There’s a lot of discussion about chemicals released into the air during the recent wildfires. But this week’s rainstorms mean the ocean is also at risk of serious pollution. LA County has indefinitely closed beaches from Malibu’s Las Flores Canyon to Santa Monica State Beach.
Jennie Dean, vice president of education and conservation at the Aquarium of the Pacific, tells KCRW that scientists are most worried about chemicals from burned materials, including heavy metals, plastics, and even flame retardants. Those are now particulates that are in the soil and air, and rain makes it easier for them to reach the ocean rapidly.
Following a storm, she expects the waters to have increased amounts of bacteria, metals, and polychlorinated biphenyls (PCBs).
Dean says scientists are still learning what all this means for sea life and aquatic plants.
“Increasing the amount of sediment that's in the ocean, you create a shading effect. Some of our local ecosystems are kelp forests. They rely on the sun to grow. So if you increase the shading that's occurring, you're therefore decreasing the productivity of those kelp forests to grow. Under very extreme circumstances, that might lead to some die-back or declines of the kelp forests. So turbidity is one consideration,” she explains. “Another one is excess nutrients. … There are nutrients, phosphates and nitrates, in the material that's running off into the ocean. … In small amounts, fertilizers are good, but in large amounts, they can cause disruption to the natural balance that exists out there. … It could cause a cascade effect, and that might look like growth of phytoplankton.”
Also, the seafood that people eat could contain more heavy metals. “It starts with the material being in the water and slowly getting ingested in small organisms, who then get eaten by bigger organisms, etc., etc., eventually up to fish that we as humans consume, or other mammals like sea lions. We don't know for sure that this will happen, but it is certainly a concern, and it's one that your listener might be familiar with when it comes to mercury.”
Thus, Dean recommends not eating from Santa Monica Bay for now. “There are acres that have been destroyed with these potential contaminants in them, and so they will be making their way to the ocean, not just this week, but for many weeks to come. And even if it's not through rain, they will be wind-blown.”
However, she points out that a year and a half after Hawaii’s Lahaina Fire, researchers aren’t seeing negative impacts on fish.
She advises people to be more careful about marine life that can’t move. “Mussels are permanently attached to structures like pilings or rocks. They are filter feeders by nature. … They're cycling through gallons and gallons of water every day to feed themselves, and in doing that, they are also then accumulating the stuff that is in the water.”
Before the fires, the Aquarium of the Pacific completed a marine report card that measured the health of around 30 species in the state.
“So 60% of those 30 species that we looked at, so 18 species, are either stable or increasing, and those are things like southern sea otters, black oystercatchers, owl limpets, and spiny lobsters. And then the other 40% are experiencing either weak or strong declines … [such as] the sunflower sea star, the ocher sea star, and black and white abalone,” Dean explains.
She adds, “The current closures, at least of beaches, is about nine miles here in Southern California. And so the distribution of most of the species in the report card extends beyond Southern California. And so that gives hope to me that the localized impacts will not necessarily transcribe to a statewide decline as a result of this single fire event.”