Sublethal effects of Texas brown tide on Streblospio benedicti (Polychaeta) larvae

The Texas brown tide bloom is noted for a concordant decline in benthic bio mass and species diversity. However, the link between harmful effects induc ed by Texas brown tide and benthos has not been demonstrated. It has been p roposed there may be a larval bottleneck, where larvae, but not adults, suf fer adverse effects. This study was performed to test the effect of brown t ide alga, Aureoumbra lagunensis, on mortality, growth and behavior of Streb lospio benedicti larvae. Growth rates and swimming speeds, but not mortalit y rates, of polychaete larvae were reduced in cultures with brown tide rela tive to Isochrysis galbana, which is about the same size as brown tide. Res ults from this research indicate that brown tide does have harmful subletha l effects for one dominant species of meroplanktonic larvae, which could he lp explain reduced adult population size. (C) 2000 Elsevier Science B.V. Al l rights reserved.