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Marine Heat Wave Off West Coast Could Prove Destructive To Sea Life

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If the heat wave lingers, it could be disastrous for the Pacific Northwest's endangered orcas, which largely depend on chinook salmon. The warmer waters can weaken the food web that sustains the salmon and brings predators of young salmon, including seabirds, closer to shore, further reducing their abundance.

Speaker 1: 00:00 A huge mass of very warm water has formed in the Pacific Ocean. And if it doesn't dissipate soon, it could be damaging to the marine ecosystem all along the coast from Alaska to southern California. In fact, this one is on its way to rivaling the so-called blob that caused the massive toxic algae blooms and proved to destructive to marine life in 2014 in 2015 Andrew lysine is a research oceanographer with the southwest fishery science center in the Hoya and he joins us now. Andrew, welcome. Hi. Glad to be here. Um, first how big, how deep and how warm is this blob?

Speaker 2: 00:38 Okay, well, in terms of size, currently it is about the second largest event. We've noted over the past 40 years that we've had data to measure these things and it's right now clocking in at about 6 million kilometers squared. And to give you some reference, Alaska is about 2 million kilometers squared. So this is like three times the size of Alaska.

Speaker 1: 01:04 Oh Wow. And how deep is it?

Speaker 2: 01:06 Well right now, actually that's something that's a little bit different than the past feature that we called the blob. The current one is actually mostly, uh, within the surface waters as far as we can tell. So it does not go as deep as the past event. And that's kind of an important difference between what we're seeing now and what we saw in the past.

Speaker 1: 01:26 Hmm. So what's causing this ocean blob?

Speaker 2: 01:28 Uh, well we think mostly these features are a response to, uh, changes in atmospheric patterns. And so back when we had the, the first blob in, uh, 2014, 2015, if you recall, that was the result of what we called the ridiculously resilient ridge, which was a, a pattern of high atmospheric pressure. Uh, and now the current one is also, again, related to atmospheric patterns. Generally it's because the, when the atmosphere has a certain pattern that changes the winds, we don't get the normal mixing that you would in the surface. And so the water can heat up in the surface water.

Speaker 1: 02:04 Hmm. So is climate change a factor here?

Speaker 2: 02:06 Climate Change? Uh, we definitely have a sort of background pattern of ocean warming. And so when we go to identify these heat waves, uh, we use sort of a comparison between what's happening and what the average conditions are leg. Now, if the whole ocean is warming over time, when we compare it to that longterm trend, we're just going to start seeing more and more of what looks like a heat wave. But that's because it's a, you know, eventually everything is warming until it'll all look like a heat wave compared to average. So it's kind of a little bit of a complicated story because you've got this longterm trend, but we are attending to see now more of these events that are warmer than the average. Um, recent work has looked at whether we're having an increase in the frequency of these events. And if you actually take out that longterm background trend, it's not really clear that we've had an increase in the frequency of the event, but we're just detecting them more because of the background. A increase in warming.

Speaker 1: 03:10 Okay. And so we know that in 2014 and 2015, um, this blob was really destructive to marine life. Uh, how serious could it be this time? How serious could the impact be on marine life?

Speaker 2: 03:23 That's, you know, that's an open question right now. It is still mostly offshore and it is a, it hasn't reached our California coast yet. It could, but we, but the two big differences are that again, the water is not as warm to the depth that it was before. The other differences that back in 2014 and 2015 we actually had sort of the blob that was located up in the Gulf of Alaska area, but southern California was actually also undergoing its own heat wave in those, in the local waters. And eventually those two features actually combined to create the one big mega huge blob that we saw. Um, and this year we do not have all the offshore warming off of California that we had back in that previous time. So likely we will not have quite as large impact in southern California that we had before. We, we're not, we're not quite clear that that will happen, but there definitely should be some impacts from this feature given how large it already is, how strong it already is and the fact that it is, you know, it's, it's coming within close proximity to the shoreline, probably some point conception north. So we expect there may be some impacts but there likely be possibly different impacts than we had before.

Speaker 1: 04:42 Okay. And while there might be some impacts felt by marine life first, uh, what about the impacts on people who go swimming in the water? Or are there any concerns in terms of bacteria growth or waterborne illnesses?

Speaker 2: 04:54 Uh, that I would die, can't comment on, but, um, the one that we will definitely, you know, people are, we're all monitoring for, not necessarily our agency, but other agencies, state agencies monitor for a harmful Algal blooms. The big one is the demark acid one that comes from pseudo nichey. So that's something that's actively being monitored and you know, warnings will be issued if that becomes a problem. But the bigger impact from that, the harmful algal bloom, I think you already mentioned it was, you know, closure to fisheries or causing toxicity in, in shellfish and other things that we would harvest to eat. That's kind of one of the bigger impacts on people.

Speaker 1: 05:32 And, and what is that impact like, uh, in terms of water, activities of fisheries, those things? W how, how deeply impacted are they by these blooms?

Speaker 2: 05:41 Well, back in the last time we had the large coast-wide bloom that we attributed somewhat to the last blob. Uh, you know, that had, that had pretty large impacts. We had to close many fisheries, uh, particularly hard hit was shellfish fisheries. Uh, those are are the kinds of things that they have the largest, the biggest impact really. And then the other impact of course we saw in southern California was straining of marine mammals. The females were leaving there. They leave their babies on the beach to go foraging and they couldn't find what they were looking for until they would just abandon their babies on the beach and head north to find better food. So that was something that a lot of people were noticing in the last event, but because we, we may not be getting that impacts in the south again this year, we were not sure if that will happen, but it could, it could happen again.

Speaker 1: 06:29 All right. I've been speaking with Andrew Lysine with the National Oceanic and atmospheric administration. Thank you so much, Andrew. Thank you.

Speaker 3: 06:40 [inaudible].

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Maureen Cavanaugh and Jade Hindmon host KPBS Midday Edition, a daily radio news magazine keeping San Diego in the know on everything from politics to the arts.