MEPS 218:87-93 (2001)  -  doi:10.3354/meps218087

Nitrogen enrichment ameliorates the negative effects of reduced salinity on the green macroalga Enteromorpha intestinalis

Krista Kamer1,2,*, Peggy Fong1

1Department of Organismic Biology, Ecology and Evolution, University of California Los Angeles, 621 Charles E. Young Drive S., Los Angeles, California 90095-1606, USA
2Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, California 92683, USA

ABSTRACT: In southern California estuaries, the green macroalga Enteromorpha intestinalis experiences wide fluctuations in both nitrogen (N) supply and salinity. We investigated the effects of simultaneous variation in N and salinity on the growth, biomass accumulation and tissue nutrient dynamics of E. intestinalis. We conducted a fully crossed 2-factor experiment in which we varied N enrichment (low, medium and high) and salinity (15, 25 and 35 psu). Overall, addition of N enhanced algal growth while salinity reduction decreased growth. High N enrichment mitigated the negative effects that reduced salinity had on dry biomass, wet:dry biomass ratios, tissue nutrients and ability to remove phosphorus from the water column. Largely, E. intestinalis abundance was governed by N availability rather than salinity, indicating that blooms of macroalgae will likely continue to proliferate in estuaries unless nutrient loading is reduced.


KEY WORDS: Enteromorpha intestinalis · Macroalgae · Nitrogen · Salinity · Estuaries · Southern California


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