Lab Matters Fall 2017 | Page 6

environmental health

by Curtis Andrews , microbiogist laboratory manager , Alabama Department of Public Health-Mobile ; Leanne Flewelling , PhD , research administrator II , Florida Fish and Wildlife Conservation Commission ; Katherine Hubbard , PhD , research scientist , Florida Fish and Wildlife Conservation Commission ; Blaine Rhodes , director , Office of Environmental Laboratory Sciences , Washington State Public Health Laboratories ; Drew Sheehan , microbiologist , Alabama Department of Public Health-Mobile ; and Sarah Wright , senior specialist , Environmental Laboratories

THE FOUR MOST COMMONLY TESTED TYPES OF MARINE TOXINS :

Algae Toxin Produced Potential Illness Location

Alexandrium *, Gymnodinium *, Pyrodinium bahemese saxitoxins

According to the US Centers for Disease Control and Prevention ( CDC ), all coastal states report some level of harmful algal blooms ( HABs ) in their marine waters every year . About 16 different marine alga can produce a wide variety of toxins .

These toxins can bioaccumulate in filterfeeding bivalve molluscan shellfish such as mussels , oysters , clams , scallops and geoducks , harm and kill marine animals , and potentially cause severe human illnesses or death . Human exposure to HAB toxins occurs primarily by eating contaminated shellfish , though some may be inhaled via wave aerosolization . Since the toxins are chemicals and not proteins , they do not break down when shellfish is cooked , pasteurized , frozen or canned . The US Food and Drug Administration ’ s ( FDA ’ s ) National Shellfish Sanitation Program establishes guidelines to ensure that shellfish are sanitary and safe for human consumption . CDC ’ s Division of Laboratory Sciences Emergency Response Branch develops analytical methods to help identify people exposed to PSPs and other algal toxins . CDC has supported exposure investigations within the US through analysis of clinical samples and works with state and local laboratories to expand their capacity to respond .

The economic impact of HABs can be felt through commercial and recreational shellfish harvesting paralytic shellfish poisoning ( PSP )

activities ( valued at $ 1 billion or more in some states ) and tourism . Many coastal states have well-established shellfish monitoring programs to protect public health and safety , ensuring these industries continue to flourish .

Alabama

Gulf of Mexico , Atlantic coast up to DE

Florida west coast , Atlantic northeast coast , Pacific coast

OR , TX , WA , Long Island Sound , Cape Cod ( MA )

Pacific coast , Atlantic northeast coast , FL

* not all species within this genus produce the toxins Source : Woods Hole Oceanographic Institute

In 1991 , the Alabama Department of Public Health began monitoring HAB biotoxins in shellfish growing areas along the Alabama Gulf Coast and at four to five regulated shellfish growing water sites . Two microbiologists routinely examine water samples microscopically to quantitate Karenia brevis , Pseudo-nitzschia and Dinophysis . These marine algae can bloom in large numbers and create the “ red tides ” found in Gulf waters .

Due to the complex nature of the only FDA-approved method ( mouse bioassay ) to quantify brevetoxin levels , oyster samples are sent to the Florida Fish and Wildlife Conservation Commission ’ s Fish and Wildlife Research Institute ( FWC-FWRI ). A review of Alabama ’ s historical data suggests blooms of significant magnitude occur about every ten years and are most active in the fall months . The impact on Alabama Gulf Coast tourism and the shellfish industry is detailed in the 2015 article , “ Red tide invades Alabama waters , shuts down fall oyster harvest .”

WA PHL Analyst David Nguyen prepares blue mussel samples for extraction and analysis of three algal toxins ( saxitoxins , domoic acid , okadaic acid ) by shucking the shells from the edible portions . Photo : Shelley Lankford

Laboratory recommendations for starting or expanding a marine biotoxin program :

1 . Identify the need for monitoring .

2 . Collaborate with and determine responsibilities among state and federal partner agencies .

3 . Train laboratory analysts to recognize target algal species and / or perform toxin testing .

4 . Pick the most conservative and trusted technology available to perform the toxin tests . You can stand a few false positives , but you cannot have ANY false negatives .

5 . Develop a multi-disciplinary response plan for each potential biotoxin affecting your state ’ s marine areas .

Florida

Florida ’ s state biotoxin testing program is a partnership between the Florida Department of Agriculture and Consumer Services ( FDACS ), the shellfish harvest area management authority , and FWC-FWRI , which provides technical support through statewide HAB monitoring and biotoxin testing . Analytes tested as part of the $ 2.7 million / year program include ASP , NSP , and PSP toxins . The eight-person program also partners with the National Oceanic and Atmospheric Administration and