Population expansion of a tropical seagrass (Halophila decipiens) in the southwest Atlantic (Brazil)

Autor(es)

Gorman, Daniel ^[1] ; Turra, Alexander ^[1] ; Bergstrom, Ellie R. ^[2] ; Horta, Paulo A. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Oceanog, Dept Oceanog Biol, Praca Oceanog 191, BR-05508120 Sao Paulo, SP - Brazil

^[2] Univ Fed Santa Catarina, Ctr Ciencias Biol, Dept Bot, Lab Ficol, BR-88040970 Florianopolis, SC - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Aquatic Botany; v. 132, p. 30-36, JUL 2016.
• Citações Web of Science: 6

Resumo

The seagrass Halophila decipiens (Ostenfeld) was recently discovered as mono-specific meadows at a number of sites within the Sao Sebastiao Channel (Sao Paulo State, Brazil). This represents a 60 km extension to the southernmost recorded limit of this genus in the southwest Atlantic and may represent a pole ward expansion of this tropical species into temperate seas. Meadows comprised patches of plantlets ranging in diameter from <1 m to >50 m; with paired leaf counts ranging from 150 to 2034/m(-2) and estimates of biomass ranging from 8.8-35.7 g OW m(-2). Across sites, biomass estimates and leaf counts were negatively correlated with depth; while all measured aspects of morphology (i.e. leaf length/width and petiole length) were greater at deeper sites suggesting a possible effect of light limitation. In a subsequent mesocosm experiment testing the physiological effects of SST from the tropics (Bahia state) and warm temperate zone (Sao Paulo state).H. decipiens returned maximum electron transport rates (ETRmax) after 14 days that were 34% lower when exposed to 20 degrees C compared to 27 degrees C (corroborating its tropical affinity), but returned similar effective quantum yields (Delta F/Fm'; 0.695-0.713) attesting to the phenotypic plasticity of the species. Overall we show that the newly discovered populations can tolerate the reduced irradiance and low temperatures of the southwest Atlantic, a trait that may have implications for the broader trend of climate mediated range shifts. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/50317-5 - Biodiversidade e funcionamento de um ecossistema costeiro subtropical: subsídios para gestão integrada
• Beneficiário: Antonia Cecília Zacagnini Amaral
• Linha de fomento: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 13/07576-5 - Ecologia populacional de invertebrados bentônicos na Baía do Araçá, litoral norte do Estado de São Paulo
• Beneficiário: Daniel Gorman
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado