Dasysiphonia Japonica: Save The Great South Bay Word Of The Week

GREAT SOUTH BAY, NY — While summer is unofficially over, some invasive species tend to overstay their welcome on Long Island.

Dasysiphonia japonica, an invasive red seaweed, is Save the Great South Bay's Word of The Week.

Commonly referred to as simply "Dasy", or siphoned feather weed, it is pronounced like the flower, "daisy". The seaweed is native to the Pacific Northwest.

According to the DEC (Department of Environmental Conservation), it first appeared on Long Island in Southold in 2009.

This aggressive invasive species clones itself asexually and thrives in nitrogen-rich waters, ultimately outcompeting native species for nutrients. As it dies, siphoned feather weed depletes oxygen levels in the environment and, when it dries out, smells like rotting eggs.

Thriving in the Bay’s newly warmer temperatures, its decaying blooms are associated with fish die-offs.

It was most recently seen washed up along the shorelines in Patchogue. Its odor is offensive and, in large quantities, it can be toxic to humans and animals.

According to the DEC, there are four main ways that New Yorkers can help reduce the spread of invasive species:

Help Detect Marine Invasive Species Early
Marine invasive species can grow and reproduce quickly and frequently. Therefore, it is extremely important to identify unwanted species in your area early. If you come across a species you believe to be invasive, take a photo and record the location and the date you found it.

Use the New York "iMap Invasives" Reporting System

Help New York State document invasive species by using the New York iMapInvasives webpage or download the iMapInvasives Mobile App. If you've found a species that isn't yet listed, contact the iMapInvasives team.

Visit the Long Island Invasive Species Management Area (LIISMA) website
Learn more about some of the terrestrial, aquatic and marine invasive species in New York's geographical area that includes Staten Island (Richmond County), Long Island (Kings [Brooklyn], Queens, Nassau and Suffolk counties), and eleven additional coastal plain islands. Visit the LIISMA webpage for more information.

Always Clean your Boat and Gear

Help prevent the spread of aquatic and marine invasive species by thoroughly cleaning your boat and recreational gear after use, and especially before introducing it into a new water body. Learn more by visiting the Prevent the Spread of Aquatic Invasive Species webpage.

Save the Great South Bay, a non-profit organization dedicated to the revitalization of Long Island's Great South Bay. To learn more about their work, visit their website here.