The finding suggests that much larger groups of plankton could mix seawater by creating currents as they swim, Dabiri says.ĭabiri says that even he was surprised at how clearly the effect showed up in the laboratory experiments. Those swirls were much larger than the animals-which are half an inch (15 millimeters) long as adults-the researchers report Tuesday in the journal Physics of Fluids.

The edges of that 'fast lane' snagged on the edges of the surrounding slower water, creating swirls and eddies known as Kelvin-Helmholtz instabilities. The jet of water the animals produced behind them as they swam was moving faster than the surrounding water, says Dabiri. This made it possible to use lasers to trigger brine shrimp migration across tanks of water in the laboratory.īy seeding the water with silver-coated, hollow glass spheres, the researchers could see the fluid flow produced by their sea-monkey herd as it followed the lasers up and down in the tank.

Although they aren't part of the vertically migrating layers in the ocean, the brine shrimp swimming motion is similar to that of krill, they are easier to raise, and they are highly attracted to light. Krill are common in the ocean but difficult to keep in the laboratory, so the researchers used brine shrimp. 'This was the first hint that animals could transport water over distances much longer than their body size,' Dabiri says.ĭabiri and colleague Monica Wilhelmus, also at Caltech, are extending that work to other important kinds of vertically migrating animals such as krill and copepods. A halo of water around the jellyfish gets dragged along by the animal as it moves. The layer of water closest to the jellyfish clings to the animal, with the 'stickiness' of the water diminishing as it gets farther away from the jellyfish. In recent years, scientists have started to seriously consider whether collective animal movements-like plankton swimming up and down en masse-could also be contributing to currents.ĭabiri and a colleague found in 2009 that jellyfish can actually move water over distances greater than their body length just by swimming. Wind-and tide-driven currents move nutrients, heat, and salt around the ocean, and help to regulate the planet's temperature, Dabiri says. If so, this mixing may need to be accounted for in simulations of Earth's future climate, Dabiri says. (See 'Sea Animals Change Climate Via Flutters and Flaps?') These collective movements might produce currents large enough to mix seawater, says study co-author John Dabiri, an engineer studying biological physics at Caltech in Pasadena. Many move up and down in the ocean in dense layers throughout the day. Plankton, tiny marine creatures often thought of as mere drifters, actually aren't always so passive. and Monia spp.Swarms of tiny animals as small as brine shrimp-known to kids the world over as Sea-Monkeys-could have an outsize effect on ocean currents when they swim together in giant herds, according to new research.

Blood worms (Chironomidae and Glycera spp.).

Malayan box turtles ( Cuora amboiensis).

Crab-eating frogs ( Fejervarya cancrivora).

American bullfrogs ( Lithobates catesbeianus).

All fish except piranhas and fish which are prescribed as protected wildlife species.

All birds except house crow ( Corvus splendens), white-vented or Javan myna ( Acridotheres javanicus), common myna ( Acridotheres tristis) , feral pigeon ( Columba livia), and birds which are prescribed as protected wildlife species.

Red-eared sliders ( Trachemys scripta elegans).

Subject to the conditions listed below, the following wildlife species are approved by the Director-General to be sold or offered for sale: Under the Wildlife Act, a person must not offer for sale or sell any wildlife except with the Director-General, Wildlife Management’s written approval to do so. The following animals are allowed for sale in pet shops: The types of animals you are allowed to sell will be printed on your pet shop licence. You will need a licence from us before your pet shop is allowed to display, sell, distribute, or export pets.

Daphnia sea monkeys