Bottom trawl surveys

Contents: 1) a history of Canadian groundfish trawling surveys and data usage in ICNAF divisions; 2) a critique of research vessel otter trawl surveys by the St. John's research and resource services; 3) a brief historical review of the woods hole laboratory trawl survey time series; 4) abundance estimates of the trawlable resources around the islands of St. Pierre and Miquelon: methods used during the French research surveys and discussion of some results; 5) use of trawl survey data in assessments; 6) catch projections and their relation to sampling error of research surveys; 7) a brief review of survey methodology with regard to groundfish stock assessment; 8) groundfish survey techniques as applied to abundance surveys for shrimp; 9) abundance estimators based on stratified random trawl surveys; 10) a comparison of estimators of location for skewed populations, with applications to groundfish trawl surveys; 11) a method of estimating the abundance of survivors of an exploited fish population using comemrcial fishing catch at age and research vessel abundance indices; 12) summer distribution of groundfishes on the Scotian Shelf; 13) distribution and sampling variability in the southern Gulf of St. Lawrence groundfish surveys; 14) the fish catching process relevant to trawls; 15) catch variability due to variations in groundfish otter trawl behavior and possibilities to reduce it through instr mented fishing gear studies and improved fishing procedures; 16) factors affecting variability of research vessel trawl surveys.