Harmful Algal Blooms

Algae are natural components of marine and freshwater ecosystems and form the foundation of most aquatic food chains. However, when blue-green algae, also known as Cyanobacteria, is present during an algae bloom event, it has the potential to be harmful to humans and wildlife (hence Harmful Algal bloom, HABs). Blue-green algae is often confused with green algae because both may produce dense mats, reduce oxygen levels, affect odor, and/or impede recreation; however green algae generally do not produce toxins. Blue green algae or cyanobacteria on the other hand, has the potential to produce harmful toxins (cyanotoxins). An overview of cyanotoxins and it's different species can be found on the Environmental Protection Agency's website.

HAB events occur naturally due to environmental factors such as nutrient levels, water flow and chemistry, algal species composition, temperature, and sunlight but may be exacerbated due to human activities such as increased nutrient pollution, invasive species, and reduced water flows. Climate change may also be contributing to the increase in HAB events. This is especially important in California and the Delta due to the effects of climate change which includes prolonged droughts and warmer average temperatures.

Monitoring harmful algal blooms in the Delta will assist in the evaluation of risk to human and aquatic health, as well as provide better understanding of connections and factors promoting or maintaining harmful algal blooms.

On September 2019, AB834 -- Freshwater and Estuarine Harmful Algal Bloom Program was passed.

In summary, the bill requires the State Water Resources Control Board (state board) to:

1. Establish a Freshwater and Estuarine Harmful Algal Bloom Program to protect water quality and public health from harmful algal blooms.
2. Coordinate immediate and long-term algal bloom event incident response,
3. Conduct and support algal bloom field assessment and ambient monitoring at State, watershed, and site specific waterbody scales,
4. Post information on or before July 1, 2021 on their website regarding algal bloom incidents and responses, among other things, in the state during the previous 3 years.
5. Authorize the state board, if it determines an algal bloom event is an emergency, as defined, to enter into contracts to aid in incident response without meeting the conditions prescribed for personal services contracts under the State Civil Service Act, including the requirement for a competitive bidding process, or any other competitive bidding requirements under existing law.

Full text of AB834 can be found at legislature.ca.gov.

Each chapter of the Delta plan includes strategies to achieve the goals of the plan. These strategies are general guidance on achieving the objective laid out in the plan and in the Delta Reform Act of 2009. Associated with these strategies are recommendations. The recommendations describe more specific and implementable actions to support the achievement of Delta Plan strategies. Strategies and recommendations may also have associated performance measures. Delta Plan performance measures track progress in achieving desired outcomes for the Delta Plan. Below are the strategies and recommendations associated with this performance measure.

Delta Plan Strategy

• Improve environmental water quality
• Require Delta-Specific water quality protection

Delta Plan Recommendations

• Protect beneficial uses
• Identify Covered Action impact
• Special water quality protections for the Delta
• Completion of regulatory processes, research, and monitoring for water quality improvements
• Implement Delta Regional Monitoring Program
• Evaluate wastewater recycling, reuse, or treatment
• Manage dissolved oxygen in Stockton Deep Water Ship Channel
• Manage dissolved oxygen in Suisun Marsh

Metric

Spatial coverage (acres) of Microcystis sp. cell concentration equivalents (cells/ml) **, in Delta waterbodies large enough to use the State Water Resources Control Board mapping tool (e.g., Discovery Bay; South Delta along Grantline Canal and Old River surrounding Fabian Tract; Big Break Regional Shoreline; and San Joaquin River between Antioch and Stockton) with densities of 100,000 cell/ml or greater, evaluated annually.

Baseline

Spatial coverage (acres) based on satellite images during the period of 2016–2017

Target

Target to be achieved by 2034:

• Zero acres of waterbodies with densities of 100,000 cells/ml

**The current performance metric tracking Microcystis was based on the measurements of the HABs Analysis Tool during development. During the later stages of development of the HABs Tool, it was concluded that tracking cyanobacteria would be more accurate instead of specifically tracking Microcystis as high densities of cyanobacteria does not mean a Microcystis specific bloom is present. Thus, the metric used in the visualizations above and the tracking of this performance will be the 100,000 cells/ml of cyanobacteria, which is equivalent to 15.8 Modified CyanoIndex of the HABs Analysis Tool.

The Delta Plan

Factors Affecting Growth of Cyanobacteria: With Special Emphasis on the Sacramento-San Joaquin Delta.

Delta Nutrient Research Plan, Draft Report

Initial impacts of Microcystis aeruginosa blooms on the aquatic food web in the San Francisco Estuary.

Cyanobacteria Harmful Algal Bloom Monitoring Strategy for the Sacramento-San Joaquin Delta

Overview of Cyanotoxins and Cyanobacteria.