New York Report #1 March 1998 BROWNBROWN TIDETIDE —— ANAN OVERVIEWOVERVIEW Brown tides are part of growing world-wide incidences of harmful algal blooms (HAB) which are caused by a proliferation of single- celled marine plants called phytoplankton. One species of phytoplankton, the microscopic alga Aureococcus anophagefferens (or-ee-oh-KAHKAH-kus ah-no-fah-JEFJEF-fer-ens) may bloom in such densities that the water turns dark brown, a condition known as “brown tide.” In 1985, severe brown tides were first reported in the Peconic Bays of eastern Long Island, Mass. New York, in Narragansett Bay, Rhode Island and possibly in Rhode Barnegat Bay, New Jersey. Since then, brown tide has Island intermittently occurred with variable intensity in Barnegat Bay and in the bays of Long Island. Connecticut New Narragansett York Bay Locations of BROWN TIDE > .50 million cells / ml NJ, NY & RI Peconic Bays > .25 million cells / ml Great South Brown tide has had particularly detrimental effects Bay on the Peconic Bay ecosystem and the economy of eastern Long Island. During intense bloom conditions, densities of the brown tide organism can approach two million cells per milliliter. These numbers far surpass typical New mixed phytoplankton densities of 100 to 100,000 in Jersey that same volume. Eelgrass beds which serve as spawning and nursery grounds for shellfish and finfish may have Barnegat been adversely impacted by decreased light penetration, Bay at least in part, due to brown tide blooms. The Peconic estuary bay scallop industry, at one point worth almost $2 million annually, was virtually eradicated to a dockside value of merely a few thousand dollars. Oysters, hard clams and possibly blue mussels have also been impacted, to varying degrees, by brown tide although long-term impacts on these shellfish are unknown. Although not known to be a health threat to humans, the presence of brown tide may reduce people’s desire for recreational fishing, boating, and swimming in affected waters. Advances have been made regarding the identification and characterization of Aureococcus anophagefferens. However, the factors that cause bloom conditions and those that allow blooms to persist need further investigation. For this reason the Brown Tide Research Initiative was developed (see page 8). The research underway, supported by the BTRI effort, is described in this Report #1. ResearchResearch ProjectProject Briefs:Briefs: CulturingCulturing Report #1 What genetic strains of brown Writer: Patrick Dooley tide algae can be cultured? Editors: Barbara Branca Cornelia Schlenk Andersen: Multiple Culture Isolates (Xenic Designers: Barbara Branca Sharon O’Donovan and Axenic), Biodiversity and Ultrastructure of Aureococcus anophagefferens. BTRI Steering Committee: Cornelia Schlenk, Chair, NYSG The overall objective of this study is to Richard Balla, US Environmental establish and maintain culture strains of A. Protection Agency, representing the anophagefferens at the Provasoli-Guillard Peconic National Estuary Program (PEP) National Center for Culture of Marine Susan Banahan, NOAA Coastal Ocean Phytoplankton (CCMP), a storehouse for Program marine phytoplankton cultures located in Hon. Jean Cochran, Southold Town Maine at the Bigelow Laboratory for Ocean Supervisor, representing the eastern Towns Science. These cultures will then be Kenneth Koetzner, NYS Dept. of available to others for research purposes. Environmental Conservation, representing To examine the genetic diversity of A. New York State anophagefferens, several distinct cultures of Dr. Robert Nuzzi, Suffolk County Dept. of Health Services, representing algae, those with and without bacteria (xenic Suffolk County and axenic), will be established by using Roger Tollefsen, NY Seafood Council, standard micropipette methods of isolation from representing SSER and PEP Citizens water samples taken at different Long Island Advisory Committees sites. This study will also investigate whether William Wise, Marine Sciences or not A. anophagefferens goes through Research Center, SUNY Stony Brook, different life stages such as a motionless, representing the South Shore Estuary coccoid stage in the sediment or a flagellated, Reserve (SSER) Council swimming stage. What are the nutritional require- New York ments of A. anophagefferens? New York Sea Grant is part of a national network of universities meeting the challenging Wikfors & Robohm: Isolation and environmental and economic needs Propagation of the Brown Tide Alga, of the coastal ocean and Great Lakes regions. Unique among the Aureococcus anophagefferens, Using Dialysis 29 Sea Grant programs nationwide Culture Techniques. because it has both marine and Great Lakes shorelines, New York Sea Grant engages in research, To date, maintaining cultures of this organism education, and technology transfer has been difficult because the various micro- to promote the understanding, sustainable development, and macronutrients it requires have not been utilization, and conservation of our identified. This study will use a new method diverse coastal resources. NYSG of dialysis culture technique to physically facilitates the transfer of research- separate the organism from water samples in based information to a great variety of coastal user groups order to obtain unialgal, bacteria-free isolates which include businesses, federal, from bloom water. The study will also state and local government elucidate which chemicals are “required by” decision-makers and managers, the A. anophagefferens. media, and the interested public. New York Sea Grant Staff Director: Dr. Jack Mattice Brown tide and photoplankton assemblage Associate Director: Dale Baker Assistant Director: Cornelia Schlenk Photo by Robert Nuzzi Communicator: Barbara Branca Project Assistant & BTRI Outreach Specialist: Patrick Dooley 2 Brown Tide Research Initiative ResearchResearch ProjectProject Briefs:Briefs: EcologyEcology What possible physiological How does brown tide meet its nutri- mechanisms initiate algal blooms tional needs in low light conditions? and allow them to persist? Keller & Sieracki: Physiological Ecology of the Glibert & Kana: Mechanisms for Nutrient and Brown Tide Organism, Aureococcus Energy Acquisition in Low Light: Successful anophagefferens. Strategies of Aureococcus anophagefferens. This project uses cultured algae to examine the It is believed that A. anophagefferens out-competes physiological factors that initiate an algal bloom. other phytoplankton by having mechanisms to The investigators will try to determine whether acquire energy and nutrients in highly turbid waters A. anophagefferens out-competes other species as are found in the Peconics. This competitive in light-limited environments. Its photosynthetic success is believed contingent on the ability to ability may give it an advantage in turbid (cloudy) supplement photosynthesis with heterotrophic waters such as Long Island embayments. Which uptake of organic compounds and to utilize two algae are predominantly grazed upon, including different pathways for assimilating organic nitrogen brown tide and other co-occurring species, will under limited-light conditions. be investigated. If the co-occurring species are This study will explore the photosynthetic, selected by grazers as their primary food source respiratory, and nitrogen uptake capabilities of while brown tide organisms are avoided, then laboratory clones of A. anophagefferens under a brown tide populations may be able to increase range of light and nutrient conditions. The results to bloom densities. from these cultured clones will be compared to To culture A. anophagefferens and other co- several other naturally co-occurring species or occurring algae, a variety of enrichment, dilution species that are representative of turbid bays. Size and single-cell isolation techniques will be used. To fractionation, serial dilution and a variety of media identify, mark and count the algae populations in types will be used to culture the algae. The use of field samples, flow cytometry and antibody methods tracer techniques will also be employed to will be employed. In this manner, the mechanisms investigate its rates of photosynthetic, respiratory, which initiate a brown tide and its bloom cycle will and nitrogen uptake. be investigated. Key Terms from Algae to Zooplankton algae Primitive, often aquatic, plants that may carry on photosynthesis, mesocosm Experimental apparatus or enclosure in which environmental but lack the flowers, roots, stems, and leaves of higher plants. factors can be manipulated. algal bloom High concentrations or densities of algae. mesozooplankton Medium sized zooplankton (size range: 20-200 anthropogenic (source of nutrients) Derived from human activities microns). (i.e., fertilizer, animal waste, sewage, automobile exhaust, urban runoff). micronutrient Nutrients required in relatively small concentrations such axenic culture The growth of a single species of organism in the absence as trace organics, metals and chelators. of living cells of another species. microzooplankton Small zooplankton (size range: 2-20 microns). culture A growth of microscopic cells in a controlled artificial environment. nitrogen A biologically important nutrient essential to plant growth. DIN Dissolved Inorganic Nitrogen (e.g., nitrate, nitrite, and sometimes DIN nutrient A substance required for growth (e.g., nitrogen, phosphorus, ammonium). vitamins, trace metals). Don Dissolved Organic Nitrogen (e.g., urea). organic Compounds containing carbon and also containing hydrogen