WILD STEELHEAD MORTALITY AND GEAR TYPE

In 2001 Bob Hooton, fish biologist for the British Columbia Ministry of Environment, evaluated the impact of bait, lures and flies on steelhead and resident fish. This paper reviews what is known through scientific evaluation of relative impacts of these fishing types.  I have provided a few interesting quotes form this paper below.

“During the Keogh River experiment, it quickly became evident that, in order to obtain the requisite sample size of steelhead hooked on artificial lures, it was necessary to commence angling sessions with that gear type.  Despite a strong bias towards artificial lure fishing prior to using bait, lures caught 99 fish while bait produced 236 or 2.38 times as many for similar hours fished.  Additionally artificial lures caught fish were hooked deep inside the mouth or gill arches and bleeding heavily in 4 of 99 cases (4.04%).  Bait caught fish were similarly hooked in 26 of 236 records (11.02%) or 2.72 times as often.”

“During the Keogh hooking mortality study discussed earlier a total of 130 and 206 

steelhead were angled in study years 1985 and 1986 respectively (Hooton, 1987). The

weir count of adult steelhead over the period that angling occurred downstream from the

fence was used to provide a reasonable approximation of the percentage of the run

captured in the time allocated. In 1985, the data revealed that project staff fished 117

hours to catch 130 steelhead that represented about 27% of the fish available. In 1986,

121 hours were angled to catch 206 fish that represented about 19% of the supply. In

other words two anglers fishing an average of one hour per day over a two month period

caught roughly one quarter of the population one year and one fifth the next. All of that

occurred in about 50 meters (164 feet) of river.”

“More recently Keogh project technicians involved in requisite sampling of steelhead

upstream from an electronic counter captured 45%, 62% and 30% of the total available

supply of steelhead in 1998, 1999 and 2000 respectively. For 2001 to date the figure

stands at 51% (personal communication, Bruce Ward, Senior Anadromous Biologist,

Ministry of Agriculture, Food and Fisheries, University of BC, Vancouver). These catch

rates resulted from two staff fishing for an hour or two per day over several kilometers of

a river that is not held to be particularly accessible or “fishable” by most steelhead

anglers. All of the fish were angled with bait.”

“What we can say, however, is that angling with baited hooks is prevalent in streams

where it is legal, that angling with bait generally results in substantially higher catch rates

and mortality rates for both target and non-target fish than angling with any other gear

type, that many of the wild steelhead stocks subjected to this combination of factors are

far below target escapement and that the status of non-target stocks and/or species is

frequently as bad or worse than steelhead.”

“Catch and release may have been oversold in that there tends to be a pervasive opinion it can be prosecuted limitlessly with no influence on the status or health of steelhead or sympatric species. With respect to fluvial resident trout populations it was accepted long ago fish are too catchable and prone to hooking mortality to sustain fishing with certain gear types. Resident fish are simply that – stationary inhabitants of the available habitat. Arguably, steelhead in most of British Columbia’s short coastal streams, are effectively resident trout. Their vulnerability is entirely comparable to fluvial resident trout.”

Rearing juvenile steelhead and resident fish are affected by gear type:

“With respect to fluvial resident trout populations it was accepted long ago fish are too catchable and prone to hooking mortality to sustain fishing with certain gear types. Resident fish are simply that – stationary inhabitants of the available habitat. Arguably, steelhead in most of British Columbia’s short coastal streams, are effectively resident trout. Their vulnerability is entirely comparable to fluvial resident trout.”

““Bruesewitz (1995, WDFW) examined the location of hooking among creeled summer and winter steelhead in different Washington State streams in the 1992, 1993 and 1994 sport fisheries. She found that the single hook and bait combination resulted in a 2.33 times higher incidence of hooking in critical locations (14.9% versus 6.4%) than did single hooks and artificial lures.”

Exposure to air and mortality rate:

“Ferguson and Tufts (1993) reported disturbingly higher mortality among domestic

rainbow trout subjected to air exposure after mimicked angling events than for control

fish or experimental fish not exposed to air. Their data revealed 100% survival among

control fish and 88% survival among exercised (i.e., “angled”) fish. Among fish that were

exercised and then exposed to air for 30 and 60 seconds immediately thereafter,

survival dropped to 62% and 28% respectively. The authors stressed their results had

important implications for Atlantic salmon sport fisheries where the marked trend was

toward catch and release but where anglers habitually hold fish out of water for

significant periods of time prior to release.

Influence of multiple captures on fish mortality:

“The influence of multiple captures of individual steelhead is another element of many

British Columbia steelhead fisheries that remains to be evaluated. Catch and tag

recovery data from a large number and range of Ministry programs indicate that in many

heavily fished streams steelhead are commonly caught two or more times. It is

reasonable to conclude the frequency of these occurrences has increased steadily over

the past two decades. The emerging and unanswered questions are whether or not

there are cumulative effects associated with multiple captures and how significant these

are from a population perspective? It is clear from the available CPUE (and mortality

rate) data presented above, however, that any risk of sub-lethal effects associated with

multiple captures would be skewed markedly toward gear types and procedures that

increased an individual fish’s frequency of exposure to those circumstances.”

Hatchery fish increase angling pressure and wild steelhead mortality

“Close examination of Steelhead Harvest Analysis (SHA) data reveals a consistent pattern on streams where hatchery steelhead have been introduced. The years immediately following first returns of harvestable hatchery fish display pronounced

increases in angling effort and record high estimates of wild steelhead caught and

released (mandatory). Catches tend to have been sustained despite conclusive

evidence of declining abundance in index streams.”

Anglers can choose to protect wild steelhead

“The angling community may wish to contemplate leaving a smaller and softer

footprint on all wild fish or risk the steady erosion of longer term opportunity. A sobering

reality is that the trends in stream fishing opportunity throughout virtually all of

southwestern British Columbia have manifested themselves in a very few generations of

steelhead. Ignoring history and assuming trends will be stabilized or reversed in the

absence of attention to fishing impacts is unlikely to produce a desirable outcome.”