Scientists are working to uncover the mystery behind what local fishermen are calling the "angel hair alga bloom". An algal bloom that began in 2012 has now engulfed the eastern coast of Guam. Tom Schils is a ficologist at the University of Guam.

"And that really, that's an outbreak that started...it's a phenomenon basically of an outbreak of green algae that started in 2012. It was contained to Pago Bay at the time," he explained. The bloom then spread all the way south to Cocos Island. "And that's when fisherman particularly got very, very worried about the phenomenon because they couldn't cast their nets anymore. Propellers got stuck in basically the floating alga all over the place," he added.

While at first the alga blooms only occurred during the summer months, they now span year-long, and have even spread west all the way to Bile Bay. "Just recently we also noticed it in luminal reef, which is just a little bit north of the harbor," noted Schils.

The alga is referred to as chaetomorpha, and scientists know very little about it. In fact, the only record of the alga dates back to 1968, and its reappearance has left researchers perplexed. "First of all," Schils continued, "we're focusing on the identity and collaborating with some researchers from New Zealand and Belgium."

He'll then try to find out what caused the outbreak, saying, "Why does this alga suddenly appear on our reefs in such mass quantities and why is the geographical footprint of this alga increasing?"

Some potential causes might be that it is an invasive species, that it resulted from overfishing, or that it is related to recent anomalies of warm ocean temperatures. And while the causes are unknown, so are the potential impacts, with Schil saying, "Will the smothering, basically will they overgrow other reef organisms, or will they create anoxic situations? We really don't have a good handle on it."

However the alga is edible and is already being consumed by local fishermen. Schils said he and his team will continue to study the occurrence until they are able to literally untangle the mystery of the angel hair alga bloom.