green Lake sediment phosphorus speciation

Green Lake, Washington, was treated with a dose of 24 mg Al/L aluminum sulfate (alum) and sodium aluminate during March–April 2004 to reduce dissolved phosphorus concentrations to ameliorate a variety of eutrophication-related problems. Four sediment cores collected six months after the alum treatment in Green Lake were used to examine the short-term effects of alum on sediment phosphorus speciation. Peaks in aluminum bound phosphorus (Al-P) and total aluminum (Tot-Al) were observed in three of the four cores analyzed, resulting in an average ratio of added Al to Al-P formed (Al:Al-P) of 112:1. By comparing this ratio to the average ratio of ~11:1 found in other alum-treated Washington lakes, it can be inferred that approximately 10% of the binding capacity of the added Al had been utilized. Assuming a final ratio of Al:Al-P of 11:1, the added Al has the potential capacity to bind a total of 21.6 g/m2 of P. The amount of sediment inorganic P that supports internal loading (Fe-P and labile-P) in the fall of 2004 was determined to be 2.8 g/m2. Thus the quantity of alum added to Green Lake should be sufficient to inactivate the remaining inorganic mobile-P and to control future P mobilization from the pool of organic sediment P.

Effects of aerobic and anaerobic conditions on P, N, Fe, Mn, and Hg accumulation in waters overlaying profundal sediments of an oligo-mesotrophic lake

Concentrations of key nutrients and metals in water overlaying profundal sediments were evaluated in replicate experimental chambers containing undisturbed sediment–water interface samples from Deer Lake, an oligo-mesotrophic lake in eastern Washington. Chambers were incubated under three sequential phases: aerobic (21 d), anaerobic (27 d), and second aerobic (14 d). In general, nutrients and metals in chamber water were lower under aerobic versus anaerobic conditions. However, in some cases compounds anticipated to appear only under anaerobic conditions, including ammonia, phosphate, and manganese, were observed during aerobic conditions. Correlation analysis elucidated a number of interactions between compounds. Phosphate correlated significantly ( p<0.05) with iron during all incubation phases, suggesting that phosphorus cycling was controlled by iron. Cycling of nitrate and ammonia was tightly and significantly coupled under aerobic conditions. During both aerobic phases, nitrate increased while ammonia decreased, likely as a result of biological nitrification. Finally, mercury appeared during mildly reducing conditions and showed a significant correlation with manganese during the anaerobic phase, suggesting that Mn oxide reduction was the source of Hg in chamber water.

The occurrence and response to toxic cyanobacteria in the Pacific Northwest, North America

Toxic cyanobacteria are of increasing concern in the Pacific Northwest region of North America. Toxic blooms have been documented in Idaho, northern California, Oregon, Washington, and British Columbia and have caused animal poisonings, lake closures, and public health concerns. Microcystins are the most commonly detected cyanotoxins in this region and have been found at water concentrations from <1 μg/L to 30 mg/L. Anatoxins have also been measured in water bodies throughout the region and have been implicated in the deaths of both domestic and wild animals. Environmental factors associated with the occurrence of toxic blooms have been studied in several western Washington lakes. In these lakes, toxic blooms occurred during conditions of high phosphorus, water temperatures, and water column stability. Migration of cyanobacteria from the sediments contributed to toxic blooms in one of the lakes. Although regulations have not been formally adopted by the states and province in this region, some local jurisdictions use the World Health Organization proposed drinking water guideline of 1 μg/L microcystin-LR to close lakes to recreational use and for drinking water supplies. Recommendations currently advocated by Oregon take into account genera-specific differences, as well as separate, less stringent guidelines for recreational water bodies not used for drinking water.

Geographic distribution and genotypic composition of invasive hybrid watermilfoil (Myriophyllum spicatum × M. sibiricum) populations in North America

The recent recognition of invasive hybrid watermilfoil (Myriophyllumspicatum × M. sibiricum) in North America has necessitated a more thorough evaluation of its overall distribution and occurrence in natural populations. A comprehensive survey of watermilfoil populations was conducted in five Minnesota lakes, three of which were suspected a priori to contain hybrid watermilfoil. DNA sequence data verified that hybrid plants between the nonindigenous M. spicatum L. and indigenous M. sibiricum Kom. occurred in three of the five lakes sampled. Myriophyllum spicatum was not detected in lakes where hybrids were prevalent. Further sampling of lakes in Idaho, Michigan, Minnesota, Wisconsin and Washington identified 30 additional hybrid watermilfoil populations. In only three of these populations the hybrid watermilfoil was found to co-occur with M. spicatum. To facilitate the field identification of the two parental species and their hybrid, morphological data from watermilfoil specimens collected across the United States were evaluated. We determined that leaf segment/leaf length measurements can effectively distinguish M. spicatum and M. sibiricum; however, hybrids are intermediate for these characters and such measurements frequently overlap with respect to their parental taxa. By incorporating a combined molecular and morphological approach to identifying watermilfoils, the hybrids can be identified readily and their distributions elucidated both within and between lakes. Because hybrids may respond differently to local ecological conditions than their parents, information on their presence and distribution should be of particular importance to management and conservation programs.

Effects of Introduced Fishes on Wild Juvenile Coho Salmon in Three Shallow Pacific Northwest Lakes

AbstractDeclines in Pacific salmon Oncorhynchus spp. have been blamed on hydropower, overfishing, ocean conditions, and land use practices; however, less is known about the impacts of introduced fish. Most of the hundreds of lakes and ponds in the Pacific Northwest contain introduced fishes, and many of these water bodies are also important for salmon production, especially of coho salmon O. kisutch. Over 2 years, we examined the predation impacts of 10 common introduced fishes (brown bullhead Ameiurus nebulosus, black crappie Pomoxis nigromaculatus, bluegill Lepomis macrochirus, golden shiner Notemigonus crysoleucas, green sunfish L. cyanellus, largemouth bass Micropterus salmoides, pumpkinseed L. gibbosus, rainbow trout O. mykiss, warmouth L. gulosus, and yellow perch Perca flavescens) and two native fishes (cutthroat trout O. clarkii and prickly sculpin Cottus asper) on wild juvenile coho salmon in three shallow Pacific Northwest lakes, all located in different watersheds. Of these species, largemouth bass were responsible for an average of 98% of the predation on coho salmon in all lakes, but the total impact to each run varied among lakes and years. Very few coho salmon were eaten by black crappies, brown bullheads, cutthroat trout, prickly sculpin, or yellow perch, whereas other species were not observed to eat coho salmon. Juvenile coho salmon growth in all lakes was higher than in nearby streams. Therefore, food competition between coho salmon and introduced fishes in lakes was probably not limiting coho salmon populations. Largemouth bass are widespread and are present in 85% of lowland warmwater public‐access lakes in Washington (n = 421), 84% of those in Oregon (n = 179), and 74% of those in the eight northwesternmost counties in California (n = 19). Future research would help to identify the impact of largemouth bass predation across the region and prioritize lakes where impacts are most severe. Nevertheless, attempts to transplant or increase largemouth bass numbers in lakes important to coho salmon would be counterproductive to coho salmon enhancement efforts.

Densities of the Milfoil Weevil (Euhrychiopsis Iecontei) on Native and Exotic Watermilfoils

ABSTRACT We compared the densities of the milfoil weevil (Euhrychiopsis lecontei) on Eurasian (Myriophyllum spicatum, exotic host) and northern watermilfoil (M. sibiricum, native host). Two lakes in Washington, Corral Lake (northern watermilfoil) and Sawyer Lake (Eurasian watermilfoil), were surveyed throughout the summer in 1998. In addition, we surveyed 17 lakes once during the summer of 1999 to determine instantaneous densities of the weevil. Summer densities (all life stages) in Corral Lake ranged from 0.2 to 0.6 weevils/stem in 1998, with the greatest numbers of weevils observed the end of June and mid August. In Lake Sawyer, summer densities ranged from 0.0 to 0.8 weevils/stem in 1998; density was highest in June and declined during the summer. The weevil appears to have at least two generations during the summer on Eurasian and northern watermilfoil. The instantaneous density of weevils (all life stages) ranged from 0.0 to 0.6 weevils/stems in 1999. Densities were greater on northern than on Eurasian watermilfoil, but these differences were not statistically significant. Weevil density, however, was positively correlated with the percentage of stems with larval damage, but negatively correlated with the length (parallel to shore) of the watermilfoil bed. No significant relationships were found between weevil density and water quality or watermilfoil frequency of occurrence. Results indicate that neither density nor the number of summer generations differ significantly between the weevil's native and exotic host.

A Comparison of Electrofishing and Scuba Diving to Sample Black Bass in Western Washington Lakes

I examined the use of scuba diving as a nondestructive, cost-effective alternative to sampling black bass with an electrofishing boat, which can injure or kill fish, is not effective in clear water or water of extreme (low or high) conductivity, can be labor intensive, and can be difficult along developed shorelines as well as intrusive to residents. I compared the relative efficiency of nighttime electrofishing and daytime scuba diving for estimating the density and size structure of black bass in three western Washington lakes. Catch per unit effort (number of stock-length fish/400 m shoreline) of electrofishing and scuba diving did not differ significantly for largemouth bass Micropterus salmoides or smallmouth bass M. dolomieu. The length-frequency distributions of sub-stock-length and longer black bass sampled while electrofishing and scuba diving were not significantly different in two of the three lakes surveyed. In some cases, scuba diving may be preferable to electrofishing because of its low impact on the resource, because it does not have the same limitations with respect to water quality, and because it is less labor intensive.

Community participation in conserving and managing inland waters

Abstract Many international and national bodies have stressed the need for community participation in the conservation and management of inland waters. Community participation is needed for three basic reasons: to implement management measures difficult to enforce without community support; to act as a mechanism in protecting inland waters through support of conservation bodies; and, through voluntary actions, to monitor, restore and rehabilitate inland water‐bodies. It is important to conserve and manage inland waters because of their many values and uses. To participate fully in conservation and management measures, the community needs to (a) recognize the importance of inland waters as a part of the global hydrological cycle, (b) have some knowledge of the nature and effects of major human impacts on inland waters, and (c) be aware of certain legal issues. The ‘community’ is heterogeneous in nature but community groups of similar interest can be recognized. They vary from small, local action groups, through national groups to international bodies. They provide advice to and support government actions; others oppose and seek to change government actions. Community involvement can be at various levels, from the relatively inactive to the vigorously proactive. Environmental education of the community should begin in childhood, continue at school and other educational institutions, and last throughout life. Information on the conservation and management of inland waters is available from many sources, but a powerful, modern source is the World Wide Web. Four case studies are discussed with particular reference to community participation: Lake Washington and Mono Lake in the US (successful outcomes), the Aral Sea in central Asia and Lake Pedder in Australia (unsuccessful outcomes). Copyright © 2002 John Wiley &amp; Sons, Ltd.

Effects of Triploid Grass Carp on Aquatic Plants, Water Quality, and Public Satisfaction in Washington State

We investigated effects of triploid grass carp Ctenopharyngodon idella on aquatic macrophyte communities, water quality, and public satisfaction for 98 lakes and ponds in Washington State stocked with grass carp between 1990 and 1995. Grass carp had few noticeable effects on macrophyte communities until 19 months following stocking. After 19 months, submersed macrophytes were either completely eradicated (39% of the lakes) or not controlled (42% of the lakes) in most lakes. Intermediate control of submersed macrophytes occurred in 18% of lakes at a median stocking rate of 24 fish per vegetated surface acre. Most of the landowners interviewed (83%) were satisfied with the results of introducing grass carp. For sites where all submersed macrophytes were eradicated, average turbidity was higher (11 nephelometric turbidity units, NTU) than at sites where macrophytes were controlled to intermediate levels (4 NTU) or unaffected by grass carp grazing (5 NTU). Chlorophyll a was not significantly different between levels of macrophyte control; therefore, we concluded that most of this turbidity was abiotic and not algal. Triploid grass carp were a popular control option and effectively grazed most submersed macrophytes in Washington State. However, calculating stocking rates based on landowner estimates of aquatic plant coverage rarely resulted in intermediate levels of aquatic plant control. Additionally, the effects of particular stocking rates varied considerably. We recommend against using grass carp in Washington lakes where eradication of submersed vegetation cannot be tolerated.

On Determining the Principal Source of Phosphorus Causing Summer Algal Blooms in Western Washington Lakes

ABSTRACT Internal loading of total phosphorus (TP) calculated from mass balance averaged 68±21% of the total (internal + external) summer loading in 14 of 17 western Washington lakes that had internal loading. Moreover, whole-lake mean TP for the 16 lakes with complete mass balance data was 50 ±9 μg·L−1, which was similar to TP (51±18 μg·L−1) predicted from summer internal P loading determined by the maximum change in lake TP. Lake TP predicted from summer external loading, assuming a nominal retention coefficient, was only 30±9 μg·L−1. In-lake management measures to control internal loading had been either implemented or recommended in 14 of the 17 lakes. Summer P was substantially reduced in 10 of 12 lakes (or separate lake basins) receiving in-lake treatments, substantiating the dominant effect of internal loading. These observations indicate that emphasis on reducing external loads only, through watershed best-management practices (BMPs), without in-lake measures, would not have been the most cost-effective approach to control summer algal blooms in these lakes, especially if external loads were nonpoint and of minor importance during summer when algal problems are most prevalent. Comparison of external and internal P loads during summer, as illustrated here, is recommended so that in-lake controls are considered with watershed controls in a balanced approach to cost-effective lake management.

Amount of phosphorus inactivated by alum treatments in Washington lakes

The effectiveness of aluminum (Al) at retaining phosphate was investigated in alum‐treated Washington lake sediments. Greater than background concentrations of Al and Al‐bound phosphorus (Al‐P) were detected in three stratified lakes (Lake Ballinger, Phantom Lake, and Medical Lake) and in three unstratified lakes (Lake Erie, Cambell Lake, and Long Lake). The ratio of added Al to P (Al:Al‐P) was approximately 11:1 by weight in all six lakes. Added Al ranged from 6 to 83 g Al m‐2 , and adsorbed P subsequently ranged from 0.5 to 7.3 g P m‐2. P bound to the added Al was apparently removed from the P cycle, as the layers of increased Al‐P due to treatment were buried in the sediment at a depth corre‐sponding to the approximate time since treatment.

Mercury and methyl mercury in freshwater seston: direct determination at picogram per litre levels by dual filtration

Here, we describe a method for directly determining sestonic mercury in lake waters at concentrations ranging down to 0.12 ng Hg/L (total Hg) and 0.01 ng MeHg/L (monomethyl mercury) in a 250-mL water sample. Detection limits for the method are 30 pg of Hg and 3.0 pg of MeHg, reported as three times the standard deviation of a procedural blank. The method involves dual filtration using ultraclean 47-mm-diameter, 0.45-µm pore size cellulose nitrate filters in an all-Teflon® filter stack. Lake water is pumped directly through a primary filter that traps suspended seston particles and then through a secondary filter that is used to estimate the integrated reagent, filter, and sorption blank. Both filters are analyzed for Hg or MeHg and the primary filter is corrected by subtracting the secondary blank. Sestonic Hg is determined after acid digestion and wet oxidation of the filters with BrCl, reduction with NH2OH-HCl followed by SnCl2, and purging via N2 onto dual gold traps for detection via cold-vapor atomic fluorescence spectroscopy. Sestonic MeHg is determined after acid distillation of the filters, aqueous-phase ethylation, purging onto Tenax®, isothermal gas chromatography separation, and detection by cold-vapor atomic fluorescence spectroscopy. The method was tested on a variety of lakes in Wisconsin, Florida, and Washington. The blank-corrected mass of sestonic mercury collected from these lakes onto primary filters ranged from 30 to 340 pg Hg and from 3 to 23 pg MeHg. The corresponding concentrations of mercury in the seston were 22-790 ng Hg/g dry weight and 3-75 ng MeHg/g dry weight. The method allowed us to demonstrate a clear negative dependence of sestonic mercury concentrations (weight:weight) on pH in Wisconsin lakes.

Monitoring warm‐water fish populations in north temperate regions: sampling considerations when using proportional stock density

AbstractThree lakes were repeatedly sampled at night using boat electric fishing, experimental gill netting, and fyke netting from May to November 1993 to evaluate the feasibility of using proportional stock density (PSD) to monitor warm‐water fish populations in Washington State, USA. Additionally, average night‐time boat electric fishing catch‐per‐effort of largemouth bass, Micropterus salmoides (Lacepéde), from 30 Washington lakes was also analysed to determine the amount of effort required to obtain adequate samples for precise PSD estimates. Temporal variations in PSD were not large enough to affect the management of warm‐water fish populations in the small Washington lakes studied. However, the considerable effort required to obtain precise PSD estimates may limit its usefulness for warm‐water fisheries surveys in the Pacific Northwest. On average, from three to 13 nights of electric fishing effort are needed to capture enough stock‐length largemouth bass for PSD estimates, depending on the precision desired (80–95%) and the location of the lake (eastern or western Washington). Catch of stock‐length fish can be maximized by using electric fishing for centrarchids and gill netting for yellow perch, Perca flavescens (Mitchill), in June or September. Adequate samples for precise PSD estimates can be difficult to obtain from Pacific Northwestern lakes, even when using recommended gear at optimum sampling times. Inability to capture an adequate sample size for precise PSD estimates may be responsible for some of the fluctuation in PSDs in some studies of warm‐water fish populations in northern areas. Managers in other northern climates may find that low sample size may account for large variations in PSDs reported.

Survival and Growth of Channel Catfish Stocked in Washington Lakes

Abstract Channel catfish Ictalurus punctatus have resided in the Pacific Northwest for more than 100 years; however, few studies have investigated their efficacy for providing put-grow-and-take sport fisheries in lakes of this region. We stocked channel catfish fingerlings into six Washington lakes containing established warmwater fish populations to evaluate their survival and growth. The survival of channel catfish stocked at 50–200 mm total length (TL) ranged from 0 to 22% (mean survival 9%) 13–15 months following stocking, which was less than that recorded in many other studies. Growth of a group of channel catfish stocked at 151–200 mm TL ranged from 236 to 405 mm 13 months following stocking, which was similar to that in regions farther east and south. With improved survival, possibly by stocking fingerlings longer than 150 mm TL, channel catfish could provide significant recreational opportunities in selected Pacific Northwest lakes.

Mortality of Largemouth Bass (Micropterus salmoides) and Steelhead Trout (Oncorhynchus mykiss) in Densely Vegetated Littoral Areas Tested Usingin situBioassay

ABSTRACT Concentrations of dissolved oxygen (DO) in dense beds of aquatic macrophytes in two western Washington lakes were routinely measured below reported lethal limits (≤1 mg L−1) for largemouth bass (Micropterus salmoides) and steel head trout (Oncorhynchus mykiss). The impact of the observed low DO concentrations on resident fish was examined both by field observation and by conducting 72 hour in situ cage bioassays. Replicate cages were placed in two Western Washington lakes at the surface, 1 m, and 2 m deep, in dense patches of aquatic macrophytes and open water. No steelhead trout mortalities occurred over 72 hours in the open water or surface water in dense patches of Myriophyllum spicatumia Lake Washington where DO concentrations were consistently > 4.0 mg L−1. No significant mortality of steelhead trout occurred in the surface cages of the floating leaf Nymphaea odorata, but all fish were dead within 12 hr at 1 m, where concentrations of DO were consistently < 4 mg L−1. No significant mortaliti...

Adaptedness of Noble Fir (Abies procera Rehd.) Beyond Its Northern Limit

Abstract The adaptedness of noble fir (Abies procera Rehd.) beyond its northern limit was examined at 12 locations distributed throughout the Maritime, Submaritime, and Subcontinental climates in south coastal British Columbia. Ten-year testing results demonstrated large site effects. Noble fir planted in the Maritime climate survived better, grew faster, entered the period of accelerated growth earlier, and maintained a higher growth rate. In the Maritime climate, the reforestation range of noble fir can be extended considerably north of its current natural distribution and to lower elevations. Low winter temperature and growing-season soil moisture appear to be the major environmental factors limiting the species' expansion into more continental climates, and these factors must be considered in planting site selection. Provenance differences in both growth and survival were significant but small compared to site differences. Adaptive variation showed gentle geographic clines indicating that northern provenances were better adapted in the Maritime climate, whereas inland provenances were superior in the Submaritime climate. Lack of strong geographic patterns suggests that local environmental factors may be important to the adaptive variation of the species. The test results suggest that introduction of noble fir to British Columbia should be limited to the Maritime region, and that northern provenances, such as French Butte, McKinley Lake, and Stevens Pass in Washington are the primary seed sources. For. Sci. 40(3):412-428.

Paleolimnological investigations of human disturbance in Western Washington lakes

Paleolimnological investigations of human disturbance in Western Washington lakes