In January it was announced that the Vermont Yankee nuclear plant leaked radioactive substances into the Connecticut River (see image above). Recently, a yellow perch was caught for miles upstream and tested positive for the radioactive strontium-90. This isotope has been linked with bone cancer and leukemia, and was found 100 times above the federal Environmental Protection Agencies limit for safe drinking water. Despite this health officials say there is no reason for alarm and that people should not limit their fish intake. Hmmmm.

The blue shark, Prionace glauca, is a common species found throughout tropical and temperate oceans. This shark is often considered to be a surface dwelling fish of the open sea, but it is also commonly found in the dark waters of the continental shelf, swimming into the sunless depths. In this study acoustic telemetry was used to follow 22 blue sharks over the continental shelf and slope, between George's Bank and Cape Hatteras, in the North Atlantic, between 1979 and 1986.

One of the most interesting points of the paper was the authors explanation for their movement patterns. Sharks exhibited highly predictable vertical migrations over several hundred meters. Most sharks, including the blue shark, have strong chemosensory capabilities. In the ocean olfactory cues would be better distributed along the horizontal plane due to the current shear between layers of differing density. Thus, an olfactory stimulus will spread as a radiating disk. By moving vertically through the ocean the sharks would significantly increase the odds of encountering such an odour trace and this is what was observed.

One of the perks of fieldwork is driving through a new country and seeing the landscape as you check out field sites. I was lucky enough to do that last week hence the lack of posts lately. So I thought I would share some of the photos of my trip rather than write up a proper post. I was traveling around Newfoundland checking out turbid estuaries, of which there are apparently none!!!!

Discusses whether their is room in science for ethics, politics and emotions. Should we be sampling sharks for scientific purposes given the pressure their populations are under worldwide?

Lizard species are already disappearing, and becoming extinct, due to global warming.

Why does a black ghost knifefish feed at a body angle of 30 degrees? This post explains how this may increase the electric field of the fish giving it a greater search area for detection of prey.

Discusses how our approach to remediation of abandoned mines and industrial wastelands should be changed. Using species that naturally occur in difficult environments with analogous conditions.

The title pretty much says it all. How to coral larvae find their way to reefs for settlement. This post discusses the role of sound for navigation in these planktonic animals.

Over 4 trillion cigarette butts are dumped into our environment each day. This post discusses a useful option for what to do with the cigarette butts.

The most abundant life on this planet is found deep beneath the waves at depths that sunlight hardly penetrates. Species that live at these depths are impossible to capture for behavioural studies where questions can then be asked about how fish at these depths 'see' the world. Thus, deep sea scientists are restricted to undertaking morphological analysis on these organisms and interpreting the results. One of the long held beliefs is that vision becomes less important for fish the deeper you go, and this is obvious when you look at eye size. Generally, after a certain point, when sunlight can no longer penetrate, the size of fish eyes becomes increasingly smaller and the non-visual senses become elaborate and highly specialised. In this post I discuss two papers that investigate what senses are utilised by mesopelagic and abyssal demersal fish species. For those of you who do not know mesopelagic fish are those that swim in the water column at depths of 500 and 1500m while abyssal demersal fish are those found near the bottom of the sea floor at depths of 2000-6000m.