Pixabay / Public Domain
Pixabay / Public Domain

Why marine creatures swim in circles

Thanks for advancements in tracking technologies, scientists have discovered an intriguing behavioural trait amongst some marine species: They sometimes swim in circles.

When studying the navigational abilities of sea turtles, Tomoko Narazaki, a marine researcher at the University of Tokyo, observed that the turtles in her study would swim in circles so constantly “just like a machine.”

Many species of whales and dolphins have supersensitive hearing because they use sound to navigate

Whales and dolphins naturally muffle loud sounds

Instead of wearing earplugs at a rock concert, imagine you could simply tune a dial inside your ears to lower the volume and protect your hearing. In a new report published in Integrative Zoology, researchers have discovered four whale species and dolphins can do just that. This could potentially shield the animals from navy sonar and oil drilling, linked to at least 500 marine mammal deaths since 1963.

Wedell seal

Seals may use Earth's magnetic field to navigate

If the hypothesis turns out to be true, it would represent the first evidence of such a trait in a marine mammal.

Randall Davis of the Department of Marine Biology at Texas A&M University, Terrie Williams, a professor of ecology and evolutionary biology at the University of California, Santa Cruz and another colleague, Lee Fuiman, associate director of the University of Texas' Marine Science Institute in Port Aransas, have been studying the behaviour of Weddell's for decades.

Navigation in Fish

Atlantic salmon parr emerging from streambed.

Coral reef fishes have a life cycle that is divided in two. They begin their life after hatching with a pelagic larval phase, lasting from a week up to two months depending on the species, and ends with a benthic phase, when the fish larvae settles to the coral reef one night. For decades the pelagic phase has been a black box to researchers. Only recently has the lid to this black box been opened.