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State of New Jersey Department of Environmental Protection

Brown Tide Assessment - Newsletters

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Newsletter 2 - July 2000 Newsletter 3 - July  2001 Newsletter 4 - October 2001 Newsletter 5 - July  2002 Newsletter 6 - October 2002

Newsletter Number 1 - June 2000

There is a substantial brown tide bloom this year in Little Egg Harbor in southern Barnegat Bay. The NJDEP has confirmed the highest counts of the brown tide algae, Aureococcus anophagefferens, were one and half million to over two million cells per milliliter on June 8. A concentration of one million cells per milliliter represents a full bloom condition. The NJ Department of Environmental Protection is conducting an assessment of the brown tide occurrence in Barnegat Bay throughout 2000. A team of scientists and managers from state and federal government agencies and academic institutions are participating in the project. This is the first of a series of Newsletters that will inform the public as to the status of the occurrence of brown tide blooms and to provide a forum to share data and expertise on this issue with the hope of reducing and managing these blooms in the future. NJDEP’s Bureau of Marine Water Monitoring and U.S. EPA are collecting water samples in Barnegat Bay and other sites. Samples are being enumerated for the brown tide organism by Dr. David Caron of the University of Southern California, using a newly developed monoclonal antibody technique that is accurate, precise, and provides information on counts, within a few days of collection. Other members of the team include USGS, Rutgers Institute of Marine & Coastal Sciences and the Center for Remote Sensing and Spatial Analysis, NJDEP’s Bureau of Shell Fisheries, Dr. Elizabeth Cosper (Coastal Environmental Studies), and Dr. O.R. Anderson (Columbia University).

Brown tide blooms, caused by a minute alga, Aureococcus anophagefferens, discolor the water a light brown. While they are not a human health threat in terms of bathing or seafood consumption, they may cause ecological damage to shellfish and submerged aquatic grasses in the Barnegat Bay.

Newsletter Number 2 - July 2000

The brown tide bloom that occurred during June and early July, in Barnegat Bay and Little Egg Harbor, subsided by July 12. The latest data from the laboratory of Dr. David Caron (Univ. of Southern California) indicate that several sites in Little Egg Harbor, including Ship Bottom and Tuckerton, NJ, had a substantial brown tide bloom with the highest concentrations of Aureococcus anophagefferens in early June. Cell counts over a million cells per milliliter (mL) represent full bloom conditions. The highest cell counts were observed in the vicinity of Little Egg Harbor with cell counts up to 2.2 million cells per mL on June 8 and reduced to 30,000 cells per mL in early July. At Tuckerton, the counts reached two million per mL on June 15 and decreased to a low of 35,000 cells per mL on July 12. At Ship Bottom, the cell numbers were 1.8 million cells per mL on June 23 and decreased to 410,000 cells per mL on July 12. Cell counts that rise to over 500,000 cells per milliliter indicate the beginning of a bloom. However the lower numbers in this range in July clearly indicated a decline from higher numbers of the bloom. Data are available at selected sampling stations during June and July (see Attachments 1-3). A list of stations corresponding to municipalities is provided (Attachment 4). Additional sampling will be conducted throughout the year.

The NJDEP recently received reports from Biosphere, Inc., an aquaculture facility located in Tuckerton, that, due to reduced growth of juvenile hard clams during the June brown tide bloom, clams were relocated to waters at Sea Bright where no brown tide blooms were reported. As the brown tide bloom subsided in later June, in Little Egg Harbor, clams were relocated back to the facility in Tuckerton. Rutgers University Extension Service (Jeff Flimlin) reported to NJDEP that mortalities in hard clam seed occurred in commercial nurseries near the bridge at Great Bay Blvd., in Great Bay, south of Tuckerton, NJ. However, the concentrations of A. anophagefferens at most of these stations were not at bloom levels.

Brown tide blooms, caused by a minute alga, A. anophagefferens, discolor the water a light brown. While they are not a human health threat from bathing or seafood consumption, they may cause ecological damage to shellfish and submerged aquatic grasses in the Barnegat Bay.

Newsletter 3 - July  2001

The NJ Department of Environmental Protection is continuing the second year of assessment of the brown tide occurrence in Barnegat Bay throughout 2001. The assessment is being conducted jointly by the NJDEP, NJ Sea Grant/NJ Marine Sciences Consortium, U. S. Environmental Protection Agency, Rutgers University, University of Southern California, and Columbia University. The goal of the assessment is to continue to characterize brown tide blooms, caused by a minute alga, Aureococcus anophagefferens, in coastal waters of New Jersey in order to identify environmental factors that may promote and sustain these blooms and to document negative impacts to natural resources so that mitigation strategies can be developed. Brown tide blooms can discolor the water a yellow brown which can be undesirable to recreational uses. While they are not a human health threat from either bathing or seafood consumption, blooms may cause ecological damage to shellfish and submerged aquatic grasses in Barnegat Bay.

The New Jersey Marine Science Consortium/New Jersey Sea Grant and the U.S. EPA are collecting water samples. Water samples are being analyzed by monoclonal analysis, a newly developed immunofluorescent technique to enumerate the minute brown tide organism, by Dr. David Caron (USC). In addition, nutrient data analyzed, as part of the U.S. EPA Coastal 2000 program will be available.

Results of sampling from April 16 through June 4, 2001 show that concentrations of Aureococcus appeared to rise, fall, and rise again within a few days in some stations in Little Egg Harbor. April concentrations at most stations sampled from northern Barnegat Bay through Little Egg Harbor were below 5.0 X 103 cells per mL (Category 1 bloom, as defined in the recently proposed *Brown Tide Index, Gastrich & Wazniak, manuscript in preparation).

By May 25, there was a significant brown tide bloom in Little Egg Harbor at Ship Bottom with a concentration of Aureococcus anophagefferens greater than 106 cells per mL which dropped to 4.0 X 105 cells per mL on May 30 but increased again to 8.4 X 105 cells per mL on June 4. There were reports of patchy spots of brown water in areas in Little Egg Harbor during May and June as well as reports that a local aquaculture facility temporarily moved their juvenile hard clams to waters that did not have brown tide blooms. On May 25, bloom concentrations of Aureococcus anophagefferens at a stations near Beach Haven Terrace were over 8.5 X 105 cells per mL and dropped to approximately 5.0 X 105 cells per mL (Category 3) by June 4. All these blooms were classified as Category 3 and potentially harmful to shellfish according to a recently proposed Brown Tide Index* explained below. Sampling results on June 11 showed that some stations in Little Egg Harbor and southern Barnegat Bay were over 5.0 X 105 cells per mL and by June 18, four of these stations had brown tide counts that increased to over one million cells per mL, or Category 3 blooms. Other stations in Little Egg Harbor had Category 2 blooms in May which increased to Category 3 blooms in June.

Results are not complete and additional sampling is underway. There were no blooms observed in northern Barnegat Bay. The Department, in cooperation with Rutgers University, will be analyzing brown tide growth in relation to specific environmental factors (e.g., salinity, temperature, nutrients, etc.) in the next year.

*Brown Tide Bloom Index (Gastrich & Wazniak, manuscript in preparation)

Category 1 brown tide blooms: <35,000 cells per milliliter (no reported negative ecological impacts)

Category 2 brown tide blooms: >35,000 to 200,000 cells per milliliter (potential moderate to severe ecological impacts on shellfish)

Category 3 brown tide blooms: >200,000 cells per milliliter (potential severe ecological impacts to shellfish, seagrasses and plankton)

Newsletter 4 - OCTOBER 2001

The NJ Department of Environmental Protection has completed the second year of assessment of the brown tide occurrence in coastal waters in cooperation with the NJ Sea Grant/ NJ Marine Sciences Consortium, U. S. Environmental Protection Agency, Region 2, Rutgers University, and the University of Southern California. 

The goal of the assessment was to characterize the spatial and temporal extent of brown tide blooms, caused by a minute alga, Aureococcus anophagefferens, in coastal waters of New Jersey. The brown tide monitoring is based on selected stations of the Bureau of Marine Water Monitoring's Coastal Monitoring Program, the U.S. EPA's Coastal 2000 program, and USGS gaging stations in order to collect as much water quality and flow data as possible. The Brown Tide Assessment Project will measure routine water quality parameters and provide data on nutrients - measurements that may be contributing factors to the promotion and maintenance of brown tide blooms.

The NJDEP used the newly developed Brown Tide Bloom Index (Gastrich &, Wazniak, 2001; see June 2001 Brown Tide Newsletter) to assess the spatial extent of brown tide blooms in 2000-01. Figures 1-3 below show a comparison of brown tide counts in April through September in 2000 and 2001. Figure 1.  shows stations in Raritan Bay and northern Barnegat Bay. Previous information indicated that brown tide blooms were not reported in this area or that elevated concentrations of brown tide occurred before 2000. However, in 2000-01, all stations had Category 2 blooms that can have potential negative impacts on shellfish.

 Stations not showing elevated brown tide counts (in blue) may not have been monitored during the months when blooms are known to occur. 

Figure 1. Brown Tide Monitoring Stations: Raritan Bay to Upper Barnegat Bay: 2000-01 

Figure 2  shows that the areas of southern Barnegat Bay and Little Egg Harbor had Category 3 blooms, the most severe brown tide blooms. Based on the criteria in the Brown Tide Bloom Index, the extent and magnitude of brown tide blooms were. comparable in 2000 and 2001 and comparable to the 1995 bloom and other anecdotal data on significant brown tide blooms in this area. 

Figure 2. Brown Tide Monitoring Stations: Southern Barnegat Bay and Little Egg Harbor 

Figure 3 shows that Category 3 blooms occurred in Great Bay which is comparable to previous information. However, the Category 2 bloom that occurred in 2000-01 at the southernmost station in Great Egg Harbor is new information compared to previous reports. 

Figure 3. Brown Tide Monitoring Stations: Great Bay south to Great Egg Harbor. 

The results indicate that while the brown tide organism was detected at most stations in 2000-0 1, potentially harmful brown tide blooms may not occur at all stations. The cause of blooms in some areas and not in others is not well understood. The implication of this analysis of brown tides during 2000 and 2001 is that 1) concentrations of brown tide in New Jersey coastal waters are high enough to contribute to potential impacts to shellfish and seagrasses in areas of Barnegat Bay; 2) future monitoring for brown tides should be extended to coastal bays south of Great Egg Harbor with more frequent sampling at stations between Great Bay and Great Egg Harbor; 3) monitoring of brown tides should be continued at existing sites along environmental gradients; and 4) assessments and research are needed to document impacts to natural resources resulting from brown tide blooms of contributing environmental factors (esp. comparisons between those sites with brown tide blooms and those without blooms) in order to better understand the contributing factors to the promotion, maintenance and termination of these blooms.

Newsletter Number 5 - July  2002

The NJ Department of Environmental Protection, in cooperation with the NJ Sea Grant/NJ Marine Sciences Consortium; U. S. Environmental Protection Agency, Region 2; Rutgers University; and the University of Southern California, completed water sampling during April and May,  2002.  This report includes partial results of data collected April through June, 2002.

 The goal of the assessment was to characterize the spatial and temporal extent of brown tide blooms caused by a minute alga, Aureococcus anophagefferens, at eleven water quality network stations in the coastal waters of New Jersey.  The brown tide concentrations were evaluated using the newly developed Brown Tide Bloom Index (Gastrich & Wazniak, 2002; see Brown Tide Newsletter, June 2001, Figs. 1-3) that relates concentrations of the brown tide organism, A. anophagefferens, to potential negative impacts on natural resources including shellfish, seagrasses and protozoa.

Figure 1 shows one station that was monitored in northern Barnegat Bay (1635E) near the Toms River.  While this station had a Category 1 (< 35,000 cells/mL) (see legend below) brown tide bloom on April 22, 2002, Aureococcus concentrations increased to a Category 2 bloom on May 20 (143,000 cells/mL).  By June 3, this station had a Category 3 bloom (242,000 cells/mL) with the highest concentration of 277,000 cells/mL on June 10. The 2002 brown tide concentrations were higher at this station than those in 2001.  In 2001, low concentrations (Category 1) occurred during this same time period.  Therefore, it will be important to monitor brown tide blooms at this station in the future to determine whether blooms are increasing in severity.

 Figure 2 shows brown tide concentrations in the southern Barnegat Bay and Little Egg Harbor for May 2002.  There were Category 2 blooms already in April at some stations (1651D, 1675, and 1719E) and concentrations at most stations increased to Category 2 and Category 3 blooms by May 20, which is early for the more severe blooms which usually occur in June. Seven of the eleven stations monitored had Category 3 blooms on May 20 with concentrations ranging from 254,000 to 851,000 cells/mL. By June 3, all stations excepting one (1823A) in this area had Category 3 blooms with the highest concentration of 842,000 on June 17 (1719E). Station 1834A located in the middle of Little Egg Harbor was the exception with Category 2 blooms in May and June.  While Aureococcus concentrations were higher in Little Egg Harbor in June in 2000 and 2001 (> 1,000,000 cells/mL), the area has experienced Category 3 blooms for three consecutive years. 

 Figure 3  shows that the one station sampled in the Little Egg Harbor Inlet (1824B) had a Category 1 bloom in April, which increased to a Category 2 bloom on May 20, and increased to a Category 3 bloom (415,000 cells/mL) with the highest concentration on June 3. 

 This information is only preliminary because monitoring for Aureococcus anophagefferens will continue during June through September in 2002.  However, initial results above indicate concentrations of brown tide in New Jersey coastal waters are high enough to contribute to potential impacts to shellfish and seagrasses in areas of Barnegat Bay and Little Egg Harbor.

Newsletter Number 6 - October 2002

The NJ Department of Environmental Protection conducted a field monitoring program consisting of water sampling and analysis of the brown tides and other water quality parameters in cooperation with the NJ Sea Grant/NJ Marine Sciences Consortium; U.S. Environmental Protection Agency, Region 2; Rutgers University; and the University of Southern California. This report includes results of data collected April through September, 2002. A more comprehensive analysis of data collected in past years is underway.

The goal of the assessment is to characterize the spatial and temporal extent of brown tide blooms caused by a minute alga, Aureococcus anophagefferens, at eleven water quality network stations in the coastal waters of New Jersey. The brown tide concentrations were evaluated using the Brown Tide Bloom Index (Gastrich & Wazniak, 2002) that relates concentrations of the brown tide organism, A. anophagefferens, to potential negative impacts on natural resources including shellfish, seagrasses and protozoa.

BROWN TIDE BLOOM INDEX
(GASTRICH AND WAZNIAK, 2002)
CATEGORY 1: < 35,000 Aureococcus anophagefferens
cells ml-¹ (No observed impacts)
CATEGORY 2:> 35,000 to < 200,000 cells ml-¹
· Reduction in growth of juvenile hard clams, Mercenaria mercenaria
· Reduced feeding rates in adult hard clams
· Growth reduction in mussels (Mytilus edulis) and bay scallops (Argopecten irradians)
CATEGORY 3: > 200,000 cells ml-¹
· Water becomes discolored yellow-brown
· Feeding rates of mussels severely reduced
· Recruitment (renewal of stock) failures of bay scallops and high mortalities
· No significant growth of juvenile hard clams
· Negative impacts to eelgrass due to algal shading
· Copepod production reduced and negative impacts to protozoa

Highlights of 2002 Brown Tide Blooms

Preliminary spatial patterns from 2000-02 show that Aureococcus was detected at every coastal station monitored for three years. Aureococcus concentrations, mainly Category 2 and 3 blooms, which may have significant potential impacts on natural resources, specifically hard clams and eelgrass, were found in Raritan Bay, Barnegat Bay, Little Egg Harbor and south in Great Egg Inlet.

Results from monitoring stations from north to south are presented below. Figure 1 shows the one station monitored in northern Barnegat Bay (1635E) near the Toms River. While this station had a Category 1 brown tide bloom (< 3.5 X 10 cells ml-¹) (see legend below) on April 22, 2002, Aureococcus concentrations increased to a Category 2 bloom on May 20 (1.4 X 105 cells ml-¹). By June 3, concentrations increased to a Category 3 bloom (242,000 cells ml-¹) with the highest concentration of 2.8 X 105 cells ml-¹ on June 10. The 2002 brown tide concentrations were higher at this station than in 2001. Therefore, it will be important to monitor brown tide blooms at this station in the future to determine whether blooms are increasing in severity.

The highest concentrations of Aureococcus in monitored New Jersey coastal bays occurred over the last three years in stations in Little Egg Harbor. Figure 2 below shows the highest concentrations of brown tide in the southern Barnegat Bay and Little Egg Harbor for 2002. The concentrations in 2002 were similar to those at the same stations in 2000 and 2001. Category 2 bloom levels were already occurring in April at some stations (1651D, 1675, and 1719E) and concentrations at most stations increased to Category 2 and Category 3 blooms by May 20, which is early for the more severe blooms, which usually occur in June. Seven of the eleven stations monitored had Category 3 blooms on May 20 with concentrations ranging from 2.5 X 105 to 8.5 X 105 cells ml-¹. By June 3, all stations in Little Egg Harbor had Category 3 blooms with the highest concentration of 8.42 X 105 ml-¹ on June 17 at Station 1719E. While Aureococcus concentrations were higher in Little Egg Harbor in June in 2000 and 2001 (>1.0 X 106 cells ml-¹) than in 2002, the area has experienced Category 3 blooms for four consecutive years. Station 1703C, in Ship Bottom (Stafford TWP), located under the Rte. 72 bridge and causeway, had the highest Aureococcus concentrations of 1.56 X 106 cells ml-¹ on June 20 while station 1719E in Beach Haven Terrace (Long Beach TWP) had the second highest concentration (1.2 X 106 cells ml-¹) on June 26. While station 1820A, located north of Tuckerton in Little Egg Harbor TWP, experienced Category 3 blooms in 2001 and 2002 at concentrations similar to other Little Egg Harbor stations, this station had the highest recorded Aureococcus concentration in June 2000 at 2.2 X 106 cells ml-¹.

Figure 3 below shows the highest concentrations of Aureococcus in Great Bay and in bays to the south. One station sampled at the mouth of the Little Egg Harbor Inlet (1824B) had a Category 1 bloom in April, which increased to a Category 2 bloom on May 20 but the concentration did not exceed 5.5 X 104 cells ml-¹ (June 10) and dropped to < 3.7 X 104 cells ml-¹ by July 24. While one station in Great Egg Inlet (2720B) was only monitored once on June 2002, it had low concentrations (Category 1) but in 2000 and 2001, this station had Category 2 blooms. Additional monitoring for brown tide should be conducted at this station and others further south.

These early findings not only warrant consideration of continued monitored at existing stations to track these blooms but also extended monitoring to Raritan Bay and other bays south of Great Bay during April through September.

Preliminary temporal patterns of brown tide blooms in 2002 show a similarity to previous years. Figure 4 shows the highest concentrations of Aureococcus at monitored stations from May through September, 2002, Category 1 concentrations (often < 35,000 cells ml-¹) during April increase to Category 2 blooms in May, and again, increase to Category 3 blooms in June. Generally, this increase in concentration occurs as the salinity increases to greater than 26 ppt. Higher salinities have been shown to be associated with brown tide blooms in other states. However, in 2002, some stations had Category 3 blooms earlier, in May, than in previous years. Aureococcus concentrations gradually decreased to Category 2 blooms in July and August. However, some stations in Little Egg Harbor show a secondary Category 3 bloom in September.

Figures 5, 6, and 7 show the annual change in concentrations of the brown tide blooms, caused by Aureococcus concentrations from May through September, at selected stations. Station 1703C had the highest concentrations of Aureococcus in 2002 and 2001 and Aureococcus concentrations are similar at other Little Egg Harbor stations. Stations are characterized by low concentrations (Category 1 blooms) in April that increase to Category 2 blooms in May and Category 3 blooms in June. Bloom concentrations usually drop sharply in July/August but this may vary and a secondary bloom may appear at some stations (e.g., 1703C in 2001) in September. Figure 7, Station 1824B, which is the southern reference point, shows much lower concentrations than the other stations. This is an area at the mouth of the Little Egg Harbor where there is substantial tidal action and influence. The lower concentrations in this area throughout the year (< 60,000 cells ml-¹) may result from increased flushing due to the tidal action mixing, which may not promote or sustain substantial blooms.

In conclusion, preliminary results show:
· Aureococcus concentrations were detected at every coastal station monitored over the last three years.
· Preliminary spatial patterns of brown tide blooms indicate that Category 3 blooms occurred every year for three years mainly June, and sometimes in May, in stations in Little Egg Harbor and southern Barnegat Bay. Category 2 blooms occurred over the same geographic area in Little Egg Harbor and throughout Barnegat Bay and other coastal bays including Raritan Bay and to the south in Great Egg Inlet.
· Preliminary temporal patterns of Aureococcus concentrations show an increase from background levels in April to Category 2 blooms in May to Category 3 blooms in June which may decrease in July and August; in some cases, secondary Category 3 blooms may occur in some stations in September; Category 2 blooms may occur for longer periods than Category 3 blooms which may contribute to increased environmental pressure on natural resources. Brown tide blooms increase during June when juvenile hard clam growth and new growth of seagrasses were reported, which may cause potentially harmful impacts to these natural resources that are already impacted by multiple stressors.
· Concentrations of brown tide in New Jersey coastal waters for the last three years (2000-2002) are high enough to contribute to significant potential impacts to shellfish and seagrasses in areas of Barnegat Bay and Little Egg Harbor.
· Other coastal bays may be at risk for brown tide blooms. Because brown tide blooms have recurred for the last three years in Barnegat Bay, Little Egg Harbor, Great Bay, and Great Egg Inlet, New Jersey (and occur further south in Maryland), additional monitoring for brown tides is needed in coastal waters farther south in New Jersey.

Recommendations for additional monitoring and studies include the following:
· Continue monitoring of Aureococcus concentrations at the 11 existing water quality network stations monitored for brown tide in 2000-2002 throughout the year (a similar recommendation was made by scientists and managers in the mid-Atlantic region at the Brown Tide Workshop in April 2001 at Monmouth University).
· Extend monitoring to additional water quality stations north in Raritan Bay and to water quality stations south from Great Bay.
· Continue to monitor water quality parameters associated with brown tide (e.g., salinity, temperature) and nutrients, especially dissolved organic nitrogen, and other environmental parameters simultaneously with brown tide counts at these stations.
· Assess and document impacts of brown tides on natural resources (e.g., hard clams, seagrasses) to identify potential harmful effects and to identify areas at risk.

A comprehensive report summarizing the results of the three year study and an assessment of potential environmental factors that may promote brown tide blooms, as well as geographic areas which may be at risk for blooms (e.g., seagrass habitats), is available.

For more information or to report a brown tide bloom, contact Dr. Mary Downes Gastrich, Brown Tide Assessment Project Manager, in the Division of Science, Research and Technology at (609) 292-1895 or email Mary.Downes-Gastrich@dep.state.nj.us.

Reference:
Gastrich, M.D. and C.E. Wazniak. 2002. A Brown Tide Bloom
Index based on the potential harmful effects of the brown tide alga,
Aureococcus anophagefferens. Aquatic Ecosystem Health and
Management. Vol. 33, No. 2, pp. 175–190.

Figure 1. 2002 Brown Tide Assessment Project Stations: Brown Tide Bloom Index Results in Raritan Bay and Northern Barnegat Bay.

Figure 2. Brown Tide Assessment Project Stations 2002: Brown Tide Bloom Index Results in Southern Barnegat Bay and Little Egg Harbor.

Figure 3. 2002 Brown Tide Assessment Project Stations: Brown Tide Bloom Index Results in Little Egg Harbor South to Great Egg Inlet.

Figure 4. Highest concentrations of Aureococcus at New Jersey coastal stations during 2002.

Figure 5. 2002 Brown tide concentrations at the northern reference point station in Barnegat Bay at Seaside Park (1635E).

Figure 6. 2002 Brown Tide Concentrations at the Ship Bottom station (1703C) in Little Egg Harbor near the Route 72 Causeway Bridge to Long Beach Island.

Figure 7. 2002 Brown Tide Concentrations at the southern reference point station (1824B) at the mouth of Little Egg Harbor.

Office of Science
Dr. Gary A. Buchanan, Manager

Mailing Address:
Mail code 428-01, P.O. Box 420
P.O. Box 420
Trenton, NJ 0862
Office Location:
428 East State St., 1st floor
Trenton, NJ 08625
Phone: (609) 984-6070
Fax: (609) 292-7340


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