Methods
Seed collection
The study ran over two years and encompassed two separate flowering
seasons. For the first year of study, reproductive shoots were collected
from 5 locations within Lake Macquarie, a barrier estuary on the central
coast of NSW, Australia (Fig. 1). The perimeter of the lake is dominated
by seagrass, most notably Z. m uelleri. There are two (2) power
stations that use the lake for cooling water and discharge the thermal
effluent back into the lake at Myuna Bay (Eraring Power Station) and
Mannering Park (Vales Point Power Station), resulting in temperatures
approximately 2-3°C higher than ambient temperatures (Macreadie &
Hardy, 2018; Suzzi et al., 2023). All sites for this study are
within the southern half of the lake to avoid a heavy metal gradient
(Roach, 2005) and extensive urbanisation in the north of the lake. In
the second year of the study, two control estuaries situated near Lake
Macquarie were included in the study, Brisbane Water and Tuggerah Lakes.
At each of these estuaries reproductive shoots were collected at 3
locations.