Brook trout

From Wikipedia, the free encyclopedia
  (Redirected from Brook Trout)
Jump to: navigation, search
Brook trout
Old colored print of brook trout
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Salmoniformes
Family: Salmonidae
Genus: Salvelinus
Species: S. fontinalis
Binomial name
Salvelinus fontinalis
(Mitchill, 1814) [1]
Subspecies

Salvelinus agassizi
S. f. timagamiensis (Henn & Rinckenbach, 1925)

Synonyms[2]

The brook trout (Salvelinus fontinalis), sometimes called the eastern brook trout, is a species of fish in the salmon family of order Salmoniformes. It is native to Eastern North America in the United States and Canada. In many parts of its range, it is known as the speckled trout or squaretail. A potamodromous population in Lake Superior is known as coaster trout or, simply, as coasters. Though commonly called a trout, the brook trout is actually a char (Salvelinus) which in North America, includes the lake trout, bull trout, Dolly Varden and the arctic char. The brook trout is the state fish of eight states: Michigan, New Hampshire, New Jersey, New York, Pennsylvania, Vermont, Virginia and West Virginia.

The specific epithet "fontinalis" comes from the Latin for "of or from a spring or fountain".

Taxonomy[edit]

The scientific name of the brook trout is Salvelinus fontinalis and was first described by naturalist Samuel Latham Mitchill in 1814. The specific epithet "fontinalis" comes from the Latin for "of or from a spring or fountain" in reference to the clear, cold streams and ponds in its native habitat. Few if any, subspecies exist. The brook trout produces two intrageneric hybrids— the Splake (S. fontinalis × S. namaycush) and the Sparctic char (S. fontinalis × S. alpinus)[3] plus one intergeneric hybrid—the Tiger trout (S. fontinalis × Salmo trutta).[citation needed]

Subspecies[edit]

  • Silver trout, (Salvelinus agassizi), is an extinct trout species last seen in Dublin Pond, New Hampshire, in 1930.[5] Considered by fisheries biologist Robert J. Behnke as a highly specialized form of brook trout.[6]


Splake[edit]

Photo of four trout lying in grass
Tiger trout (top 3), Splake (bottom)

The splake is an intrageneric hybrid between the brook trout and lake trout (Salvelinus namaycush). Although uncommon in nature, they are artificially propagated in substantial numbers for stocking into brook trout or lake trout habitats.[7] Although they are fertile, back-crossing in nature is behaviorally problematic and very little natural reproduction occures. Splake grow more quickly than brook trout and become piscivorous sooner and are more tolerant of competitors than brook trout.[8]

Tiger trout[edit]

The Tiger trout is an intergeneric hybrid between the brook trout and the brown trout (Salmo trutta). Tiger trout occur very rarely naturally, but are sometimes artificially propagated. Such crosses are almost always reproductively sterile. They are popular with many fish stocking programs because they can grow quickly, and may help keep rough fish populations in check due to their highly piscivorous (fish-eating) nature.[9]

Sparctic char[edit]

The Sparctic char is an intergeneric hybrid between the brook trout and the arctic char (Salvelinus apinus).[10]

Description[edit]

Photo of hand holding a trout
Brook trout from lake in Wyoming's Wind River Range
Photo of a trout in an aquarium
Captive brook trout in aquarium

Fisheries biologist Robert Behnke describes three forms of the brook trout. A large lake form evolved in the larger lakes in the northern reaches of its range and is generally piscivorous as adults. A sea-run form that migrates into salt-water for short periods of time to feed evolved along the Atlantic coastline. Finally, Behnke describes a smaller generalist form that evolved in the small lakes, ponds, rivers and streams throughout most of the original native range. This generalist form rarely attains sizes larger than 12 inches (30 cm) or lives for more than 3 years.[11] All three forms have the same general appearance. The brook trout has a dark green to brown color, with a distinctive marbled pattern (called vermiculations) of lighter shades across the flanks and back and extending at least to the dorsal fin, and often to the tail. A distinctive sprinkling of red dots, surrounded by blue haloes, occur along the flanks. The belly and lower fins are reddish in color, the latter with white leading edges. Often, the belly, particularly of the males, becomes very red or orange when the fish are spawning.[citation needed]

The species reaches a maximum recorded length of 86 cm (34 in) and a maximum recorded weight of 6.6 kg (15 lb). It can reach at least seven years of age, with reports of 15-year-old specimens observed in California habitats to which the species has been introduced. Typical lengths vary from 25 to 65 cm (9.8 to 25.6 in), and weights vary from 0.3 to 3 kg (0.66 to 6.61 lb). Growth rates are dependent on season, age, water and ambient air temperatures, and flow rates. In general, flow rates affect the rate of change in the relationship between temperature and growth rate. For example in spring growth increased with temperature at a faster rate with high flow rates than with low flow rates.[12]

Range and habitat[edit]

Map of native and non-native range of Brook trout in U.S.
U.S. Native and Introduced ranges of Brook Trout (Salvelinus fontinalis)[13]
Hand holding small trout
Native Appalachian brook trout

Brook trout are native to a wide area of Eastern North America, but increasingly confined to higher elevations southward in the Appalachian Mountains to northern Georgia and northwest South Carolina, Canada from the Hudson Bay basin east, the Great LakesSaint Lawrence system, the Canadian maritime provinces and the upper Mississippi River drainage as far west as eastern Iowa.[11] Their southern historic native range has been drastically reduced, with fish being restricted to higher elevation, remote steams due to habitat loss and introductions of brown and rainbow trout. As early as 1850, the brook trout's range started to extend west from its native range through introductions. The brook trout was eventually introduced into suitable habitats throughout the western U.S. during the late 19th and early 20th century at the behest of the American Acclimatization Society and by private, state and federal fisheries authorities.[14] Acclimatization movements in Europe, South America and Oceania resulted in brook trout introductions throughout Europe,[10] in Argentina[15] and New Zealand.[16] Although not all introductions were successful, a great many established wild, self-sustaining populations of brook trout in non-native waters.

Habitat[edit]

Photo of tree covered stream in mountains
Typical southern Appalachian brook trout habitat

The brook trout inhabits large and small lakes, rivers, streams, creeks and spring ponds. They prefer clear waters of high purity and a narrow pH range and are sensitive to poor oxygenation, pollution and changes in pH caused by environmental effects such as acid rain. The typical pH range of brook trout waters is 5.0 to 7.5, with pH extremes of 3.5 to 9.8 possible.[17] Water temperatures typically range from 34 to 72 °F (1 to 22 °C). Warm summer temperatures and low flow rates are stressful on brook trout populations—especially larger fish.[18] Brook trout have a diverse diet that includes larval, pupal and adult forms of aquatic insects (typically caddisflies, stoneflies, mayflies and aquatic dipterans), and adult forms of terrestrial insects (typically ants, beetles, grasshoppers and crickets) that fall into the water, crustaceans, frogs and other amphibians, molluscs, smaller fish, invertebrates and even small aquatic mammals such as voles.[citation needed]

The female constructs a depression in a location in the stream bed, sometimes referred to as a "redd", where groundwater percolates upward through the gravel. One or more males approaches the female, fertilizing the eggs as the female expresses them. A majority of spawnings involve peripheral males which directly influences the amount of eggs that survive into adulthood. In general the larger the number of peripheral males present the more likely the eggs will be cannibalized.[19] The eggs are slightly denser than water. The female then buries the eggs in a small gravel mound; they hatch in 95 to 100 days.[citation needed]

Coasters[edit]

A potamodromous population of brook trout native to Lake Superior, which migrate into tributary rivers to spawn, are called "coasters".[20] Coasters tend to be larger than most other populations of brook trout, often reaching 6 to 7 pounds (2.7 to 3.2 kg) in size.[21] Many coaster populations have been severely reduced by overfishing and habitat loss by the construction of hydroelectric power dams on Lake Superior tributaries. In Ontario and Michigan, efforts are underway to restore and recover coaster populations.[22]

Salters[edit]

When Europeans first settled Eastern North America, semi-anadromous or sea-run brook trout, commonly called "salters" ranged from southern New Jersey, north throughout the Canadian maritime provinces and west to Hudson Bay. Salters may spend up to three months at sea feeding on crustaceans, fish and marine worms in the spring not straying more than a few miles from the river mouth. The fish return to freshwater tributaries to spawn in the late summer or autumn. While in saltwater, salters gain a more silvery color, losing much of the distinctive markings seen in freshwater. However, within two weeks of returning to freshwater, they assume typical brook trout color and markings.[21]

Angling[edit]

Old colored print of three men fishing from a boat
Nathan Currier lithograph of Arthur Fitzwilliam Tait's painting "Catching a Trout", 1854 - Depicts fishermen catching a brook trout near South Haven Church in a mill pond on Carman's river Long Island, New York
Colored drawing of trout jumping for a fly
Brook trout chasing an artificial fly from American Fishes (1903) [23]

Although there's an element of myth about the story, purportedly Daniel Webster, an avid angler, caught a large (~14.5 pounds (6.6 kg)) brook trout near the Old South Haven Church in a mill pond on Carman's river on Long Island, New York in 1823 (or 1827).[24] The event was immortalized in Arthur Fitzwilliam Tait's 1854 painting "Catching a trout". Until it was displaced by introduced brown trout (1883) and rainbow trout (1875), the brook trout was the trout that attracted the most attention of anglers from colonial times through the first 100 years of U.S. history. Sporting writers like Genio Scott Fishing in American Waters (1869), Thaddeus Norris American Anglers Book (1864), Robert Barnwell Roosevelt Game fish of North America (1864) and Charles Hallock The Fishing Tourist (1873) produced guides to the best-known brook trout waters in America.[25] As brook trout populations declined in the mid-19th century near urban areas, anglers flocked to the Adirondacks in upstate New York and the Rangeley lakes region in Maine to pursue brook trout.[25] In July, 1916 on the Nipigon River in northern Ontario, an Ontario physician, John W. Cook, caught a 14.5-pound (6.6 kg) brook trout which stands as the world record.[26]

The brook trout is a popular game fish with anglers, particularly fly fishermen. Today, many anglers practice catch-and-release tactics to preserve remaining populations, and organizations such as Trout Unlimited have been in the forefront of efforts to institute air and water quality standards sufficient to protect the brook trout. Revenues derived from the sale of fishing licenses have been used to restore many sections of creeks and streams to brook trout habitat.[27]

The current world angling record brook trout was caught by Dr. W. J. Cook on the Nipigon River, Ontario, in July 1915. The 31-inch (79 cm) trout weighed only 14.5 pounds (6.6 kg) because, at the time of weighing, it was badly decomposed after 21 days in the bush without refrigeration. This is the longest-standing angling world record.[28] A 29-inch (74 cm) brook trout, caught in October 2006 in Manitoba, is not eligible for record status since it was released alive.[29] This trout weighed approximately 15.98 pounds (7.25 kg) based on the accepted formula for calculating weight by measurements and it currently stands as the record brook trout for Manitoba.[30]

Artificial propagation and aquaculture[edit]

Brook trout are also commercially raised in large numbers for food production, being sold for human consumption in both fresh and smoked forms.[31] Because of its dependence on pure water and a variety of aquatic and insect life forms, the brook trout is also used for scientific experimentation in assessing the effects of pollution and contaminated waters.[citation needed]

Conservation status[edit]

Brook trout populations depend on cold, clear, well-oxygenated water of high purity. As early as the late 19th century, native brook trout in North America became extirpated from many watercourses as land development, forest clear-cutting, and industrialization took hold.[32] Streams and creeks that were polluted, dammed, or silted up often became too warm to hold native brook trout, and were colonized by transplanted smallmouth bass and perch or other introduced salmonids such as brown and rainbow trout. The brown trout, a species not native to North America, has replaced the brook trout in much of the brook trout's native water. Brook trout populations, if already stressed by overharvest or by temperature, are very susceptible to damage by the introduction of exogenous species. Many lacustrine populations of brook trout have been extirpated by the introduction of other species, particularly percids, but sometimes other spiny-rayed fishes.[citation needed]

In addition to chemical pollution and algae growth caused by runoff containing chemicals and fertilizers, air pollution has also been a significant factor in the disappearance of brook trout from their native habitats. In the U.S., acid rain caused by air pollution has resulted in pH levels too low to sustain brook trout in all but the highest headwaters of some Appalachian streams and creeks.[33] Brook trout populations across large parts of eastern Canada have been similarly challenged; a subspecies known as the aurora trout was extirpated from the wild by the effects of acid rain.[34] Today, in many parts of the range, efforts are underway to restore brook trout to those waters that once held native populations, stocking other trout species only in habitats that can no longer be recovered sufficiently to sustain brook trout populations.[citation needed]

Organizations such as Trout Unlimited and Trout Unlimited Canada[22] are partnering with other organizations such as the Southern Appalachian Brook Trout Foundation,[35] the Eastern Brook Trout Joint Venture,[36] state, provincial and federal agencies to undertake projects that restore native brook trout habitat and populations.[citation needed]

As an invasive species[edit]

Although brook trout populations are under stress in their native range, they are considered an invasive species where they have been introduced outside their historic native range.[37][38][39] In the Northern Rocky Mountains, non-native brook trout are considered a significant contributor to the decline or extirpation of native cutthroat trout (Oncorhynchus clarki) in headwater streams.[40] Non-native Brook trout populations have been subject to eradication programs in efforts to preserve native species.[41][42] In Yellowstone National Park anglers may take an unlimited number of non-native brook trout in some drainages. In the Lamar River drainage, there is a mandatory kill regulation for any brook trout caught.[43] In Europe, introduced brook trout, once established have had negative impacts on growth rates of native brown trout (S. trutta).[10]

Notes[edit]

  1. ^ "Salvelinus fontinalis". Integrated Taxonomic Information System. Retrieved 2006-01-30. 
  2. ^ "Synonyms of Salvelinus fontinalis (Mitchill, 1814)". Fishbase. Retrieved 2014-02-23. 
  3. ^ "Sparctic Char: Strange Nighttime Saltwater Spawners from Europe!". http://www.fishwithjd.com/. Retrieved 2013-12-25. 
  4. ^ Aurora trout Recovery Team (ATRT) (July 2006). "Recovery Strategy for the Aurora trout (Salvelinus fontinalis timagamiensis) in Canada" (PDF). Fisheries and Oceans Canada. Retrieved 2014-01-06. 
  5. ^ World Conservation Monitoring Centre (1996). "Salvelinus agassizi". IUCN Red List of Threatened Species. Version 2012.1. International Union for Conservation of Nature. Retrieved 2006-05-10. 
  6. ^ Behnke, Robert J.; Tomelleri, Joseph R. (illustrator) (2002). "Brook Trout Salvelinus fontinalis". Trout and Salmon of North America. The Free Press. pp. 275–280. ISBN 0-7432-2220-2. 
  7. ^ "Splake". Maine Department of Inland Fisheries. Retrieved 2013-01-06. 
  8. ^ "NAS - Nonindigenous Aquatic Species Salvelinus fontinalis x namaycush". U.S. Geological Survey. Retrieved 2014-01-06. 
  9. ^ "Tiger trout". UtahFishingInfo.com - Utah Fishing Information. Retrieved 2014-05-28. 
  10. ^ a b c K. Jannson (2013). "NOBANIS – Invasive Alien Species Fact Sheet Salvelinus fontinalis" (PDF). Online Database of the European Network on Invasive Alien Species – NOBANIS www.nobanis.org. Retrieved 2013-12-26. 
  11. ^ a b Behnke, Robert J.. "Brook Trout". About Trout-The Best of Robert J. Behnke from Trout Magazine. Guilford, CT: The Lyons Press. pp. 85–90. ISBN 978-1-59921-203-6. 
  12. ^ Xu, Calin (Nov 2010). "Context-specific influence of water temperature on brook trout growth rates in the field". Freshwater Biology 55 (11): 2253–2264. doi:10.1111/j.1365-2427.2010.02430.x. Retrieved 2013-09-27. 
  13. ^ "NAS - Nonindigenous Aquatic Species Salvelinus fontinalis". U.S. Geological Survey. Retrieved 2014-01-06. 
  14. ^ Karas, Nick (2002). "Expansion of the Brook Trout's Range Within the United States". Brook Trout: A Thorough Look at North America's Great Native Trout- Its History, Biology, and Angling Possibilities, Revised Edition. NY: Lyons Press. pp. 331–339. ISBN 978-1-58574-733-7. 
  15. ^ "Salvelinus fontinalis Aurora trout". http://animaldiversity.ummz.umich.edu/. Retrieved 2013-12-26. 
  16. ^ "Brook Char or Brook Trout". http://www.fishingmag.co.nz/. Retrieved 2013-12-26. 
  17. ^ "Brook Trout (''Salvelinus fontinalis'')". Chebucto.ns.ca. Retrieved 2013-07-10. 
  18. ^ Xu, C.L. (June 2010). "Size-dependent survival of brook trout Salvelinus fontinalis in summer: effects of water temperature and stream flow". Journal of Fish Biology 76 (10): 2342–2369. doi:10.1111/j.1095-8649.2010.02619.x. Retrieved 2013-09-27. 
  19. ^ Blanchfield, Paul (Mar 1999). "The cost of peripheral males in a brook trout mating system". Animal Behaviour 57 (3): 537–544. doi:10.1006/anbe.1998.1014. Retrieved 2013-09-27. 
  20. ^ "A Completion Report on the Lake Superior Coaster Brook Trout Initiative" (PDF). Great Lakes Fishery Commission. Retrieved 2013-12-27. 
  21. ^ a b Karas, Nick (2002). "Salters and Coasters". Brook Trout: A Thorough Look at North America's Great Native Trout- Its History, Biology, and Angling Possibilities, Revised Edition. NY: Lyons Press. pp. 100–119. ISBN 978-1-58574-733-7. 
  22. ^ a b "Coaster Brook Trout". Trout Unlimited Canada. Retrieved 2014-05-28. 
  23. ^ Gill, Theodore; Goode, G. Brown (1903). American Fishes-A Popular Treatise upon the Game and Food Fishes of North America. Boston: L. C. Page and Company. 
  24. ^ Karas, Nick (2002). "Daniel Webster and his "Devil Trout"". Brook Trout: A Thorough Look at North America's Great Native Trout- Its History, Biology, and Angling Possibilities, Revised Edition. NY: Lyons Press. pp. 3–14. ISBN 978-1-58574-733-7. 
  25. ^ a b Schullery, Paul (1996). "The Fly-fishing Exploration". American Fly Fishing-A History. Norwalk, CT: The Easton Press. pp. 43–57. 
  26. ^ Karas, Nick (2002). "Dr. John William Cook and his "Devil Trout"". Brook Trout: A Thorough Look at North America's Great Native Trout- Its History, Biology, and Angling Possibilities, Revised Edition. NY: Lyons Press. pp. 15–26. ISBN 978-1-58574-733-7. 
  27. ^ Moeller, Scott (August 2009). "Species Profile-Closeup on the Brook Trout". Minnesota Department of Natural Resources. Retrieved 2014-05-30. 
  28. ^ "Dr. JW Cook's World Record Brook Trout Was Caught in 1915". Brooktrout.ca. Retrieved 2013-07-10. 
  29. ^ "Browny. ''The Fish'', Fish'n Line Magazine". Anglingmasters.com. Retrieved 2013-07-10. 
  30. ^ "Brook trout records". bigbrooktrout.com. Retrieved 2014-04-10. 
  31. ^ "Trout Profile". Agricultural Marketing Resource Center. March 2012. Retrieved 2014-05-28. 
  32. ^ "Eastern Brook Trout: Status and Threats". Trout Unlimited for the Eastern Brook Trout Joint Venture. Retrieved 2013-12-29. 
  33. ^ Camuto, Christopher (1990). "Air and Rain". A Fly Fisherman's Blue Ridge. New York: Henry Holt & Company. pp. 85–87. ISBN 0-8050-1466-7. 
  34. ^ "Royal Ontario Museum's page on the Aurora trout". Rom.on.ca. Retrieved 2013-07-10. 
  35. ^ "The Southern Appalachian Brook Trout Foundation". Retrieved 2013-12-27. 
  36. ^ "Protect, Restore and Enhance". Retrieved 2013-12-29. 
  37. ^ Jason B. Dunham, Susan B. Adams, Robert E. Schroeter and Douglas C. Novinger (2002). "Alien invasions in aquatic ecosystems: Toward an understanding of brook trout invasions and potential impacts on inland cutthroat trout in western North America" (PDF). Reviews in Fish Biology and Fisheries 12: : 373–391. 
  38. ^ "Salvelinus fontinalis (fish)". IUCN SSC Invasive Species Specialist Group (ISSG). Retrieved 2014-01-06. 
  39. ^ Peterson, Lesley (Spring 2013). "Loved in Eastern Canada, Loathed in the Rockies: The Two Sides of Brook Trout" (PDF). Currents (Trout Unlimited Canada) 19 (2): 1–3. Retrieved 2013-01-06. 
  40. ^ Shepard, Bradley B. (2009). "SWG Final Report: Factors that influence invasion of nonnative brook trout (Salvelinus fontinalis)and their displacement of native cutthroat trout (Oncorhynchus clarkii) in the Northern Rocky Mountains". Montana Department of Fish, Wildlife & Parks. Retrieved 2014-04-13. 
  41. ^ Frank, Charles W. (2014-04-02). "Under the Radar – The Trout Eradication Program Save the Fish". eTerritorial Dispatch Yuba County, Sutter County, Nevada County and Colusa County. Retrieved 2014-04-13. 
  42. ^ Carmona-Catot, Gerard; Moyle, Peter B.; Aparicio, Enric; Crain, Patrick K.; Thompson, Lisa C.; Garci'A-Berthou, Emili (2010-11-01). "Brook Trout Removal as a Conservation Tool to Restore Eagle Lake Rainbow Trout" (PDF). North American Journal of Fisheries Management (American Fisheries Society) 30: 1315–1323. doi:10.1577/m10-077.1. 
  43. ^ "2013 Yellowstone National Park Fishing Regulations" (PDF). National Park Service. Retrieved 2014-04-13. 

Further reading[edit]