Title

Expansion Of Harmful Brown Tides Caused By The Pelagophyte, Aureoumbra Lagunensis Deyoe Et Stockwell, To The Us East Coast

Keywords

Aureoumbra; Brown tide; Grazing; Harmful algal blooms; Nutrients

Abstract

Brown tides caused by the pelagophyte Aureoumbra lagunensis DeYoe et Stockwell have formed ecosystem disruptive algal blooms in shallow lagoons of Texas (TX), USA, for more than two decades but have never been reported elsewhere. During the summer of 2012, a dense brown tide occurred in the Mosquito Lagoon and northern Indian River Lagoon along the east coast of Florida (FL), USA. While chlorophyll a levels in this system have averaged 5μgL-1 during the past two decades, concentrations during this brown tide reached ~200μgL-1. Concurrently, levels of nitrate were significantly lower than average and levels of dissolved organic nitrogen were significantly higher than average (p<0.001 for both). Sequences of the 18S rRNA gene of the bloom community and of single cell isolates were identical to those of Aureoumbra lagunensis DeYoe et Stockwell from TX. The A. lagunensis brown tide in FL bloomed to densities exceeding 106cellsmL-1 (quantified with a species-specific immuno-label) from July through September, began to dissipate in October, but maintained densities exceeding 105cellsmL-1 in some regions through December of 2012. The decline of the bloom was associated with near-hypoxic conditions and more than 30 fish kills reported within the Mosquito Lagoon in September 2012, a number far exceeding all prior monthly reports in this system dating to 1996. Wild northern quahog populations (a.k.a. hard clam, Mercenaria mercenaria) suffered mass die offs during the brown tide and eastern oysters (Crassostrea virginica) that settled during 2012 were significantly smaller than prior years. Clearance rates of hard clams and eastern oyster were significantly reduced in the presence of Mosquito Lagoon bloom water and A. lagunensis monocultures isolated from the Mosquito Lagoon at densities of ~106cellsL-1. The expansion of harmful brown tides caused by A. lagunensis to these estuaries represents a new threat to the US southeast coast. © 2013 Elsevier B.V.

Publication Date

7-1-2013

Publication Title

Harmful Algae

Volume

27

Number of Pages

29-41

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.hal.2013.04.004

Socpus ID

84880289045 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84880289045

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