RNR 1001 : Exam 3 Lecture Study Guide
Document Summary
Dominant commercial fisheries groups: finfishes (110 mmt), crustaceans, and mollusks, kelp (32 mmt) Stock fluctuations due to exploitation and environmental factors. Habitat loss and degradation have also played an important role (non-exploited fish: shortnose sturgeon, Fisheries and the law of the commons: excellent example of a renewable resource, stocks increase each year from growth and reproduction, sustainable harvests maintain the principal . Law of commons: exploitation without ownership resource decline. Controlling fishing effort through limits on harvest, gear, crew size, area, season, etc. Fatigue due to high density of water high density makes movement difficult; darters, frog fish, leafy sea dagon. Stress from the temperature/dissolved oxygen relationship for poikilotherms: oxygen declines as temperature increases; temp goes up, ventilation rates go up, then threshold is reached. Turbidity problems, reduced primary production, invertebrate mortality, larval fish mortality, reduced foraging by visual predators, lower reproduction (great barrier reef, lake saint clair)
