Researchers use
‘robomussels’ to monitor climate change
Tiny
robots have been helping researchers study how climate change affects biodiversity.
Developed by Northeastern University scientist Brian Helmuth,
the “robomussels” have the shape, size, and color of actual mussels, with miniature
built-in sensors that track temperatures inside the mussel beds.
For
the past 18 years, every 10 to 15 minutes, Helmuth, professor in the College of Science and
the School of
Public Policy and Urban Affairs, and a global research team of
48 scientists have used robomussels to track internal body temperature, which
is determined by the temperature of the surrounding air or water, and the
amount of solar radiation the devices absorb.
They place the robots inside
mussel beds in oceans around the globe and record temperatures. The researchers
have built a database of nearly two decades worth of data enabling scientists
to pinpoint areas of unusual warming, intervene to help curb damage to vital
marine ecosystems, and develop strategies that could prevent extinction of certain species.
“They
look exactly like mussels but they have little green blinking lights in them,”
says Helmuth. “You basically pluck out a mussel and then glue the device to
the rock right inside the mussel bed. They enable us to link our field observations
with the physiological impact of global climate change on these ecologically
and economically important animals.”
The
research appeared in a new paper published in
the journal Scientific Data.
A barometer of climate change
For
ecological forecasters such as Helmuth, mussels act as a barometer of climate
change. That’s because they rely on external sources of heat such as air temperature
and sun exposure for their body heat and thrive, or not, depending on those conditions.
Using fieldwork along with mathematical and computational models, Helmuth forecasts
the patterns of growth, reproduction, and survival of mussels in intertidal zones.
Over
the years, he and his colleagues have found surprises: “Our expectations of
where to look for the effects of climate change in nature are more complex than
anticipated,” says Helmuth.
For example, in an earlier paper in
the journal Science, his team found that hotspots existed not only
at the southern end of the species’ distribution, in this case, southern California;
they also existed at sites up north, in Oregon and Washington state.
“These
datasets tell us when and where to look for the effects of climate change,” he
says. “Without them we could miss early warning signs of trouble.”
The
robomussels’ near-continuous measurements serve as an early warning system. “If
we start to see sites where the animals are regularly getting to temperatures
that are right below what kills them, we know that any slight increase is
likely to send them over the edge, and we can act,” says Helmuth.
It’s not only the mussels that may be pulled back from the
brink. The advance notice could inform everything from maintaining the biodiversity
of coastal systems to determining the best—and worst—places to locate
mussel farms.
“Losing
mussel beds is essentially like clearing a forest,” says Helmuth. “If they go,
everything that’s living in them will go. They are a major food supply for many
species, including lobsters and crabs. They also function as filters along
near-shore waters, clearing huge amounts of particulates. So losing them can
affect everything from the growth of species we care about because we want to
eat them to water clarity to biodiversity of all the tiny animals that live on
the insides of the beds.”