Drakes Estero. Consequently, only the obligate probers are likely to be negatively affected by mariculture on intertidal flats in Drakes Estero, while most species remain unaffected and some that forage visually on surface prey may benefit from invertebrates associated with culture bags and epibiotic growth on the bags and oysters. Feeding shorebirds do not seem prone to being flushed by normal activities of culturists, but insufficient information exists to know how closely culturists can approach the birds without causing retreat by walking or flying.