The Importance of Soil Health

By Erin Brooks, Natural Resources Conservation Service

It would have been hard to find any reference to soil health twenty years ago. Soil was conventionally treated as an inert growing medium. Today’s explosion of interest in soil health reflects a fundamental shift in soil science and a corresponding shift in the way we care for our nation’s soils. Soil is now recognized as a living ecosystem teeming with billions of bacteria, fungi, and other microbes that are the foundation of an elegant symbiotic ecosystem.

The complex soil ecosystem provides numerous benefits. These include:
1. Creating nutrients for plant growth,
2. Absorbing and holding rain for plant use during dry periods, and
3. Preventing soil and pollutants from leaving farm fields.

Healthy soil serves as a firm foundation for agricultural activities

Soil health is dynamic and changes in response to management practices.  Management practices can affect the amount of organic matter in the soil, the presence of which is critical for soil ecosystem function. Management practices also affect soil structure, soil depth, and water and nutrient holding capacity.  Soil health is improved when farmers mimic nature; when the myriad of creatures that comprise the soil food web are cared for and not abused.  A fully functioning soil produces the maximum benefit at the least cost.

It is crucial to integrate and follow all soil health management principles for the soil to become and remain healthy.

5 Principles of Soil Health

  1. 1. Minimizing soil disturbance
    2. Maximizing diversity of plants/crops
    3. Keep living roots in the soil
    4. Keep the soil covered with plants or residue at all times
    5. Incorporate livestock

The Boise River Enhancement Plan recommends adoption of these agricultural best management practices to enhance water quality in the Boise River and its tributaries.

Residue left between crop rows – no bare ground

Cover Crop – maximizing a living root, ground cover and plant diversity

Bringing Our Soil Back to Life

You can learn more about soil health and agricultural best management practices at the 9th Annual Soil Health Symposium on February 15.  Speakers include David Montgomery – University of Washington, Olga Walsh – University of Idaho, Shawn Nield – Idaho NRCS and Joel Packman – University of Idaho. The symposium will be held at the Four Rivers Cultural Center in Ontario, OR. Information and registration

Unique Partnership Will Reduce Boise River Pollution

by Dr. Jack Harrison

Water in the Boise River will have less sediment and phosphorus because of a new partnership between the City of Middleton and Drainage District No. 2 (DD2). The innovative water quality improvement project will remove sediment and phosphorus from the Mill Slough, a major Boise River tributary. This partnership between the City and DD2 demonstrates how cities and the agricultural community can work together to reduce non-point pollution in the Boise River watershed.

Mayor Taylor

Middleton Mayor Darin Taylor leads a tour at the Mill Slough project site

on tour

Chris Yarbrough, IDFG and Jessica Harrold, Ada Soil and Water Conservation District and BREN visit the project site.








Middleton Mayor Darin Taylor said, “The Boise River is our front yard and we want to take care of it. We created this opportunity to partner with Drainage District 2 and do something neither of us could do on our own.”

Irrigation return often carries sediment and phosphorus

The Mill Slough discharges to the Boise River near Middleton Road and is one of twelve Boise River tributaries identified in the 2015 Lower Boise River Total Maximum Daily Load (TMDL) that need to contribute less sediment, bacteria and nutrients to the Boise River. According to US Geological Survey data, Mill Slough has the fifth highest discharge of total phosphorus when compared to other Boise River tributaries. Discharge loads average 125 pounds per day.


Project engineer Jack Harrison, HyQual

The Mill Slough is an integral part of DD2’s drainage system that serves the north side of the Boise River. The Mill Slough conveys irrigation water that flows off agricultural fields known as return flow, stormwater from urban residential areas, and municipal wastewater discharged from the City of Star. The three-phase water quality improvement project, as conceived and developed by Dr. Jack Harrison with HyQual P.A., starts with construction of an automatic weir structure installed in the Mill Slough a short distance upstream from the Boise River.

The weir will increase the Mill Slough water level and form a small sediment settling basin. To prevent downstream spiraling of nutrients that collect in the settling basin, DD2 and the City will remove sediment and phosphorus from the basin.  The sediment will be sampled and removal rates tracked to demonstrate the effectiveness of this “in-channel” treatment.  Sediment and phosphorus removed from the settling basin will be applied to City-owned land. It is estimated the project will result in an average annual sediment load reduction to the Boise River of about 900 tons/year and a total phosphorus load reduction of about 365 pounds-P/yr.

In the next phase of the project, the phosphorous-rich water in Mill Slough would be diverted south over City-owned land using historic overland flow channels that drain to the river. The final phase of the project could include a higher level of water quality treatment via expanded riparian flow channels and newly constructed wetlands and/or treatment basins. Read the Mill Slough Water Quality Plan Description.

Mill Slough

Mill Slough in Middleton

To help finance the Project, the City and DD2 jointly applied for a matching grant of $172,500 from the Lower Boise Watershed Council (LBWC).  The LBWC was awarded $250,000 from the State of Idaho’s Agricultural BMP General Fund, and, on October 12, 2017, the LBWC approved a grant in the amount of $172,500 for the joint City/DD2 Project.

Putting Down Roots at the Hyatt Reserve

Abe helps Granddad Gary collect seeds.

Energetic groups of adults and kids spread out across the City of Boise’s Hyatt Hidden Lakes Reserve in early December in search of the fuzzy dry flower heads of rabbitbrush plants. The once-bright yellow flowers had turned a faded beige and harbored thousands of tiny seeds the volunteers carefully collected in paper sacks. Back at the trailhead, experts with the Land Trust of the Treasure Valley and Golden Eagle Audubon Society and Boise River Enhancement Network Coordinating Team members Tamsen Binggeli, Lisa Harloe, Erin Brooks, Kathy Peter and Charissa Bujak helped the volunteers plant the seeds in germination trays. The volunteer native plant gardeners then took the trays home to tend until the seeds germinate and the rabbitbrush seedlings are big enough to transplant.

Native plant gardeners Hilary, Silas and Lisa

Rabbitbrush in summer bloom.

All the fun is part of the Hyatt Hidden Lakes Reserve Habitat Enhancement Project, a partnership between the City of Boise, Boise River Enhancement Network, Land Trust of the Treasure Valley and other local organizations supported, in part, by funding from the National Fish and Wildlife Foundation. The goals of the project are to improve the hillside habitat by restoring native plants and provide opportunities for community members of all backgrounds to develop a connection to this unique outdoor space. The seed gathering and plant growing is part of the project’s community plant nursery, a program to have volunteers grow plants well adapted to local conditions and use them for site restoration. The rabbitbrush grown from seeds collected by these volunteers will be ready to plant at the reserve in about one year.

Sean Finn of the Golden Eagle Audubon Society helps coordinate the community plant nursery. Sean explains, “The plants grown from local seed will be well-adapted to the soil and climate and should thrive at the reserve. Just like the plants, the volunteer gardeners are putting down roots and gaining a long-lasting connection with the wild places in their neighborhood.”

Halle collects seeds.

Tamsen planting seeds.









The anticipation of returning to plant rabbitbrush they grew themselves was evident as volunteers carried their germination trays carefully to their cars with instructions for care over the winter.  Gathering seeds and growing the plants that will be used to improve bird habitat at the reserve is full of rewards. It’s an activity people of all ages, abilities and backgrounds can enjoy. Teams from Big Brothers Big Sisters of Southwest Idaho participated, and one young volunteer described the event as “pretty cool.”

Amber, Nara and Jai plant seeds.

The project is also engaging new residents that have come to Boise from many nations in the community nursery. Involving refugees in conservation helps them build a connection to their new home. Using seeds gathered at the reserve, project leaders helped fifteen new Boise residents from Bhutan prepare two germination trays, one with rabbitbrush and one with sagebrush. The men visited the reserve with project volunteers in October where they saw rabbitbrush and sagebrush and used binoculars to get close-up looks at the birds. Counselor Sally Guaspari said, “Visiting the reserve was a really rewarding experience. Most of the men were farmers by trade in their native Bhutan, so they have a strong appreciation of nature and plants.  Tending to the germination trays connects them to the community and they will be eager to take another trip to the reserve.”

Amber and Nanda’s tray is protected from squirrels.




The volunteer native plant gardeners will be back in the spring to transplant the seedlings into growing pots for the summer, and next fall, the new rabbitbrush will be planted at the reserve.





The project is led by the Land Trust of the Treasure Valley, Boise River Enhancement Network, and the City of Boise. Project partners include U.S Fish and Wildlife Service, Idaho Office of Refugees by Jannus, Big Brothers Big Sisters of Southwest Idaho, Golden Eagle Audubon Society, Intermountain Bird Observatory, Boise State University, The Wetlands Group, Idaho Fish and Game, Idaho Weed Awareness Campaign, and Partners for Clean Water.


Improved Habitat Ahead for Hyatt Reserve

The Boise River Enhancement Network, the Land Trust of the Treasure Valley and other organizations and volunteers are working with the City of Boise to reduce weeds and improve habitat for birds at the City of Boise’s Hyatt Hidden Lakes Reserve. The groups are implementing recommendations of the Hyatt Hidden Lakes Reserve Master Plan with support from the National Fish and Wildlife Foundation. 

The Hyatt Hidden Lakes Reserve Habitat Enhancement Project will improve the upland habitat on the hillsides now overrun with undesirable species including feral cereal rye, kochia, tumble mustard, and cheat grass. The invasive plants provide poor habitat and pose a fire risk to the reserve and surrounding neighborhoods. The Boise River Enhancement Plan recommends increased control of invasive and non-native plants. 

Eric Willadsen, Stewardship Coordinator for the Land Trust of the Treasure Valley said, “Native plants will attract more birds and wildlife, reduce the risk of fire and beautify the reserve. There’s tremendous potential for improvement.”

Feral cereal rye dominates the hillsides at the reserve. Photo – Land Trust of the Treasure Valley

Firewise Native Plants

Project partners assembled a team of habitat experts who visited the reserve in September and made site-specific recommendations that Martha Brabec, Boise City Department of Parks and Recreation Open Space Specialist, has incorporated into the draft Hyatt Hidden Lakes Revegetation Proposal

Ada County Weed Control applied herbicide to some areas in the reserve this fall to kill invasive grasses. Volunteers and staff will plant drought-tolerant species including sagebrush, sandberg’s bluegrass, Canada bluegrass and sheep fescue in these areas in 2018.  Low flammability shrubs such as oakleaf sumac and mockorange and low growing grasses will be planted in the uplands on the western edge of the reserve. Clusters of chokecherry, golden current, rabbitbrush, and sagebrush will be planted in the transition zone between the wetlands and uplands. 

Habitat experts look at the disturbed hillsides at the reserve. Photo – Land Trust of the Treasure Valley

Open House Features Special Presentation on Birds

Visitors have observed 124 species of birds at the reserve. These include finches, wrens, sparrows, woodpeckers, swallows, warblers, hummingbirds, doves, quail, hawks and other species that use the uplands. The proposed enhancements will greatly improve nesting, foraging, and cover habitat for the upland birds. Native plants support populations of insects and critical pollinators too. Heidi Ware of the Intermountain Bird Observatory will make a special presentation on the “Hillside Birds of the Hyatt Reserve and the Plants They Love” on Thursday, November 30 as part of the Hyatt Reserve Open House.


Native plants support healthy populations of insects and pollinators. Photos by Ken Miracle.

The Open House is Nov. 30 from 5:30 – 7:30 pm at the Boise WaterShed, 11818 W Joplin Rd, Boise, and presentations start at 6:00. Information about the project and the draft Hyatt Hidden Lakes Revegetation Proposal will be provided and public comments will be accepted.

“We want to hear what reserve users and reserve neighbors think about the proposal. Engaged community members created this special pocket of urban open space and strong community involvement is needed now to make these desired improvements,” said Martha Brabec.

The project is led by the Land Trust of the Treasure Valley, Boise River Enhancement Network, and the City of Boise. Project partners include U.S Fish and Wildlife Service, Idaho Office of Refugees by Jannus, Big Brothers Big Sisters of Southwest Idaho, Golden Eagle Audubon Society, Intermountain Bird Observatory, Boise State University, The Wetlands Group, Idaho Fish and Game, Idaho Weed Awareness Campaign, and Partners for Clean Water.

Native basin big sagebrush flourishes on the south hillside. Photo by Ken Miracle.

Fall at the Reserve

With support from the National Fish and Wildlife Foundation, BREN, the Land Trust of the Treasure Valley and many other community partners have started a new project at the City of Boise’s Hyatt Hidden Lakes Reserve. The goals of the 18-month project are to improve hillside habitat at the reserve and introduce new visitors to the urban open space.

Alan Crockett

Alan Crockett plants willow donated by Idaho Power at the reserve on Nov. 3

Xylem Inc. employees Marie, Michael, Ladd and Kristin spent a morning removing russian olive trees at the reserve.

BREN Coordinating Team member Lisa Harloe points out ducks to Indra, a new resident from Bhutan on Oct. 30.

Mu Hla Htoo and Hserry enjoy bird watching during a project field trip on Oct. 17.


The reserve has a variety of wetland and hillside habitat. Photos by Ken Miracle.


Many birds are found at the reserve. Photos by Art Robertson.

Story Map of Urban Growth in the Treasure Valley

BSU’s MILES project just released a Story Map that documents historic growth in the Treasure Valley and provides future growth scenarios, and their impacts to different ecosystem services and land use changes, through 2100, in order to inform policy decisions about the sustainable management of local resources.

Check out the Story Map Here!

The importance of the Boise River as a driver of growth is documented, as well as impacts from past engineering, current development and future growth scenarios.

MILES stands for Managing Idaho’s Landscapes for Ecosystem Services, which is part of the Idaho EPSCoR Research Infrastructure Improvement Program. The MILES project is collaboration between Boise State University, Idaho State University and the University of Idaho, and was funded in part by the National Science Foundation. Learn more about this program Here.

Information from the MILES project was incorporated into the Boise River Enhancement Plan. The MILES Team also provided critical feedback on the Plan.

New Partnership Improves Wildlife Habitat and Enriches Lives

The Boise River Enhancement Network is thrilled to be a lead partner in a new and innovative project at the Hyatt Hidden Lakes Reserve. Nestled in a residential and commercial area in West Boise, the reserve is a hidden gem of nature. The series of ponds, wetlands and hillsides blend together to create a unique pocket of wildlife habitat in the center of urban Treasure Valley.

Reserve Entry sign

Photo by Ken Miracle

The reserve, managed by the City of Boise City Parks and Recreation and Public Works Departments, is guided by a 17-year-old community-generated Master Plan. Visitors can enjoy nature trails with benches, interpretive signs and there are restrooms and two parking areas. Community members and people from near and far use the reserve year-round, attracted by the rich bird life, the wide paths and the outstanding scenery.

BREN and the Land Trust of the Treasured Valley secured a grant to build on the past success of the reserve and improve the habitat and introduce new visitors to the site.  With support from the National Fish and Wildlife Foundation, the U.S. Fish and Wildlife Service’s Urban Wildlife Conservation Program, and more than a dozen community partners, the 18-month ‘Multi-Cultural Habitat Enhancement Project’ (project) is an innovative initiative that’s already generating enthusiasm.

Bird-friendly, fire-resistant vegetation will replace the weeds on hillsides at this popular walking and birding destination and the partnership will provide new residents from many nations the opportunity to visit the urban reserve and participate in habitat stewardship activities. The goal is for community members of all backgrounds to develop a connection to this unique outdoor space.

“One of the great things about living in the Treasure Valley is enjoying nature close to home,” said Tim Breuer, Project manager and Executive Director of the Land Trust of the Treasure Valley. “This new initiative is meant to improve habitat and introduce new residents to these special places.”

Visitors use bird checklist

Lisa Harloe assists visitors with their bird checklist

On October 17, 2017 BREN Coordinating Team members Lisa Harloe and Heidi Ware were part of a team of project partners that helped 40 students from the English Language Center (ELC) explore the reserve. The ELC is a skill development center for adult refugees who recently arrived in Idaho, and it was the first time to the reserve for all of them.

ELC instructor Steve Rainey said, “Connecting with nature is healing, and a group trip is a great way to discover this public park. Now the students can go to the reserve with their families and, if they want, there will be opportunities for them to work side-by-side with other volunteers to take care of this welcoming place.”

Qaiser birding     Birding

Qaiser (left) and the other visitors saw many of the birds that live at the reserve including American coots, Pied-billed grebes, and Red-winged blackbirds.


Debris removed

Volunteers from many organizations have already started removing debris to prepare the reserve for plantings next year. City of Boise Open Space Restoration Specialist Martha Brabec is drafting the Hyatt Habitat Enhancement Plan with help from volunteer habitat experts, including BREN Coordinating Team members Tamsen Binggeli and Lisa Harloe and BREN volunteers Roger Rosentreter and Alan Crockett. The City of Boise actively encourages community stewardship of its reserves and seeks to expand and diversify its capacity.

Heidi, Kristin, Tim      lunch volunteers

(left) BREN CT member Heidi Ware, Boise Watershed and BREN volunteer Kristin Gnojewski, and LTTV Executive Director Tim Breuer. (right) BREN volunteers David Monsees, Caroline Morris and Jeanette Ross served up a great lunch for everyone at the reserve on Oct. 17

“Public volunteers play a key role in wildlife habitat conservation in urban areas and being a conservation volunteer enriches their lives,” said project partner Ally Turner, U.S. Fish and Wildlife Service biologist, “This exciting project will introduce newly arrived residents to the Hyatt Hidden Lakes Reserve and to the rewarding experience of working with others to protect the places we love.”

The project is led by the Land Trust of the Treasure Valley, Boise River Enhancement Network, and the City of Boise. Project partners include U.S Fish and Wildlife Service, Idaho Office of Refugees by Jannus, Big Brothers Big Sisters of Southwest Idaho, Golden Eagle Audubon Society, Intermountain Bird Observatory, Boise State University, The Wetlands Group, Idaho Fish and Game, Idaho Weed Awareness Campaign, and Partners for Clean Water.

Monitoring Shows Progress Towards Reducing Boise River Phosphorus Levels

By Lauren Perreault, USGS

For decades, the lower Boise River downstream of Lucky Peak Reservoir has been highly enriched with phosphorus. Too much of a good thing, the high concentrations of phosphorus create a cycle of excessive plant growth, decreased oxygen for fish, and even algal blooms. But things may be turning around. Water-quality monitoring by the U.S. Geological Survey (USGS) shows that phosphorus concentrations in the lower Boise River are down one third since 2015.

From below Lucky Peak Dam to the confluence near Parma, the Boise River winds through cities, towns and farmlands, and that takes a toll on its water. While the river is relatively cold and clear upstream at places like Barber Park, it becomes warmer, carries more sediment, and contains more aquatic plant life as it moves downstream to its mouth near Parma. These changes are caused in part by increased amounts of phosphorus in the river, which cause problems by increasing plant growth. Besides being a nuisance to recreationists, this excess plant matter consumes oxygen that is dissolved in the water when it decays, and too little dissolved oxygen is harmful to fish and other aquatic life.

The Boise River near Barber Park above the City of Boise is relatively cold and clear, versus the Boise River near Parma is warmer, carries more sediment, and has more excess aquatic plant growth.

So where does the excess phosphorus come from? The short answer is: all of us. A little bit of it comes from water and soil runoff from forested lands upstream. Municipal wastewater contains lots of phosphorus, and while much of it is removed during the treatment process, some is still in the water when it’s released back into the river. Fertilizers often contain phosphorus, and soil and water runoff from lawns and fields can carry some of this phosphorus into the river. Some phosphorus also comes from shallow groundwater. This phosphorus may come from leaky septic systems and from the application of both fertilizer and irrigation water that already has a lot of phosphorus in it from upstream sources. After it’s applied to fields, this water and phosphorus can infiltrate into shallow groundwater and eventually makes its way into the river.

Recognizing these impacts, the Idaho Department of Environmental Quality (DEQ) established total phosphorus limits for the lower Boise River in 2015 to address water quality issues. The U.S. Geological Survey has worked with DEQ and the Lower Boise Watershed Council to monitor water quality in the Boise River since the 1970s. This partnership brings local stakeholders on the Council, including cities, irrigation districts, and industries, together with local regulators and federal resources to help understand and solve problems here in Idaho.

Most recently, the USGS has been collecting water quality samples six times a year from the Boise River between Star and Middleton, and from near Parma. These samples are analyzed for a variety of constituents, including phosphorus and other nutrients. Partnering with the City of Boise, the USGS also uses an automatic sampler to collect samples every 49 hours from the Boise River near Parma; these samples are analyzed for total phosphorus (phosphorus in all forms). By comparing the phosphorus in these recent samples to previous data, the USGS has recently shown that phosphorus in the Boise River near Parma decreased by about one third (36 percent) over the past two years. From 1987 to 2012, the average annual phosphorus concentration (the mass of phosphorus per a volume of water) was 0.32 milligrams per liter (mg/L). The average total phosphorus concentration from 2015 through 2017 was 0.21 mg/L. So in the past two years, total phosphorus has declined by almost half of the amount needed to achieve the water quality target, which is 0.07 mg/L.  Although the high flows in spring 2017 helped dilute phosphorus in the river, the overall decline was apparent well before these record spring flows.

Monthly average measured phosphorus in the Boise River near Parma is lower than previous phosphorus levels. The difference is biggest during the winter. The difference is smallest during irrigation season (May through October) and storms.

This reduction is good news for the Boise River, and shows that work done throughout the basin to reduce phosphorus inputs is having an impact. Best management practices installed to reduce soil erosion and water runoff are likely making a difference in agricultural inputs. In the meantime, cities throughout the Treasure Valley have been upgrading their wastewater treatment facilities and removing more phosphorus than before. One way to understand the impact of these upgrades is to look at loads. Similar to concentration, a load is the mass of phosphorus but per a set unit of time. In this case, the load refers to the mass of phosphorus that moves through the Boise River near Parma in a day.

From 2012 to 2013, the average annual wastewater phosphorus load from Boise, Meridian, Nampa and Caldwell was about 1387 pounds per day (lb/day). During 2015 to 2017, this load decreased by about 50 percent to 644 pounds per day. During the same time, the total Boise River load near Parma decreased about 30 percent from its previous level, 2398 lb/day, to 1653 lb/day.

The municipal wastewater phosphorus load has decreased by about 50 percent over the past two years. This has helped decrease the total phosphorus load in the Boise River near Parma, but further reductions are needed, particularly during storms and the irrigation season.

However, the biggest improvement comes during the non-irrigation season, when the municipal load represents the greatest proportion of the total phosphorus load in the Boise River near Parma. This shows that although good progress has been made towards meeting the phosphorus target – and improving water quality – there is a lot more progress to be made by all of us.

Fortunately, many irrigators are working to install new water and erosion control structures, municipalities continue to upgrade their facilities, and innovative projects are intercepting and cleaning up phosphorus-laden waters throughout the valley. Continued water quality monitoring in the lower Boise River will track the progress made by these improvements, as fish, recreationists and the river reap the benefits.

Citizen Science! Boise Watershed Watch

by Kati Carberry, BREN Coordinating Team Chair

Hi Fellow Boise River Enthusiasts,

The Boise River Watershed Watch Day is coming up on Saturday September 30th from 10:00-12:00.  Watershed Watch is a great program led by the Boise Watershed where a Team Leader and a group of citizen scientists monitor an assigned surface water site along the Boise River. On the day of the event more than 20 sites from Lucky Peak to Caldwell will be monitored for DO, pH, turbidity, Temp, bacteria, TSS, TP, macroinvertebrates, and invasive species. Watershed Watch is the perfect way to get kids engaged in science.

Figure 1. Watershed Watch volunteers identifying macroinvertebrates

Clean water is essential to support healthy fisheries, wildlife habitat and ecosystem function in addition to drinking, irrigation and recreation. Water quality enhancement is a goal of BREN, and a number of strategies are described in the Boise River Enhancement Plan. Many water quality reports for the lower Boise River can be accessed through our website.

BREN is going to be monitoring two sites this year, one at the Star Bridge and one at the Linder Bridge. If you would like to volunteer as a citizen scientist at a BREN site (Linder Bridge or Star Bridge), please sign up. I really think all of you would enjoy this one day event, and it is a great opportunity for your friends and family to become involved with BREN.

This will be the 10th consecutive year of Watershed Watch and it is amazing to see the amount of historical data that has been collected on the Boise River from this one day annual event. Below is a link to more information and how to register.  Feel free to pass this on to anyone else you think would be interested.!/  Register Here

Registering is super easy and quick. Once you are at the site, click on the link to register in the middle of the page. From there you will be asked to fill out a simple registration form. Please make sure to select the Linder Bridge Site in Eagle site # 29, or the Star Rd. Bridge site # 25 (see below for website images).

See you on September 30!


What’s that Scum? Perhaps it’s a Harmful Algal Bloom…

By Graham Freeman, Idaho DEQ

Harmful Algae Blooms (HABs) seem to be making all of the news these days, from newspapers to national television, from Florida to Washington and most places in between.  So what exactly are Harmful Algal Blooms and why are they such a hot subject right now? Let’s dive in, or maybe we should observe from the shore…

Cyanobacteria, also known as blue-green algae, are single celled, prokaryotes that have been around for billions of years. Similar to green algae (eukaryotes), cyanobacteria uses photosynthesis to create sugars and releases oxygen as a byproduct of this chemical reaction.  Cyanobacteria are often credited for oxygenating the atmosphere billions of years ago.  When cyanobacteria rapidly reproduce in aquatic environments they create blooms with hundreds of millions of cyanobacteria cells.

We often refer to cyanobacteria blooms as Harmful Algae Blooms for several different reasons.  First and most obvious, cyanobacteria blooms are often smelly and unsightly.  Not many people want to swim or fish in waterbodies that look akin to slime you might see in an episode of the Simpsons.  Secondly, algae cells from any type of bloom, harmful or otherwise, eventually die off.  Once the cells die off, decomposition sets in and scavenger bacteria consume the dissolved oxygen from the water.  If the rate of cell death is rapid enough or large enough, dissolved oxygen concentrations can drop low enough to stress or kill fish and other aquatic organisms.  Finally, certain taxa of cyanobacteria are known producers of toxins, which are potentially toxic to humans, pets, livestock, and other wildlife.

Cyanotoxins are toxins produced by cyanobacteria and are considered some of the most poisonous naturally occurring substances.  Cyanotoxins generally fall into a couple of different chemical classes that are known to damage to the liver, interfere with the nervous system, cause cancer, irritate the skin,  and new research is showing that some cyanotoxins may play a role in neuro-degenerative conditions such as ALS and Alzheimer’s. More info on cyanotoxins can be found here  on Environmental Protection Agency’s website.  While there are thousands of different cyanobacteria species, remember that most cyanobacteria do not produce cyanotoxins. Additionally, some species of known toxin producing cyanobacteria may not produce cyanotoxins one day and begin to produce toxins the next day. Most people will assume that cyanotoxins are produced to stop planktovors (animals that eat plankton) from eating the cyanobacteria. However, it appears that this isn’t necessarily the case. Research indicates that cyanotoxins may be used by cyanobacteria in their normal metabolic processes, for nutrient uptake, for example.

If you follow the news closely, you’ve probably heard about HABs or at least some of the problems associated with cyanobacteria blooms.  In 2014, a HAB contaminated a drinking water source leaving hundreds of thousands of people without water in Ohio.  Just this year, 32 cattle were killed by a Harmful Algae Bloom in Oregon.   In 2016, 11 confirmed HABs were reported on Idaho’s lake and rivers.  During the first half of the summer of 2017, there have already been seven confirmed HABs.

Anecdotally, it appears that HABs are increasing in frequency and intensity across the nation.  This could be a product of the public being more informed and therefore reporting more blooms or it could be a product of poor water quality.  In the United States there are over 100,000 miles of rivers and streams, 2.5 million acres of lakes, reservoirs, and ponds, and more than 800 square miles of bays and estuaries that have poor water quality due to excess nutrients (nitrogen and phosphorus).  Cyanobacteria are commonly associated with nutrient, specifically phosphorus, enriched waters.   Additionally, at warmer water temperatures cyanobacteria reproduce more quickly and can out-compete nontoxic green algae.  If the average global temperature continues to rise, we may see many more HABs on nutrient enriched waterbodies.

Now that you all know a little about cyanobacteria, cyanotoxins, and HABs – let’s talk about identifying and avoiding the blooms. Cyanobacteria blooms can take on many different colors and structure depending on the composition of the bloom. Often times cyanobacteria blooms cause surface scum that looks like spilled paint, with blue, green, and white colors.  Some blooms will cause the water to look like pea soup. Because of wind and wave action, HABs are known to accumulate around shores of lakes and reservoirs, which can be particularly dangerous to animals looking for a drink.  It is difficult to visually confirm a HAB and it is impossible to tell if a bloom is toxic through visual observation. Because HABs are difficult to identify, we encourage people to avoid contact with all suspicious looking water and report suspected blooms to the local Public Health District, waterbody manager, or the Department of Environmental Quality.   If you are in doubt of the condition or safety of the water, stay out of the water. When in doubt, stay out!

The majority of the cyanobacteria exist in aquatic ecosystems without causing any problems.  When conditions get just right, cyanobacteria begins to multiply and can create HABs, which are potentially toxic to humans, livestock, and other wildlife.  Right now, there are not many short term solutions to reducing or eliminating HABs.  Efforts to reduce HABs should focus on improving water quality, specifically reducing the inputs of nutrients to waterbodies.  Reducing fertilizer inputs on agricultural fields, reducing erosion, and improving wastewater treatment processes are ways to limit phosphorus load to waterbodies.  Additionally, we can all do our part by limiting fertilizer applications on residential lawns and cleaning up pet waste.

For more information on HABs and current water quality advisories in Idaho, please visit this website.