Aurora trout
 | This article relies largely or entirely on a single source. (July 2011) |
| Aurora trout | |
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| Subspecies: | S. f. timagamiensis
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| Trinomial name | |
| Salvelinus fontinalis timagamiensis (Henn, 1925)
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Introduction
The Aurora trout are considered to be a sub species of the Brooke Trout. They were originally believed to be the brook trout with a simple color distinction. Through further examination in 1967 of their features they were designated as a sub-species.[1] Differences in features include the lack of yellow and red spots that are common to the brook trout. Both the Aurora trout and brook trout are of the Salmon family.
Description
Distinct characteristics of the Aurora trout are its hooked lower jaw. The humped backs of the Aurora trout are a deep purple on females while the males of the species have one that is jet-black and have a white underbelly. They have silver flanks that occasionally have a purple sheen, the back of which are an olive-brown. The colouration of their bodies is magenta hue to a bright, nearly fluorescent orange. Their pectoral, pelvic and anal fins have white leading edges followed by a black line and orange or red cover the rest of the fin.[2]
The Aurora trout differs from the brook trout because they do not display the same vermiculations (wormlike movement). Juvenile Aurora trout show vemiculations like the brook trout but this fades with growth. The size of the Aurora trout reaches 60cm total length and 3.5 kg in weight.[2]
The largest recorded catch of the Aurora trout was made by Geoff Bernardo in September of 1993. It weighed 1.7kg and was taken out of Carol Lake in Northern Ontario.[2]
History
The aurora trout, Salvelinus fontinalis timagamiensis, is a variant or subspecies of the brook trout native to two lakes in the Temagami District of Ontario, Canada. The existence of the fish was brought to the attention of the angling world by four American anglers who were taken by Archie King of Latchford, Ontario Canada into Ontario's Lady Evelyn River System in 1923. Recognising the fish as different or unique, the anglers took a specimen back to the Carnegie Museum in Pittsburgh in the United States, where Dr. Arthur W. Henn was asked to identify the fish. He wrote about the fish in 1925 wherein he and Rinckenbach identified it as a distinct species, Salvelinus timagamiensis but, since a seminal re-examination of the material by Sale in 1967, taxonomists now agree the fish is, in a fact, at most a subspecies of the brook trout, named Salvelinus fontinalis timagamiensis. Genetic data have not so far supported its taxonomic distinction.[3]
The Aurora Trout was originally found in North Eastern Ontario and was named by William H. Rinkenbach after the Canadian Northern Lights. Paul Graf, manager of the provincial fish hatchery in Charlton, Ontario, breeded the Aurora in captivity. He is responsible for today’s population. Graf wasn’t the first to bring eggs into captivity. A.Elsey a biologist at Swastika took 10,000 eggs from connecting streams and attempted to increase the population. Unfortunately, he was unsuccessful due to human handling of the eggs. The following time the eggs were caught in a different area rather than streams and were airlifted rather than human hands. This attempt was successful, but the population is increasing again due to acid rain. The Aurora trout can now be found in 12 different lakes including the two original. The committee on the status of Wildlife labeled the species to be endangered and it is still on that list. The trout is protected by the Federal Fisheries Act.
Spawning Characteristics
The Aurora trout spawns in late October and early November at temperatures of 4-6 C. the reproduce in lake shoals as opposed to their counterparts the brook trout who prefer stream spawning. the Aurora trout has a fecundity that can reach 7000 eggs.[2]
Environment
Native to only two lakes in the whole world, the aurora trout is facing possible extinction. The two lakes which the trout is native to, Whirligig and Whitepine, are located in northern Ontario, in close proximity to metal smelters. In the 1960s the lakes were so affected by acid rain, that the pH balance became not good enough for the unique aurora trout. Reintroduction of aurora trout was attempted in the 1990s following a whole-lake liming to develop water pH. This proved successful, and populations of the aurora trout since then have been steady. However, in 2001 and 2002 the pH once again dropped to critical levels. The Aurora trout spawns only in lakes with groundwater springs, and changes in the quality or quantity of these springs can affect the fish drastically. Acid raid, the main cause of the trout’s original disappearance from its original habitat, continues to pose a major threat; the trout’s survival depends upon the maintenance of water pH at acceptable levels. As well, industrial activity such as logging and mining continue to putting too much stresses on the species. The endangered aurora trout are a special Canadian treasure, worthy of our attention. Past human activities have threatened the native populations, it is now critical to learn from the past to ensure that this ecological treasure is not lost forever.
Aurora trout occurred naturally in Whitepine Lake and Whirligig Lake in northeastern Ontario, and has been reintroduced to these two lakes and 10 others. Aurora trout prefer colder waters—below 20°C and look for these by moving to deeper water or by inhabiting groundwater springs. A water pH of at least five is essential for the fish to reproduce successfully and flourish.
Cause of endangerment
The Aurora Trout is both provincially and nationally endangered and is at risk as a species because of different forms of pollution that is affecting their environment. Acid rain and very low levels of pH in the water are causing extreme decreased reproduction rates. Found only in the Temagami District in Ontario, the Aurora trout live in lakes of high elevation and only reproduces in lakes that have underground springs. Changes to the sources of the underground springs can have significant affects on the Aurora trout. The main reasons the Aurora trout are currently at risk are Acid rain runoff and low pH levels in the water, which affect their ability to actively reproduce at a normal rate. This deficit in production levels has had drastic effects on population. In addition, mining, logging and other industrial activities are presently posing problems for the trout.[4]
Attempts at re-population
COSEWIC and SARA (Species at Risk Act) have designated the Aurora Trout as endangered and protected and is protected under the federal Fisheries Act. Previous attempts to save the Aurora trout population has been made by breeding the species in captivity and rereleasing them into their natural habitat. As a result the trout is currently reproducing in a naturally self-sustaining manner in one of the lakes. Continual monitoring of the quality of water, phytoplankton, zooplankton, and benthic invertebrates in native lakes every month and assessments of population with regards to this data collection. Further development in the captivity breeding and reintroduction methods that are taking place at Hill’s Lake Fish Culture Station are to increase the genetic material that can be collected by enlarging the number of families.[4]
References
- ^ Scott and Scott, W.B and N.G (1998). Atlantic fishes of canada. Toronto, Canada: University of Toronto Press. pp. 144–145. ISBN 0-8020-5172-8.
{{cite book}}: Check|isbn=value: checksum (help) - ^ a b c d Coad, Brian W. (1995). Encyclopedia of Canadian fishes. Singapore: Canadian museum of nature and canadian sportfishing production Inc. pp. 72–74. ISBN 0-9692391-7-3.
- ^ Recovery Strategy for the Aurora trout (Salvelinus fontinalis timagamiensis) in Canada Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, July 2006.
- ^ a b "Aurora Trout". Fisheries and Oceans Canada. Retrieved 1 November 2012.
External links
- The Aurora Trout ... a Species at Risk in Ontario Fisheries and Oceans Canada (2010-09-27)