logo  Harmful Algal Blooms (HABs) - Division of Water Monitoring and Standards


Expert Team Resources


The New Jersey Department of Environmental Protection (NJDEP) contracted with an independent team of Harmful Algal Bloom (HAB) subject matter experts (HAB Expert Team) to develop, among other things, the following list of publications as a resource for lake managers, environmental consultants, lake organizations, municipal officials, non-profit organizations and other similar groups working to identify, monitor and manage HABs in New Jersey. The publications have been carefully selected to provide useful technical information to help non-experts understand their options for identifying conditions that can lead to a HAB, preventing/reducing the risk of HAB development, and managing a resource (i.e. a waterbody) that has developed a HAB.

Below are recommended steps that non-experts should take to understand the issues, and how to approach HABs in their waterbody. The publications in this document will aid in providing information for these steps.


  1. Gather Existing Data and Information on the Waterbody
    • Contact federal, state, local, academic and private organizations for existing data such as water chemistry, HAB cell count (ideally at the species level), bathymetry, and stormwater and agriculture runoff inputs.

  2. Identify Data Gaps and Collect New Data as Needed

  3. Identify the Problem
    • Determine if you are dealing with a HAB and define, as best you can, the composition of the HAB and what other issues exist in the waterbody you are managing.

  4. Engage All Stakeholders

  5. Develop a Long Term Plan That Improves Water Quality and Habitat in the Waterbody
    • Be sure to take the use of the waterbody into consideration (swimming, fishing, boating, drinking water supply), morphology of the lake, cost, and positive/negative side effects when selecting management measures and treatment methods.
    • The composition and development of the bloom needs to be considered in the context of the specific waterbody, especially when it comes to selecting mitigation and management strategies. In many cases, species do not necessarily correlate to toxin production.
    • Be sure to incorporate costs to monitor the chemical and physical properties of the waterbody to evaluate the effectiveness of management measures and treatments. Allow flexibility to adjust the plan as needed based on the outcome of evaluation.

  6. Implement the Plan

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Before implementing a HAB strategy or technology for a waterbody, it is crucial to understand that not all waterbodies have the same water quality dynamics, and not all HABs have the same characteristics. There can even be variability from one area of a lake/reservoir to another, and part of this is dictated by conditions within specific drainage areas. Therefore, not all HAB prevention, mitigation and management strategies and technologies implemented in one waterbody will produce the same results in another waterbody or across different locations in a large waterbody. It is imperative that the hydrologic and morphological characteristics, water chemistry, and biological condition of each waterbody be taken into consideration, along with the HAB composition and development, prior to selecting a prevention, mitigation and/or management strategy or technology.

Algal blooms can cause harmful effects mainly due to 1) excessive biomass accumulation, temporarily or persistently, and/or 2) toxin production. Cell size can vary greatly among the various cyanobacteria species. Therefore, it is important to have cell count data at the species level to help determine if an excessive biomass accumulation exists.

Even among cyanobacteria, differences in cell / natural unit sizes can uncouple biomass from cell counts. e.g. microcystis is small compared to something like Dolichospermum, so fewer cells of the latter could equate to a bloom or 'excessive biomass' compared to something small like Microcystis.

HABs can be caused by a variety of species, not all of which have the potential to generate toxins, but which can still be harmful to the ecosystem and local economy. The composition and development of the bloom needs to be considered in the context of the specific waterbody, especially when it comes to selecting mitigation and management strategies. In many cases, species do not necessarily correlate to toxin production. It is important to know whether you are dealing with a HAB and to define, as best you can, the composition of the HAB and what issues exist in the waterbody you are managing.

To better understand the terms used in this document please keep in mind the following definitions:

Algae: Algae is a common term used to describe a highly variable group of photosynthetic organisms, often aquatic, that lack true stems, leaves, roots, and flowers. This term is applied to several taxonomic groups, including cyanobacteria.

Cyanobacteria: Cyanobacteria are a type of bacteria capable of photosynthesis. Although they are not true algae, they are often referred to as “blue‐green algae.” Cyanobacteria are typically sampled and analyzed as part of algal assemblages rather than bacterial assemblages in aquatic ecosystems.

Algal Bloom: Excessive growth of algae or cyanobacteria that can result in a visible thick coating or mat on the surface of a waterbody. The distribution and concentration of blooms may be affected by weather conditions and lake morphology features such as depth, shape and orientation of the lake in relation to predominant wind direction. Even when present in a bloom, cyanobacteria do not always produce cyanotoxins.

Algal Toxins: Any number of natural toxins produced by algae and cyanobacteria. Toxins released by algae and cyanobacteria can be harmful to aquatic and terrestrial wildlife, domestic animals and humans. When toxins in a bloom reach a level at which they can be harmful, the bloom is determined to be a HAB.

Harmful Algal Bloom (HAB): A HAB is an algal bloom that can be dangerous to people and animals. Some, but not all, HABs produce chemicals that can be toxic to humans and animals if ingested, inhaled, or if contacted by skin or mucous membranes. These toxins can also accumulate in fish and shellfish, which can cause illness when either are consumed. HABs can occur in both freshwater and marine water environments.

Cyanobacterial HAB (CyanoHAB): A cyanobacterial HAB, also referred to as a Harmful Cyanobacteria Bloom or HCB, is the name given to the excessive growth, or “bloom,” of cyanobacteria, some of which can produce one or more types of potentially harmful toxins (cyanotoxins). CyanoHABs can occur under suitable environmental conditions of light, temperature, nutrients and calm water. These blooms can result in a thick coating or “mat” on the surface of a waterbody, often in late‐summer or early fall.

Adaptive Management: Adaptive management creates a loop where management strategies are continually monitored and evaluated to determine effectiveness. Results of these evaluations inform adjustments or changes to the strategy. Effective management strategies are ecosystem specific and require a thorough understanding of the biological, chemical, and physical features of the lake or waterbody, the potential causes of a bloom, and the species composition of a bloom. Selecting and implementing the best combination of management strategies is crucial to meet the goal of reducing HABS.


Algal Blooms and Lake Ecosystem Function

Each lake and reservoir is a unique ecosystem that is composed of the entire area, or watershed, that drains into it. It is necessary to have a basic understanding of how lake ecosystems function in order to develop appropriate water quality monitoring programs, make informed management decisions, and select effective best management practices that address the conditions that lead to HABs. Actions taken to address nonpoint source pollutants and HABs at a specific location on a waterbody must take into consideration the intended and unintended consequences throughout the entire ecosystem. Taking an ecosystem approach when managing a waterbody will provide long term solutions that will not only reduce the occurrence of HABs, but improve overall water quality and habitat in the waterbody. The documents listed below have been selected to guide the development of an ecosystem system approach that will provide long and short term benefits that will ultimately lead to reduced HABs events.

wwwalker.net/pdf/lake_reserv_guidance_manual.pdf

Olem, H. and G. Flock, eds. 1990. Lake and Reservoir Restoration Guidance Manual. 2nd edition. EPA 440/4-90-006. Prepared by North American Lake Management Society. USEPA. Washington, DC.

  • This manual provides information on protecting and restoring lakes and reservoirs. The primary focus is on water quality and the effects that excessive inputs such as silt, nutrients and growth of plants can have on it. The goal of the manual is to provide community leaders with the information necessary to help define problems, understand underlying causes, evaluate techniques to address the problem, and develop/implement a lake management plan as well as evaluate its effectiveness.


crsreports.congress.gov/product/pdf/IF/IF10690

Gatz, L. 2020. Freshwater Harmful Algal Blooms: An Overview. Congressional Research Service Version 7.

  • This document was prepared as an update to Congress on HABs. It provides a good overview of what HABs are and possible causes of HABs. It also provides a national perspective on the efforts to address the problem and the research that is needed.


pubs.usgs.gov/twri/twri9a7/twri9a7_7.5.pdf

Graham, J., Keith Loftin, Andrew Ziegler, and Michael Meyer. 2008. Cyanobacteria in lakes and reservoirs: Toxin and Taste-and-Odor Guidelines. Cyanobacteria Version 1 (9/2008); USGS TWRI Book 9.

  • This manual provides a description of lake and reservoir structure, function and restoration. It gets back to the "grassroots" and what was learned during the early years of the Clean Water Act and Clean Lakes Program


tandfonline.com/doi/pdf/10.1080/07438149409354462

Kortmann, R.W. and P.H. Rich. 1994. Lake Ecosystem Energetics: The missing management link. Lake and Reservoir Management Journal, 8(2):77-97.

  • Kortmann and Rich describe ecosystem structure and function, flow of energy and matter through the ecosystem, and how energetics relate to managerial practices for lakes. Although technical, it is intended to also reach a non-expert audience.


Molot LA, Schiff SL, Venkiteswaran JJ, Baulch HM, Higgins SN, Zastepa A, Verschoor MJ, and Walters D. 2021. Low sediment redox promotes cyanobacteria blooms across a trophic range: implications for management. Lake and reservoir management.

  • Molot et al. examine the oxidation-reduction processes at the sediment-water interface of lakes with different depth structures and trophic states, and how those redox relationships are involved with the initiation of CyanoHABs.


Lake Management

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Lake management is a complex process that requires an interdisciplinary approach and a long-term commitment of financial resources and implementation of management measures. The resources in this section are intended to provide a general overview to help determine which management techniques may be effective in addressing a HAB. Consulting with a lake management expert may be an appropriate next step for proper design and implementation.

Best management approaches will vary on a lake-by-lake basis and, given that HABs are influenced by a rapidly changing climate, reconsideration of management techniques (adaptive management) will be required in the future. Adaptive management is particularly critical in New Jersey, where continued urbanization is likely to drive changes in water quality, especially nutrient availability.


Bishop WM and Richardson RJ. 2018. Influence of Phoslock (R) on legacy phosphorus, nutrient ratios, and algal assemblage composition in hypereutrophic water resources. Environmental Science and Pollution Research, 25:5, 4544-4557.

  • Bishop and Richardson show that binding of phosphorus via the addition of Phoslock can effectively manage cyanobacterial blooms in small ponds via a strong shift in the N:P ratio.


aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.2011.56.6.2051

Carey, C.C. and E. Rydin. 2011. Lake trophic status can be determined by the depth distribution of sediment phosphorus. Limnology Oceanography 56(6) 2051-2063.

  • Carey and Rydin discuss the importance of phosphorus as a key limiting nutrient in freshwater lake systems and how phosphorus that enters the water column of a lake may be deposited onto lake sediments. A fraction of this phosphorus in the sediment can be recycled back into the water. The process and factors that can facilitate this process are explored.


nalms.org/wp-content/uploads/LakeLine/35-1/Articles/35-1-4.pdf

Moore, Barry, M. Mobley, J. Little, B. Kortmann, and P. Gantzer. 2015. Aeration and Oxygenation Methods for Stratified Lakes and Reservoirs. Lakeline Spring 2015.

    Moore et al. provide a comparison of Diffused Air Circulation, Hypolimnetic Aeration, Layer Aeration and several other oxygenation methods that are available. Mechanical circulation approaches (e.g. upward and downward pumping strategies) were not included, just compressed air and pure oxygen.


mass.gov/files/documents/2016/08/uk/practical-guide-no-pics.pdf

Wagner, K. 2004. The Practical Guide to Lake Management in Massachusetts. Executive Office of Environmental Affairs, Commonwealth of Massachusetts.

  • This guide provides strategies that can be considered for the control of eutrophication and aquatic plants. A general overview of key aspects of the strategies can help make an initial assessment of whether a strategy is appropriate for your waterbody.


dec.ny.gov/docs/water_pdf/dietlakeintro.pdf

NYSFOLA. 2009. Diet for a Small Lake: The Expanded Guide to New York State Lake and Watershed Management. New York State Federation of Lake Associations, Inc.

  • This guide provides an overview of lake management and information to help the non-professional make informed decisions. It is designed to motivate private citizens who may not have knowledge or experience in the field of lake and watershed management. Examples from within New York State are provided to illustrate the topics. Appendices F, G and H contain internet resources, references cited, and additional readings for those who seek more information. Please note, references to state laws and government structure are specific to New York State.


HAB Prevention and Mitigation Strategies and Best Management Practices


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These papers provide information on various strategies and best management practices for addressing HABs. At a minimum, the following should be considered when selecting a strategy: effectiveness in different locations and over time (long/short term), possible intended or unintended consequences, cost (including operation and maintenance costs) and regulatory/permitting restrictions. These resources are intended to provide general information that will lead to informed decisions on management strategies to provide cost-effective long-term reductions in HABs.

***It is important to be aware that NJDEP permits may be needed to implement certain measures. This not only applies to the use of algaecides but also to certain preventative measures that could result in a disturbance of the riparian area adjacent to a lake or tributary or the disturbance of the lake bottom. For example, a lake drawdown for dam repair or aquatic vegetation control requires a permit from NJDEP Division of Fish and Wildlife. The application of a herbicide or biological treatment may need an Aquatic Pesticide Permit from NJDEP Pesticide Enforcement and/or a NJPDES Permit from NJDEP Division of Water Quality.


oceandecade.org/assets/uploads/documents/Cyano_mitigation_GlobalHAB2019_1576062296.pdf

Burford, M.A., Gobler, C.J., Hamilton, D.P., Visser, P.M., Lurling, M., and Codd, G.A. 2019. Solutions for managing cyanobacterial blooms: A scientific summary for policy makers. IOC/UNESCO, Paris (IOC/INF-1382)

  • Burford et al. provide a high-level summary of challenges to, and approaches for, managing cyanobacterial blooms. Physical, chemical, and biological approaches are covered, and the summary is fairly comprehensive. The paper includes a table showing management options and actions, target, cost, scientific evidence, and difficulties associated with each approach.


resources.ext.vt.edu/

Dindinger J., Kyler, K., Rockler, A., Sample, D., Fox, L., and Hughes, S. 2020. Basic Principles of Watershed Restoration and Stormwater Management in the Chesapeake Bay Region.

  • The Chesapeake Region has been at the forefront of nonpoint sources management for decades, and this document provides an overview of the most relevant urban stormwater management and watershed restoration issues and common mitigating practices.




Water Research Foundation. 2020. International stormwater BMP database 2020 Summary Statistics: waterrf.org/system/files/resource/2020-11/DRPT-4968_0.pdf.

Database link: bmpdatabase.org/

  • Chapter 4 describes transformation and removal mechanisms as well as summaries of performance data for several stormwater treatment best management practices, including detention basins, bioswales, bioretention, biofilters, porous pavement, etc.

Monitoring and Forecasting

HABs are complex and have the potential to negatively impact the coastal economy of lakes and other waterbodies used for recreation and drinking water. Establishing an appropriate monitoring program for a waterbody is crucial to determine how nutrient levels and algal populations vary seasonally. There are many tools and technologies currently available for monitoring HABs, and factors such as cost, maintenance of equipment, and monitoring location and timing must be considered to ensure the data collected will meet your requirements. Carefully collected data will be useful to help identify an algal bloom versus a HAB, forecast when conditions are likely for a HAB event to occur, and identify areas where implementing best management practices will be effective at reducing nutrients and occurrence of blooms.


hcb-1.itrcweb.org/

Interstate Technology Regulatory Council. 2021. Strategies for Preventing and Managing Harmful Cyanobacterial Blooms.

  • This document focuses on strategies that can be used in freshwater aquatic environments. Guidance is provided to help select monitoring, excess nutrient reduction, management and communication approaches that may be appropriate for use in your waterbody.


epa.gov/ground-water-and-drinking-water/cyanotoxin-management-tools-public-water-systems

  • This page provides resources to help public water systems plan for and manage cyanotoxins in their drinking water. It includes CMP templates and example plans, protecting drinking water sources, preventing HABs in source water and addressing nutrient pollution.


epa.gov/cyanohabs/cyanotoxins-preparedness-and-response-toolkit-cprt

The Cyanotoxins Preparedness and Response Toolkit (CPRT) is an online tool to help states and tribes prepare for potential HABs in freshwater bodies and know how to respond to protect public health


Brient, L., Lengronne, M., Bertrand, E., Rolland, D., Sipel, A., Steinmann, D., Baudin, I., Legeas, M., Le Rouzic, B., and Bormans, M. 2008. A phycocyanin probe as a tool for monitoring cyanobacteria in freshwater bodies. Journal of Environmental Monitoring 2008, 10, 248-255

  • This study assesses the performance of a submersible probe for measuring phycocyanin-specific fluorescence as a function of cyanobacterial biomass, with the goal of using it as a tool for management. Advantages and limits of the probe are discussed when compared to traditional analyses.


onlinelibrary.wiley.com/doi/epdf/10.1111/fwb.12334

Molot, L.A., S.B. Watson, I.F. Creed, C.G. Trick, S.K. McCabe, M.J. Verschoor, R.J. Sorichetti, C. Powe, J.J. Venkiteswaran, and S.L. Schiff. 2014. A novel model for cyanobacteria bloom formation: the critical role of anoxia and ferrous iron. Freshwater Biology. 2014. 59, 1323–1340.

  • Molos et al. present a novel conceptual model that examines the critical role anoxia and ferrous iron have on the formation of noxious filamentous and colonial cyanobacteria blooms.


Impacts of Climate Change

Climate change is expected to result in increases in temperature, increases in nutrients, altered hydrology due to changes in the frequency and intensity of rainfall, changes in duration of ice cover, and other variables that will increase the difficulty of managing HABs. These papers discuss how climate change can increase the frequency and duration of HABs. It is important to consider possible climate change impacts when developing effective long-term management strategies.


Carey, C.C., B.W. Ibelings, E.P. Hoffmann, D.P. Hamilton, J.D. Brookes. 2012. Eco-physiological adaptations that favour freshwater cyanobacteria in a changing climate. Water Research 46 1394-1407. Elsevier.

  • Carey et al. examine how changing environmental factors will have substantial effects on freshwater phytoplankton species composition and biomass and how these changes could favor cyanobacteria over other phytoplankton.


Predicting the effects of climate change on freshwater cyanobacteria blooms requires consideration of the complete cyanobacteria life cycle

Cottingham, KL, Weathers, KC, Ewing, HA, Greer, ML, and Carey, CC. 2021. Predicting the effects of climate change on freshwater cyanobacteria blooms requires consideration of the complete cyanobacteria life cycle. J. Plankton Research (2021) 43(1): 10-19.

  • Cottingham et al. describe the life cycle of akinete-producing cyanobacteria, the influence of climate change, including storm mixing events, and the importance of considering life cycle stages for predicting and managing blooms.


Kortmann, R.W. 2021. Managing Reservoir Stratification in a Variable Climate. NEWWA Journal- In Press, March 2021

  • Kortmann reviews climatic weather patterns of 2018-2019 as they affected thermal stratification structure and stimulated unusually early and intense cyanobacteria blooms in several lakes and reservoirs of the Northeast.

paerllab.web.unc.edu/wp-content/uploads/sites/17493/2020/06/Paerl-and-Barnard-2020-Harmful-Algae.pdf

Pearl HW and Barnard MA. 2020. Mitigating the global expansion of harmful cyanobacterial blooms: Moving targets in a human- and climatically-altered world. Harmful Algae, 96, 101845.
  • In a recent review, Pearl and Barnard summarize various management methods for CyanoHABS.


aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.10557

Winslow, L. A., Read, J. S., Hanson, G.J.A., Rose, K.C., and Robertson, D.M. 2017. Seasonality of change: Summer warming rates do not fully represent effects of climate change on lake temperatures. Limnology and Oceanography, 62, 2168-2178.

  • Winslow et al. investigate a variety of effects of climate change on lake ecosystem seasonal phytoplankton succession, dominance by cyanobacteria, and other productivity and respiratory processes



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