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
When protecting endangered fish species, recreational angling hasn’t always been a main concern, however, this viewpoint is starting to change among scientists and managers. Fishing mortality, even at what might be considered low levels, can negatively affect population growth and recovery efforts. Recreational angling has even been proposed as the cause of the decline of some Canadian freshwater fish species (Post et al. 2002). Despite this, a recent paper by Cooke et al. (2016) puts forward the idea that catch-and-release recreational fisheries can be a useful force for the conservation of endangered species. They provide 6 case studies where allowing catch and release angling for endangered fish may actually have helped conservation efforts. One example they use, that hits somewhat
Whether you are sitting lakeside or beach-side on a sweltering summer’s day, there is no doubt that you will start to feel a little sluggish as the temperature creeps upwards of 30°C. As the sun sits high overhead, you may even begin to nod off, only to wake minutes later searching clumsily for your (once) cold drink and a bit of shade. You head inside, put some ice in your drink and bask in the beauty of AC until your next venture outside – after all, we only get a few weeks of this in Canada. You reached what’s known as your upper thermal limit, and luckily you are able to seek refuge and cool off with a cold-one. All
While angling for brook trout you may have noticed small differences between fish depending on the stream you are angling in even when you are within the same watershed. This forces us to alter the type of flies we use depending on the stream, sometimes even changing as we progress downstream. While most of the fly preferences of trout can be explained by differences in the environment, sometimes it seems that they are simply different fish. Obvious reasons for this are barriers, such as dams, that prevent brook trout in one tributary from breeding with trout from another. A recent paper, however, found that sometimes the reasons are more cryptic than that. The study by Kazyak et al. (2016) discovered