Sometimes when angling, I get the sense that not all fish are the same, even when they’re the same species, seem to be the same size, appear to be the same sex, and have been caught within the same hour of the same fishing excursion. For example, one fish is particularly feisty, and a real treat to bring in, while others have very little fight and kind of make me think I’ve caught a ‘log bass’ (aka, snag). A recent study suggests it may not be my imagination playing ticks on me. Researchers from the University of Eastern Finland (Härkönen et al. 2014) have found evidence that not all brown trout of the same age class and sex behave the same.
Schindler and Smol Hill Times Column Above is a link to the PDF of an opinion piece by two eminent biologists, David Schindler and John P. Smol, that was published yesterday in the Hill Times regarding the need to restore the Fisheries Act to its full strength. It mentions an announcement, coming from the government in the next few weeks, that they will be reviewing environmental protections weakened by the Harper government.
To deal with hourly and seasonal changes in energy demand some hydro-electric dams change the flow of water through the dam. This is called hydro-peaking, and high energy demand results in peaks in river flow during the day. At night however, when everyone is asleep, discharge from the dam is reduced. Along with flow, water level changes, and habitats that are underwater at sunset may dry out overnight. A recent study by Kennedy et al. (2016) decided to find out what that means for aquatic insects that lay their eggs in the rivers affected by hydro-peaking. They recruited rafting groups to set up light-traps at sunset to catch egg-laying adults. The use of “citizen scientists” was necessary to obtain the amount of data they