One of the challenges of staying warm during winter fishing is doing so without adding bulk. Big, bulky clothing can certainly keep you warm but it can get in the way of casting and, more importantly, can be a real drag trying to cram into properly fitted waders. The alternative for many is to wear winter outer layers on top of waders, which defeats the purpose of anything more than waist-high waders. The answer is highly compressible winter outer layers that provide the warmth, water resistance and wind protection that spending a winter day on the water demands. In an effort to find potential candidates, we reviewed a series of winter outer layers designed to be low-bulk and provide serious protection from the elements. One of the standouts was Patagonia's Nano Puff jacket.

As tested, the Patagonia Nano Puff Jacket in Forge Grey.

The Patagonia Nano Puff is the synthetic counterpart to Patagonia's Down Jacket, both highly compressible winter jackets designed to be used as the middle or outermost component of a layered clothing system. Though both jackets still work very well without a sophisticated set of under-layers, it's important to realize that the key to successful temperature management during winter activities is layering. Wicking base layers (leave your cotton garments at home), combined with the proper mid and/or outer layers allow today's technical clothing to manage moisture and temperature the way they were designed to.

A disturbing new study indicates that the survival rates of wild Chinook salmon may be far less than previously thought. The study, which was conducted on California's Mokelumne River, used an innovative test to determine the proportion of wild to hatchery raised fish in an unmarked population. The study's findings reveal that as few as 4 percent of the fish returning to the Mokelumne to spawn are of wild origin.

Researchers collected over 1000 chinook carcasses and tested their otoliths (ear bones) for sulfur isotopes. Testing for the accumulation of certain chemical elements in bone can tell scientists a great deal about the early stages of a fish's life. In this case, the presence of higher amounts of sulfur isotopes allowed researchers to identify differences in the early dietary influences in individual fish, and thus separate hatchery raised fish from those which fed in the wild.