Mainers who visited the beaches this summer might have noticed a slimy, foul-smelling red algae on shore. This is Dasysiphonia japonica, an invasive algae species that first appeared here in 2007 and has rapidly spread throughout the Gulf of Maine. While native kelp has been declining in the fast-warming waters, D. japonica thrives. This shift has the potential to dramatically alter our oceans and harm Maine’s tourism and fisheries industries.

Research from the University of New Hampshire shows that D. japonica now covers up to 90% of the seafloor in surveyed areas, and once it’s established, it is effective at keeping kelp out. This also alters marine populations and behavior. Fish like cunner, which hide among long blades of kelp to avoid predators, are becoming more vulnerable as they lose that habitat. Another study found that rapid bloom-and-decay events (like the piles that wash up on beaches) can cause high mortality in larval mussels, oysters and juvenile fish. These are just a few examples of the impact it’s having.

Unfortunately, eradicating the species from the Gulf of Maine is not easy. Because it reproduces by fragments, simply pulling it spreads it further, and its widespread presence makes removal efforts costly and futile. What we can do is invest in understanding how this species is reshaping our coastal ecosystem. At a time of federal spending cuts to climate research, Maine must advocate for funding to organizations studying invasive species, so we are better prepared to protect our waters as the Gulf continues to warm.

Kevin Mullan 
South Portland