A new study claims that turbulence caused by motorboats is killing zooplankton
A new study claims that turbulence generated by speeding motorboats kills significant numbers of zooplankton.
Experiments on copepods,
tiny crustaceans that live and float in water, show that a third die in waters
frequented by propeller-driven boats – significantly more than in bodies of water not used by boats.
According to a study published in the Journal of Experimental Marine Biology and Ecology, even a small amount of turbulence can affect a copepod’s ability to feed and grow.
“A number of studies have been performed that looked at the impacts of much smaller scale turbulence on zooplankton,” said Samantha Bickel, a PhD student at the Virginia Institute of Marine Science in Gloucester Point, US, who carried out the research.
“But to my
knowledge, no one had explored the idea that the intense turbulence generated
by boats could have an adverse impact on zooplankton.”
Bickel’s findings showed that 34% of copepods were found dead in a heavily-used channel while only 5-6% were dead in a marina and along a shoreline. More copepod carcasses were found inside boat wakes (14%) than outside boat wakes (7%) and the fraction of dead copepods increased with increasing turbulence intensity.
However, scientists have not yet been able to establish how many boats might cause a problem, and much would depend on their size and speed, which have a large effect on the turbulence they create.
“When viewed at a global scale, the portion of zooplankton killed by boat-generated turbulence is probably minimal,” Bickel says.