Ponds on Cape Cod with toxic algae, 2009-2011

Blue-green algae creates "toxic algae blooms." They have been known to kill dogs and people. While only a few people have been sickened by algae blooms in the US, about 50 people were killed in Brazil from drinking water tainted with algae.

In 1998, four dogs were poisoned--two of them died--from drinking water at Cliff Pond in Nickerson State Park.  One of the dogs that died belonged to Jeff Hook--and he thinks the four dogs are just the tip of the iceberg.  A few years later, he had a second dog die at Cliff Pond.

In an email Jeff wrote: "I lost two dogs after they were poisoned by algae at Nickerson State Park, and haven't been back there since. I am concered about the same problem occuring at Hawksnest Pond--tho I do not see or smell a problem so far. The blue-green algae at Nickerson was so intense it killed my 50-pound dogs in less than ten minutes. And I mean killed them dead. That was 1996 and the park officials didn't even know what blue-green algae was. Nor did the vets I went to.  Nowadays people seem more knowledgable about it."

Toxic algae blooms are caused by complex factors--but all starts when too many nutrients get into a pond. The nutrients are like loading the gun. The exact trigger is unknown--it might be warm weather and/or other factors.

Hinkleys Pond

In 2009, Hinkleys Pond in Harwich had its water sampled during routine water quality measurements. Everyone was surprised when technicians notified the town that the pond's water had five times the acceptable level of blue-green algae. The pond was immediately closed. More.

Hawksnest Pond

Hawksnest, to my knowledge, has never had an algae bloom of any kind.  That's because Hawksnest has the best water quality of any pond in Harwich, based on many years of data from the Town's volunteer sampling program.

Cleaning up after dogs, keeping vegetation intact along the shore, and preventing erosion, will keep the pond in tip-top condition.

The map below shows ponds where there have recently been blue-green algae advisories.


View Cape Cod ponds with blue-green algae advisories in a larger map

To see all the ponds, zoom out (click the minus sign, upper left).You can get the pond name and year of data by moving your cursor over the pond and clicking.

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Data is from the MA Dept. of Public Health, for 2009, 2010, and 2011.


Update 6/28/12

Swan Pond (salt water) near South Dennis also had an algae bloom in 2006 & 2009, though it was not reported as a toxic one.
Long Pond in Falmouth, the town drinking water supply, in 2010.  Not considered a toxic bloom.
Queen Sewell Pond in Buzzards Bay, in 2009.
Long Pond in Harwich/Brewster.