Preliminary research results have found 100 microplastic particles
in northern star coral polyps. In the photo above, the northern star coral is
attached to a rock and near green alga, commonly called sea lettuce, and red
alga. (Frank Carini/ecoRI News)
By FRANK CARINI/ecoRI News staff
The hard coral off the shores of southern New England isn’t nearly as glamorous as its tropical counterparts — in fact, it’s barely noticed even by experienced divers — but it could play a vital role in determining the size and depth of the world’s plastic footprint.
“Coral can’t run, so it
makes for a good model to see how much plastic is in a particular habitat,”
said Randi Rotjan, a research assistant and professor of biology at Boston
University. “My guess is that coral takes in a lot of plastic because it can’t
run away from it.”
ecoRI News recently met up
with Rotjan, Boston University research technician Cara Johnson and Michael
Lombardi of Middletown-based Ocean Opportunity Inc. at
Fort Wetherill State Park during a dive to place a substrate to collect
northern star coral larvae. The substrate will be collected in six weeks and
brought back to Rotjan’s laboratory to
be studied.
 |
| Michael Lombardi holding the substrate upon which northern star coral larvae will be collected. (Frank Carini/ecoRI News) |
Basically, the team is studying the impact microplastics are having on northern star coral along the urban coast of New England. Plastic pollution is already a known problem.
For instance, at least two-thirds of the world’s fish stocks are suffering from plastic ingestion, according to estimates, as much of the planet’s plastic pollution eventually makes its way into the ocean.
Rotjan’s project stems from
concern about the 6,350 million to 245,000 million metric tons of plastic in
the world’s oceans, and the 4.8 million to 12.7 million metric tons of new
plastic that enter the ocean annually.
Rotjan noted, however, that laboratory tests have concluded that urban coastal coral responds to microplastics differently than ocean coral, because of myriad reasons including sewage treatment.
Rotjan noted, however, that laboratory tests have concluded that urban coastal coral responds to microplastics differently than ocean coral, because of myriad reasons including sewage treatment.
Preliminary results have
found 100 microplastic particles, such as microbeads used in toothpaste and
facial scrubs, in northern star coral polyps, according to Rotjan.
“Microplastics come from
water bottles, bags, polar fleeces,” Rotjan said. “People are shedding
microplastics constantly.”
 |
| Randi Rotjan collecting some northern star coral off the Jamestown shore. (Michael Lombardi/Ocean Opportunity) |
The grant-funded research
project titled “Hidden Problems in Secret Corals: Exploring Microplastic
Abundance in Local, Temperate Corals Along an Urban Gradient” hopes to answer
the questions of whether there is a greater prevalence of microfibers in urban
areas and determine the impact of sewage treatment on coral’s microplastic
ingestion.
“We want to find out if this
coral is ingesting the plastic or spitting it out,” Rotjan said. “Either way,
though, the bacteria is likely staying behind.”
Corals are basically a
natural jumble of animals with stony skeletons and a plant-like hunger for
sun-soaked energy derived from symbiotic photosynthesizing algae living inside
them.
Coral reefs, such as the world-famous Greater Barrier Reef in Australia, are home to about 25 percent of marine species, and that is just the beginning of their environmental and economic importance. Coral reefs, for instance, shelter built-up coastlines against severe weather.
Coral reefs, such as the world-famous Greater Barrier Reef in Australia, are home to about 25 percent of marine species, and that is just the beginning of their environmental and economic importance. Coral reefs, for instance, shelter built-up coastlines against severe weather.
Coral reefs worldwide,
however, are dying. Pollution, development, warming and acidifying oceans, and
harmful fishing practices, such as dynamiting and bleaching them to capture
fish for aquariums, have conspired to threaten 75 percent of reefs worldwide.
Since northern star is a
temperate coral that survives the temperature shifts from summer to winter, it
could also potentially provide insight into climate-change resiliency for
tropical coral species. Roger Williams University’s Sharp has been researching
this issue for several years.
Rotjan noted that northern
star coral has the potential to transform the understanding of symbiosis — a
biological partnership that is vital in tropical corals but is only sometimes
used by northern star.
The continued research of this coral could play an important role in better understanding the functions of coral-reef biology and how corals can tolerate a changing climate, she said.
The continued research of this coral could play an important role in better understanding the functions of coral-reef biology and how corals can tolerate a changing climate, she said.
Northern star coral, like
its reef-building counterparts in the Caribbean, likes warmer waters, but it
also thrives in the colder depths off Rhode Island and the rest of southern New
England.
Northern star is also able to survive with only small amounts of algae, because this coral species derives less than half of its energy from photosynthesis. It feeds largely on plankton snared with tentacles.
Northern star is also able to survive with only small amounts of algae, because this coral species derives less than half of its energy from photosynthesis. It feeds largely on plankton snared with tentacles.
However, unlike its tropical
counterparts, which can grow to the size of a car, northern star coral only
grows to the size of a fist, which is rare.
