Recent implementation of size-based regulations in recreational fisheries for walleye Sander vitreus have led to more released walleyes and presumably to more losses of released fish. We conducted this study to estimate hooking mortality in Mille Lacs, Minnesota, and to determine factors that influence the survival of released walleyes. Volunteers and Minnesota Department of Natural Resources employees sampled walleyes with common angling methods in 2003 and 2004 on Mille Lacs (n ¼ 1,246). Simple hooking mortality rates ranged from 0% (95% confidence interval ¼ 0-1.8%; n ¼ 204) in May, when lake water temperatures were less than 208C, to 12.2% (9.2-15.9%; n ¼ 392) in the July-August period, when lake water temperatures were at least 208C. We used logistic regression within generalized linear or additive models to determine influential variables. Hooking mortality was most associated with water temperature, bleeding, fish length, hook location, and fish floating upon release. Mortality increased as the water warmed above 188C and was higher for fish that bled at temperatures less than 248C but similar for both bleeding and nonbleeding fishes at temperatures of 248C or more. Fish hooked in the throat or stomach died at higher rates than fish hooked in the jaw, inner mouth, or gills and those that were externally foul-hooked, especially when they were smaller. Although fish of medium length (300-600 mm) were more likely to be deep hooked, they died less frequently than walleyes of other lengths. Cutting the line did not significantly improve survival in deeply hooked fish. Mortality was similar between live bait jigs and live bait regular hooks. Most observed hooking mortality was caused by damage to major internal organs. Hooking mortality is minimized when anglers fish in cool water, use active fishing methods, and catch medium-length walleyes.

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Anglers sometimes use alternatives or modifications to J‐shaped hooks to reduce hooking mortality in fish that are caught with live baits and then released. One such modification, the removal of barbs, has been evaluated for several fish species but has shown little promise for reducing hooking mortality; however, barbless hooks have not been evaluated for walleye Sander vitreus. We evaluated relative mortality for walleyes (228–419 mm total length) that were caught by means of bobber fishing with leeches on barbed (n = 179 fish) or barbless (n = 209) live‐bait octopus hooks or on barbed jigs (n = 193); after capture, the fish were held for 120 h in net pens. Holding mortality was a function of water temperature, cage density, bleeding level, and hook location; fish length and angler handling time did not significantly affect mortality. We combined hook location and bleeding level to create a single variable, hooking damage, which was used to replace the two variables in the initial model. This second model was similar to the first, indicating that hooking damage was correlated with mortality when controlling for the effects of water temperature and cage density. We also determined that hooking damage was correlated with hook type. For the 228–419‐mm walleyes in our study, barbed jigs caused less damage than live‐bait hooks and damage levels were similar between barbed and barbless live‐bait hooks. Given specified levels of hooking damage, holding mortality was independent of hook type. We hypothesize that the fish in this study were too small to swallow the jigs well and thus were hooked less critically and bled less than fish that were caught with live‐bait hooks. This study illustrates how gear type can affect hooking mortality based on the amount of damage caused when the fish is caught and adds to the body of literature indicating that the removal of barbs from hooks does not increase fish survival.Received March 15, 2010; accepted November 17, 2010

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The development is described of a viable kilo-scale synthesis of the Na v 1.8 sodium channel modulator, N-methyl-6-amino-5-(2,3,5-trichlorophenyl)pyridine-2-carboxamide (PF-1247324) in five steps, starting from 6-amino-5-bromo-2-picoline, in 33% overall yield. Two key steps required significant optimisation to improve yield and reproducibility. Oxidation of 6-acetamido-5-bromo-2-methylpyridine by permanganate to give the corresponding carboxylic acid derivative was improved by adding potassium dihydrogen phosphate, which moderated the reaction mixture pH and doubled the yield. The potassium fluoride-promoted Suzuki-Miyaura coupling between 2,4,5-trichlorophenylboronic acid and methyl 6-amino-5-bromopyridine-2-carboxylate, catalysed by tri(tert-butyl)phosphinepalladium (0), proceeded reliably to completion at room temperature in high yield when water was added. Anhydrous reaction mixtures reacted much more slowly, and 'wet' mixtures led to significant protodeboronation in the absence of sufficient active catalyst. In the final step, amidation of the ester with methylamine gave PF-1247324.