Pfiesteria Monitoring

*The DNR monitoring team has produced Pfiesteria updates that provide information about the occurrence of fish kills and other adverse affects.  Read the updates here.

In 1997, the occurrence of fish kills, fish health events and associated human health events were linked to the presence of toxic Pfiesteria piscicida on the Lower Eastern Shore of Maryland. The State Department of Natural Resources has initiated a new year of intensive monitoring for toxic outbreaks of Pfiesteria. Maryland DNR is once again coordinating Pfiesteria monitoring efforts with other agency and academic partners through the Pfiesteria Study Team as it has each year since the 1997 events. The Pfiesteria monitoring program is integrated with water and living resource quality assessments through the broader Chesapeake and Coastal Bay Monitoring Program.

The study design for the Pfiesteria monitoring program is categorized into four levels under the general headings of "Rapid Response" and "Comprehensive Assessments" (Tables 1: Level I-IV definitions, Figure 1 and 2: sampling stations).

Rapid response (Level I) is classified as the immediate investigation of a reported fish health or suspicious human health problem. The primary objectives of rapid response are to 1) determine the nature of the fish health or human health problem, 2) ascertain if Pfiesteria-like organisms and their toxins may have been involved and 3) determine if the river closure criteria have been met. Under this level of response, teams will quickly evaluate fish communities and other appropriate parameters (e.g., lesion incidence, water quality measures such as dissolved oxygen, salinity, etc.) to determine if a toxic outbreak can be ruled out as the likely cause of the fish health problem and if the State of Maryland's river closure criteria have been met. If closure criteria are met, rivers will be monitored intensively for all parameters until re-opened. Current scientific knowledge also indicates that the behavior of Pfiesteria and Pfiesteria-like organisms is seasonal and episodic in nature. Therefore, closure and reopenings will be reassessed as necessary. This protocol is based on evolving scientific knowledge and experience with Pfiesteria and Pfiesteria-like organisms and is subject to continuous evaluation.

Comprehensive assessment (Levels II-IV, Tables 1 and 2, Figure 1 and 2, above) will involve the intensive monitoring of fish health, water quality, habitat and Pfiesteria activity in previously closed tributaries (Level II). Additional comprehensive characterization will be performed on tributaries (Level III) that, based on historical data, have water quality and habitat characteristics (nutrient enrichment, moderate salinity, etc.) similar to those associated with Pfiesteria-related outbreaks (Tables 1 and 2, Figure 1 and 2, above). Level II and III comprehensive assessment efforts will involve the continuation of fish health, longitudinal water quality and habitat sampling transects on these tributaries begun in 1998. Level IV response will involve the long term fish health, water quality monitoring programs from the Chesapeake Bay and tributaries (Tables 1 and 2, Figures 1 and 2, above). Examining data from these programs provides our broadest scale view of Maryland's waters intended for other purposes but being utilized in these investigations to provide a context for environmental conditions in areas outside of affected waterways.

Table 1. 2000 Field Response to Pfiesteria Outbreaks.

LEVEL I: Rapid response to fish kills or fish health problems.
Fish Community: sampled to determine if closure criteria associated with Pfiesteria-like organisms are met.
Pfiesteria: three water samples collected within the site of a fish kill or lesion outbreak if no other cause is apparent (see Table 2 for analyses to be conducted).
Water Quality and Habitat: Physical parameters measured in all cases. Standard chemical parameters collected at the same time and location as the fish and Pfiesteria test samples (see Table 2 for analyses to be conducted).

In the event of a closure:
Fish Community: sampled daily until re-opening criteria are met.
Pfiesteria: sampled daily for first three days and every third day thereafter until re-opening criteria are met.
Water Quality and Habitat: standard physical and chemical parameters collected at the same time and location as Pfiesteria test samples.

LEVEL II: Previously closed tributaries (Pocomoke, Manokin, Chicamacomico Rivers), and
LEVEL III: Risk assessment of selected tributaries (Nanticoke, Wicomico, Big Annemessex, Trappe Creek, St. Martins, and Middle Rivers), and
LEVEL IV: Existing programs (baywide)
Fish Community: Sampled twice monthly by seine and cast net (where appropriate) mid-April through mid-November in all Level II and III systems. Sampled by a variety of techniques and schedules in Level IV systems.
1) Water samples collected from 100 Level II, III and IV sites per month to be tested for Pfiesteria presence/absence by molecular probe.
2) Sediment collected from Level II, III and IV sites during fall 2000 (approximately 150 total collections).
Water Quality and Habitat:
1) 8 to 12 longitudinal stations per Level II and III system sampled once a month (Pocomoke, Chicamacomico and Middle River twice a month) for standard physical and chemical parameters
2) Standard physical and chemical parameters monitored monthly at long-term water quality monitoring stations (Level IV).

Table 2. Parameters to be measured for 2000 response to potential Pfiesteria outbreaks.

Fish Community
a. Species composition and abundance: Levels I, II, III, and IV
b. Frequency and type of external anomalies: Levels I, II, III, and IV
c. Histology and pathology of selected specimens: All levels as appropriate

- Pfiesteria-like cells/ml (water only): Level I
- Toxicity of Pfiesteria-like organisms (water only): Levels I
- SEM confirmed species identification (water samples): Levels I
- Molecular probe identification of Pfiesteria: Levels I, II, III, IV
- Sediment survey of Pfiesteria-like organism presence and toxicity: Levels II, III, IV

Water Quality and Habitat
- Standard in-situ physical/chemical parameters: Levels I, II, III, IV

Dissolved Oxygen
Specific conductance
Secchi depth

- Standard grab sample chemical parameters: Levels I, II, III, IV

    Chlorophyll a
    Total suspended solids

- Longitudinal fluorometry of surface water (Levels II, III)

- Phytoplankton community composition: Levels II, III (subset of stations)

- Water column urea: Levels I, II, III

- Sediment: Levels II, III, IV

    Grain size analysis
    Particulate carbon, nitrogen, phosphorus
    Pfiesteria and related dinoflagellates: presence/absence

In 2000, intensive water quality monitoring was initiated in April on nine river systems for the Pfiesteria monitoring program (Middle, Pocomoke, Manokin, Big Annemessex, Nanticoke, Wicomico, Chicamacomico/Transquaking Rivers in Chesapeake Bay and St. Martin River and Trappe Creek in the Coastal Bays). This year, we will not only be monitoring with a focus on Pfiesteria piscicida, but a second toxic species of Pfiesteria that was recently named by Dr. Howard Glasgow who is working in the laboratory of Dr. JoAnn Burkholder at North Carolina State University. This new species is known as Pfiesteria shumwayae (see press release from March 2000). A genetic probe is already available and in use to identify this species in water samples. Maryland Department of Natural Resources has evidence that P. shumwayae is found in Chesapeake Bay based on water samples collected in 1998 and 1999 (Figure 3). We are monitoring for both species of Pfiesteria this year.

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