Snorkel Surveys - have been used for the enumeration of both summer and winter steelhead. Summer steelhead surveys generally take place between August to October, when streams are at base flows and very clear, and after most escapement has taken place. Winter surveys generally occur between February and April during periods of low flow and turbidity.

Index reaches varying in length from 6-10 km are swum by experienced crews of 2-3 biologists and technicians, with each crew swimming about half of the survey section. In general, the index reaches were found from earlier basin-wide surveys (1970s) to contain a majority of adult steelhead. Summer run surveys provide a very good indication of steelhead populations while winter run surveys provide a relative or stock minimum abundance.

For rivers like the upper Gold, Heber and Tsitika rivers, there are more than 20 consecutive years of summer steelhead snorkel counts, using the same methods and many of the same crew members. There are from 10-15 years of steelhead escapement counts for another six streams, and 5-10 years of escapement observations for about another 10 streams.

The long-term trend in combined snorkel counts from the Gold, Heber and Tsitika rivers follows a similar pattern to that of Vancouver Island steelhead catch. Further, snorkel counts from the Gold River correlated well with high angler catches reported for that stream (r = .84, p<.001), even though sport caught fish are predominantly winter steelhead. Regional staff have observed a similar correlation between snorkel counts of winter steelhead and angler catches in the Englishman River on the Island's east coast. Strong correlations between mean wild steelhead catch per angler day for west coast Vancouver Island streams and snorkel counts of summer steelhead in the Gold (r = 0.87) and Heber (r = 0.89) rivers since have also been reported.

Further testimony to the strength of the technique is DFO's use of provincial counts of summer coho in the upper Gold River, done coincidentally with enumeration of summer steelhead. DFO uses the annual Gold River count in combination with counts from Carnation Creek and the Stamp River, as key indicators of the "health" of west coast Vancouver Island coho stocks (K. Simpson, Coho Response Team, DFO, pers. comm.).

Limitations to use of snorkel surveys include the fact that they are labour intensive and subject to weather and streamflow conditions. On streams with marginal water clarity (less then 3 m), they are not recommended. Where rivers are lake-headed, or contain many tributaries, steelhead can disperse before swims are completed. Hence they are more useful as relative rather than absolute predictors of abundance.

top

Hatchery steelhead now comprise an important part of angler catch on Vancouver Island, and only hatchery steelhead can be legally harvested. By regulation, these must be recorded directly on an angler's licence, whereas released fish and the number of days spent fishing are not. This means that an angler's ability to recall individual fishing trips and catch success will affect the reliability of data collected by the Steelhead Harvest. Furthermore, active and successful anglers are known to respond at a higher rate than inactive or unsuccessful anglers, consequently population estimates derived from such procedures are generally biased upwards (known as positive response bias).

In spite of these sampling limitations, the questionnaire provides a province-wide database of steelhead angler catch and effort, by stream, that allows for an improved understanding of steelhead abundance trends using estimates of catch per angler. The reliability of the questionnaire's trend data can be reinforced by other stock assessment techniques described in this section.

top

Obviously returns to the brailer do not account for hatchery steelhead remaining in the rivers, or those taken in various fisheries downstream or at sea. At the Robertson Creek Hatchery, steelhead return to their rearing site volitionally (i.e., swim unassisted into the brailer), whereas Puntledge steelhead are directed into the hatchery by an impassable fence spanning the river.

Hydroacoustic and electronic counters have been used mainly by DFO and the Pacific Salmon Commission for enumerating salmon escapements to the Fraser River and on larger Vancouver Island streams like the Stamp on the west coast. They work best in confined river channels or in fish passage structures (like fishways) where flows are laminar with little or no turbulence. They must be regularly calibrated for target fish size and checked for performance. Based on results from a trial at the Keogh River fence in 1998, electronic counters may have greater potential for enumerating winter steelhead in several Island streams where fish migrate past fences or through fishways at natural obstructions or dams (e.g., Stamp, Quinsam, Salmon, Big Qualicum and Cowichan rivers). An important limitation to more widespread use of this technology is its relatively high cost.

top

Hatchery Broodstock Capture - places highly skilled anglers (regular fisheries staff and contractors) on rivers they know well under a range of "fishable" conditions. Season-long catch per angler day (CpAD) on each stream is generally a good indicator of trends in steelhead run strength. Keogh run size was significantly correlated to the combined sport catch from the neighboring Quatse and Cluxewe rivers (r = 0.66, p<.05), after removal of an outlier for the 1985-86 datum. While regional data from broodstock programs (exclusively) have yet to be statistically analyzed with other measures of steelhead stock abundance (like fence and snorkel counts), similarly strong correlations are expected.

Some of the limitations of this method include its relatively high cost (i.e., contracting skilled anglers), susceptibility to weather and flow conditions, and repeat capture rates on released fish which can significantly increase CpAD.

top

Angling Guide Reports - written reports from licenced freshwater angling guides describing results from guided fishing trips (i.e., number of angler days and catch by stream or lake), must be submitted annually (by May 31) to WLAPs regional headquarters in Nanaimo. This information, combined with in-season contacts between guides and regional fisheries staff, is useful in assessing relative steelhead run strengths in various rivers.

The limitations to written guide reports include the fact they are generally received well after the winter steelhead season has ended, and secondly, they tend to vary in quality depending on an individual guide's business skills.

top

Creel Surveys and Conservation Officer Checks - creel surveys were conducted on several Vancouver Island rivers in the late 1970s and early 1980s. There were extremely useful for determining in-season angler effort and catch for direct comparison to similar estimates from the Steelhead Harvest Questionnaire. Since the late 1980s, regional fisheries ability to undertaken comprehensive creel surveys has been appreciably affected by budget/staff cuts and changing workload priorities.

The Habitat Conservation Trust Fund supported the hiring of up to four contract employees to undertake intensive winter steelhead stock monitoring throughout Vancouver Island between 1998 and 2002. These technicians conducted roving creel surveys, snorkel counts and angling to determine run strengths in various Vancouver Island streams. This information proved invaluable in better defining winter steelhead stock sizes, angler effort and catch rates, as well as changes in the distribution of steelhead fishing on the Island following ongoing regulation amendments.

Conservation officer checks serve two important purposes, namely enforcement of existing sport fishing regulations, and data acquisition on angler effort and catch. Uniformed staff are also perceived as "ambassadors" of the ministry's steelhead conservation message, and so serve an important angler education role as well.

As alluded to previously, the primary constraint on both creel surveys and more conservation officer involvement revolves around operational budgets and workplan priorities.

top

In terms of limitations, fry counts do not reflect pre-spawning mortalities related to fisheries or natural predation and disease. Density-independent factors like floods and droughts can drastically reduce egg to fry survival, masking original spawner abundance. The work is labour intensive and requires a well-trained (and certified) crew for field sampling and data analysis.

top