title: Pollutant tracking for 3 Western North Atlantic sea grasses by remote sensing: Preliminary diminishing white light responses of Thalassia testudinum, Halodule wrightii, and Zostera marina.
abstract: Sea grasses are foundation species for estuarine ecosystems. The available light for sea grasses diminishes rapidly during pollutant spills, effluent releases, disturbances such as intense riverine input, and tidal changes. We studied how sea grasses' remote-sensing signatures and light-capturing ability respond to short term light alterations. In vivo responses were measured over the entire visible-light spectra to diminishing white-light on whole-living-plants' spectral reflectance, including 6h of full oceanic-light fluences from 10% to 100%. We analyzed differences by various reflectance indices. We compared the sea grasses species responses of tropical vs. temperate and intertidals (Halodule wrightii, and Zostera marina) vs. subtidal (Thalassia testudinum). Reflectance diminished with decreasing light intensity that coincided with greater accessory pigment stimulation (anthocyanin, carotenoids, xanthins). Chlorophyll a and Chlorophyll b differed significantly among species (Thalassia vs. Halodule). Photosynthetic efficiency diminished at high light intensities. The NDVI index was inadequate to perceive these differences. Our results demonstrate the leaf-level utility of data to remote sensing for mapping sea grass and sea grass stress.
authors.affiliation: Yale University, School of Forestry and Environmental Studies, 370 Prospect Street, New Haven, CT 06511, United States. Electronic address: athoraug@msn.com.
authors.forename: Anitra
authors.initials: A
authors.lastname: Thorhaug
authors.affiliation: Yale University, School of Forestry and Environmental Studies, 370 Prospect Street, New Haven, CT 06511, United States.
authors.forename: Graeme P
authors.initials: GP
authors.lastname: Berlyn
authors.affiliation: Yale University, School of Forestry and Environmental Studies, 370 Prospect Street, New Haven, CT 06511, United States; Wesleyan University, College of the Environment, Middletown, CT 06457, United States.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Poulos
authors.affiliation: State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Forestry, Guangxi University, Daxuedonglu 100, Nanning 530005, Guangxi, China.
authors.forename: Uromi M
authors.initials: UM
authors.lastname: Goodale
mesh_terms: D035961:Alismatales / Q000737:chemistry* / Q000528:radiation effects; D001267:Atlantic Ocean; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D031321:Hydrocharitaceae / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D010788:Photosynthesis; D010860:Pigments, Biological / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry / Q000528:radiation effects; D058998:Remote Sensing Technology; D035962:Zosteraceae / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D010860:Pigments, Biological; D002734:Chlorophyll; C037184:chlorophyll b; D000077194:Chlorophyll A
keywords: Accessory pigments; Diminished light; NDVI; Partial absorption; Remote sensing; Sea grass