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TOM WHEELER:

Welcome to the Econews Report. I'm your host this week, Tom Wheeler, executive director of EPIC, the Environmental Protection Information Center. And we are talking about golden mussels, a new invasive threat to our region and to the state of California on today's show. And joining me from the California Department of Fish and Wildlife is Thomas Jabusch. Hey, Thomas, -- or "Tomas", excuse me, Tomas -- welcome to the show.

THOMAS JABUSCH:

Yeah, good morning and thanks for having me on your show.

WHEELER:

Hi, excited to have you, from one Tom to another. And then we are also joined by Michiko Mares, the general manager of the Humboldt Bay Municipal Water District. Hey, Michiko.

MICHIKO MARES:

Good morning, Tom. Nice to be here today.

WHEELER:

And so for full disclosure, I am also on the board of the Humboldt Bay Municipal Water District, although I'm going to try to take off that hat for today's show and just be here as Tom Wheeler, environmental activist type, all right? So golden mussels, this is a new invasive threat here in the state of California. Thomas, can you tell us about the progression of golden mussels in this state? Because as I understand it, it's pretty new, but it's also spread pretty aggressively since it's been introduced.

JABUSCH:

Yeah, so in terms of being new, yes, they were first discovered last year in October in the port of Stockton. That was the first discovery of golden mussels in the state. They were discovered by staff at the California Department of Water Resources. They did a routine check of their water quality instruments that they have in the port. They found those mussels and they were submitted to the lab and identified as golden mussel. That was the first discovery of golden mussel on this continent, actually. How long they've been here, we're not really sure. Some other researchers at the Department of Water Resources analyzed some older samples that they had archived from the water project from 2023. They found DNA evidence that the mussels were already around in spring 2023, but they flew under the radar until last fall.

WHEELER:

So you said that this is the first occurrence on this continent. On this continent, yeah. We have some kind of understanding of the nature of golden mussel invasions because it has occurred elsewhere, on other continents, invasion. What do we know from South America about how golden mussel invasion occurs?

JABUSCH:

Yeah, maybe backing up even a little more. So originally, these mussels are from Southeast Asia, most likely from Southern China originally, and have been spreading first around Southeast Asia and China, including Hong Kong, and making trouble in their water supply and been spreading to other Asian countries, including Korea and Japan, and then made their way to South America and spreading through the continent now. So Brazil is affected, Argentina, Uruguay, Paraguay, Bolivia. Yeah, and they've been spreading fairly rapidly. Some numbers that have been published that they were moving 150 miles a year upstream in some of those major watersheds. So that's a pretty alarming rate and causing a lot of problems in the energy generating industry, like affecting hydropower plants. And so, yeah, so that's actually because of the problem. That's how the research in South America is funded, because the power generator put a lot of money into that. So, yeah, causing a lot of infrastructure problems and causing, of course, a lot of problems in the ecosystem.

WHEELER:

So on infrastructure, why are these an issue for power plants, for other water infrastructure? What about them and their life history makes them an issue?

JABUSCH:

Well, one of the features of these mussels is that they have a very short life cycle, so they reproduce very fast, and they can rapidly spread and encrust surfaces, substrates that they like, including pipes, water pipes, dams, water infrastructure basically, boats, aquaculture has been affected. So basically, they're biofouling everything, rapidly encrusting surfaces and creating a lot of additional costs in maintenance and repair. So it's very troublesome as they're in your system.

WHEELER:

And ecologically, you also mentioned that they are a concern here in the state of California. Why is this a concern for the ecological health of California's waters?

JABUSCH:

Well, so maybe let's back up. Mussels are filter feeders. So they are actually very effective filter feeders, especially these mussels. They can go through a pint of water in about an hour and basically mop away everything that's nutritious to them. And so they are competing for food sources in the water, and because they're such effective filter feeders, they also can turn a whole ecosystem, a whole food web around, redirecting nutrients and competing for food and nutrients of other organisms. So they directly compete with native fishes, sport fishes we care about, but they also just take their food away.

WHEELER:

And we have other native freshwater mussels here in California that they compete against. Perhaps you can describe some of our native wildlife and the threat status of some of these freshwater mussels, because as I understand it, as a category of life in this Anthropocene, in this mass extinction event that we're seeing, freshwater mussels have been one of the species that has been particularly hard hit and are at particular risk because of things like development and climate change and pollution.

JABUSCH:

Mm-hmm. Yeah, well, so we do have some native mussels in California, Unionets, floaters, California floaters. They're pretty rare, but yeah, they would definitely be affected if these invasive mussels would also be invading the same habitat. So I'm not sure what else I can tell you because we know so little. So it's more general concern. So I mean, the basic issue is that this is new, so we don't really know the impacts, what we should be expecting. But if we look at places that have been affected by these mussels, the effects are overall negative for what's been there before. That is, well, these golden mussels are an invasive species. And we consider an invasive species an invasive species that's causing harm to the environment or to the economy or public health. So, yeah.

WHEELER:

When we have mussels, when they do invade an area, what are the options left to us? So if we fail to contain their expansion, is there any way to engage in treatment of affected areas?

JABUSCH:

Well, our water agencies are looking into options, they're doing research right now of how to minimize impacts on infrastructure, what control options they have, and there's some chemical options, there's treatment options like hot water, UV, whatnot. So that's for infrastructure. And then of course, continued mechanical removal, for example. But all of that is difficult to do in a natural lake, in a reservoir, out in nature. So pretty much once you got the mussels, it's really hard to get rid of them. So we already have quagga and zebra mussels on the continent, and there's very few success stories where they've been successfully eradicated. So the best option we have is preventing their spread from water bodies where they're already in, to other water bodies that don't have the mussels yet. So that's our best options, preventing the further spread.

WHEELER:

And you've mentioned two other mussels that folks may be familiar with because we've been talking about these as a community for longer, the quagga and zebra mussels. How does the golden mussel compare to these other species? For example, does it have kind of a wider variety of habitats that it can utilize or does it require as much calcium in the water? Is it similar? Are these invasion events going to be similar to the already invasive quagga and zebra mussels that we've been contending with?

JABUSCH:

So first of all, there's a lot of similarities in these mussels in their impacts. And yeah, you hinted at calcium and all that. The problem with the golden mussel is that it's adaptable to a wider range of environmental conditions, including they need less calcium to survive, to establish. They can do well in brackish water also. So our estuary space and lagoons are potentially at risk of golden mussel. And they also take higher temperatures than quagga and zebra mussels. So in summary, they have a wider range of environmental tolerance, making more waters in California more vulnerable than they are to quagg and zebra mussels.

WHEELER:

Which is obviously a concern for us. Yes. Okay, so we're here in Humboldt County, you know, far northern California. Where are the closest known infection areas for golden mussels?

JABUSCH:

Golden mussels, okay. Yeah, golden mussels are actually closer to you up there than zebra mussels because, well, they've been spreading throughout the Delta, so that's the closest location basically at this point.

WHEELER:

And they're transferred in a way similar to quagga or zebra mussels by bringing water equipment, boats, other things that store water from one area that might be infected and having the larval mussels and bringing it into a new area, is that right? Yeah.

JABUSCH:

The most common ways of spreading these mussels are with the water that's infested with these mussels. So that's how they're spreading right now. They're in the delta. The delta is often called the heart of our water supply system. And unfortunately, they are in the state water project now, and in the federal water project, so in the water projects, and have been spreading to reservoirs in the Central Valley. And of course, the other pathway for them to get from one water body to another is with watercraft with boats, either attached to the hull as mussels, or as you say, the larvae might be in bilge water or in other water that's collected on the boat. So, and that's why this clean, drain and dry message is really the best, you know, the message we can spread, because it's very low cost and very effective if we as boaters, recreators do that and not spread mussels from one water body to another.

WHEELER:

We'll say that one more time, clean, drain and dry, what are we as water users to do to do our part to stop the spread of not only the golden mussels but quagga and zebra mussels and whatever else that we might not know yet that we might be spreading? What is the best recommendation?

JABUSCH:

Yeah, you're making a good point. This clean, drain and dry actually applies to all aquatic invasive species that we don't want to spread from one water body to another. So what we need to do, of course, bigger boats are always a little bit of a higher risk, but it applies to any watercraft. If you have a motorized boat or if you're just kayaking, it's the same message. Once you leave the water, you want to make sure your boat, your kayak is clean of all debris, plants, whatever. If there is a cleaning system around, an opportunity to wash out the spot, then use that and make sure everything is nicely clean. And then, of course, you also need to drain that water and then open your bilges and make sure your boat is drained. And then also make sure it's dry before you go to the next water body.

WHEELER:

Thank you so much. You are listening to the Econews report. We are talking about golden mussels, a new invasive threat to our region and to the state of California, but it's also spread pretty aggressively since it's been introduced. And joining me from the California department of fish and wildlife is Thomas Jabusch. And then we are also joined by Michiko Mares, the general manager of the Humboldt Bay Municipal Water District. Michiko, I think that this is now a great time to contextualize this and bring it home locally. So Michiko, you are the general manager of the Humboldt Bay Municipal Water District. For those folks who may not think about where their water comes from, can you introduce the district and what it provides for the Humboldt Bay region?

MARES:

Yeah, so Humboldt Bay Municipal Water District is responsible for delivering treated potable water to two-thirds of Humboldt County. We have a dam located on the upper Mad River at Ruth Lake, and Humboldt Bay Municipal Water District manages all the water infrastructure located at Ruth Lake, and Ruth Lake Community Services District manages all the creation at Ruth Lake.

WHEELER:

All right. So we provide all potable water. Our reservoir is up at Ruth Lake. That's where we're able to store water. It passes through Matthews Dam, which is a hydroelectric dam. So we have the kinds of infrastructure that are vulnerable to things like quagga, zebra, and golden mussels, right? As someone who manages a water infrastructure system, what would an invasion mean to the district and how might that impact the district's operations?

MARES:

Right. And to just highlight before I get into that, that in fact, Ruth Lake has the perfect conditions for the golden mussels to thrive. Based on our pH and our calcium, we have all of the components that would allow it to spread rapidly. If we were to get the golden mussels in Ruth Lake, it has the potential to damage our water infrastructure that we use to deliver water to Humboldt County, as well as fouling our hydroelectric plant, and then also passing the golden mussel into the river, which flows down through our community and to Humboldt Bay. So if we were to get the golden mussel, it would be, as Thomas noted, very difficult, if not impossible, to combat and remove. It's not as simple as you just add something to the water and it goes away. It would be mechanically cleaning our infrastructure regularly, which would greatly increase our operational and maintenance cost.

WHEELER:

And those costs, of course, would be then passed along to water users. So if you drink water in the McKinleyville to Eureka region, you are a Humble Bay Municipal Water District customer and you will be impacted by this. So Ruth Lake, the reservoir for the Humble Bay Municipal Water District is also a popular summer recreation spot. So looking out my window, it is gray and probably like 55 degrees right now in Eureka, California. But at Ruth Lake, I'm sure today it's going to be in the 80s and beautiful. And the water is cold and clean and is a favorite spot for vacationers to escape this coastal haze and have some fun. Can you talk about recreation on the lake and the threat to recreation from golden mussels?

MARES:

Well, of course, I think Thomas really highlighted the way that the golden mussel could be introduced to Ruth Lake is from watercraft that are infected with the golden mussel. And then if they were to launch into Ruth Lake, and if they had the golden mussel on the boat or within their ballast tanks, that would be a means of introducing the golden mussel to Ruth Lake. So we do have several things in place to combat the introduction of the golden mussel to Ruth Lake. We already have a mandatory watercraft inspection program that is fairly well established. Through the years, we've been working really hard to block any uncontrolled and unauthorized access to the lake. So people can't put their watercraft into the lake without an inspection. And this watercraft inspection includes kayaks, canoes, motorized, non-motorized, all watercraft vessels are to be inspected at our mandatory inspection locations.

We also have an existing exit banding program. So for local users, if they were in the lake, they can get an exit band and that stays on their watercraft. So if they were to go to a different water use area, that band would be removed and they would not be able to come back into the lake without going through our watercraft inspection program. So the exit banding is a way of, if you only put in at Ruth Lake and you've never gone anywhere else, if you have that exit band, you can come back and go right back into the lake. So we do have a lot of these programs already in place. We have some additional restrictions that we are implementing this season. And one of them is that there will be a mandatory 30-day quarantine for all watercraft that have ballast tanks. So that means that a watercraft will get a mandatory 30-day quarantine band and they will not be allowed to launch into the lake without that mandatory 30-day period and inspection to confirm that in fact, their boat is cleaned, drained, and dried.

WHEELER:

And for folks who might not want to go through the hassle and it's just their own kayak or whatever it is, what are the consequences should you be caught attempting to bring in an unbanded watercraft into Ruth? What's the punishment like here for scofflaws?

MARES:

You know, that's a great question. I believe that our prevention plan notes that there is a $5,000 fine, I believe, for noncompliance with the requirements. But it is difficult to enforce some of these requirements. We do not have, for example, we do not have regular law enforcement in this area. And we ourselves, Humboldt Bay Municipal Water District and Ruth Lake CSD, we are not set up for enforcement. So that is an interesting question that you pose. I wish that it was, there was an easy answer. But certainly, we do not have law enforcement up there specific to Ruth Lake to be monitoring and enforcing these requirements. So the best case scenario is controlling access, which is what we've done. We've really restricted access to the lake by having two boat launch areas and then placing very large boulders around all the other access points on the lake to, again, try to restrict access.

WHEELER:

Okay, so I urge people to take it seriously. And it's not to say that there is not ever law enforcement on the lake. Law enforcement is opportunistically at the lake. And on big summer weekends, like Memorial Day weekend, there was increased law enforcement presence at the lake. So don't risk it. You'll get a $5,000 fine. You'll be banned from bringing that boat back into the lake should you violate the rules. I will promise, as a Humboldt Bay Municipal Water District board member, that we will come down on you should I find out that you violated the rules here. So the district is also looking to have new investments for folks to help decontaminate boats. Can you talk about some of the grants that you're applying to and some kind of long-term vision for how we might deal with this issue?

MARES:

Right. An option to a mandatory 30-day quarantine is to have your watercraft decontaminated, but at this time, we do not have any designated decontamination systems at Ruth Lake or located in Humboldt County. We did submit a grant application to CDFW for a decontamination system, which would be like a dip tank where it would be high-temperature water that would be run through the boat to decontaminate it to kill those golden mussels so that we'd have a safe launch into the lake as part of the inspection program. So we're really hopeful that CDFW awards us that grant so that we can provide to our users an option to a mandatory 30-day quarantine period.

WHEELER:

So, if the district finds that folks are not taking this seriously, if folks are moving boulders or dropping in boats in areas without having been inspected, what might occur? What are the kind of future actions that the district has considered but has not resulted to imposing yet?

MARES:

Certainly one option that is on the table that certainly we don't want to have to do is to suspend all watercraft entry into the reservoir, which many of our sister agencies have chosen to do for this season. But many of those agencies don't have inspection programs in place and they did not have a lot of the early monitoring systems in place. We did have a lot of the programs in place that are needed to monitor and restrict and hopefully prevent the introduction of the golden mussel. But certainly if we were unable to control watercraft entry, that is always an option is to just suspend watercraft use of the lake.

WHEELER:

And a couple of things that Thomas said earlier that I wanted to highlight, golden mussels are geographically closer to the Humboldt Bay Municipal Water District and to Ruth Lake than quagga or zebra mussels, which have occurred further south in the state of California. So, conceptually, there is perhaps an easier path for the spread of golden mussels to the lake. Somebody in the delta pulls their boat out, drives it up I-5, and drops it into the lake to go water skiing. That is an entirely reasonable path, not terribly far, for the spread.

And Michiko, as you said, the pH and the calcium levels in Ruth Lake also make this a pretty hospitable place for golden mussels as far as we understand their ecology. As I know, there has been some question about calcium levels in the lake for other invasive mussels, but here we are more decidedly in that sweet spot for golden mussels. So it is an enhanced risk for golden mussels. So the district is taking this threat seriously. Okay, so I know that we've talked about this before on the show, but I think that this is really the point to reinforce, which is how we can stop the spread of golden mussels. So Thomas, perhaps one more time, clean drain and clean drain dry. That's it, right? What are the steps that folks should take to ensure that they are good actors and that they are not contributing to the spread of invasive species? And you are muted.

JABUSCH:

Yeah, once we're done, once we're done recreating, like I'm also sailing and kayaking, we need to make sure we pull out the watercraft and we clean it up pretty good so that there's no visible debris anywhere. That's the cleaning part. If there's cleaning equipment standing around, take advantage and use it, like rinse everything down on the spot where you're pulling that boat out. The second step is draining so that all that water that potentially has muscles stays, whatever else, stays where it's at and doesn't come with you to the next water body. So that's the draining part. Drain your tanks, drain your boat, flip your kayak around. And then, of course, the drying part.

WHEELER:

Well, Thomas is frozen, but I think I can fill in and say dry just means what it sounds like. Make sure that your equipment is dry before it comes into the lake. This is an aquatic species. It will die outside of water. So we want to ensure that that your equipment is dry before you move and put it into a new water body. And this is a way that we can all help to stop the spread of golden mussels. Unfortunately, we are out of time. I hope that everyone is able to go and enjoy Ruth Lake, but in doing so that you do do it responsibly. And I'd like to thank my guests, Thomas Jabusch from the California Department of Fish and Wildlife, and Michiko Mares from the Humboldt Bay Municipal Water District. Thank you.

MARES:

Yeah, thank you for the invite today, Tom. I appreciate it.

WHEELER:

And join us again on this time and channel next week for more environmental news from the North Coast of California.