Rotten Egg Stench Engulfs Massachusetts City. Here's The Bizarre Reason Why

Gloucester, Massachusetts, is no stranger to the smell of salt and sea. The coastal city has long been a hub for its scenic beaches and fresh seafood. Recently, however, a new unfamiliar smell has permeated Gloucester: that of rotting seaweed.

Some claim the stench is akin to raw sewage, others rotten eggs, while others simply state it's overpowering. Amidst concerns, officials published an explanation on the City of Gloucester Facebook page on September 3rd. The culprit of the stinky smell is an invasive seaweed called Heterosiphonia japonica. Among other seaweed characteristics, the large marine algae grows close to the shore. In late August, strong winds from Hurricane Erin carried the seaweed ashore. Once the tide receded, it left bundles of the red invasive organism along the beaches, where they're now decomposing in the sun.

According to the city officials, there's nothing to worry about. The smell is "natural and will fade soon." Yet while the unpleasant odor along the beaches of Gloucester will likely dissipate, the unfamiliar phenomenon is part of a greater global trend that's here to stay. Invasive organisms and more frequent weather events like hurricanes are becoming the norm as human activity irrevocably changes the environment.

Native to the Pacific, Heterosiphonia japonica appeared in Rhode Island in 2007. Since then, the bushy red seaweed has spread aggressively north and south, gaining a foothold along the east coast of the United States. Eventually, it made its way to Gloucester. Foreign to North Americans, Heterosiphonia has a knack for washing up in vast piles when the tides are strong enough to carry it onto the shore. But in its native habitat in the western North Pacific, the algae is far less successful.

In fact, Heterosiphonia makes up fewer than 1% of the biomass of seaweed in its native waters around Japan. Furthermore, unlike in North America, the algae has a sporadic growth cycle in its native range, only occurring a few times a year. When it was first discovered growing in France in 1984, scientists were uncertain about its ability to propagate in foreign waters. However, data soon showed that the seaweed has an incredible tolerance for differences in salinity and temperature. As a result, in the Atlantic ocean, where the local ecology isn't adapted for competition with such a tenacious organism, Heterosiphonia has managed to spread like wildfire.

Heterosiphonia's range now extends from Norway to Italy in the eastern Atlantic and from Newfoundland to Florida in the western Atlantic. Its introduction is cause for concern. Besides the potential to smell bad when it washes onto shore, Heterosiphonia could pose a major threat to the biodiversity of each new ecosystem it invades. Many invasive species have destroyed ecosystems in a relatively short amount of time. In the case of Heterosiphonia, only time will tell.