Water Red in Harbor (Algae)

Observation by Aaron Merculief:

St. George Harbor during early fall of September 2012, a community member who works around the harbor noticed the redness in the harbor as the water doesn't get disturbed too much from the weather like the waters around the island (St. George). The community members who brought this to my attention said they haven't seen anything like this. It appears the red goo was only on the surface of the water and no more that 1 to 1.5 feet deep.

• Microscope video 1 – Red sea water observed - St. George, AK (rt - 0:40)
• Microscope video 2 – Red sea water - St. George, AK (rt - 0:59)

Comments from LEO Editors:

In addition to collecting excellent images and video, Aaron collected water samples from the harbor and analyzed them under a microscope. He thinks the color is caused by living organisms rather than something inorganic like dust. Water samples collected by Aaron were forwarded to the University of Alaska Fairbanks Institute of Marine Science (IMS) for more analysis. To preserve a sample for shipping, Biological Oceanographer, Dean Stockwell states, "samples can be collected in a small glass bottle with drops of iodine added until the water takes on a straw-like color, like tea."

It's also good to be aware that discolored water can sometimes occur from a spill. If you are concerned about the possibility of a spill you can contact Alaska Department of Environmental Conservation Spill Prevention and Response to report a spill.

Dean Stockwell with IMS and Matthew Johnson, Associate Scientist at the Woods Hole Oceanographic Institution, were able to identify the species from Aaron's microscope images. Both suspect that the cause of the red color to not be phytoplankton, which is commonly associated with red tides, but rather a non-toxic ciliate called Myrionecta rubra (or Mesodinium rubrum), which are quite common in the Bering Sea. Under the microscope, they are active swimmers and distinguished by a two-lobed shape and the presence of many little arm-like flagella.

Resources:

Alaska Department of Environmental Conservation (ADEC) – If you are concerned about food safety from harmful algal blooms, red tides, or paralytic shellfish poisoning, you can find more information on the State of Alaska's Division of Environmental Health website, Food Safety & Sanitation Program to help you get started.