Public Health

Biotoxin and bacterial closures are a key consideration when selecting a site because they can prevent you from selling your shellfish during certain times of the year or after heavy rains. Understanding these Bureau of Public Health restrictions will help you avoid being closed for long periods of times or during times of peak demand. You either want to avoid closure-prone areas or create a plan for how to prepare yourself for them.

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DMR Bureau of Public Health

The Department of Marine Resources Bureau of Public Health regulations dictate where you can grow shellfish; and when and how you can harvest your product. The area you are considering might be closed for part of the year (e.g., in the warmer summer months) or infrequently (e.g., after heavy rain), which means you cannot harvest and sell product during that time. Timing of any closures is important to understand because you want to avoid being closed during times of peak demand, such as Fourth of July weekend. The bottom line is this: contact DMR Bureau of Public Health well before you apply for your site.

Bacterial closures are generally predictable and apply to small areas. Bacterial closures are divided into three types; those driven by long-term sampling datasets which cause waterbodies to be classified as Prohibited or Restricted; those areas that are usually open to harvesting but close on a known condition such as seasonally, based on high river flow, based on the performance of a treatment plant, or one inch of rainfall; and emergency closures such as a two-inch of rainfall “flood” event or an oil spill.

Biotoxin closures cover wide swaths along the coast and are difficult to predict. DMR Bureau of Public Health can help you understand when biotoxin closures have occurred in an area historically.

Bacterial Closures: Prohibited and Restricted classifications are usually in place for years and only allow limited kinds of activities to occur. Closures based on a condition such as rainfall or high river flow are most prevalent in spring and fall and can be highly site-specific. Similarly, two-inch “flood” emergency closures are most common in the spring and fall. DMR Bureau of Public Health defines these classifications here:

Biotoxin Closures: The phytoplankton bloom season is unpredictable and changes from year to year generally occurring between May and December.

You should contact the DMR Bureau of Public Health to get a sense of the timing and frequency of biotoxin and bacterial closures. DMR has a biotoxin guidance document for aquaculturists available to provide detailed information: You should also check their maps before harvesting any shellfish. This can help you anticipate and plan ahead for times when you can’t harvest and sell your crops. DMR also has an email and text service called govdelivery which sends out announcements when closures occur.

You can contact the Department of Marine Resources Bureau of Public Heath using this email: [email protected]

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