Visit Nantucket, MA Homepage
habs, harmful algal blooms, nantucket
Project

HABs Weekly Report

Head of Hummock, Capaum Pond, and Washing Pond are under yellow cautionary status.

Harmful Algal Blooms Monitoring Program

Harmful Algal Bloom (HAB) Update

The following locations have switched to a RED WARNING status.

The following locations have switched changed their status:
YELLOWHead of Hummock
YELLOWCapaum Pond
YELLOWWashing Pond



Why? This site has algae concentrations that have increased above the risk threshold set by the state.
What does this mean?

  • Avoid any direct contact (skin or ingestion) with the water even if the water looks normal colored.
  • Do NOT eat anything from the body of water or drink the water (even accidentally).
  • Do not use the body of water for swimming, boating, kayaking, paddling, or other recreational activities.
  • If any skin becomes contaminated, thoroughly rinse with freshwater and soap immediately to avoid any skin irritation (this includes pets too.)

Please be aware that CAPAUM POND has shown harmful algae concentrations increasing for the past two weeks. Though current concentrations are below the state’s risk threshold, please take extra caution regarding direct water contact via skin or ingestion at this pond.


All other monitored ponds are under a Yellow Cautionary status:

  • Gibbs
  • Long Pond
  • Maxcy
  • Miacomet
  • Stump
  • Tom Nevers
  • Clarks Cove
  • Lower hummock
  • Sesachacha

Why? These sites have algae concentrations that are below the harmful risk threshold set by the state.

What does this mean?

  • Reduce prolonged direct contact (like that of swimming or wading) with the water even if the water looks normal colored.
    • Thoroughly rinse with freshwater and soap immediately to avoid any skin irritation (this includes pets too) if you do choose to enter the water.
  • Do NOT eat anything from the body of water or drink the water (even accidentally).
  • If recreation is to be had, use alternatives like boating/kayaking type of activities that are more indirect uses of the pond.

Signs will be posted near the water at all tested locations. Please check the signs before swimming, boating, fishing, or letting pets near the water.

What the signs mean

  • Green: Water activities are okay. Be careful and avoid drinking the water.
  • Yellow: Use caution. Reduce direct contact with water. Boating and kayaking are safer choices.
  • Red: Stay out of the water. Do not swim, wade, or touch the water or anything in it.

Keep pets safe too: Pets can get sick from harmful algal blooms. Do not let them swim in or drink the water if yellow or red signs are posted.

Thank you for adhering to these suggestions.