Pesticides, microplastics may threaten sea star recovery, study finds
A new study shows that exposure to pesticides and microplastics could set back the recovery of sunflower sea stars, marine creatures once common in the tide pools along Oregon’s coast but now nearly extinct. The starfish, a keystone species native to the Northwest, have been decimated by a mysterious wasting disease over the past decade. As they died off, purple sea urchins – staples of starfish diet – have multiplied and devoured kelp forests off the Oregon coast, leaving lifeless zones covered with purple urchins and nothing else. Oregon has seen an increase in the sightings of sunflower sea stars over the past few years, giving hope for their recovery. But the study by researchers at Portland State University and the University of Washington has shown that human-made contaminants such as pesticides and microplastics could hurt the stars’ comeback.The researchers subjected larval sunflower sea stars to the insecticide imidacloprid and to polyester microfibers in concentrations that are typically found in coastal areas. Both contaminants have migrated via runoff into streams, rivers and oceans. Imidacloprid is widely used to control fleas, bedbugs, flies, roaches and termites as well as to treat seeds before they are planted to protect against wireworms and seed maggots. The insecticide has been found to adversely affect some organisms such as bees. Polyester microfibers are a type of microplastic now commonly found in the environment, including marine organisms such as salmon. Hundreds of thousands of microfiber strands are shed from clothes during each washing and drying cycle. The study found that the insecticide caused gut malformations in the starfish and other signs of stress such as accelerated growth and higher mortality rates at early developmental stages, which could impact the stars’ long-term survival, researchers said. “Sunflower stars have enough to deal with right now, with their particular sensitivity to a syndrome that is still present in the wild,” Jason Hodin, researcher at the University of Washington and study coauthor, said in a statement. “The least we can do is to reduce additional stressors on marine ecosystems, such as pesticide inputs and plastic contamination.” Scientists still don’t know the cause of the star wasting disease, though they say it was accelerated by an extreme heat wave in the Pacific Ocean that started in late 2013 and lasted for more than 700 days. Researchers said the study underscores the urgent need to understand the effects of contaminants on marine species. “The implications of our study go beyond the sunflower sea star,” said Allie Tissot, the study’s lead researcher and a doctoral candidate at Portland State University. “As marine ecosystems continue to face the multiple threats of climate change and diverse anthropogenic pollutants, the ability to predict and mitigate the impacts of contaminants on marine life will be crucial for the future of biodiversity conservation.”— Gosia Wozniacka covers environmental justice, climate change, the clean energy transition and other environmental issues. Reach her at gwozniacka@oregonian.com or 971-421-3154.
A new study shows that exposure to pesticides and microplastics could set back the recovery of sunflower sea stars.
A new study shows that exposure to pesticides and microplastics could set back the recovery of sunflower sea stars, marine creatures once common in the tide pools along Oregon’s coast but now nearly extinct.
The starfish, a keystone species native to the Northwest, have been decimated by a mysterious wasting disease over the past decade. As they died off, purple sea urchins – staples of starfish diet – have multiplied and devoured kelp forests off the Oregon coast, leaving lifeless zones covered with purple urchins and nothing else.
Oregon has seen an increase in the sightings of sunflower sea stars over the past few years, giving hope for their recovery.
But the study by researchers at Portland State University and the University of Washington has shown that human-made contaminants such as pesticides and microplastics could hurt the stars’ comeback.
The researchers subjected larval sunflower sea stars to the insecticide imidacloprid and to polyester microfibers in concentrations that are typically found in coastal areas. Both contaminants have migrated via runoff into streams, rivers and oceans.
Imidacloprid is widely used to control fleas, bedbugs, flies, roaches and termites as well as to treat seeds before they are planted to protect against wireworms and seed maggots. The insecticide has been found to adversely affect some organisms such as bees.
Polyester microfibers are a type of microplastic now commonly found in the environment, including marine organisms such as salmon. Hundreds of thousands of microfiber strands are shed from clothes during each washing and drying cycle.
The study found that the insecticide caused gut malformations in the starfish and other signs of stress such as accelerated growth and higher mortality rates at early developmental stages, which could impact the stars’ long-term survival, researchers said.
“Sunflower stars have enough to deal with right now, with their particular sensitivity to a syndrome that is still present in the wild,” Jason Hodin, researcher at the University of Washington and study coauthor, said in a statement. “The least we can do is to reduce additional stressors on marine ecosystems, such as pesticide inputs and plastic contamination.”
Scientists still don’t know the cause of the star wasting disease, though they say it was accelerated by an extreme heat wave in the Pacific Ocean that started in late 2013 and lasted for more than 700 days.
Researchers said the study underscores the urgent need to understand the effects of contaminants on marine species.
“The implications of our study go beyond the sunflower sea star,” said Allie Tissot, the study’s lead researcher and a doctoral candidate at Portland State University. “As marine ecosystems continue to face the multiple threats of climate change and diverse anthropogenic pollutants, the ability to predict and mitigate the impacts of contaminants on marine life will be crucial for the future of biodiversity conservation.”
— Gosia Wozniacka covers environmental justice, climate change, the clean energy transition and other environmental issues. Reach her at gwozniacka@oregonian.com or 971-421-3154.