Williston Watershed Arctic Grayling
These fish are at risk because they are adapted to particular habitats and are unable to respond to sudden environmental changes.
Ministry of Water, Land and Air Protection unlogged trees. The aquatic commu- these 15 streams supported grayling. nity within the reservoir altered, They were absent from all 3 resurveyed favouring those species most suited to Finlay Reach streams, were found in very the new conditions. low numbers in 3 of the 4 Peace Reach Why are Williston watershed Industrial activities also contributed streams and were present in only 1 of the Arctic Grayling at risk? to declining populations. Expanding 8 Parsnip Reach streams. In a 1977 creel rctic Grayling within the drainage road systems and boat access increased survey, grayling were the most common system of the Williston Reservoir angler harvest in previously remote gamefish taken in the Peace and Finlay have a restricted distribution above areas and led to overfishing and en- Forks areas, making up, respectively, 58 Athe W.A.C. Bennett Dam on the forcement problems. Improper cul- and 23 percent of angler harvests. Dur- Peace River. Populations within the vert installation created barriers to ing a 1989 creel survey, however, grayling Williston Reservoir and its tributaries fish movement. Siltation from log- comprised about one percent of the have been isolated from the ging activities buried catch in these same areas. remainder of the Peace system The decline stream bottom mater- Healthy populations of Williston since at least 1963, when prepara- of the ial, reducing spawn- watershed Arctic Grayling now remain tions to construct the dam com- ing success and the only in the larger, often remote systems, menced. In 1972, the reservoir Williston availability of cover such as the Osilinka, Mesilinka, Omin- achieved full pool. Both the reser- watershed and feeding areas. eca, Ingenika and Finlay drainages. voir and stream populations Sun on clear-cuts in- In 1995, the BC Conservation Data remained reasonably abundant Arctic creased spring snow- Centre classified the Williston water- and widespread until about 1982, Grayling melt and stream flows, shed Arctic Grayling as critically im- when grayling in all small and and decreased late perilled, placing it on the provincial medium-sized streams flowing was due to summer flows. Acti- Red List. The Williston population has directly into the reservoir rapidly the change vities involving poor been placed in the highest risk class disappeared. By 1988, only popu- road or pipeline con- due to the significant declines in lations native to the largest river from river struction or the re- several populations and the species’ systems survived. habitat lease of non-native vulnerability to habitat degradation and Biologists believe that popula- fish species can still overfishing. Although no habitat is tions declined due to a combina- to reservoir threaten grayling sur- completely protected, some grayling tion of factors: loss or degrada- habitat. vival. In general, Arctic streams receive enhanced protection tion of key spawning and rearing Grayling are specifical- through regional and other planning areas; changes to the food supply and ly adapted to particular habitats and processes. Angling regulations have type of cover available; disruption of are unable to respond to sudden envi- prohibited a kill fishery since 1995; all migration patterns; competition with ronmental changes. Arctic Grayling caught in the watershed species more adapted to lake living; must be released. and overfishing. What is their status? Native grayling are adapted to river e can get an understanding of the What do they look like? environments and some of the decline seriousness of the decline by com- n general, Arctic Grayling have trout- was due to the change from river habi- paring earlier studies to more like bodies, a short head, large dark- tat to reservoir habitat. Like salmon and Wrecent surveys. In 1975, BC Envi- green-and-gold eyes, a small mouth trout, grayling return to spawn at the ronment surveyed 57 streams in the Iwith teeth in both jaws and a deeply same place where they hatched; several Parsnip, Finlay and Peace reaches of the forked tail. Their scales are larger than affected populations relied upon spawn- reservoir. Arctic Grayling were found in those of either trout or char. They are ing and rearing habitat that was inun- 11 of 29 Parsnip Reach streams, 6 of 13 easily distinguished from other North dated as the reservoir filled. Food sources Finlay Reach streams and 11 of 15 Peace American fish by their greatly enlarged, changed from terrestrial insects and in- Reach streams, and were numerous fan-shaped dorsal fin. Typically, fish vertebrates drifting with the stream wherever they were present. Between caught by anglers in the Williston current to prey such as plankton in 1989 and 1991, BC Environment resur- drainage vary from 20 to 40 centimetres the open water and invertebrates that veyed 15 of the 28 streams where long and weigh up to 1 kilogram. In other live on bottom substrates, debris and grayling were found in 1975. Only 4 of areas they may reach 75 cm and 2.7 kg. The adult Arctic Grayling is striking- The black dorsal fin is edged with Males are more vividly coloured than ly coloured. The head is olive green and mauve, often with a wider blue band females, especially during spawning. iridescent mauve. The body is steely grey below. Between each of the 19 to 24 Mature males have much longer dorsal with hints of olive, blue or purple, with supporting rays are columns of spots. and pelvic fins than mature females. scattered black spots towards the front Those near the edge may be orange- (younger fish have more spots along the red, mauve or wine-coloured, while the What makes them unique? sides). The scales along the sides are sil- remainder are iridescent blue-green to he Rocky Mountains are one of very grey to dark blue, with a spectacular emerald green. The pelvic fins are black the major barriers to fish movement blue-green iridescence. Under sunlight, with mauve or orange lines. The re- in North America and very different the scales may be outlined in yellow. maining fins are dusky to bronze. Tspecies groups are found to the west and east. Upper Peace grayling coexist Present range of Williston watershed they drift downstream. As fry grow, with a group of fish species unique in Arctic Grayling in British Columbia their diet may include larger terrestri- North America. This situation is al insects that fall into the water. thought to have arisen as glacial ice Larger fish eat a more varied diet, melted and allowed fish to move across but prefer both the larval and adult the Rocky Mountains between the stages of aquatic insects and terres- upper Peace and Fraser rivers. This trial species like bees, grasshoppers, occurred less than 10 000 years ago. wasps and ants. They may also feed Arctic Grayling were apparently on zooplankton, fish eggs and unable to cross over or establish a small fish. Terrestrial insects are a population, as they are not found in favourite summer food in many the Fraser system. populations. In the Sukunka River, Williston grayling do not appear just east of the Williston water- to be genetically diverse, which sug- not build nests or redds, although shed, a study found that two to five gests that they evolved from a rela- shallow pits may be formed during year olds fed mostly on surface or drift- tively small founder population. pre-spawning activity. Males and ing insects in the summer and on ben- females swim side by side, the male thic insects in the winter. Older How do they reproduce? arches its dorsal grayling establish and maintain feed- hroughout their global range Grayling fin over the fe- ing territories through a series of Arctic Grayling mature at are easily male’s back, both ritualized challenge displays. varying ages, depending on fish vibrate and Tgrowth rate and location. In distinguished they release the Where do they live? the Williston watershed, spawners from other eggs and sperm rctic Grayling are found through- likely average four to five years at together. out the northern drainages of maturity and normally live six to North Female grayling Canada. In British Columbia they eight years. Mature fish may produce between Aare distributed from the Peace and American spawn every year. 3000 and 14000 Stikine river systems north to the Yukon Typically, grayling begin mi- fish by their small, sticky eggs, border. Williston watershed Arctic grating to their spawning greatly which become Grayling are found in the reservoir and grounds before the ice breaks lodged 2 to 3 cm several large rivers draining to the reser- up in the spring. They begin enlarged, deep among the voir, including the Finlay, Ingenika, spawning just after spring fan-shaped stones. The eggs Omineca, Mesilinka, Parsnip and floodwaters peak, when water hatch in two to Nation watersheds. temperatures reach 4°C, and con- dorsal fin. four weeks, de- Within the Williston watershed, tinue from mid May to mid June. pending on water Arctic Grayling prefer the clear, cold Arctic Grayling usually spawn in temperature. After three to four days, waters of stream habitats ranging from tributary streams over clean stones in the small, weakly swimming fry emerge large mainstem rivers to small streams. 30 to 80 cm of water. Males arrive at from the gravel. Arctic Grayling are at They may make seasonal use of some the spawning grounds first, seeking their most vulnerable during this systems, such as the Wicked River. isolated spawning territories among part of their life cycle and can easily After hatching and emerging, fry stones, boulders, bedrock or large be killed by high water, turbulence, swim downstream from the spawn- woody debris. The strongest males starvation or stranding. ing grounds to take up residence occupy the best spawning territories, in shallow, low-velocity areas along which they aggressively defend against What do they eat? stream edges or in side channels. For any other male that they can see. Their oth juvenile and adult Arctic two to three weeks after hatching, the spectacular dorsal fin is prominently Grayling are opportunistic feeders. fry feed constantly in small groups or displayed to impress rival males. Fry feed on aquatic stages of midges, dense schools. As they grow, they Females hold in deep pools before Bblack flies and stoneflies and other move to deeper, faster water. briefly entering male territories to benthic (bottom dwelling) inverte- Arctic Grayling are known for release their eggs. Female grayling do brates, or the young stages of insects as migrating long distances between spawning, summer feeding decisions in some areas. and overwintering areas. They Further studies of Williston usually return to the same grayling life history, stocks areas each year and do not and ecology are necessary. stray elsewhere. In many To conserve and restore areas, grayling distribute grayling populations, water- themselves in the summer shed management plans are by size, with juveniles using being developed. This is par- the lower reaches, subadults ticularly important in view in the middle reaches and of the declining populations the largest adults occupying facing rapid resource and the upper stream reaches. access development. Where Adults prefer to feed in pools feasible, restoration pro- or glides downstream of jects can be helpful. Stream long, steep riffles, often with fertilization is also being schools of Mountain White- explored to offset the im- fish. When they share deep- pacts of flooding. water habitat with Mountain Resource and land use , Whitefish, the Arctic Gray- ( practices now incorporate ). Ted Down photo ling remain close to the top, methods for reducing habi- watching the surface for food to drift by, Largescale Suckers, Lake Whitefish, tat impacts. Road planning attempts while the whitefish stay near the bot- Slimy and Prickly sculpins, Kokanee to minimize sedimentation, channel tom, hunting for prey among the rocks. and several smaller species. Bull Trout, and stream flow changes, and access In the Parsnip watershed, grayling Lake Char, Northern Pikeminnow and problems. Roads and culverts are being use mainstem and tributary habitat Burbot are the top predators in the eco- designed and maintained with gray- for fry, juvenile and subadult rearing. system; some of these predators may ling needs and capabilities in mind. Studies in the Sukunka drainage east occasionally feed on grayling. Pipeline routes and of the reservoir showed that grayling These fish crossings are being used a variety of habitats depending What can we do? prefer the planned to reduce on life stage and season. Recently he habitat provisions of the or eliminate sedi- emerged fry were found in slow back Fisheries Act, angling regula- clear, cold ment impacts. channels, older fry in the side-channel tions and Red-listing status waters of Since grayling are riffles and larger juveniles and adults T alone will not guarantee that found throughout in the pools. Adults swim downstream Williston watershed Arctic stream northern Canada and in September and October to hold Grayling habitat and populations habitats British Columbia, over the winter in the reservoir or will be protected or restored. most people are un- large mainstem pools. Most fry also Although catch and release regu- ranging aware that Williston migrate to deeper winter habitat. lations have been implemented, from large Reservoir popula- From December to March, most fish their effectiveness is unknown tions are imperilled. remain at one location. and remaining populations are mainstem Continuing wide- Arctic Grayling are found with a still vulnerable. Intensive angling rivers spread public and variety of other species in the Williston can readily capture most of the industry awareness watershed. Rainbow Trout can tolerate fish in a given population. to small is vital to galvanize warmer water and often predominate Efforts are needed on several streams. efforts to conserve in these conditions. Mountain White- fronts. Although much research the habitat and popu- fish, always the most abundant species, has been done under the Peace/ lations of this beautiful northern species. often accompany grayling schools. Williston Fish and Wildlife Comp- If you are interested in conserving Similarly, small Longnose Suckers ensation Program, biologists and the Williston grayling, you can begin may mix with young grayling fry. managers still lack sufficient infor- by learning about these fish and their Other fish species present include mation to make informed land use needs. If you are an angler, follow the , , . , , - . . . Peace/Williston Fish & Wildlife Compensation Program photo Ted Down photo angling regulations. You can also help by support- ing or volunteering for conservation or steward- ship groups. Enforcing laws and regulations is dif- ficult in remote areas; if you see any violations, Observe, Record and Report them by calling the hotline at 1-800-663-WILD (9453) or contacting your local RCMP detachment, Conservation Officer or fisheries staff. Ultimately, the future of Williston Reservoir Arctic Grayling will rest on the combined efforts of citizens, industry, scientists and government. . Peace/Williston Fish & Wildlife Compensation Program photo
, : Biodiversity Branch Ministry of Water, Land and Air Protection PO Box 9374, Stn. Prov. Govt. Victoria, British Columbia V8W 9M4 http://wlapwww.gov.bc.ca/wld
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