Responses of corals to chronic turbidity.
Sci Rep
; 10(1): 4762, 2020 03 16.
Article
em En
| MEDLINE
| ID: mdl-32179846
ABSTRACT
Dredging increases suspended sediment concentrations (SSCs), causing elevated water turbidity (cloudiness) and light attenuation. Close to dredging, low light periods can extend over many days, affecting phototrophic epibenthic organisms like corals. To improve the ability to predict and manage dredging impacts, we tested the response of corals to an extended period of elevated turbidity using an automated sediment dosing system that precisely controlled SSCs and adjusted light availability accordingly. Replicates of four common species of corals encompassing different morphologies were exposed to turbidity treatments of 0-100 mg L-1 SSC, corresponding to daily light integrals of 12.6 to 0 mol quanta m-2 d-1, over a period of â¼7 weeks. Symbiotic dinoflagellate density and algal pigment concentration, photosynthetic yields, lipid concentrations and ratios and growth varied among the turbidity treatments, with corals exhibiting photoacclimation within low turbidity treatments. A range of physiological responses were observed within the high turbidity treatments (low light), including bleaching and changes in lipid levels and ratios. Most corals, except P. damicornis, were capable of adjusting to a turbidity treatment involving a mean light level of 2.3 mol photons m-2 d-1 in conjunction with a SSC of 10 mg L-1 over the 7 week period.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Sedimentos Geológicos
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Antozoários
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Processos Fototróficos
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Aclimatação
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article