Researchers explain ocean water quality advisories
LAHAINA – It’s been a wet and wild winter, with an abundance of flash floods, high surf warnings, high wind watches, severe weather alerts and brown water advisories issued for the County of Maui.
Perhaps the most disturbing was the advisory issued last week Tuesday (March 7). The State of Hawaii Department of Health Clean Water Branch (CWB) advised the public to stay out of the waters off Launiupoko Beach Park due to a high count of enterococci.
Contact with this water, it read, may cause illness.
Enterococci are fecal in origin – a bacteria found in the intestine of all warm-blooded animals, including humans. Because the bacteria are always present in animal and human waste and are easy to detect, they are used as indicators of water quality conditions.
Launiupoko Beach Park is a preferred recreational site for the families of our community. On the weekends, it is standing room only with bouncing castles, surfers, baby luaus, weddings and memorials a standard fare of activities, not to mention watching sunsets and swimming.
The Lahaina News had an interview with Myron Honda from the CWB; he was very helpful as was Dana Reed, Water Quality Program manager, Maui Nui Marine Resource Council.
On Wednesday, Honda reported the advisory was lifted, adding: “Through routine monitoring, we are now required to notify the public whenever there is an exceedance of a threshold level. So this is something that we are required to do.
“The monitoring has been going on for many years now, but now we’re required to notify the public whenever our indicator levels reach a certain level. Prior to this, what we have been doing was just notifying the public whenever there was a sewage spill.”
“Keep in mind,” Honda continued, “that this is an indicator that is not ideal for Hawaii, because the indicator grows in soil; the indicator grows in water, in the streams. Whenever there is a heavy rain and the stream flows into the ocean, the indicator counts go up, or whenever there is surface water runoff.”
Reed further explained, “An indicator bacteria is one that is found in the human gut (which can then be in human feces). However, enterococcus is also found in the guts of other mammals (rats, cats, dogs, etc.) and also has been known to live in the soil here in Hawaii. When there are high levels of this bacteria in the water, it could INDICATE that there might be human fecal matter (due to sewage) in the water.”
The threshold level for enterococcus in the ocean is 130 cfu (colony forming units).
“The level of enterococcus on March 2, 2017, at Launiupoko was 364 cfu. The level at Canoe Beach on that same day was 10 cfu. That is why an advisory was issued for Launiupoko but not Canoe beach,” Reed said.
Not all 17 species of enterococcus are equal; nor do all cause illness in humans.
“Some species just live in our gut in a benign fashion. However, when there are high levels in the water, it is best to stay out of the water, because there could be enterococcus pathogens (which make you sick); and, even if the enterococcus is just in the water, because it lives in the soil, it is likely that the water is brown, and you should stay out anyway,” Reed said.
Honda agreed with Reed’s assessment.
“We are not that concerned with the spikes. It goes up one day, drops down the following day. We are more concerned with the ones that stay up for days and days, and we’re also concerned with the brown water.”
On the CWB website, doh.hawaii .gov/cwb, there is currently, as of March 13, a brown water advisory from Maalaea to Wailea.
“Whenever we issue a brown water advisory, we stop routine monitoring. We already posted. The whole idea behind the advisory is to notify the public saying, ‘Hey, you know what, don’t go in!’ “
“A brown water advisory,” he added, “is a little bit more concerning than a high level of enterococcus content. A high level of enterococcus content is just that; it’s just high levels of enterococcus. Whereas with the brown water advisory, we have a whole bunch of other things that we don’t test for – other pollutants, things like pesticides, fertilizer and dead animals – not to mention the sharks. The brown water advisory is a little more concerning or should be to everybody.”
“If the water looks brown, stay out,” he stressed.
For the Department of Health, the coastal waters are tested weekly by Meghan Dailer.
Reed heads Hui O Ka Wai Ola, a community team of 17 volunteers, testing for temperature, pH, salinity, dissolved oxygen, turbidity (water clarity), total nitrogen, total phosphorous, nitrates and nitrites, phosphates, silicates, and ammonium.
“We also collect sediment samples if the water clarity is not good,” Reed explained.
The hui has been collecting samples the past 10 months.
Next week, learn more about Hui O Ka Wai Ola.