DOCSLIB.ORG

The Brown Trout in Maine

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Brown Trout in Maine THE BROWN TROUT IN MAINE Carl N. Fenderson Regional Fishery Biologist Fishery Research and Management Division PUBLISHED BY Maine Department of Inland Fisheries and Game ROLAND H. COBB, Commissioner Augusta, Maine 1954 TABLE OF CONTENTS Page Introduction 3 PART I Brief History of the Brown Trout in Maine 5 Some Facts About Brown Trout 5 Brown Trout vs. Landlocked Salmon 6 Returns to the Fishermen 8 Summary 11 References 11 PART II How to Tell Brown Trout from Salmon 12 2 THE BROWN TROUT IN MAINE INTRODUCTION The advisability of introducing brown trout, Salmo trutta Linnaeus, into lakes and streams of Maine has long been a con- troversial issue. A native of Europe, this fish has been artifi- cially propagated and distributed all over the world, frequently as a substitute for some native species no longer considered capable of supporting a sport fishery. Coming as it has from various European areas, the brown trout is known by a variety of common names. Some of the more commonly used names are Scotch sea-trout, sea-run brown trout, Von Behr trout, Loch Leven trout, German trout, and Swiss lake trout. Recent advances in fishery science have shown that the intro- duction of fishes not native to a region must be attended with care. Brown trout were introduced into Maine waters in large numbers by early fish-culturists as a possible, convenient solu- tion to a supposed decline in the native salmon fishery. Intro- duction of brown trout into Maine waters takes on added signif- icance with the realization that the life histories and habitat requirements of the native landlocked salmon, Salmo salar Lin- naeus, and brown trout are very similar. In fact it is this last consideration that primarily interests us here in Maine. Most other states do not have the landlocked salmon, at least not as a native species supporting a sizeable sport fishery. For this reason we must evaluate our position concerning brown trout very carefully. The Fisheries Research and Management Division has just completed, as one of its several research proj- ects, a two-year study of the brown trout in a typical Maine lake. Branch Lake, Ellsworth, was chosen for the study because of its reputation as a brown trout lake, and because it possesses physical characteristics in common with many other Maine lakes. Data obtained from other Maine lakes were also utilized in the study. Results of this study are summarized in two parts. In Part I the relationships between brown trout and our native game fishes are discussed; Part II deals with the field identification of brown trout and salmon. 3 This booklet was written primarily for the sportsman. Bulky tables and technical data of interest only to fisheries workers have been omitted. The work was undertaken with Federal Aid to Fish Restora- tion funds under Dingell-Johnson Project Number F-8-R. Grateful acknowledgment is due the following persons for their assistance in conducting the study and preparing the manu- script: Dr. W. Harry Everhart and members of the Fishery Research and Management Division, Department of Inland Fish- eries and Game; Mr. Robert S. Rupp; and Messrs. Edward and William Hanson. The color print of the brown trout was photographed by Mr. Arthur Rogers, Warden Supervisor, Department of Inland Fish- eries and Game. The author is indebted to Mrs. Jane Ingraham Rupp for pre- paring the drawings and graph. 4 PART I BRIEF HISTORY OF THE BROWN TROUT IN MAINE Brown trout were first introduced into Maine waters back in the days when early fish-culturists were busy at their newly born profession of raising game fishes and distributing them all over the world as the miracle cure-all for fisheries problems. The largest hatchery-fish producer in those days was the United States Fish Commission. It was this organization that first brought brown trout into Maine. One of the first introductions of brown trout in the United States took place in Branch Lake, Ellsworth, in 1885. Approxi- mately 7,000 fry were distributed in the lake and its tributaries. These fry resulted from a shipment of eggs taken at Loch Leven, Scotland, of which 10,000 were allotted to Maine and hatched at the Federal Hatchery, Bucksport, Maine. During the period be- tween 1885 and 1900, brown trout were introduced into 16 dif- ferent lakes between Bangor and the coast. Between 1900 and 1932, brown trout plantings were fewer, but the trend in recent years has been to stock more and more browns. SOME FACTS ABOUT BROWN TROUT The life history of the brown trout is much the same as that of its close relative, the landlocked salmon. Both need clean, cool water to satisfy their living requirements. The brown trout is normally a stream spawner, seeking out the cool tributary streams where there is an abundance of clean rubble bottom in the riffle areas. The females dig egg pits in the loose rubble using their tails and bodies as excavators. Larger females may dig three or four egg pits up to 12 inches deep, located in a nesting area ( called a redd) which may extend 20 to 30 feet along the stream bottom. Each egg pit is constructed so that an eddy current is set up in- side holding the eggs and milt firmly in the bottom even though the current may be swift. For this reason natural fertilization is better than 90 percent effective. A large female may lay over 3,000 eggs. The males are busy defending their chosen territories against the intrusion of rival males prior to the actual spawning act. After a brief courtship period the male and female settle over 5 the egg pit and the eggs and milt are extruded simultaneously. The eggs are then covered with gravel and rubble by the female. Clear, cool water percolating through the stream bed may keep the eggs alive even though the water level may drop enough to expose the spawning beds. Brown trout spawn from the latter part of October into Feb- ruary, depending upon the temperature and flow of water. The young hatch out the following spring and spend the first two or three years of life in the stream feeding on small insects and other minute animal life. Later, moving out into the lake, they depend more and more on a fish diet as they increase in size. The importance of the tributary streams in the life cycles of our stream spawning trout and salmon cannot be overemphasized. Frequently the outlet to a lake represents the only suitable spawning area. This is especially true for our native salmon. It has been proved time and again that when conditions are suit- able, natural reproduction is far more valuable than the stock- ing of hatchery-raised fish in maintaining good fishing. BROWN TROUT VS. LANDLOCKED SALMON There is every indication that brown trout will displace our native salmon in lakes where they both occur. Branch Lake, Ellsworth, is a good example. Not too many years ago the main spawning tributary, Winkumpaugh Stream, supported large runs of salmon in the fall. Early records show that Winkumpaugh Stream was one of the principal sources of salmon eggs for the Federal Hatchery formerly located at Green Lake, Dedham. Today no salmon can be found spawning in this stream, al- though brown trout use it extensively every fall as a spawning area. Growth is much faster in the lake than the stream. The fol- lowing total lengths in inches and weights in pounds and tenths of pounds are typical of brown trout growth in Branch Lake: Summers of Growth 1 2 3 4 5 6 7 8 9 10 Length 3.1 5.7 12.0 15.8 19.8 23.4 24.7 26.8 27.1 27.6 Weight — — 0.6 1.7 3.2 5.2 5.4 7.9 8.0 11.0 Compared with growth rates of landlocked salmon thus far available for Maine lakes, growth of the Branch Lake brown trout is intermediate between the slower growing Moosehead 6 Lake salmon and the faster growing Long Pond, Mount Desert Island salmon up to the fifth year of life. Beyond five years the growth rate of brown trout in Branch Lake exceeds those of salmon reported in the Maine Lake Surveys with the exception of East Grand Lake. Over 90 percent of the brown trout catch from Branch Lake in 1952 and 1953 was made up of fish that were four, five, and six years old. Brown trout, once they have become well estab- lished in a lake, tend to increase in average size and at the same time become increasingly difficult to catch. In recent years brown trout six pounds or over have dominated the "One That Didn't Get Away Club" roster compiled by the Maine Development Commission. This has led to the mistaken idea that the brown trout is yielding excellent fishing in our Maine Lakes. Results of the Branch Lake study indicate that the brown trout popula- tion is composed mainly of larger and older fish. Compared to the numbers of brown trout taken by fishermen, fish 6 pounds or over are not uncommon. A 10 pound limit would be more suit- able for meeting the requirements of the "One That Didn't Get Away Club." The tendency of a brown trout population to become " over- balanced " with large fish predominating is not peculiar only to our Maine lakes. Poor fishing returns have led other states to evaluate their positions concerning brown trout. The brown trout population of Convict Lake, California has been described as a "burden on the biological economy of the lake." A two-year study of Convict Lake has shown that only highly skilled fisher- men are able to take the shrewd browns with the result that large browns are over-abundant in the lake and seriously lower its productivity in terms of catchable native trout.
Load more

Recommended publications
  • Onseriation of Bull Trout
    United States - De artment of Iariculture Demographic and Forest Service Intermountain Research Statlon Habit4 Reauirements General Technical Report INT-302 for ~onseriationof September 1993 Bull Trout Bruce E. Rieman John D. Mclntyre THE AUTHORS CONTENTS BRUCE E. RlEMAN is a research fishery biologist with Page the lntermountain Research Station, Forestry Sciences Introduction ................................................................... 1 Laboratory in Boise, ID. He received a master's degree Ecology ......................................................................... 1 in fisheries management and a Ph.D. degree in for- Biology and Life History ............................................ 2 estry, wildlife, and range sciences from the University Population Structure.................................................. 3 of Idaho. He has worked in fisheries management and Biotic Interactions ...................................................... 3 research for 17 years with the ldaho Department of Habitat Relationships ................................................ 4 Fish and Game and the Oregon Department of Fish Summary ...................................................................7 and Wildlife. He joined the Forest Service in 1992. His Implications of Habitat Disturbance .............................. 7 current work focuses on the biology, dynamics, and' Extinction Risks ......................................................... 9 conservation of salmonid populations in the Intermoun- Viability ...................................................................
    [Show full text]
  • Stream Habitat Needs for Brook Trout and Brown Trout in the Driftless Area
    Stream Habitat Needs for Brook Trout and Brown Trout in the Driftless Area Douglas J. Dietermana,1 and Matthew G. Mitrob aMinnesota Department of Natural Resources, Lake City, Minnesota, USA; bWisconsin Department of Natural Resources, Madison, Wisconsin, USA This manuscript was compiled on February 5, 2019 1. Several conceptual frameworks have been proposed to organize in Driftless Area streams. Our specific objectives were and describe fish habitat needs. to: (1) summarize information on the basic biology 2. The five-component framework recognizes that stream trout pop- of Brook Trout and Brown Trout in Driftless Area ulations are regulated by hydrology, water quality, physical habi- streams, (2) briefly review conceptual frameworks or- tat/geomorphology, connectivity, and biotic interactions and man- ganizing fish habitat needs, (3) trace the historical agement of only one component will be ineffective if a different com- evolution of studies designed to identify Brook Trout ponent limits the population. and Brown Trout habitat needs in the context of 3. The thermal niche of both Brook Trout Salvelinus fontinalis and these conceptual frameworks, (4) review Brook Trout- Brown Trout Salmo trutta has been well described. Brown Trout interactions and (5) discuss lingering un- 4. Selected physical habitat characteristics such as pool depths and certainties in habitat management for these species. adult cover, have a long history of being manipulated in the Driftless Area leading to increased abundance of adult trout. Brook Trout and Brown Trout Biology 5. Most blue-ribbon trout streams in the Driftless Area probably pro- vide sufficient habitat for year-round needs (e.g., spawning, feeding, Brook Trout.
    [Show full text]
  • Are Brown Trout Replacing Or Displacing Bull Trout Populations In
    Pagination not final (cite DOI) / Pagination provisoire (citer le DOI) 1 ARTICLE Are brown trout replacing or displacing bull trout populations in a changing climate? Robert Al-Chokhachy, David Schmetterling, Chris Clancy, Pat Saffel, Ryan Kovach, Leslie Nyce, Brad Liermann, Wade Fredenberg, and Ron Pierce Abstract: Understanding how climate change may facilitate species turnover is an important step in identifying potential conservation strategies. We used data from 33 sites in western Montana to quantify climate associations with native bull trout (Salvelinus confluentus) and non-native brown trout (Salmo trutta) abundance and population growth rates (␭). We estimated ␭ using exponential growth state-space models and delineated study sites based on bull trout use for either spawning and rearing (SR) or foraging, migrating, and overwintering (FMO) habitat. Bull trout abundance was negatively associated with mean August stream temperatures within SR habitat (r = −0.75). Brown trout abundance was generally highest at temperatures between 12 and 14 °C. We found bull trout ␭ were generally stable at sites with mean August temperature below 10 °C but significantly decreasing, rare, or extirpated at 58% of the sites with temperatures exceeding 10 °C. Brown trout ␭ were highest in SR and sites with temperatures exceeding 12 °C. Declining bull trout ␭ at sites where brown trout were absent suggest brown trout are likely replacing bull trout in a warming climate. Résumé : Il importe de comprendre comment le climat pourrait faciliter le renouvellement des espèces pour cerner des stratégies de conservation potentielles. Nous avons utilisé des données de 33 sites de l’ouest du Montana pour quantifier les associations climatiques avec l’abondance et les taux de croissance de populations (␭) d’ombles a` tête plate (Salvelinus confluentus) indigènes et de truites brunes (Salmo trutta) non indigènes.
    [Show full text]
  • Growth of Brook Trout (Salvelinus Fontinalis) and Brown Trout (Salmo Trutta) in the Pigeon River, Otsego County, Michigan*
    [Reprinted from PAPERS OF THE MICHIGAN ACADEMY OF SCIENCE, ARTS, AND LETTERS, VOL. XXXVIII, 1952. Published 1953] GROWTH OF BROOK TROUT (SALVELINUS FONTINALIS) AND BROWN TROUT (SALMO TRUTTA) IN THE PIGEON RIVER, OTSEGO COUNTY, MICHIGAN* EDWIN L. COOPER INTRODUCTION ITIHE Pigeon River Trout Research Area was established in Ot- sego County, Michigan, in April, 1949, by the Michigan De- partment of Conservation. It includes 4.8 miles of trout stream and seven small lakes. The stream has been divided into four ex- perimental sections, and fishing is allowed only on the basis of daily permits. This makes possible a creel census that assures examination and recording by trained fisheries workers of the total catch. Most of the scale samples upon which the present study is based are from fish taken in the portion of the stream in the research area. The fish were collected by two different methods: by hook and line, and by electric shocking. In all, scale samples were obtained from 4,439 brook trout (Salvelinus fontinalis) and 1,429 brown trout (Salmo trutta) older than one year; the collections were made be- tween April 20, 1949, and November 30, 1951. VALIDITY OF AGE DETERMINATION BY MEANS OF SCALES Evidence in favor of the method of determining the age of brook trout by means of scales was 'presented in an earlier publication (Cooper, 1951). Further support for this method is given here because of the availability of fish of known age and also because the trout in the Pigeon River usually form quite distinct annuli, making the interpretation of age a relatively simple task (Pl.
    [Show full text]
  • Brown Trout (Salmo Trutta): a Technical Conservation Assessment
    Brown Trout (Salmo trutta): A Technical Conservation Assessment Prepared for the USDA Forest Service, Rocky Mountain Region, Species Conservation Project April 26, 2007 Laura Belica1 with life cycle model by David McDonald, Ph.D.2 11623 Steele Street, Laramie Wyoming 82070 2Department of Zoology and Physiology, University of Wyoming, P.O. Box 3166, Laramie, WY 82071 Belica, L. (2007, April 26). Brown Trout (Salmo trutta): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/assessments/ browntrout.pdf [date of access]. ACKNOWLEDGMENTS I would like to thank the many biologists and managers from Colorado, Kansas, Nebraska, South Dakota, and Wyoming and from the national forests within Region 2 who provided information about brown trout populations in their jurisdictions. I also extend my appreciation to David B. McDonald at the University of Wyoming for the population demographic matrix analysis he provided. Thank you to Nathan P. Nibbelink for coordinating the cost- share agreement with the USDA Forest Service. I especially thank Richard Vacirca, Gary Patton, and David Winters of the USDA Forest Service for their help in bringing this report to completion. I thank Nancy McDonald and Kimberly Nguyen for their attention to detail in preparing this report for publication. Finally, I would like to thank Peter McHugh for graciously taking the time to review and comment on this assessment. AUTHOR’S BIOGRAPHY Laura A. T. Belica received a M.S. degree in Zoology and Physiology from the University of Wyoming in 2003 (as L.A. Thel). Her research interests center around the ecology of fishes, hydrology, and watershed management, especially as they relate to the management of aquatic ecosystems and native fishes.
    [Show full text]
  • Volume II Quinn River Lahontan Cutthroat Trout
    Oregon Native Fish Status Report – Volume II Quinn River Lahontan Cutthroat Trout Existing Populations Lahontan cutthroat trout populations in the Quinn River basin are remnant of a larger population inhabiting pluvial Lake Lahontan during the Pleistocene era. The Quinn River Lahontan Cutthroat Trout SMU is comprised of four populations (Table 1). The McDermitt, Tenmile, and Oregon Canyon populations are considered extinct due to hybridization and introgression with non-native hatchery rainbow trout (Coffin and Cowan 1995, Bowers et al. 1994, ODFW Aquatic Inventory Project, unpublished data, R. Perkins, ODFW Ontario Field Office, personal communication). The McDermitt population was also subject to strong competition with brook trout in the headwater reaches and brown trout in the lower reaches. Lahontan cutthroat trout in the Sage population are isolated above a man-made partial barrier and express a resident life history strategy. Table 1. Populations, existence status, and life history of the Quinn River Lahontan Cutthroat Trout SMU. Exist Population Description Life History No McDermitt McDermitt, Cottonwood, Payne, Indian creeks , Riser creek -- and tributaries No Tenmile Tenmile Creek -- Yes Sage Sage and Line Canyon Creeks Resident No Oregon Canyon Oregon Canyon Creek -- Lahontan cutthroat trout from Sage Creek were transplanted into Tenmile Creek as a conservation measure. Since then they have hybridized with rainbow trout and pure Lahontan cutthroat trout no longer exist in Tenmile (R. Perkins, ODFW Ontario field office, pers. Comm..). Cutthroat trout were also introduced in Indian Creek (McDermitt population) in 1980 and 1981 (Hanson et al. 1993). Recent population surveys found cutthroat trout x rainbow trout hybrids in upper Indian Creek.
    [Show full text]
  • Status of Brown Trout (Salmo Trutta Fario L.) in Garhwal Himalaya with a Note on It Morphometric Characteristics
    Environment Conservation Journal 12(3) 47-52, 2011 (ISSN 0972-3099) Abstracted and Indexed Status of brown trout (Salmo trutta fario L.) in Garhwal Himalaya with a note on it morphometric characteristics M.S. Rawat Babita Bantwanl, Dhyal Singhl and O.P. Gusain2 Received: 10.09.2011 Accepted: 15.11.2011 Abstract The history of introduction of brown trout in Garhwal Himalaya is 100 years. However, the scientific information on brown trout is grossly lacking. The present study is a part of investigation on various aspects of brown trout inhabiting the River Asiganga in Uttarkashi district of Uttarakhand. The status of brown trout was ascertained in River Asiganga and other reports from elsewhere in the region. The morphometric study was based on 253 fish specimens collected from River Asiganga. In addition to the 12 body measurements of the fish, red/orange and brown spots on body were also studied. Keywords: River Asiganga, brown trout, body spots, teeth Introduction Brown trout (Salmo trutta fario L.) belonging toand Sehgal, 1992). As such, various aspects of family salmonidae are indigenous to Europe, Northbrown trout have been extensively dealt with in America, Africa, Australia, New Zealand, Papuadifferent parts of the world by Frost (1939), Ball New Guinea (Moyle 2002), while, native western (1961),Michael(1970),Elliott(1972,1976), Asian countries are Armenia, Afghanistan and Edwards et al. (1979), Lobon-Cervia et al. (1986), Turkey. In Asia, the fish has been introduced inBelaud (2002), Alp et al. (2003, 2005), Arslan et India, Sri Lanka and Nepal. With large variabilityal. (2004), Maric et al. (2004), Oscoz et al.
    [Show full text]
  • Brook Trout Brown Trout Rainbow Trout Golden
    IDENTIFICATION BROOK TROUT The front edges of the pectoral fins (sides and bottom of the trout) are white. Red spots with bluish halos dot the body. The tail is nearly square. The brook trout is Pennsylvania’s official State Fish. BROWN TROUT A brown trout’s body is golden-brown. The body has lsrge dark spots with pale halos. Sometimes the body also has red or yellow spots. The fins are yellowish-brown. They have no spots or white edges. The tail usually has few or no spots. GOLDEN RAINBOW TROUT The golden rainbow is also known as a palomino trout. A golden rainbow’s body is deep-yellow or orange-like. The sides are unmarked, but some golden rainbows have a darker-orange lateral line. The tail is nearly square. RAINBOW TROUT A rainbow trout’s body is greenish. The adults usually have a pinkish lateral stripe. Rainbow trout also have many small, black spots on the body. The tail is heavily spotted. The inner mouth and gums are white. IN THE LAKES... LAKE TROUT The lake trout is found only in a few of Pennsylvania’s STEELHEAD deepest and coldest lakes. Lake trout are bright-gray, often Steelhead trout are rainbow trout that live in Lake Erie and olive, shading to silvery white on the belly. They are pro- ascend Lake Erie tributaries. A steelhead’s body is silvery. fusely covered with large light-colored spots, and the tail is deeply forked. Pennsylvania Angler & Boater Fishing & Boating Memories Last A Lifetime.
    [Show full text]
  • Lahontan Cutthroat Trout in the Upper Truckee River
    Lahontan Cutthroat Trout in the Upper Truckee River: Restoration of a Threatened Species in a Fluvial Headwater Environment Project Area N Expansion Area .2008 -2011: beginning of manual removal of brook trout in additional 10 miles stream .Future - 2023: continue implementation in streams and begin removal of brook trout in 85 acres of lake Meiss Meadows .1988-1990: rotenone to remove brook trout .early 1990s: LCT re-introduced & brook trout found .mid 1990s: manual removal of brook trout in upper 5 miles stream & 8 acres lake .2007-2009: no brook trout found, resting treatment .one of the only high meadow LCT populations in Sierra Nevada Project Area Expansion Area Meiss Meadows Manual Removal Methods • Late August thru October • Delineated reaches by natural barriers (low water barriers, falls, and beaver dams) • 3-pass depletion, on varying reach lenght • Species identified and measured to size class • Brook and Rainbow trout sacrificed • Speckled dace returned to upstream reach • LCT returned upstream of Barrier T1BA4 in RL trib and 36B in UTR; sacrificed below due to hybridization threats 3 Pass Depletion Depletion B37-B36A (307 m) 30 LCT 20 BKT SPD 10 # of fish 0 1 2 3 Pass Depletion B34-B33 (254 m) 40 LCT 30 BKT 20 RBT # of fish 10 0 1 2 3 Pass Meiss Meadows LCT in Meiss Meadows Lahontan Cutthroat1996-2009 Trout Catch Upper Truckee River 1996 - 2009 2000 1500 Adult 1000 Juveniles 500 NUMBER OF NUMBER OBSERVED FISH 0 1997 1999 2001 2003 2005 2007 2009 YEAR Brook Trout Catch in MeissBrook Meadows Trout Upper Truckee River1996 Electrofishing-2009
    [Show full text]
  • Brown Trout – Salmo Trutta
    Brown Trout – Salmo trutta Range - The brown trout is native to Europe and Asia. They are found in the lakes and streams from Norway to Morocco, and from Pakistan to Iceland. Izzak Walton mused about trout, brown trout. Brown trout were first brought to the United States in the mid 1860’s. Brown trout eggs were transported across the Atlantic and incubated in New York in 1864 but the success of this effort was not good. In February 1883 the ship Wera arrived in New York City from Germany, carrying 80,000 brown trout eggs. The eggs were sent to hatcheries in Northville, Michigan, and Caledonia, New York. In the spring of 1884 the U.S. Fish Commission released fry hatched from these eggs into the Baldwin River. Today, brown trout are found in almost every state in the Untied States. They have replaced native brook, rainbow, and cutthroat trout throughout the United States in the process and are one of the most sought after game fishes in the US. Food Habits - Brown trout feed when water temperatures range from 50 to 74 degrees. The species consumes terrestrial and aquatic insects, which proably makes up most of its diet across its range, but is also highly piscivorous. An average size brown trout (14 inches) is able to consume small minnows, suckers, and other trout, including their own offspring. Brown trout have an affinity for cover such as undercut banks and instream woody debris. This is not necessarily due to innate cunning. Brown trout eye function is best in low light conditions there fore they seek darker habitats than some other trouts.
    [Show full text]
  • Trout and Char of Central and Southern Europe and Northern Africa
    12 Trout and Char of Central and Southern Europe and Northern Africa Javier Lobón-Cerviá, Manu Esteve, Patrick Berrebi, Antonino Duchi, Massimo Lorenzoni, Kyle A. Young Introduction !e area of central and southern Europe, the Mediterranean, and North Africa spans a wide range of climates from dry deserts to wet forests and temperate maritime to high alpine. !e geologic diversity, glacial history, and long human history of the region have interacted with broad climatic gradients to shape the historical and cur- rent phylogeography of the region’s native trout and char. !e current distributions and abundances of native species are determined in large part by their fundamental niches (i.e., clean, cold water with high dissolved oxygen). Brown Trout Salmo trutta are relatively common and widespread in the northern and mountainous areas of the region but occur in isolated headwater populations in the warmer southern areas of the region. !ese southern areas provided glacial refugia for salmonids and today har- bor much of the region’s phylogenetic diversity. Despite relatively narrow ecologi- cal requirements in terms of water quality, native and invasive trout and char occur throughout the region’s rivers, lakes, estuaries, and coastal waters. Despite having only a single widely recognized native trout species, the region’s range of environments has produced a remarkable diversity of life histories ranging from dwarf, stunted, short and long-lived, small- and large-sized, stream-resident, lake-resident, fluvial potamo- dromous, adfluvial potamodromous, and anadromous (see Chapter 7). Only one trout and one char are native to the region, Brown Trout and Alpine Char Salvelinus umbla.
    [Show full text]
  • Arctic Char in Northern Alaska
    1 Dolly Varden & Arctic Char in Northern Alaska Dolly Varden & Arctic Char Distribution for Alaska and Chukotsk Peninsula 2 What is a char? Char are members of the family Salmonidae and the genus Salvelinus. The family Salmonidae includes all the salmonid fishes: Genus: Oncorhynchus rainbow trout, Pacific salmon, cutthroat trout Genus: Coregonus whitefish Genus: Thymallus grayling Genus: Salmo brown trout, Atlantic salmon Genus: Salvelinus Dolly Varden, Arctic char, lake trout, bull trout, brook trout 3 In Alaska, species of char include: Dolly Varden Salvelinus malma Arctic Char Salvelinus alpinus Lake Trout Salvelinus namaycush Bull Trout Salvelinus confluentus Brook Trout Salvelinus fontinalis (introduced in Southeast Alaska) Illustrations by Joseph R. Tomelleri 4 How is a char different from any other salmonid? Char are distinguished from other salmonid fishes by having light spots on a dark background and by the lack of teeth on the shaft of the vomer (upper palate). Chars Light spots/dark background Other Salmonids Dark spots/light background 5 What is in a fish’s name? Within the scientific community, the first person to formally describe a fish earns the right to name the fish. No one has ever seen a fish like you before! You are gray & purple & have large lips. You have 3 rays in your dorsal fin and you lack anal & ventral fins I will name you, Finus missingus. That fish and others like it from the same location become the “type specimen” to which scientists compare similar fish from other locations to determine if they are the same species or a different species. On my last expedition, I found a fish that was gray & purple, had large lips, 3 dorsal fin rays, and lacked anal & ventral fins.
    [Show full text]