NOAA. (2023, June 16). Toxic Algal Bloom Suspected in Dolphin and Sea Lion Deaths
This article was written in the first two weeks of June, and speaks of how algae is the suspected culprit behind the mass deaths of hundreds of sea lions and dozens of dolphins. The species is called pseudo-nitzschia, and it causes these mass deaths by releasing a neurotoxin called domoic acid into the food web. The consumption of this food web goes all the way through it, and it ends up in dolphins, sea lions and seabirds which eat the fish who are closest to these algal blooms. The neurotoxins spread by the algae were projected to be from north Orange county all the way up to San Luis Obispo. The domoic acid is released into the water and food sources for predators, but also poses a threat for humans if it is consumed in foods. This means that a lot of fisheries could have fish in them with trace amounts of domoic acid during the summer months.
This article is helpful because it shows how dangerous algae can be. In the first two weeks of June, when this article was written, it was stated that hundreds of sea lions and up to 60 dolphins had already died. According to the article, over a thousand reports of sick aquatic mammals arrived between June 8th and June 14th. It is relevant to environmental science because this overwhelming amount of reports is more than what scientists can handle. Especially with the role that sea lions and dolphins play as predators, the sudden dying of these aquatic mammals can cause a further collapse. The dead zones created by the toxic algae show the cascading effect of over consuming and pollution. Additionally, the longer length of algal blooms may combine with the scale to completely overwhelm and measures to stop the blooms. This is why more preventative measures need to be taken, rather than corrective action, because at this stage it is too stressful for the ecosystem and the people who are working to preserve it.
This is such an interesting story! Why did the domoic acid get released from the algae in the first place? Do you think this might pose a serious risk for people, even ones that don’t eat fish?
Hi, thank you for reading. Unfortunately in the article, it is not mentioned how the domoic acid is produced. It is my understanding that this type of algae, Pseudo-Nitzschia, produces this naturally. The combination of phosphate/nitrate fertilizers and raising temperatures/CO2 fosters great conditions for these algae to grow way more than they should, so the acid accumulates in the water and animals that swim through it. This is still a fairly new area of study within environmental science, so the entire mechanisms are still unknown. As for the safety of it, it is extremely dangerous when consumed, but small quantities of domoic acid may be present in waters and you can swim in it. The algae mostly blooms in the warm months so don’t swim too close to then, but the main concern remains contaminated seafood.
This is a really interesting story that presents a pressing issue. I wonder what preventative measures we could take to help reduce the destruction of this ecosystem.
Thank you for reading. The best preventative measure would probably be to limit fertilizers, but that also prevents profits and no one would ever agree to it. For now, as study continues, the best thing to do is to predict these blooms so we can better mitigate the effects of it.