A New Freezing Technique for Sampling Salmonid Redds

摘要

This report describes a new multiprobe freeze method for determining salmonid redd sediment particle size distribution. This method will collect salmonid eggs and alevins in the redd at any stage of development, any air or water temperature, any stream depth, and determine their horizontal and vertical location. This method allows larger size samples to be collected which can help improve understanding of embryo and alevin survival rates and causes of their mortality.