Hooking Mortality of Walleyes Captured in Porcupine Bay, Washington

Abstract

Two groups of walleyes Stizostedion vitreum were captured at Porcupine Bay, an embayment of the Spokane River near its entrance to Lake Roosevelt, Washington. One group of 180 fish was caught on hook and line and put in a floating net‐pen. Another group (controls) of 164 walleyes was captured by electrofishing and put in a second floating net‐pen, identical to the first. After 12 d, the total mortality in both groups was one fish taken by angling. A second fish taken by hook and line was injured, and its survival was doubtful. With a total loss of two fish, the hooking mortality was determined to be 1.1%.

Hooking mortality: A review for recreational fisheries

“…Fielder (1992) indicated that total (weigh-in plus delayed) mortality was 21% in South Dakota tournaments, and Goeman (199D reported high variability (5.7 to 47.1%) in postrelease mortality in a Minnesota tournament. Because total mortality averaged 40% in the Minnesota study and was higher than reported elsewhere (1.1%, Fletcher, 1987;5 to 16%, Payer et al, 1989;0.8%, Schaefer, 1989) for the species, Goeman (1990 attributed the difference to tournament (e.g., handling, weighing) conditions.…”

“…For example, Feathers and Knable (1983) determined mortality of largemouth bass occurred when captured at depths greater than 18.3 m. Depressurization at depths less than 9.1 m resulted in significantly lower initial (occurring within 24 h) mortality than at 9-1 to 18.3 m. Damage was both more serious and obvious when depressurization occurred at depths of at least 18.3 m. Lee (1992) determined that deflation of an expanded swim bladder did not impair survival and could improve the survival of released largemouth bass caught from great depths. Fletcher (1987) reported that the hooking mortality of walleyes caught from depths of no more than 10 m was only 1.1%. However, he added that higher mortalities, resulting from distended swim bladders that may protrude from their mouths, would occur when fish were caught at depths up to 30 m. Faccin (1983) reported that the mortality of rainbow trout ranged from 10 to 33% among fish confined at depths of 1 to 3 m compared to 50 to 70% among fish restrained at 6 m. The difference in mortalities may be attributed to swim bladder air pressure adjustments at the greater depth.…”

Walleye Predation on Hatchery Releases of Kokanees and Rainbow Trout in Lake Roosevelt, Washington

“…Hooking mortality has been demonstrated to be negligible when walleyes are released immediately after being caught (Fletcher 1987;Payer et al 1989;Schaefer 1989); however, several studies have demonstrated that short-term delayed mortality of tournament-caught walleyes can be substantial (Goeman 1991;Fielder and Johnson 1994;Hoffman et al 1996). Increased mortality was generally related to poor weather conditions (high winds and rough water), high water temperatures, high bag limits, non-recirculating live-wells, and lack of penalties for dead fish.…”

Simulated Equilibrium Walleye Population Density under Static and Dynamic Recreational Angling Effort

“…The effect of postrelease mortality was examined for each fishery regulation. To determine the harvest at time t, H t , postrelease mortality, K, was modeled over the range (0-40%) of observed postrelease mortality (Fletcher 1987; Reeves and Brue-…”