The densities of two common intertidal/shallow subtidal bivalves, Soletellina alba and Arthritica helmsi, were sampled in vegetated and unvegetated habitats of the Hopkins River estuary on three occasions during the autumn/winter 1995. Winter flooding coincided with mass mortalities of the infaunal bivalve S. alba, but not A. helmsi. Mortalities were apparent for individuals living deeper in the sediment (≈35 cm) in vegetated and unvegetated habitats, but small S. alba (<1 mm) were less susceptible to mortality than larger individuals (>1 mm). Mortalities were similar across different habitat types and sediment depths, and at multiple sites within close proximity to the estuary mouth.

Sheep are seasonally-polyoestrous short-day breeders. Although the domesticated breeds have longer breeding seasons than the feral breeds, their maximum ovulation rates are only achieved over a relatively short period. The effect of these seasonal shifts in ovarian response on the success of ovum recovery for genetic improvement or breed conservation is unknown. The aim of the present study was to assess the efficiency of ovum recovery procedures for genetic conservation outwith the normal breeding season.