Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Fish and Fisheries”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81Linked to original sources
USGS2004

Swimming performance of upstream migrant fishes in open-channel flow: A new approach to predicting passage through velocity barriers

The ability to traverse barriers of high-velocity flow limits the distributions of many diadromous and other migratory fish species, yet very few data exist that quantify this ability. We provide a detailed analysis of sprint swimming ability of six migratory fish species (American shad (Alosa sapidissima), alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), striped bass (Morone saxatilis), walleye (Stizostedion vitreum), and white sucker (Catostomus commersoni)) against controlled water velocities of 1.5-4.5 m??s-1 in a large, open-channel flume. Performance was strictly voluntary: no coercive incentives were used to motivate fish to sprint. We used these data to generate models of maximum distance traversed, taking into account effects of flow velocity, body length, and temperature. Although the maximum distance traversed decreased with increasing velocity, the magnitude of this effect varied among species. Other covariate effects were likewise variable, with divergent effects of temperature and nonuniform length effects. These effects do not account for all of the variability in performance, however, and behavioral traits may account for observed interspecific differences. We propose the models be used to develop criteria for fish passage structures, culverts, and breached dams.

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS2012

Structure of marine predator and prey communities along environmental gradients in a glaciated fjord

Spatial patterns of marine predator communities are influenced to varying degrees by prey distribution and environmental gradients. We examined physical and biological attributes of an estuarine fjord with strong glacier influence to determine the factors that most influence the structure of predator and prey communities. Our results suggest that some species, such as walleye pollock ( Theragra chalcogramma ), black-legged kittiwake ( Rissa tridactyla ), and glaucous-winged gull ( Larus glaucescens ), were widely distributed across environmental gradients, indicating less specialization, whereas species such as capelin ( Mallotus villosus ), harbor seal ( Phoca vitulina ), and Kittlitz's murrelet ( Brachyramphus brevirostris ) appeared to have more specialized habitat requirements related to glacial influence. We found that upper trophic level communities were well correlated with their mid trophic level prey community, but strong physical gradients in photic depth, temperature, and nutrients played an important role in community structure as well. Mid-trophic level forage fish communities were correlated with the physical gradients more closely than upper trophic levels were, and they showed strong affinity to tidewater glaciers. Silica was closely correlated with the distribution of fish communities, the mechanisms of which deserve further study.

Alaska↗
USGS1973

Endrin uptake and release by fingerling channel catfish (Ictalurus punctatus)

Fingerling channel catfish ( Ictalurus punctatus ) offered diets containing 0.04–4.0 μg endrin/g food (dry weight) rapidly accumulated the pesticide. Amounts in the tissues were directly proportional to amounts in the food. Dietary endrin had no measurable effect on growth or mortality. After endrin was withdrawn from the diet, it rapidly disappeared and could not be detected after 41 days. In fish exposed to 0.5 μg endrin/liter of water, mortalities began at tissue levels of 0.7 μg endrin/g of wet whole fish and total mortality occurred at levels near 1.0 μg/g.

Journal of the Fisheries Research Board of Canada↗
USGS1980

Sterility method of pest control and its potential role in an integrated sea lamprey ( Petromyzon marinus ) control program

The sterility method of pest control could be an effective tool in the sea lamprey ( Petromyzon marinus ) control program in the Great Lakes. Some of the requirements for its successful application have been met. A field study demonstrated that the release of male sea lampreys, sterilized by the injection of 100 mg/kg of P , P -bis(1-aziridinyl)- N -methylphosphinothioic amide (bisazir), will reduce the number of viable larvae produced. The actual reduction in reproductive success that occurred was directly related to the ratio of sterile to normal males in the population. The technique can be used in many ways in an integrated control program and has considerable potential for the more effective control of the sea lamprey. Eradication is a distinct possibility. Key words : sea lamprey, Petromyzon marinus ; pest control, fish control, sterile-male technique, sterilization, chemosterilants, bisazir, Great Lakes

Canadian Journal of Fisheries and Aquatic Sciences↗
USGS1948

The value of certain drugs, especially sulfa drugs, in the treatment of furunculosis in brook trout, Salvelinus fontinalis

Furunculosis of salmonoid fishes is a dread epizootic disease caused by a general infection by Bacterium salmonicida. In this experiment, treatment was tried with sulfonamides and another drug, “furacin” or “2–20–99” (new drug). The four treatments first used were: (1) sulfamerazine, (2) sulfathiazole, and (3) furacin, each administered by being mixed with the food; and (4) furacin added to the water of the troughs. For assignment of treatments, the troughs containing fingerling brook trout, approximately 8 months old and running 30 to the pound, were grouped in four blocks of five troughs–three blocks of fingerlings with furunculosis, and one block of fingerlings of similar age and size but free from this disease. In each block, one trough received no medication. The various treatments were assigned to troughs by random selection. The block of healthy fish was to test for possible serious ill effects from any of the treatments, and was located some distance from the infected fish. Treatments were begun August 30, 1945, and those involving sulfamerazine and sulfathiazole were continued through 25 days. The furacin treatments, less promising than the sulfonamide treatments, were replaced by sulfanilamide and sulfadiazine, each in the food, on the sixteenth day. Furacin in the water was not beneficial but furacin in the food had some helpful effect. Results with sulfanilamide and sulfadiazine were not encouraging. Sulfathiazole seems to have been more beneficial than furacin, but decidedly less effective than sulfamerazine. The improvement with sulfamerazine was impressive. Mortality dropped rapidly within a few days, generally was light after a week, and within 2 weeks almost completely stopped. Through 25 days, the loss was 17 percent, as compared with 50 percent among the infected lots not receiving medication. The data indicate that 8 grams of sulfamerazine per day per 100 pounds of fish is sufficient, and that a considerably lower dose is at least beneficial. Until further information is available, 8 grams of sulfamerazine per day per 100 pounds of fish, to be continued for at least 6 days after mortality stops, is recommended.

Transactions of the American Fisheries Society↗
USGS1952

Movements of yellow perch marked in southern Green Bay, Lake Michigan, in 1950

To obtain information on the post-spawning movements of yellow perch that spawn in southern Green Bay, Lake Michigan, 4,172 fish caught in drop nets were marked by tagging with monel-metal strap tags attached to the right operculum and 24,799 were marked by clipping off the second or membranous dorsal fin. Marking was done during the period from May 3 to 17, 1950, at six main stations, all located in the southern end of Green Bay. The average length of the tagged perch was 7.3 inches and all fell within the range 5.5–14.4 inches. Most (90.9 percent) of the fish were below the minimum legal length of 8.0 inches. The follow-up procedure consisted of informing commercial and sports fishermen of the program and enlisting their cooperation in watching for marked fish; accounts of the investigation were released through newspapers and descriptive posters were distributed. The personnel connected with the investigation examined catches frequently. The large majority (101 or 79.5 percent) of the 127 tagged perch recaptured in the experimental nets during the marking operations were retaken at the tagging station at which they were released. Of the 108 tagged perch captured by commercial fishermen and anglers following the opening of the season on May 20, 96 were taken by drop nets, 6 by gill nets, and 6 by hook and line. The mean lengths for the three groups were 7.7, 7.1, and 9.25 inches, respectively. All recoveries were made in the Wisconsin waters of Green Bay. Most of the “open-season” recoveries (86 fish; 79.6 percent) were made during the period May 20-May 31. Recaptures during subsequent months were: June–14; July–7; August–none; September–1. Of the 86 perch recaptured May 20–31, 70 were retaken inside and 16 outside the tagging area. The majority (14 of 22) of those recovered after May 31 were retaken outside the tagging area. The average length of the 20 tagged yellow perch recaptured by drop nets (data restricted to fish from a single type of net to avoid bias from gear selectivity) outside the tagging area (8.42 inches) was 0.96 inch greater than the mean length (7.46 inches) of the 76 fish retaken inside the area. This statistically highly significant difference lends support to the belief of commercial fishermen that the larger of the yellow perch that spawn in southern Green Bay move out soon after spawning. The percentage of recapture of tagged perch increased sharply with increase in the size of the fish. Not one of 169 tagged fish less than 6.5 inches long was recovered. The rates of recapture at greater lengths were: 6.5 to 8.9 inches–2.5 percent; 9.0 to 9.9 inches–11.4 percent; 10.0 to 14.4 inches–16.7 percent. Among the several factors suggested in explanation of this relationship, the most important appear to be the lesser ability of the smaller fish to survive the rigors of handling and tagging, greater loss of tags from the smaller fish, and the greater likelihood of overlooking the smaller of the tagged fish in the sorting of the catch. The factors just mentioned and the lack of knowledge of the efficiency of measures taken to obtain records of recoveries preclude the 2.6-percent return of all tagged fish from being accepted as an approximation of the rate of recapture. Neither should the 6.6-percent return of tagged fish of legal size (8 inches and longer) be taken as an estimate of the rate of exploitation. Although 465 fin-clipped perch were recovered in the experimental nets during the marking operations, only 68 of 24,799 fish so marked were recovered after the fishing season opened. All but one of these 68 were retaken near the point of marking. The difficulty of detecting a perch with a missing membranous dorsal is believed to be a major cause of the poor returns from fin-clipped fish. These investigations have demonstrated that for studying migration of yellow perch, tagging is superior to fin-clipping as a method of marking. The technique of the tagging, however, needs to be improved, and better means must be found to trace tagged fish of small size. Furthermore certain small regions in the bay not at present open to commercial fishing must be explored in order to obtain more comprehensive information as to migration.

Transactions of the American Fisheries Society↗
USGS1989

Distribution and migration of adult striped bass in Lake Whitney, Texas

Thirty adult (3.2–8.6 kg) striped bass Morone saxatilis were tagged with ultrasonic transmitters and tracked for up to 475 d in 9,510‐hectare Lake Whitney, a Texas reservoir, to determine seasonal distribution, migration patterns, and water temperatures occupied. Striped bass distribution in summer was limited to an area near the dam, where they survived temperatures as high as 29.0°C. Tagged fish generally were found in the coolest water available (27.0–29.0°C) that contained adequate dissolved oxygen (>4.0 mg/L) in summer and occupied the warmest water (7.4–8.8°C) in winter. For the rest of the year, the fish were distributed throughout available water temperatures. Beginning in autumn, most striped bass moved up the reservoir to and into the main tributaries and remained there until spring, when they returned to the main reservoir. No spawning run up main tributaries was observed in either of the two study years, possibly due to low inflows. Individual fish displayed a preference for certain areas to which they returned yearly.

Texas↗
USGS1999

Movements of adult chinook salmon during spawning migration in a metals-contaminated system, Coeur d'Alene River, Idaho

Spawning migration of adult male chinook salmon Oncorhynchus tshawytscha was monitored by radio telemetry to determine their response to the presence of metals contamination in the South Fork of the Coeur d'Alene River, Idaho. The North Fork of the Coeur d'Alene River is relatively free of metals contamination and was used as a control. In all, 45 chinook salmon were transported from their natal stream, Wolf Lodge Creek, tagged with radio transmitters, and released in the Coeur d'Alene River 2 km downstream of the confluence of the South Fork and the North Fork of the Coeur d'Alene River. Fixed telemetry receivers were used to monitor the upstream movement of the tagged chinook salmon through the confluence area for 3 weeks after release. During this period, general water quality and metals concentrations were monitored in the study area. Of the 23 chinook salmon observed to move upstream from the release site and through the confluence area, the majority (16 fish, 70%) moved up the North Fork, and only 7 fish (30%) moved up the South Fork, where greater metals concentrations were observed. Our results agree with laboratory findings and suggest that natural fish populations will avoid tributaries with high metals contamination.

Transactions of the American Fisheries Society↗
USGS1999

Laboratory evaluation of a lake trout bioenergetics model

Lake trout Salvelinus namaycush , aged 3 and 6 years and with average weights of 700 and 2,000 g, were grown in laboratory tanks for up to 407 d under a thermal regime similar to that experienced by lake trout in nearshore Lake Michigan. Lake trout were fed alewife Alosa pseudoharengus and rainbow smelt Osmerus mordax , prey typical of lake trout in Lake Michigan. Of the 120 lake trout used in the experiment, 40 were fed a low ration (0.25% of their body weight per day), 40 were fed a medium ration (0.5% of their body weight per day), and 40 were fed a high ration (ad libitum). We measured consumption and growth, and we compared observed consumption with that predicted by the Wisconsin bioenergetics model. For lake trout fed the medium ration, model predictions for monthly consumption were unbiased. Moreover, predicted cumulative consumption by medium-ration lake trout for the entire experiment (320 d for smaller lake trout and 407 d for larger lake trout) agreed quite well with observed cumulative consumption; predictions were as close as within 0.1 to 5.2% of observed cumulative consumption. Even so, the model consistently overestimated consumption by low-ration fish and underestimated consumption by high-ration fish. The bias was significant in both cases, but was more severe for the low-ration trout. Because the low-ration and high-ration regimes were probably unrealistic for lake trout residing in Lake Michigan and because the model fit our laboratory data rather well for medium-ration trout, we conclude that applying the Wisconsin bioenergetics model to the Lake Michigan lake trout population in order to estimate the amount of prey fish consumed by lake trout each year is appropriate.

Transactions of the American Fisheries Society↗
USGS2000

Growth and food consumption by tiger muskellunge: Effects of temperature and ration level on bioenergetic model predictions

We measured growth of age-0 tiger muskellunge as a function of ration size (25, 50, 75, and 100% C max ) and water temperature (7.5–25°C) and compared experimental results with those predicted from a bioenergetic model. Discrepancies between actual and predicted values varied appreciably with water temperature and growth rate. On average, model output overestimated winter consumption rates at 10 and 7.5°C by 113 to 328%, respectively, whereas model predictions in summer and autumn (20–25°C) were in better agreement with actual values (4 to 58%). We postulate that variation in model performance was related to seasonal changes in esocid metabolic rate, which were not accounted for in the bioenergetic model. Moreover, accuracy of model output varied with feeding and growth rate of tiger muskellunge. The model performed poorly for fish fed low rations compared with estimates based on fish fed ad libitum rations and was attributed, in part, to the influence of growth rate on the accuracy of bioenergetic predictions. Based on modeling simulations, we found that errors associated with bioenergetic parameters had more influence on model output when growth rate was low, which is consistent with our observations. In addition, reduced conversion efficiency at high ration levels may contribute to variable model performance, thereby implying that waste losses should be modeled as a function of ration size for esocids. Our findings support earlier field tests of the esocid bioenergetic model and indicate that food consumption is generally overestimated by the model, particularly in winter months and for fish exhibiting low feeding and growth rates.

Transactions of the American Fisheries Society↗
USGS1996

Natural thermal refugia for temperate warmwater stream fishes

The seasonal use of an Ozark spring branch by fishes was evaluated from January 1993 to January 1995. Temperatures in the spring branch were fairly constant, at 13.5 ± 1°C, and usually exceeded the temperature of a receiving stream during the November–March coldwater period. Black redhorse Moxostoma duquesnei , smallmouth bass Micropterus dolomieu , shadow bass Ambloplites ariommus , and longear sunfish Lepomis megalotis showed a temporal pattern of use in the spring branch. The lowest use was during the April–October warmwater period, and the greatest use was during the coldwater period. During cold periods, biomass of these four species in the spring branch was significantly greater and fish size significantly larger than in similar habitats in the adjoining stream. The weight per unit length of fish using the spring branch during cold periods was also significantly greater. Shadow bass and longear sunfish had significantly greater relative stomach contents than conspecifics in equivalent habitats from the adjoining stream, but had similar relative numbers of eggs. Large concentrations of adult fish used spring branches during the coldwater period, and these fish may be more vulnerable to angling than conspecifics in similar habitats in adjoining streams dominated by surface water. Thus, we suggest that stream managers consider the usefulness of fish refuges in spring branches and adjacent thermally influenced areas.

Missouri↗
USGS2005

Refining boat electrofishing equipment to improve consistency and reduce harm to fish

A major concern with electrofishing is the standardization of sampling equipment and methods, particularly when collections are used to monitor spatial and temporal changes in fish communities. Standardization can not only ensure that stock assessment is consistent - that is, the data collected over time and space have equal meaning and are not influenced by differences in gear or gear application - but also reduce injury by constraining power to ranges that are likely to immobilize fish but unlikely to harm them. Standardization of electrofishing equipment requires adjusting power output to keep constant the amount of power transferred to fish in diverse water conditions. In this study, the power level thresholds required to immobilize and injure fish under controlled laboratory conditions were identified for various size-species combinations and applied to establish power minima and maxima suitable for successful and safe boat electrofishing. The target settings identified allowed survival of 99.4% of the fish collected and held for 2-3 h during field trials; all the mortalities were small fish (???53 mm long). The standardization procedure described herein may be adapted to single boats or fleets and can promote consistency in electrofishing, although it does not completely avoid harm to fish. Because electrofishing is an active capture method applied to changing microenvironments, complete standardization and total avoidance of harm to individual fish are not feasible with present technology, but standardization of controllable variables is advisable.

North American Journal of Fisheries Management↗
USGS2006

The effects of river impoundment and hatchery rearing on the migration behavior of juvenile steelhead in the Lower Snake River, Washington

We used radiotelemetry to monitor the migration behavior of juvenile hatchery and wild steelhead Oncorhynchus mykiss as they migrated through Lower Granite Reservoir and Dam on the lower Snake River, Washington. From 1996 to 2001, we surgically implanted radio transmitters in 1,540 hatchery steelhead and 1,346 wild steelhead. For analysis, we used the inverse Gaussian distribution to describe travel time distributions for cohorts (>50 fish) of juvenile steelhead as they migrated downriver. Mean travel rates were significantly related to reach- and discharge-specific water velocities. Also, mean travel rates near the dam were slower for a given range of water velocities than were mean travel rates through the reservoir, indicating that the presence of the dam caused delay to juvenile steelhead over and above the effect of water velocity. Hatchery steelhead took about twice as long as wild steelhead to pass the dam as a result of the higher proportions of hatchery steelhead traveling upriver from the dam. Because upriver travel and the resulting migration delay might decrease survival, it is possible that hatchery steelhead survive at lower rates than wild steelhead. Our analysis identified a discharge threshold (???2,400 m3/s) below which travel time and the percentage of fish traveling upriver from the dam increased rapidly, providing support for the use of minimum flow targets to mitigate for fish delay and possibly enhance juvenile steelhead survival.

Washington↗
USGS2007

Temperature-mediated differences in bacterial kidney disease expression and survival in Renibacterium salmoninarum-challenged bull trout and other salmonids

Resource managers considering restoration and reconnection of watersheds to protect and enhance threatened populations of bull trout Salvelinus confluentus have little information about the consequences of bacterial kidney disease (BKD) caused by Renibacterium salmoninarum. To better understand the response of bull trout to R. salmoninarum challenge, we conducted several laboratory experiments at two water temperatures. The extent, severity, and lethality of BKD in bull trout were compared with those of similarly challenged lake trout S. namaycush, Arctic char S. alpinus, Chinook salmon Oncorhynchus tshawytscha, and rainbow trout O. mykiss. The lethal dose of bacterial cells necessary to induce 50% mortality (LD50) was 10-fold lower at the 15??C challenge than at the 9??C challenge. Of the species tested, bull trout were relatively resistant to BKD, Arctic char were the most susceptible among Salvelinus species, and Chinook salmon were the most susceptible among Oncorhynchus species tested. Mean time to death was more rapid for all fish tested at 15??C than for fish challenged at 9??C. These results suggest that infection of bull trout with BKD likely poses a low risk to successful restoration of threatened populations. ?? Copyright by the American Fisheries Society 2007.

North American Journal of Fisheries Management↗
USGS2010

The bioenergetic consequences of invasive-induced food web disruption to Lake Ontario alewives

Alewives Alosa pseudoharengus are the dominant prey fish in Lake Ontario, and their response to ecological change can alter the structure and function of the Lake Ontario food web. Using stochastic population-based bioenergetic models of Lake Ontario alewives for 1987–1991 and 2001–2005, we evaluated changes to alewife production, consumption, and associated bioenergetic ratios after invasive-induced food web disruption. After the disruption, mean biomass of alewives declined from 28.0 to 14.6 g/m 2 , production declined from 40.8 to 13.6 g·m −2 ·year −1 , and consumption declined from 342.1 to 137.2 g·m −2 ·year −1 , but bootstrapping of error sources suggested that the changes were not statistically significant. Population-based bioenergetic ratios of production to biomass ( P/B ratio), total consumption to biomass ( Q/B ratio), and production efficiency did not change. Pathways of energy flow measured as prey-group-specific Q/B ratios changed significantly between the two time periods for invasive predatory cladocerans (from 0.6 to 1.3), Mysis diluviana (from 0.4 to 2.5), and other prey (from 0.8 to 0.1), but the observed decline in the zooplankton Q/B ratio (from 10.6 to 5.5) was not significant. Gross production efficiency did not change; values ranged from 8% to 15%. Age-group mean gross conversion efficiency (GCE) declined with age; GCE ranged from 7.5% to 11.0% for yearlings, was approximately 5% for age-2 alewives, and was less than 2% for age-3 and older alewives. The GCE increased significantly between the time periods for yearling alewives. Our analyses support the hypothesis that after 2003, alewives could not sustain their growth while feeding on zooplankton closer to shore. Modeling of observed spatial variation in diet and alternative occupied temperatures demonstrates the potential for reducing consumption by alewives. Our results suggest that Lake Ontario alewives can exploit spatial heterogeneity in resource patches and thermal habitat to partially mitigate the effects of food web disruption. Fish management implications are discussed.

North American Journal of Fisheries Management↗
USGS2010

Influences of acid mine drainage and thermal enrichment on stream fish reproduction and larval survival

Potential effects of acid mine drainage (AMD) and thermal enrichment on the reproduction of fishes were investigated through a larval-trapping survey in the Stony River watershed, Grant County, WV. Trapping was conducted at seven sites from 26 March to 2 July 2004. Overall larval catch was low (379 individuals in 220 hours of trapping). More larval White Suckers were captured than all other species. Vectors fitted to nonparametric multidimensional scaling ordinations suggested that temperature was highly correlated to fish communities captured at our sites. Survival of larval Fathead Minnows was examined in situ at six sites from 13 May to 11 June 2004 in the same system. Larval survival was lower, but not significantly different between sites directly downstream of AMD-impacted tributaries (40% survival) and non-AMD sites (52% survival). The lower survival was caused by a significant mortality event at one site that coincided with acute pH depression in an AMD tributary immediately upstream of the site. Results from a Cox proportional hazard test suggests that low pH is having a significant negative influence on larval fish survival in this system. The results from this research indicate that the combination of low pH events and elevated temperature are negatively influencing the larval fish populations of the Stony River watershed. Management actions that address these problems would have the potential to substantially increase both reproduction rates and larval survival, therefore greatly enhancing the fishery.

Northeastern Naturalist↗
USGS1961

Use of 3-trifluormethyl-4-nitrophenol as a selective sea lamprey larvicide

The recent discovery of a group of chemical compounds that are significantly more toxic to sea lampreys than to other aquatic organisms offers promise of an early and effective control of this pest. The sea lamprey has all but destroyed the lake trout populations of Lakes Huron and Michigan. In Lake Superior, production of the lake trout fishery has declined to record low levels. Only a rapid and drastic reduction in sea lamprey predation can save the lake trout population there. Other species of food and game fishes have suffered severe decreases from persistent attack by the lamprey. The sea lamprey spends only a small portion of its life as a parasite in the Great Lakes. The fully grown and sexually mature adults migrate into streams to spawn and thereafter die. The eggs hatch in a week to 10 days and the larvae remain in the stream bottom for 5 years or longer before metamorphosis into the adult form. Following this transformation the young lampreys migrate downstream to the lakes to begin their parasitic existence. The life cycle of the sea lamprey has been described in detail elsewhere (Applegate 1950; Applegate and Moffett 1955). Control of the adult lampreys distributed throughout a body of open water as large as one of the Great Lakes, by known and available techniques, is not feasible. Fortunately, this pest can be attacked effectively at those stages in its life cycle when it is concentrated in restricted areas. Various devices have been developed which prevent spawning by blocking the streams below the spawning grounds. Electrical weirs, that repel or destroy the lampreys, have been used (Applegate, Smith, and Nielsen 1952; Erkkila, Smith, and McLain 1956). A serious shortcoming of this control method is the time required to achieve the desired effect. Even though the adults have been destroyed before spawning, 5 or more generations of larval lampreys are already in the stream-enough to provide an annual supply of parasitic adults for an equal period of time. Almost all the larvae of the sea lamprey live in the spawning streams. Treatment of these streams with selectively toxic chemicals that kill the larvae provides immediate reduction of all generations in the population before they become parasites. Control of the species can thus be achieved without a delay of several years.

Technical Report↗
USGS1988

Proceedings of a workshop on the development and evaluation of habitat suitability criteria: A compilation of papers and discussions presented at Colorado State University, Fort Collins, Colorado, December 8-12, 1986

The development of reliable habitat suitability criteria is critical to the successful implementation of the Instream Flow Incremental Methodology (IFIM), or any other habitat based evaluation technology. It is also a fascinating topic of research, for several reasons. First, the “science” of habitat quantification is relatively young. Descriptions of habitat use and partitioning can be traced back to Darwin, if not further. Attempts to actually quantify habitat use can be found predominantly during the last two decades, with most of the activity occurring in about the last five years. Second, this work is challenging because we are usually working with fish or some other organism that lives out of sight in an environment that is foreign to humans. Most of the data collection techniques that have been developed for standard fisheries work are unsuited, without modification, for criteria development. These factors make anyone involved in this type of research a pioneer, of sorts. Pioneers often make new and wonderful discoveries, but they also sometimes get lost. In our opinion, however, there is an even more rewarding aspect to criteria development research. It seems that the field of biology has tended to become increasingly clinical over the years. Criteria development demands the unobtrusive observation of organisms in their natural environment, a fact that allows the biological to be a naturalist and still get paid for it. The relative youth and importance of habitat quantification have resulted in rapid advancements in the state of the art. The expansion of methods is vividly demonstrated simply by comparing the two Instream Flow Information Papers written on the subject in 1978 and in 1986. One of the missions of the Aquatic Systems Branch (formerly the Instream Flow Group) is to serve as a clearinghouse for new techniques and methods. In keeping with this role, a workshop was conducted during December 1986 to discuss current and newly evolving methods for developing and evaluating habitat suitability criteria. Participation in this workshop was largely by invitation only. The objective was to obtain insights into problems and possible solutions to criteria development, from the perspective of professionals closely involved with the subject. These proceedings of that workshop are intended to supplement the information contained in Instream Flow Information Paper 21, "Development and Evaluation of Habitat Suitability Criteria for Use in the Instream Flow Incremental Methodology." The workshop was closely arranged in five sessions, roughly following the outline of Information Paper 21. The first session dealt with various aspects of study design and how they can influence the outcome of a study. Session two investigated techniques for developing criteria from professional judgment, and some of the problems encountered when personal or agency prejudice enters the picture. Session three concentrated on field data collection procedures, whereas session four examined methods of converting field data into curves. Field verification studies were discussed in session five. Each presentation in the workshop was followed by a question and answer period of 15 to 30 minutes. These discussions were recorded, transcribed, and appended to the end of each paper in these proceedings. We have attempted to capture the essence of these discussions as accurately as possible, but hope that the reader can appreciate the difficulty in translating a free-ranging discussion (from a barely audible tape) to something that makes sense in print. These question and answer sessions constitute the peer review for each of the papers. This provides the reader with the unique opportunity to review the interactions between authors and reviewers.

Book↗