HomeMy Public PortalAboutCyanobacteria Risk Categories 2022 Draft 3.25.22
Association to Preserve Cape Cod 1 March 25, 2022
Dear Cyano Program Partner:
The Association to Preserve Cape Cod (APCC) is committed to providing the best possible information to the
public about the presence and severity of cyanobacteria outbreaks in the Cape’s lakes and ponds. As a part of
that effort, APCC has been attending meetings with the Cape and Islands Health Agents Coalition (C&I HAC)
to expand the discussion of cyanobacteria monitoring and responses on Cape Cod. These meetings were also
attended by our partners, which included cyanobacteria experts Nancy Leland, who is affiliated with the
University of New Hampshire Center for Freshwater Biology, and Karen Malkus-Benjamin, former Coastal
Health Agent for the town of Barnstable, and members of the Brewster Ponds Coalition. Our discussions
centered on providing outreach to health agents concerning cyanobacteria risks, explaining the EPA and
CyanoCasting cyanobacteria monitoring and analysis methods, discussing local and regional responses to
cyanobacteria monitoring data, and communication of results to public officials and the public.
In parallel with these meetings, APCC and the Barnstable County Department of Health and the
Environment’s (BCDHE) Water Quality Lab began planning a new and important advancement in regional
capability for cyanobacteria toxin testing. Beginning in 2022 as a complement to APCC’s well-established
monitoring program, the BCDHE Water Quality Lab will expand its cyanobacteria toxin testing capabilities to
provide local officials with precise toxin measurements from ponds pre-identified by APCC as potentially
containing cyanobacteria toxin levels of concern. APCC’s proactive cyanobacteria monitoring data will be
used to flag ponds that will receive confirmatory toxin testing by the BCDHE Water Quality Lab to determine
whether an advisory is warranted. To ensure that samples for toxin testing are collected on the same date,
time, and place as samples for cyanobacteria monitoring, APCC will collect GRAB samples for toxin analysis at
the same time and location as our samples for cyanobacteria analyses. Samples for toxin analyses will be
collected and preserved according to EPA protocols (Surface Water Sampling, Method 546). In the event that
APCC’s cyanobacteria data indicate the potential for toxin levels of concern, the corresponding GRAB
sample(s) will be sent to the County for toxin analysis. The County Water Quality lab will then pass on its
results and recommendations to local officials and APCC. These results will supplement data collected and
communicated by APCC. The simultaneous collection of samples for cyanobacteria and cyanotoxin will help
to ensure that cyanotoxin analyses (if warranted) correspond to cyanobacteria monitoring data in terms of
time and place. This proactive sampling approach will avoid a common pitfall of reactive sampling that can
occur when cyanobacteria monitoring data are collected on one date and confirmatory samples are collected
several days to a week later when conditions may have changed.
APCC has listened to input and comments from health agents and other interest groups. The input we have
heard has resulted in changes and improvements to our program highlighted by the new regional capability
for toxin testing provided by the BCDHE Water Quality Lab. As new materials or information are produced by
program partners, they will be considered for incorporation into the attached document.
Sincerely,
Andrew Gottlieb, Executive Director
Kevin Johnson, Ecologist
Jo Ann Muramoto, Ph.D., Director of Science Programs
Association to Preserve Cape Cod 2 March 25, 2022
APCC 2022 Cyanobacteria Risk Categories
for Communication of Results via Reports and the Interactive Map
Introduction
APCC’s Cyanobacteria Monitoring Program partners with officials at the town, county, state,
and federal levels as well as local pond associations and residents to conduct cyanobacteria
monitoring in Cape Cod ponds. Each season, data is collected biweekly and shared with local
officials and the general public through reports, emails, and an interactive map of monitoring
results found on our website (https://apcc.org/our-work/science/community-
science/cyanobacteria/). Our goals are to raise public awareness of the health and ecological risks
posed by cyanobacteria blooms, to help inform proper responses to cyanobacteria concerns in
order to promote public health, to monitor priority ponds across the Cape, and to motivate public
action to address the causes of harmful cyanobacteria blooms (HCB) by improving water quality.
Cyanobacteria are an ancient group of photosynthetic microorganisms common in freshwater
systems on Cape Cod and worldwide. Under the right conditions, they can multiply rapidly and
form harmful cyanobacteria blooms. According to the Centers for Disease Control and
Prevention, certain common cyanobacteria genera can produce toxins known as cyanotoxins that
can be harmful to humans (CDC). HCBs have increased worldwide, including in the U.S.,
because of nutrient enrichment and rising water temperatures due to warming resulting from
climate change. As HCBs are expected to increase, the need for increased cyanobacteria
monitoring and awareness has never been greater.
Cape Cod ponds are commonly heavily used for swimming, boating, paddle boarding, and
fishing. Due to the increasing prevalence of HCBs and the resulting increased threat of public
exposure to cyanobacteria, the Massachusetts Department of Public Health (MDPH) has
guidelines for municipal officials to post and remove advisories at ponds for established
thresholds for cyanobacteria concerns (MDPH). Frequent cyanobacteria monitoring of ponds
provides the data for resource managers to track cyanobacteria trends in their ponds throughout
the season, apply relevant public health criteria, and to be proactive about posting and removing
recreational advisories.
APCC’s cyanobacteria monitoring program provides scientifically sound data on cyanobacteria
composition, concentrations, and predicted toxin concentrations. Our program uses and follows
the EPA’s Quality Assurance Project Plan (QAPP) for cyanobacteria monitoring, developed by
EPA for the Cyanobacteria Monitoring Collaborative or CMC (CMC QAPP). The QAPP was
developed by EPA Region 1 scientists, including Hillary Snook and others, with the goal of
encouraging and facilitating widespread monitoring of cyanobacteria. The QAPP is based on
Association to Preserve Cape Cod 3 March 25, 2022
methods created by EPA scientists and other cyanobacteria specialists, including Dr. Jim Haney
and Nancy Leland with the University of New Hampshire Center for Freshwater Biology. The
method involves taking concentrated samples of “Bloom Forming Colonies” (BFCs) through a 3-
meter student plankton net tow and unconcentrated samples of “Whole Lake Water” (WLW)
through a meter integrated tube.
APCC also utilizes the CyanoCasting method developed by Nancy Leland (Leland, 2018), which
builds on the methods described in the QAPP by including metrics that allow for the forecasting
of potential imminent cyanobacteria blooms. The forecasting ability of this method provides
valuable advance warnings of potential HCBs to inform proactive responses, such as increased
frequency of specific toxicity testing or precautionary advisories and postings of ponds to warn
the public of imminent cyanobacteria blooms. The ability to predict and anticipate potential
HCBs based on frequent monitoring is a unique and valuable feature of APCC’s program and
stands in contrast to reactive responses involving measurement of cyanobacteria concentrations
after a bloom has occurred (Leland et al. 2018, Leland et al 2019).
Massachusetts Department of Public Health (MDPH) Guidelines for Cyanobacteria
The MDPH cyanobacteria webpage describes guidelines for cyanobacteria in recreational
freshwater bodies that are described as follows (“Guidelines for Cyanobacteria at Recreational
Freshwater Locations”) (MDPH).
“DPH recommends issuing a public health advisory for HABs at recreational freshwater
locations when at least one of the following criteria is met:
1. A visible cyanobacteria scum or mat is evident.
2. Total cell count of cyanobacteria exceeds 70,000 cells/mL.
3. Concentration of the toxin microcystins exceeds 8 µg/L; or
4. Concentration of the toxin cylindrospermopsin exceeds 15 µg/L
Guideline values are based on US Environmental Protection Agency (US EPA) and World
Health Organization (WHO 1999) (WHO 2003) recommendations. When issuing an advisory,
signage should be posted at each access point at the waterbody warning against any contact
with the water.
Rescinding a Public Health Advisory
Cyanobacteria cells can release cyanotoxins into the water when they die. Therefore, algal
toxins may be present when a visible scum or mat is no longer evident. DPH recommends the
rescinding of a public health advisory after two successive samples, collected a week apart,
demonstrate cell counts or toxin levels below the quantitative guideline values.” (MDPH).
APCC Cyanobacteria Risk Communication in 2022
APCC’s updated method of communicating and interpreting results will no longer be referred to
as “Warning Tiers,” but rather “Cyanobacteria Risk Categories” comprised of three categories:
“Acceptable,” “Potential for Concern,” and “Use Restriction Warranted.”
Association to Preserve Cape Cod 4 March 25, 2022
The “Acceptable” category will be applied to ponds where no concerning results are found and
APCC deems that additional toxin testing will not be necessary based on our monitoring results.
The “Potential for Concern” category will be applied to ponds where concerning results or trends
are found that could serve as an early warning of cyanobacteria risks. APCC will send samples in
this category to the BCDHE Water Quality Lab for confirmatory toxin testing. A “Pet Advisory”
may also be warranted for ponds in this category. APCC has developed the criteria for these two
categories with recommendations from Karen Malkus-Benjamin, former Coastal Health Agent
for the town of Barnstable, and Nancy Leland to distinguish between ponds with safe results
requiring no additional toxin testing and potentially concerning results requiring additional toxin
testing.
The “Use Restriction Warranted” category will be applied to ponds where results exceed one or
more of the following four criteria: criteria for microcystin based on MDPH guidance, criteria
for cyanobacteria scum layers based on MDPH guidance, criteria for anatoxin-a based on the
draft Health Agent Guide, or where the health agent has already posted an advisory for
cyanobacteria. Ponds that are placed in this category warrant posting of a recreational use
advisory by health agents and will be marked in red on APCC’s map. Ponds in this category will
be sampled weekly and APCC will continue to send samples to the BCDHE Water Quality Lab
for confirmatory toxin testing until the pond is deemed safe to reopen or the advisory is removed.
Use Restrictions and Advisories
Use restrictions and advisories are issued at the discretion of the municipal health agents. As of
this writing, there is no commonly utilized set of guidelines in use for health agents across the
Cape that provides consistency in posting criteria. As a result, members of the public are advised
to contact the health agent in each town (see the contact list provided on APCC’s website) to
determine the official status of the pond about which they are interested. While ponds exceeding
MDPH standards as discussed above will be marked in red, this coloration does not always mean
a use restriction has been issued by the town. APCC will update our list of restricted ponds as we
are informed by the respective towns, but APCC does not speak for the towns unless otherwise
and explicitly noted on our posting map.
As part of the C&I HAC meetings, former Barnstable coastal health agent Karen Malkus-
Benjamin developed the Cyanobacteria Health Agent Guide (2022) to assist health agents in
decision making for cyanobacteria advisory responses based on data. While the Health Agent
Guide remains in draft form and has not yet been formally adopted, APCC encourages the C&I
HAC to review, adopt, and implement the guide. The draft Health Agent Guide is included as
Attachment 1 to provide information to health agents and APCC partners. Further updates to this
draft guide may be adopted by the C&I HAC, and APCC guidance will be updated to reflect any
such action.
APCC’s risk categories are closely tied to the current draft of the Health Agent Guide. However,
an important difference between APCC’s risk categories and the categories in the Health Agent
Guide is that the latter includes three nuances of recreational advisory postings including
“Warning,” “Swimming Beach Closure,” and “Pond Closure,” whereas APCC only has one such
Association to Preserve Cape Cod 5 March 25, 2022
category, “Use Restriction Warranted.” APCC’s “Potential for Concern” category roughly
equates to the “Pet Advisory” as both indicate that concerning results are still below concern
thresholds for standard human advisory notices. For simplicity in communication, APCC will
use the “Use Restriction Warranted” category to include all recreational advisory postings.
APCC’s recommendations for removing a recreational use advisory will mirror the reopening
guidance from the draft Health Agent Guide. For a microcystin toxin exceedance or bloom,
APCC will recommend lifting a recreational use advisory or closure after two consecutive
weekly tests contain microcystin concentrations less than 8 parts per billion (ppb) and no
presence of cyanobacteria bloom material. For an anatoxin-a toxin exceedance or bloom, APCC
will recommend a recreational use advisory or closure be lifted the week following an
exceedance if anatoxin-a concentrations are below 10 ppb and there is no evidence of
cyanobacteria bloom material.1 Health agents are solely responsible for the issuance and removal
of recreational use advisories or closures related to water clarity.
Cyanobacteria Risk Categories Discussion
Using these updated risk categories, APCC will interpret our monitoring results to inform health
agents and the public of when cyanobacteria conditions are deemed safe (Acceptable), when
cyanobacteria trends are becoming concerning (Potential for Concern), and when an advisory is
warranted (Use Restriction Warranted).
All specific criteria for these categories are included in Table 1 at the end of this document.
The criteria for these categories do not include cell counts or cylindrospermopsin, as neither
APCC nor the BCDHE Water Quality Lab has the capacity to test for these metrics.
To assign a Cyanobacteria Risk Category to a pond for a given monitoring period, the most
hazardous result among multiple criteria will determine the category in which the pond is placed.
A pond that meets even a single criterion in the “Use Restriction Warranted” category will
placed in that category. Likewise, a pond that meets even a single criterion in the “Potential for
Concern” category, but does not meet any criteria in the “Use Restriction Warranted” category,
will be placed in the “Potential for Concern” category. If a pond meets no criteria in the “Use
Restriction Warranted” or the “Potential for Concern” categories, that pond is placed in the
“Acceptable” category. All descriptions and criteria for these categories are summarized in the
table and discussed below.
APCC Cyanobacteria Risk Categories
Acceptable
Definition: No concerning cyanobacteria results at the time and place of sampling. To the best of
our knowledge and based on our monitoring results, regular recreational usage of the pond is safe
with respect to cyanobacteria and toxins. Map color is blue. Formerly the Low Warning Tier1.
Recommended Sampling Frequency: Biweekly.
Recommended Action: APCC will continue biweekly monitoring.
Potential for Concern
Association to Preserve Cape Cod 6 March 25, 2022
Definition: Monitoring results at the time and place of sampling indicate either moderate risk for
potential exposure to cyanobacteria toxins or a likelihood for higher cyanobacteria risks in the
near future. While these conditions pose low health risks to adults, risks are higher for children
or pets, particularly if contaminated water is incidentally ingested. Children may inadvertently
consume pond water while swimming and pet exposure can result from directly drinking pond
water or from grooming after swimming. Due to lower body masses, children and pets are more
susceptible to cyanobacteria risks than adults. A “Pet Advisory” may be posted at public access
points. Map color is yellow. Formerly the Moderate Warning Tier1,2.
Recommended Sampling Frequency: Weekly.
Recommended Action:
1. Samples should be analyzed for cyanotoxins by the BCDHE Water Quality Lab. APCC
or the town will provide a GRAB sample and, if available, a SCUM sample to the
BCDHE Water Quality Lab. If the sample is Microcystis spp. dominant, test for
microcystin. If the sample is Dolichospermum spp. dominant, test for anatoxin-a. If the
sample is dominated by a different genus or is a mixed assemblage, test for both.
2. Post a “Pet Advisory” or similar advisory according to municipal policies and procedures
until the pond is once again Acceptable.
Use Restriction Warranted
Definition: Monitoring results at the time and place of sampling indicate a high risk for potential
exposure to cyanobacteria toxins, based on one or more of the following criteria: 1) presence of
microcystin according to MDPH guidance, 2) presence of cyanobacteria scum layers according
to MDPH guidance, 3) presence of anatoxin-a according to the draft Health Agent Guide, or 4) a
municipal health agent issues a closure for any other reason related to cyanobacteria.
Recreational risk to adults is moderate following exposure. Recreational risks are especially high
for children and pets following exposure through accidental ingestion of contaminated water.
Children may inadvertently consume pond water while swimming and pet exposure can result
from directly drinking pond water or from grooming after swimming. Due to lower body masses,
children and pets are more susceptible to cyanobacteria risks than adults. A “Use Restriction
Advisory” has been recommended for public access points. Map color is red based on the
application of the following criteria: County sample for microcystin exceeds 8 ppb or for
anatoxin-a exceeds 10 ppb; presence of a visible scum in excess of MDPH guidelines, or if a
municipal health agent issues a closure for any other reason related to cyanobacteria. Formerly
the High Warning Tier1,2,3.
Recommended Sampling Frequency: Weekly.
Recommended Action:
1. Samples should be analyzed for cyanotoxins by the BCDHE Water Quality Lab. APCC
or the town will provide a GRAB sample and, if available, a SCUM sample to the
BCDHE Water Quality Lab. If the sample is Microcystis spp. dominant, test for
microcystin. If the sample is Dolichospermum spp. dominant, test for anatoxin-a. If the
sample is dominated by a different genus or is a mixed assemblage, test for both.
2. Post a “Use Restriction Advisory” or similar advisory according to municipal policies
and procedures and otherwise notify the public to avoid contact and exposure until the
pond completes the criteria to be reopened or for the advisory to be removed by the local
health agents.
Association to Preserve Cape Cod 7 March 25, 2022
APCC 2022 Cyanobacteria Risk Categories Table of Criteria
APCC 2022 Cyanobacteria Risk Categories
Criteria APCC
Acceptable
APCC
Potential for Concern
Use Restriction
Warranted
Microcystin
Predicted microcystin
by APCC.
Less than or equal to 8 ppb
microcystin predicted in
APCC’s BFC (bloom-
forming colonies) sample4.
Greater than 8 ppb microcystin
predicted in APCC’s BFC
sample4.
Measured microcystin
by County.
Less than 4 ppb
microcystin measured in
GRAB or SCUM sample.
Between or equal to 4 and 8
ppb microcystin measured in
GRAB or SCUM sample.
Greater than 8 ppb microcystin
measured in GRAB or SCUM sample3.
Cyanobacteria
Biomass
Cyanobacteria growth
rate calculated by
APCC.
Less than 0.07 in all APCC
samples1,2,4.
Greater than or equal to 0.07 in
any APCC sample1,2,4.
Cyanobacteria bloom
material confirmed by
APCC.
None present at the time
and place of sample
collection.
A slight cyanobacteria scum or
small patches of cyanobacteria
bloom material sampled and
confirmed1.
Significant cyanobacteria scum or large
patches of cyanobacteria bloom
material sampled and confirmed1,3.
Anatoxin-a
Measured Anatoxin-a
by County.
Less than 4 ft of visibility for
any pond with elevated pico-
cyanobacteria concerns2.
Greater than or equal to 10 ppb
Anatoxin-a measured in GRAB or
SCUM sample1.
Notes
To interpret cyanobacteria data using this table, the most hazardous result determines the category the pond is placed in from right to left. A pond that
meets even a single criterion in the “Use Restriction Warranted” column will placed in that category. Likewise, a pond that meets even a single criterion
in the “APCC Potential for Concern” category, but does not meet any criteria in the “Use Restriction Warranted” category, will be placed in the “APCC
Potential for Concern” category. If a pond meets no criteria in the “Use Restriction Recommended” or the “APCC Potential for Concern” category, that
pond is placed in the “APCC Acceptable” category.
1 Developed with recommendations from cyanobacteria expert Karen Malkus-Benjamin, former Coastal Health Agent for the Town of Barnstable.
2 Developed with recommendations from cyanobacteria expert Nancy Leland affiliated with the University of New Hampshire Center for Freshwater
Biology.
3 Criteria attributed to MDPH.
4 Predictive cyanobacteria metrics that project and estimate risks, rather than reactive cyanobacteria metrics that measure risk after a bloom has occurred.
Table 1. APCC 2022 Cyanobacteria Risk Categories Table of Criteria.
Association to Preserve Cape Cod 8 March 25, 2022
Footnotes
1 Developed with recommendations from cyanobacteria expert Karen Malkus-Benjamin, former
Coastal Health Agent for the Town of Barnstable.
2 Developed with recommendations from cyanobacteria expert Nancy Leland affiliated with the
University of New Hampshire Center for Freshwater Biology.
3 Criteria attributed to MDPH.
4 Predictive cyanobacteria metrics that project and estimate risks, rather than reactive
cyanobacteria metrics that measure risk after a bloom has occurred.
Work Cited
Centers for Disease Control and Prevention (CDC) webpage on “Harmful Algal Bloom (HAB)-
Associated Illness”. https://www.cdc.gov/habs/general.html
Leland, N.J. 2018. Fundamentals of Cyano-casting: cost-effective monitoring techniques for
cyanobacteria surface blooms and cyanotoxin levels. In cooperation with UNH Center for
Freshwater Biology. http://lim-tex.com/wp-
content/uploads/2018/05/CyanoCasting_Handbook_v18.pdf
Leland, N.J. and Haney, J.F., 2018. Alternative Methods for Analysis of Cyanobacterial
Populations in Drinking Water Supplies: Fluorometric and Toxicological Applications Using
Phycocyanin. Journal of Water Resource and Protection, 10, 740-761. Posted at:
https://www.scirp.org/journal/PaperInformation.aspx?paperID=86671&
Leland, N.J., J.F. Haney, K. Conte, K. Malkus-Benjamin and B. Horsley. 2019. Evaluation of
size structure in freshwater cyanobacteria populations: methods to quantify risk associated with
changes in biomass and Microcystin concentrations. Journal of Water Research and Protection,
2019, 11, 810-829. Posted at:
https://www.scirp.org/journal/paperinformation.aspx?paperid=93424
Leland, N.J., R. A. Landon, and J.F. Haney. September 2020. Trophic interactions between
anadromous juvenile Alewife (Alosa pseudoharengus) and cyanobacterial populations in a
shallow mesotrophic pond. Natural Resources, 2020, 11, 394-419. Posted at:
https://m.scirp.org/papers/102960 .
Malkus-Benjamin, Karen. 2022. Cyanobacteria Health Agent Guide. Draft (see Attachment 1).
Massachusetts Department of Public Health (MDPH) website on “Guidelines for cyanobacteria
at recreational freshwater locations”. https://www.mass.gov/info-details/guidelines-for-
cyanobacteria-at-recreational-freshwater-locations
U.S. EPA (United States Environmental Protection Agency) (2021). Surface Water Sampling.
https://www.epa.gov/sites/default/files/2017-
07/documents/surface_water_sampling201_af.r4.pdf?VersionId=UWp.tCIlmVPv9SW6xeJX5Zi
7NCqtdNhZ
Association to Preserve Cape Cod 9 March 25, 2022
U.S. EPA (United States Environmental Protection Agency) (2019). Recommended Human
Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins
and Cylindrospermopsin. EPA-822-R-19-001 (PDF).
www.epa.gov/sites/default/files/2019-05/documents/hh-rec-criteria-habs-document-2019.pdf
U.S. EPA (Environmental Protection Agency). 2017, revised 2021. Cyanobacteria Monitoring
Collaborative Program (CMC). Quality Assurance Program Plan (QAPP) for the Cyanobacteria
Monitoring Collaborative Program. Rev: 0, April 26, 2017: Posted at: https://cyanos.org/wp-
content/uploads/2017/04/cmc_qapp_final.pdf.
U.S. EPA (Environmental Protection Agency). 2016. Method 546: Determination of Total
Microcystins and Nodularins in Drinking Water and Ambient Water by Adda Enzyme-Linked
Immunosorbent Assay. https://www.epa.gov/sites/default/files/2016-09/documents/method-546-
determination-total-microcystins-nodularins-drinking-water-ambient-water-adda-enzyme-linked-
immunosorbent-assay.pdf
World Health Organization. 1999. Toxic cyanobacteria in water: a guide to their public health
consequences, monitoring and management.
https://www.who.int/water_sanitation_health/resourcesquality/toxcyanbegin.pdf
WHO (World Health Organization) (2003). Guidelines for Safe Recreational Water
Environments, Volume 1: Coastal and Fresh Waters. (PDF)
http://apps.who.int/iris/bitstream/handle/10665/42591/9241545801.pdf?sequence=1