This past year, invasive weeds in the Delta were likely the worst it’s ever been, with the low flows due to the drought and lack of cold, freezing temperatures allowing the invasive water hyacinth to proliferate and choke much of the Delta’s waterways. Water hyacinth is the most visible of the Delta’s invasive weed problem, creating dense mats up to six feet thick that make navigation difficult if not impossible, as well as threatening the ecological balance of the ecosystem, but there are other invasive weeds, such as egeria densa, spongeplant, and arundo that are just as problematic.
At the Delta Plan Interagency Implementation Committee, committee members heard about the latest efforts to deal with the problem. “I know when we think of invasive species, many types come to mind, but only a handful negatively impact Delta residents, local, state, and federal agencies as much as aquatic weeds,” said Chair Randy Fiorini. “The extreme nuisance and economic hardship that have become synonymous with invasive aquatic vegetation have also galvanized several interagency efforts to combat the problem. Supervisor Piepho gets a lot of credit for initiating local awareness and in bringing a team of people together to attach this pesky problem.”
Here to report on the progress is Dr. Patrick Moran, a Research Entomologist with the USDA Agricultural Research Service, Exotic and Invasive Weeds Research Unit, and Acting Deputy Director Christopher Conlin with Cal State Parks Division of Boating and Waterways, the lead state agency tasked with addressing the problem.
PATRICK MORAN, Research Entomologist with the USDA Agricultural Research Service, Exotic and Invasive Weeds Research Unit
Dr. Patrick Moran began by stating the mission of the U. S. Department of Agriculture (USDA). “We do research to solve problems, and there are a number of key elements of our mission and our current five-year action plan, and a lot of these research topics do involve protection of natural resources, including water and soil that are relevant to agriculture and also to the protection of natural ecosystems,” he said. Other parts of the mission include ensuring high quality safe food and other ag products, enhancing the natural resource base and the environment, sustaining a globally competitive US ag economy, and to provide economic opportunities.
“A key aspect of our research also is that we transfer the technology to the end users – the state agencies, federal agencies, counties, and private stakeholders for them to improve agriculture and protection of natural resources,” he said.
Dr. Moran said the USDA has been doing research in the Delta for years, with a number of their scientists have been looking at different aspects of invasive aquatic weeds, such as some of the water quality aspects. He said they also have been serving a specific regulatory function with the Division of Boating and Waterways as the federal nexus for their aquatic weed control programs to help them submit the permit applications to the US FWS and NMFS to get their approvals to do their aquatic weed programs; that’s been going on since about 2000.
“This area-wide project is a really new and exciting thing,” he said. “Aquatic weeds are a huge problem in the Delta, and there’s been a lot of effort and funds expended for management, but the problem has been coordination of the science and the management, and trying to bring together the best technology to improve management outcomes and to protect water resources, to protect navigation, and for agriculture. At the USDA Agricultural Research Service, we’re in it to protect the water resources which are so precious for agriculture, the natural ecosystems, and for domestic use as well.”
The three main goals of this project are:
To redesign and implement improved management of invasive aquatic weeds in the Delta, focusing initially on the floating of water hyacinth, submerged egeria or Brazilian water weed, and emergent/riparian arundo, a giant grass that grows along the banks of the canals.
Improved management of disease vectoring mosquitoes that occur in these areas that have been invaded by weeds, and looking at that association between invasive weeds and mosquito populations that can vector disease.
To identify agricultural inputs that could be influencing the success, actually not just agriculture but all different kinds of inputs into the Delta that could be influencing the success of the aquatic weed management programs.
“The USDA ARS is heavily involved in this project from the point of view of research,” Dr. Moran said. “This is what we call an area-wide pest management project, which is a program which has been around for about 20 years from the USDA Agricultural Research Service. The main focus of these projects is implementation, rather than research; however there is some research involved to bring about the best possible implementation outcome.”
He said there have been a number of projects funded for individual insect or weed pests, but this is the first area-wide pest management project that’s focused on multiple invasive weeds of natural or semi-natural ecosystems and all the different aspects of that.
The USDA ARS is involved in research that’s designed to give division of Boating and Waterways and others the knowledge they need to improve the control outcomes. There the many different things they are working on that can lead directly to new technologies for improved control outcomes, he said. Division of Boating and Waterways also gives them information about the efficacy of the treatments and the ways in which research can be integrated into their control programs to get the best possible research data as well as control results, he said.
The NASA Ames Research Center in the South Delta is a major partner and important in this project, Dr. Moran said. “They are helping with remote sensing of weed populations and detecting where the weeds are occurring, where they are growing the fastest, and where they are moving because these populations move around, especially the floating water hyacinth can move with the change in the south Delta pumping, water currents, and drought. They are doing remote sensing using satellites and airplanes to quantify in new ways where the weeds are occurring. They give this information to the Division of Boating and Waterways to help them prioritize control locations. They can also do this historical analysis over time to see where the weeds are the worst, year after year after year, and that can be figured into the control programs as well.”
“NASA has been doing some really good work on the remote sensing,” Dr. Moran said. “They are using LANDSAT which is a satellite based system to quantify where the water hyacinth is at a given time. It flies over every two weeks, and they can turn this information into what’s called a multi-spectral image which then we can use that to determine where the water hyacinth is.”
“They are overlaying that information also on the huge amount of data that’s available on, for example, nutrients input in to the Delta, so on the left there you see a map of potential nutrient input sites; on the right where the water hyacinth is occurring,” he explained. “You can overlay that information and use it in modeling to predict potentially where the water hyacinth is going to be growing the most, the fastest, and therefore where it’s going to be causing the most problems. And this is going to be done for the egeria densa, the Brazilian water weed as well.”
He said that four entities at the University of California Davis are also involved. “The Department of Entomology and Nematology is doing different studies on agricultural inputs and on the potentially critical tie in of mosquitoes with the aquatic invasive weeds,” he said. “The Department of Plant Sciences is helping with the growth studies; the Agricultural Issues Center is doing a bioeconomic model, tying in the cost and damage of the invasive aquatic weeds with the benefits of the area wide pest management approach.”
The initial project was funded as a pilot project last year in the southern and western Delta, but new funding received this year will allow the program to expand to the entire Delta, Dr. Moran said. “We’ve already had the Contra Costa and San Joaquin mosquito vector control districts involved; they have their critical mission to protect public health, and they are reporting to us information on the association between the aquatic weeds and the mosquitoes, and tying it into when and where the Division of Boating and Waterways is treating. We’re doing research at the ARS on the association between the mosquitoes and the weeds, and this can be used to improve control outcomes for both the mosquitoes and the weeds in the future.”
New funding has brought in new partners, he said. “The Delta Conservancy is involved with arundo, since Division of Boating and Waterways does not control arundo, but the Delta Conservancy has an arundo control program they started last year,” he said. “This has a mapping component, so this will help me to identify sites where I can do biological control as my own area of expertise is actually biological control, but I am working on all different control methods in this project.” He noted that California Department of Food and Ag, the Cooperative Extension, and a number of agencies are participating in the meetings.”
Dr. Moran then concluded with the expected benefits and outcomes of the program.
Improved area‐wide management of water hyacinth and egeria in the Delta, led by the Division of Boating and Waterways‐CA Parks and achieved through science‐based control prioritization and optimization. “The idea is to reduce the control inputs and reduce the costs while having improved control outcomes,” he said. “Some of these weeds have been under control programs, such as water hyacinth, for quite awhile, but the idea here is to achieve economically and ecologically improved control outcomes.”
Other outcomes include integration of biological control into arundo control and habitat restoration plans led by the Delta Conservancy, a decrease in water loss/waste, and in economic damage caused by aquatic and riparian weed invasions, improved efficiency of suppression of potentially disease‐vectoring mosquito populations in areas adjacent to aquatic weed infestations, and increased opportunities for restoration of wetland and aquatic habitats under the Delta Plan and BDCP.
“This falls well into the high-priority research in terms of the research we’re doing,” he said. “The protection of Delta communities, communities at risk and flood protection – the invasive aquatic weeds falling into that high priority research category. So again, this isn’t totally a research project, but it does have a critical research component.”
“That’s all I have … “
CHRISTOPHER CONLIN, Acting Deputy Director, California State Parks, Division of Boating and Waterways
Christopher Conlin began by noting that the multi-agency effort currently underway has been a result of the effort of Supervisor Piepho and others also in the same room; those efforts have been boosted by recent legislation.
The people who are actually on the water, executing the control strategy are the folks from the Aquatic Invasive Weed Species section of the Division of Boating and Waterways within California State Parks, he said.
The program is permissive, which means it is executed almost solely from the Harbor and Watercraft Revolving Fund, which also supports recreational boating access throughout the entire state of California. “It’s not a limitless fund,” he said. “It is derived from gas tax, but the amount that we can use for this particular control program is controlled by the legislature.”
He said while other programs exist that are elimination programs for plants like hydrilla, this is not a program designed to eliminate, but is simply control. “The species are invasive and they reproduce rapidly, but the understanding right now it that it would take a unconscionable amount of money to eliminate them, particular in a Delta type environment, so the best we can do right now is control,” he said. “We balance public health, economy, and environment, and all of them rate very highly in this analysis but they must be balanced against each other so that we can provide a good opportunity to control the plants while not destroying an environment like the Delta, which is pristine. We’re also worried about public health; it’s that same water from the Delta being pumped out into people’s homes and onto the plants that we’re eating on the table.”
The recent legislation, AB 763, was an important change, Mr. Conlin said. “That legislation allowed the two of us to communicate more broadly and openly,” he said. “Basically what it did is it said that the lead agency for doing control of invasive species in the Delta is Boating & Waterways Division, and it gave us a mandate to cooperate and collaborate with our federal and state partners. That has worked out very well. That, in addition to the area wide study, has really amplified our efforts, and what you now have is a architecture where we get all the benefits of the experience, the science, the effectiveness of the USDA, Fish and Wildlife, NOAA, NASA, UC Davis, all coming in to help us in this tremendous problem and try and provide us as many benefits as we can.” He added that the partnership seems to grow on a weekly basis.
The program covers 68,000 acres of the Delta, a unique area, he said. “There’s only one other tidal Delta area like this in the world, it’s in China, and they throw billions of dollars a year at this problem. And they still haven’t solved it either, so it is a unique environment, and we’re working within that to try and do the best that we can.”
Controlling aquatic invasive weeds is a resource intensive program, he said. “We had a budget of about $9 million for the last year which was devoted exclusively towards just the invasive weeds we treat in the Delta,” he said. “The four weeds that we right now are given authority to control are water hyacinth, a floating weed; egeria densa, a subsurface weed; spongeplant, which is a surface type weed that floats on the top; and curly leaf pondweed, another bottom dwelling plant that is out there in the Delta. Curly leaf pondweed is the most recent on that list and is a direct result of AB 763 and our cooperation with USDA and others.”
Mr. Conlin said they entered a budget change proposal for $3.9 million to provide additional staffing, equipment, and herbicide that was supposed to come in 2015-16 but they were able to obtain the money early. “We get the one-time $3.9 million, and then an annual allocation of $2.8 million,” he said. “What that buys us is 8 field technicians; we right now have 12 field technicians out in the boats actually doing the spraying, so this almost doubles the number of people we have out there on the water.” He added that the $3.9 million is coming still from the Harbor and Watercraft Revolving Fund, so it is not new money, it still is coming from the same funding.
“Three scientists that are going to come in,” he said “The primary reason for these scientists is to better meld with folks like Dr. Moran and the other agencies out there, so that we can come up with a more strategic plan and we can do a better job of studying this environment. I was particularly tickled to see a lot of the efforts that are going on in the previous briefs with the science; that’s where we want to be, we want to come up with better solutions on how to control these invasive plants.”
The main control strategy is herbicide, which is also the most expensive, Mr. Conlin pointed out. “The reason why is because a paint bucket filled with pellets that are used on a plant like egeria costs about $1500 for one bucket. We are treating currently 1500 acres of that on a 12 week program; you go through a lot of buckets fast. So millions of dollars into herbicide; we’d like to get away from that, or at least do it more effectively.”
Mr. Conlin said they started on time in March, which is the earliest they are allowed to start using herbicides. “We started treating on March 4 for the floating aquatic vegetation – the water hyacinth and spongeplant. We’ve done about 409 acres of that so far all across the Delta. Efficacy is moderate right now, which means that we’re starting to see some level of control. If you look out and you see some of the plants and they are browning and starting to die, right now that is absolutely due to the herbicides that we’re using.”
“We haven’t had a freeze out there in months and that kills us,” he said. “The freeze and flows in the Delta is the best way to get this stuff out, that’s Mother Nature doing her best. Mother Nature, unfortunately this year, hasn’t been on our side.”
Mr. Conlin said they are treating the submerged aquatic weeds – the egeria and the curly leaf pondweed on a 12 week treatment cycle. “We’re doing 1500 acres,” he said “We’re getting moderate efficacy; you start to see some browning at the top of those, whitening on the leaves, and then they start to kind of drop off, and that is in key locations around the Delta. It’s not quite as widespread throughout the Delta as the water hyacinth. Because it is a submerged plant, it attached to the bottom and then grows up that way, whereas the water hyacinth and the spongeplant being free floating, can wander all throughout the Delta based on whatever the winds and the flows and the tides are doing which is more problematic trying to catch up with that. At least with the bottom submerged vegetation, we can target areas.”
The integrated control strategy includes chemical treatments, mechanical harvesting, biological controls, manual removal, and mapping. He said the reason they use chemical treatments (or herbicides) so much is that it’s the most reliable method that can be used. “It stops the growth of the plants and it decreases their flowering, and if you can at least stop the growth, then you have the opportunity for the plants to die and not increase as rapidly.”
“These are some of the most rapidly growing plants in the world, and we’re just lucky enough to have them here in our Delta,” he said. “They also predominantly come from places like the Amazon, so the more the climate changes to look like the Amazon, the more prolific these plants are, unfortunately.”
Mr. Conlin said they have been doing mechanical harvesting for about 2 years with some good effect. “This is literally getting in and hauling out the biomass out of the Delta,” he said. “It’s the most laborious and most expensive way of treating and trying to control because these plants are 90%+ water, so they are heavy when you pull them out, and if you do it wrong, and you break them up, what you end up doing is increasing them, like a hydra. You cut the heads off and you get millions of more heads, so it has to be done exactly right.” He noted that they were working on a contract for harvesting services across the Delta.
Mr. Conlin said they were hopeful about biological controls. “Will it ever eliminate the problem? Probably not, but even if it take 5 or 10%, that’s that much less we have to take out, and the beauty of it is it removes biomass, so it gets rid of this stuff that is floating around on the water, which is great for us.”
The biggest issue is trying to figure out where the plants are, and this is where NASA and the mapping has been very helpful, he said. “With the floaters, they are going wherever they want in the Delta, and across 68,000 acres, it’s very hard to track them. NASA gives us a little bit of an ability to do that. NASA also is working some of their telemetry and multi-spectral photography where we might be able to pick up even some of the subsurface plants and get a feel for where they are.”
He said they have many partnerships on the federal, state, and local levels. They have reached out to various Delta agencies, as well as just about every agency sitting at this table right now; even some of the sheriff’s organizations have reached out to them. “We cannot get enough partnerships out there now as we try and open this up and make a more collaborative approach to trying to take out this problem,” he said.
Mr. Conlin then turned to the plan of attack for this year. “We started off with a review of what we did last year in 2014 and in previous years, trying to come up with targeting on where the biggest hot spots were for these plants and where we could hit it fastest and have the best effect with the chemical controls and mechanical controls,” he said. “Following that, we issued a lot of public notifications and let everybody know and actually got out onto the water. This is one of the first times in several years that we started the treatment on time, in March, ready to go. We’re allowed to treat only from March until November, so it’s crucial that we get on the water as soon as we can to try and get ahead of the problem.”
He said that there has been increased levels of public engagement, including multiple town halls and forums, reaching out to media, and a weekly email notifying stakeholders of their activities, as well as a report card on how they are doing.
The solution set includes the integrated control strategy, mechanical harvesting, and scientific studies, including holding a scientific symposium in the near future which Mr. Conlin believes will be beneficial.
Mr. Conlin said that he thinks that there are parameters that can be opened up in the biological opinions if there was better science on the issue. “We’re limited to certain months of treatment, we’re limited to only certain herbicides, and we’re limited very much in the amount of herbicides we can use,” he said. “So what we would like to do is make that a little bit more flexible and adaptive, so that when we have these large amounts of weeds out there in the Delta, if possible, we can push some of those parameters without causing any injury to the Delta or to the people that use it, and still be able to take out these weeds.”
He said they were also doing process control improvements and some internal reorganization, working to build bridges with their partners so that they are able to leverage all their creativity and abilities.
He then presented a table showing the aggregate treatments since 2009, noting the harvesting is very much on an upward trend. “The new thing on there is this hyacinth removal that we did with DWR. We were able to take out about 36,000 cubic yards of this out of the Delta in order to free things up and stop it from choking up,” he said. “We’re going to do be doing more of this in the future, but again this isn’t the solution. It’s just one more tool in the tool kit to help things work better.”
“We appreciate that forums like this allow us to get the word out and that allow us to get more information into the hands of people,” he said. “We would encourage folks to get on to the DBW website if they have any questions about how do we treat or how can they can do things defensively against the weeds. They can also sign up for our alert system so we can tell them, if they are a marina owner or even a boater, and they can get all the alerts on where we’re going to be and what we’re doing out there.”
“Subject to your questions, that’s my brief … “
David Murillo from the Bureau of Reclamation noted that there was a big problem with water hyacinth last year at the Tracy facility. “You said freezing and flows are our friend, if we don’t get that, do you think the spraying is going to make a significant difference, or should we be planning on mobilizing groups again to remove it mechanically?”
Mr. Conlin said they were not going to rule that out, but it’s their intent to get ahead of the problem. “We’re trying to get out on the water and hit this stuff as early as we can to limit it; that’s the purpose of doing our own contract on the mechanical removal, so that when we can find choke points out there, we can hit them hard and try and take care of this before it flows all the way down and gets into your waters there. … Last year we were probably at the topmost part of the bell curve as far as the growth of the weeds and everything; it’s just the way it was with the drought. This year, we want to knock it back, and see if we can knock it back each year, back, back, back. We’re never going to eliminate it, but if we can keep it off the top of the bell curve and hit that stuff as early as we can, get that biomass down to a reasonable level, then I think we can offset the issues that you had last year.”
Contra Costa Supervisor Mary Piepho said that it’s been extremely challenging at the local level. “How do we develop and implement a comprehensive Delta wide invasive aquatic and terrestrial weed program and consistent with funding, not just the permit process, but how do we consistently fund it? Because we at the local level don’t want to show up at your doorstep with a big problem, but also have some part of a solution with it. I’ve offered up a couple of ideas on revenue opportunities or at least thoughts to be pursued, and I’m happy to be a champion to carry that forward so that you have the resources as we develop this comprehensive plan … I say this is a statewide problem, these weeds, they are not just a Delta weed problem, they affect the Central Valley farmers, they affect in-Delta farmers, they affect the environment, they affect the economy, they affect the water exporters. I just think it’s a win-win all around if we can keep the plan building, keep the momentum moving forward, and really keep your leadership … From the local perspective, just let us know how we can help. We’re here to do it.”
Secretary of Agriculture Karen Ross asked if any biological controls had been identified yet. Where is the best promise in biological controls?
Dr. Moran said that the US Army Corps of Engineers introduced a couple of weevil species and a moth to control water hyacinth back in the early 1980s, and only one of those three agents established, which was the weevil. “I also work with another insect that was discovered, like the weevils, by the USDA-ARS in South America. It’s been permitted for release in California. I’ve been starting to do some work with that in and out of the Delta as a new biocontrol agent for water hyacinth. We don’t have any control agents for Brazilian water weed. We’ve been working in our quarantine laboratory in Albany; we have a quarantine laboratory where we can study insects that are not yet permitted for release and make sure they are biologically safe, they only attack the target weed; make sure they are efficacious, do a lot of damage to the weed, and look at their biological life cycle. We don’t have anything available for field use for Brazilian water weed; we’re working on it.”
“In the case of arundo, we have two insects which have been released in the Rio Grande Basin in Texas and New Mexico, and I’m releasing them here in California right now,” Dr. Moran continued. “Those are again permitted for use in California, so we do have some, and we’re seeing impacts in the area where we’ve released them in Texas and New Mexico. So for two out of the three, we do have insects available for field deployment, as we would say, but we need to get some insects. There is an extensive a permitting process for these insects, a long process that requires consultation with the USFWS, potentially for the Delta also NOAA NMFS, because of the fish species. So we’re working on that as well.”
Supervisor Mary Piepho said that something to consider might be for the state legislature to consider legislation that would limit or eliminate the sale of these weeds for aquarium purposes which is typically how they end up the Delta. She suggests public education at point of sale. She also suggest perhaps an aquatic invasive weed fee on boater registrations. “That would take some legislation and leadership to move something like that forward, but I’d much rather see some consistent revenue consistently to address the problem than these hot and cold efforts and really have some consistently for the value of the state, and maybe our water exporters might want to jump in and help contribute.”