An offensive odor that some liken to a sewer smell has been permeating large areas of Pacific Palisades. Some blamed local businesses, others blamed the sewer lines that run along Pacific Coast Highway, which is across from the Pacific Ocean. The one thing everyone agreed on was the smell was bad, real bad.
The South Coast Air Quality Management District was contacted by a resident, and said that “dead algae is to blame. As the algal bloom associated with the red tide decays, it releases hydrogen sulfide, which results in the offensive smell.”
Another reader wrote: “The recent smell is prevalent all over the Westside. It’s been super stinky here in Santa Monica! This is an article link posted by the Santa Monica Daily Press with a good explanation of the culprit. click here.
The Santa Monica Daily Press in an October 29 story (“Stinky Ocean Odor Is the Price to Pay for Stunning Ocean Glow”), explained that there was a massive amount of algae, which are reddish brown during the day, but at night they emit a blue bioluminescence. “As the algae die, bacteria break them down causing the smell that is noticeable throughout town.
“’It was a pretty massive bloom up and down the coast so it may last a matter of days to a week or so,’ said Laura Rink, Associate Director of Operations at the Heal the Bay Aquarium. ‘With the current winds and currents, hopefully it sweeps it away.’”
Yet another person said it was the phytoplankton causing the smell.
Are phytoplankton and algae the same thing? No. Online it noted that many algae, such as the diatoms, form part of phytoplankton. Other algae is anchored to the seabed and are unable to float.
The definition of phytoplankton is that they are small and able to float on the sea surface. When phytoplankton break down, they decompose and release dimethyl sulfide (DMS), which has a strong smell. The smell can become more pronounced when there’s a high concentration of plankton, like during algal blooms.
Blame the smell on dying plankton. But why now? Why October?
According to one source, seasonal winds (Santa Ana) and currents along with warm fall temperatures can enhance upwelling (deep, cold, nutrient-rich water rises to the surface, replacing the warmer surface water), making the scent more noticeable.