Today, October 8th, is World Octopus Day! Octopus have been around for a long long time, so why do we need an international octopus day?
Right now more than 50,000 tons of octopus are caught each year. And scientists still have little idea how many octopuses are out there in the oceans—or even how to go about measuring them. Octopuses, being asocial animals, don’t swim in schools that can be tracked and measured. And researchers are only just now devising ways to estimate an octopus’s age, as various species—and even individual populations in different environments—grow at various rates and live for anywhere from months to several years. And assessing populations accurately demands this sort of basic info.
So on this International Octopus Day, take a little time to remember these incredible eight-armed animals out in the oceans, quietly catching crabs, masquerading as other animals and occasionally even using tools.
And here is a nice infographic from dailyinfographic.com!
A new study shows that plankton, including sea monkeys, may be able to have an impact on ocean mixing. Researchers Monica Wilhelmus and John Dabiri at the California Institute of Technology used lasers to herd groups of sea monkeys, and observed the effect of the sea monkey movement on the water they swam in (see video below). News articles here and here.
The researchers were able to observe the hydrodynamic influence of swimming brine shrimp by using lasers to coax their movements. A horizontal green laser was used to lure them to the surface, while a vertical blue laser encouraged them to focus their path along a central column, according to the release.
The scientists were then able to scale up their measurements by creating a model to better understand how a school of zooplankton numbering in the billions might influence ocean currents.
A vertical migration of newly hatched A. salina (a species of brine shrimp, commonly known as Sea-Monkeys) is triggered by means of a blue luminescent signal. Animals were introduced at the top right corner of the tank resulting in a large concentration of organisms within that region at the beginning of the video. After the blue laser beam was triggered, the organisms located the brightest spot at the bottom of the container, where the blue beam reflected off the surface. Thus, collective motion was induced toward that spot. Once the organisms reached that position, the light source was identified above, triggering vertical motion to the top. A red laser sheet at the center of the tank illustrates the lack of attraction to this particular light signal. Playback is four times faster than real time. (Credit: M. M. Wilhelmus and J. O. Dabiri/Caltech)
Another great article from Southern Fried Science. This time Andrew David Thaler gives us info on an awesome new attraction in Baltimore’s Inner Harbor, highlighting the need for systems to clean up our oceans. A water cleaning system called the water wheel. Check out the great article here to learn about the cool project.
Situated at the mouth of Jones Falls–a major tributary for Baltimore’s Inner Harbor–the Water Wheel’s water wheel is powered by current (and supplemented by solar panels). The wheel drives a series of rakers that pull floating trash out of the Falls and onto a conveyor belt, where it is deposited in a floating dumpster.