Aquatic Sciences Meeting, Albuquerque 2001

SS22 Strategies To Reduce Mortality in Marine and Freshwater Phytoplankton

Date: Wednesday, February 14, 2001, Time: 9:45:00 AM

Location: Acoma/Zuni/Tesuque

Smayda, T, J, UNIVERSITY OF RHODE ISLAND GRADUATE SCHOOL OF OCEANOGRAPH, KINGSTON, USA, tsmayda@gso.uri.edu

ALLELOCHEMICAL STRATEGIES OF PHYTOPLANKTON AND NUTRIENT ACQUISITION: A RELATIONSHIP?

Allelochemically-based strategies of phytoplankton may have multiple roles and survival value beyond facilitating interspecific competition and cellular defense. Under laboratory conditions, allelochemic substances influence growth rate, cause death and cell lysis, and affect population growth curves, with at least five different, species-specific allelochemical strategies known. Effects on competing species appear to be punctuated, rather than continuous, and influenced by the growth stages and nutrient status of the producer and targeted species. At the cellular level, allelopathogens serve in antimicrobial defense and confer protection to overwintering (resistant) stages. At the population level, anti-predation strategies facilitate genetic exchange, dispersal, and prolong survival favoring induction of life cycle changes. At the community level, allelochemicals may function in community organization and structuring. Field and laboratory results are applied to evaluate whether beyond these diverse benefits a fundamental and unifying function of allelochemical strategies, whether at the cellular or population level, is to facilitate nutrient acquisition in order to delay, or alleviate nutrient limitation. The contrasting bloom and species succession behavior of diatoms and harmful flagellate species is considered from this perspective.

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Aquatic Sciences Meeting, Albuquerque 2001

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