Effects of eutrophic seawater and temperature on the physiology and morphology of Hypnea musciformis J. V. Lamouroux (Gigartinales, Rhodophyta)

• Published in: Ecotoxicology (London) Vol. 24; no. 5; pp. 1040 - 1052
• Main Authors: de Faveri, Caroline, Schmidt, Éder C, Simioni, Carmem, Martins, Cintia D. L, Bonomi-Barufi, José, Horta, Paulo A, Bouzon, Zenilda L
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-07-2015; Springer; Springer Nature B.V
• Subjects: Ammonium; ammonium compounds; Analysis; anthelmintics; anti-inflammatory activity; Antiviral agents; Biomass; Cadmium; carotenoids; Carrageenin; Cell morphology; cell walls; Chemical analysis; Chlorophyll; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Eutrophic waters; Eutrophication; Gigartinales; growth retardation; Hypnea; Hypnea musciformis; Indicator species; kappa carrageenan; Light microscopy; Morphology; Photosynthesis; Photosynthesis - physiology; Physiological aspects; physiological response; Physiology; Pigments; pollutants; Reduction; Rhodophyta; Rhodophyta - cytology; Rhodophyta - growth & development; Rhodophyta - physiology; Runoff; Sea water; Seawater; Sewage; Sewage - adverse effects; sewage treatment; starch granules; Synergism; Temperature; urban areas; urbanization; Wastewater treatment; Water analysis; Water Pollutants - toxicity; Water pollution; Water Purification; Photosynthetic efficiency; Temperature; Photosynthetic pigments; Morphology; Eutrophic seawater
• ISSN: 0963-9292; 1573-3017
• DOI: 10.1007/s10646-015-1444-6

As both food and source of a kappa-carrageenan, Hypnea musciformis represents a species of great economic interest. It also synthesizes substances with antiviral, anti-helminthic and anti-inflammatory potential and shows promise for use as a bioindicator of cadmium. In this study, we investigated the combined effects of seawater from three urbanized areas (area 1: natural runoff, NRA; area 2: urbanized runoff and sewage with treatment, RTA; area 3: urbanized runoff and untreated sewage, RUS) and three different temperatures (15, 25 and 30 °C) on the growth rate, photosynthetic efficiency, photosynthetic pigments and cell morphology of H. musciformis. After 4 days (96 h) of culture, the biomass of H. musciformis showed differences that fluctuated among the areas and temperature treatments. Specifically, the specimens cultivated in 35 °C had low values of ETRₘₐₓ, αETR, βETR, and F ᵥ/F ₘ photosynthetic parameters, as well as changes in cell morphology, with reduction in photosynthetic pigments and drastic reduction in growth rates. When combined with the extreme temperatures, high concentrations of ammonium ion in seawater effluent caused an inhibition of photosynthetic activity, as well as significant variation in chlorophyll a and carotenoid contents. As observed by light microscopy, the synergism between different temperatures and pollutants found in eutrophic waters caused changes in cellular morphology with increased cell wall thickening and decreased floridean starch grains. H. musciformis also showed important changes in physiological response to each factor independently, as well as changes resulting from the synergistic interaction of these factors combined. Therefore, we can conclude that extreme temperature combined with the effect of eutrophic waters, especially RUS, caused distinct morphological and physiological changes in the red alga H. musciformis.