Comparative ecophysiology of bloom-forming macroalgae in the Indian River Lagoon, Florida: Ulva lactuca, Hypnea musciformis, and Gracilaria tikvahiae | Health & Environmental Research Online (HERO)

Health & Environmental Research Online (HERO)

Print Feedback Export to File

This record has one attached file:

Citation
Tags

HERO ID

3294134

Reference Type

Journal Article

Title

Comparative ecophysiology of bloom-forming macroalgae in the Indian River Lagoon, Florida: Ulva lactuca, Hypnea musciformis, and Gracilaria tikvahiae

Author(s)

Whitehouse, LNA; Lapointe, BE

Year

2015

Is Peer Reviewed?

Yes

Journal

Journal of Experimental Marine Biology and Ecology
ISSN: 0022-0981

Volume

471

Page Numbers

208-216

DOI

10.1016/j.jembe.2015.06.012

Web of Science Id

WOS:000359167700025

Abstract

Macroalgal blooms are ecological responses to nutrient enrichment in shallow seagrass-dominated estuaries. For decades the Indian River Lagoon (IRL) a biodiverse estuary in east-central Florida, has experienced persistent blooms of red drift macroalgae, including Gracilaria and Hypnea spp. Since 2013, extensive blooms of green macroalgae, such as Chaetomoipha and Ulva spp., have developed. To better understand IRL nutrient effects on bloom-forming macroalgae, field and laboratory studies (2012) assessed nitrogen (N) versus phosphorus (P) limitation and morphological/physiological characteristics in relatively urbanized (Titusville, FL) versus rural (Fort Pierce, FL) IRL segments. Field studies indicated Ulva lactuca, Hypnea musciformis, and Gracilaria tikvahiae all grew fastest in Titusville (average +/- SD; 0.49 +/- 0.07, 035 +/- 0.03, and 0.14 +/- 0.05 doublings d(-1), respectively). However, U. lactuca had the most rapid biomass doubling time (2 days). Laboratory nutrient enrichment assays revealed 3-fold increases in rapid light curve (RLC) maximum values and 2-fold faster growth at high concentrations of N and P for U. lactuca. This superior growth and photosynthesis was attributed to higher surface area:volume ratios averaging (+/- coefficients of variation, %) 5652 +/- 2.15 cm(2) g dry wt.(-1) compared to lower ratios for H. musciformis (110.7 +/- 3.97 cm(2) g dry wt.(-1)) and G. tikvahiae (91.1 +/- 1.81 cm(2) g dry wt.(-1)). Finely- and coarsely-branched H. musciformis and G. tikvahiae were similar photosynthetically but not morphologically based on a functional/form model. These data provide a physiological basis explaining bloom distributions and the recent success of green macroalgae in the increasingly eutrophic IRL (C) 2015 Elsevier B.V. All rights reserved.

Keywords

Indian River Lagoon; Photosynthesis; Walz Diving-PAM; Physiology; Macroalgae; Harmful algal blooms