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Recreational Water Communication Toolbox for Cyanobacterial Blooms

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Purpose of the Toolbox

Recreational water managers should explore multiple ways to inform people using recreational waters, as well as pet and livestock owners, of the health risks associated with cyanobacteria and their toxins. Communication to the public may occur through signage at the recreational water body, radio and TV announcements, and social media.  Messages should clearly define the different levels of risk and contamination, for example, the exposure potential for specific recreational activities.

This toolbox provides resources for communicating risk to the public about cyanotoxins in lakes, rivers or other recreational water bodies. Recreational water managers should also be aware that toxins may be transported and affect downstream waters.

The communication toolbox is a ready-to-use, “one-stop-shop” to support states, tribes, territories, and local governments in developing, as they deem appropriate, their own risk communication materials. It includes editable press release templates, social media posts and other quick references. For additional information on writing for social media, see the Centers for Disease Control and Prevention’s Social Media Tools, Guidelines & Best Practices.

Managers typically use a combination of notification methods to address the diversity of stakeholders in their community and the nonresidents who might travel to a particular recreational water body. For example, signs posted at the beach, which are necessarily limited in size and scope, can reference a website, Twitter handle, or other source with more detailed or up-to-date information. States, local public health departments, or managers may also choose to take different actions based on jurisdiction of the water body and the severity of the problem. That is, posting an advisory or warning might be appropriate when the cyanobacterial cell density levels or cyanotoxin levels are slightly above a pre-determined action level (e.g., “Algal Bloom Advisory: Levels of toxins may cause illness in recreating children”); whereas closing public access to a water body might be appropriate when increased cyanotoxin levels present a greater risk.

A notification should be simple, clear, and authoritative. The core elements of a notification include the following:

  • Key Notification Message: Closure or Warning Issued; Closure or Warning Lifted.
  • List of unsafe activities (e.g., swimming, wading, fishing).
  • List of approved activities (e.g., boating, canoeing, kayaking)
  • Reason, duration and cause for the notification (e.g., high levels of cyanotoxins or cyanobacteria, HAB event, HAB event suspected and sampling underway).
  • Location affected by the notification (i.e., because cyanobacterial blooms are often transient and variable in their spatial distribution, it is important to convey the message that recreational activities may be restricted to a specific area of the water body such as a swimming beach or dock).
  • Potential consequences of swimming in/contact with contaminated water (e.g., gastrointestinal irritation).
  • Actions taken by beach managers to monitor the bloom.
  • How to get information on health risks and/or report related illness in humans, pets or livestock (e.g., hotline).
  • Agency contact information.

As a precaution, the World Health Organization recommends that the following guidance should be included in public information relating to cyanobacterial blooms:

  • Avoid areas with visible cyanobacterial or algal concentrations and/or scums in the water as well as on the shore. Direct contact and swallowing appreciable amounts are associated with the greatest health risk.

  • Where no scums are visible, but the water shows strong greenish discoloration and turbidity, test if you can still see your feet when standing knee-deep in the water (after wading in without stirring up sediment). If not, avoid bathing— or at least avoid ingestion of water, i.e., submersion of your head. In such situations, avoid waterskiing because of potentially substantial exposure to aerosol toxins.

  • If sailing, sailboarding or undertaking any other activity likely to involve accidental water immersion in the presence of cyanobacterial or algal blooms, wear clothing that is close fitting in the openings. The use of wet suits for water sports may result in a greater risk of rashes, because cyanobacterial or algal material in the water trapped inside the wet suit will be in contact with the skin for long periods of time.

  • After coming ashore, shower or wash yourself to remove cyanobacterial or algal material.

  • Wash and dry all clothing and equipment after contact with cyanobacterial or algal blooms and scum.

  • For more information see World Health Organization, Guidelines for safe recreational water environments (PDF)(253 pp, 1 MB) Exit. (Specifically, see Chapter 8: Algae and Cyanobacteria in Fresh Water.)

State/Tribal Examples

The following links exit the site Exit

Many states have developed signage and other documents to notify members of the public about cyanobacterial blooms and potential health effects. We have included a few examples here:

  • Sign Icons created by the California Department of Public Health. The Environmental Health Investigations Branch of the California Department of Public Health created sign icons to represent various allowable and prohibited activities (e.g., to wash fish before eating or for pets and humans to avoid contact with cyanobacteria). The icons have been used to create signs with simple, clear messages. [See California's Examples of Icon Use ]

  • [See Harmful Algal Bloom (HAB) sign from Indiana ]. Several state government departments in Indiana collaborated on a sign which contains information on how to identify a HAB, and the effects a HAB may have on people, pets and fish, and a 4-level alert system based on water quality testing results (low risk, advisory, caution, and beach closed).

  • Algae Information webpage form the Massachusetts Department of Health and Human Services.  This webpage provides links to several resources including guidelines and fact sheets, photos to identify cyanobacterial blooms, brochures in 9 languages, a pet safety poster (English and Spanish), and links to CDC and EPA pages.

  • Upper Mississippi River Harmful Algal Bloom Response Resource Manual. The Upper Mississippi River (UMR) HAB Work Group developed the manual for states in the UMR basin. The document contains example press releases from several states along the UMR (pages 23-40).

  • [See Universal, standardized signage from Nebraska ]. Nebraska will deploy this signage at its 52 public lakes and recreational waters in the 2017 swim season at the request of recreational water managers across the state. The signs will use simple symbols (circle with slashes over certain activities, not others) to identify which activities are permitted (e.g., fishing, swimming, waterskiing, etc.).

  • [See Health Alert from Wisconsin ]. This example warns people not to swim if they cannot see their feet in knee-deep water, to keep their pets away from waters that may be affected by HABs, and to consult their local health department, the state Department of Natural Resources, or the Department of Health Services for more information.

  • Yurok Tribe's Guidelines for Public Health Advisories. These guidelines include information about when to post and when to remove public health advisory signs based on microcystin cell density levels.

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