Determining light stress responses for a tropical multi-species seagrass assemblage.
Existing mitigations to address deterioration in water clarity associated with human activities are based on responses from single seagrass species but may not be appropriate for diverse seagrass assemblages common to tropical waters. We present findings from a light experiment designed to determine the effects of magnitude and duration of low light on a mixed tropical seagrass assemblage. Mixed assemblages of three commonly co-occurring Indo-West Pacific seagrasses, Cymodocea serrulata, Halodule uninervis and Halophila ovalis were grown in climate-controlled tanks, where replicate pots were subjected to a gradient in light availability (0.9-21.6 mols PAR m-2 day-1) for 12 weeks. Increased shading resulted in declines in growth and changes in cellular and photosynthesis responses for all species, although time-scale and magnitude of response were species-specific. Applying management criteria (e.g. thresholds) relevant to one species may under- or over-estimate potential for impact on other species and the meadow as a whole.
['Statton|John|J|', 'McMahon|Kathryn|K|', 'Lavery|Paul|P|', 'Kendrick|Gary A|GA|']
D000222:Adaptation, Physiological D035961:Alismatales D001315:Australia D018533:Biomass D031321:Hydrocharitaceae D008027:Light D010788:Photosynthesis D018515:Plant Leaves D011157:Population Dynamics D012623:Seawater D013045:Species Specificity D013312:Stress, Physiological D014329:Tropical Climate
Stress Response Seagrass assemblage Tropical seagrass Dredging Light reduction