2015-10-13 Planning & Organisation Agenda Attachment 1 to Item 7 Oyster Recruitment Assessment Report

3.1 Spatial Variation in Recruitment of Planostrea pestigris

Intertidal Oyster Recruitment

The number of oysters recruiting to tiles deployed intertidally was greatest at Site WC3 in
Weyba Creek and Site T1 in the Noosa River at Tewantin, and was lowest at site LW1 in
Lake Weyba (Figure 5 and Figure 6. A greater number of oysters recruited onto horizontal
than vertical tiles, and the differences among sites was less pronounced for vertical tiles due
to fewer recruits overall (Figure 52). There was a distinct lack of oysters recruiting to the
upper surface of the horizontal tiles deployed intertidally, likely due to exposure at low tide
and smothering from a thick layer of sediment. Similarly on vertical tiles only 6 oysters
recruited to the outer surfaces, with the majority of oysters recorded to the inner surface.
Oysters generally recruited in far greater numbers onto the underside of horizontal plates
than on plates oriented vertically (Figure 5).




      Figure 5.    Average number (± SE) of oyster recruits (P. pestigris) on horizontal and vertical
                   surfaces deployed at intertidal sites




2
    PERMANOVA: site x orientation interaction pseudo-F6,42 = 8.89, p = 0.0001


Restoration of Noosa Estuary: An Assessment of Oyster Recruitment                                       9