Fig. 1

Map showing locations from which oysters (Saccostrea echinata) were sampled (circle markers). SMP, Semporna (4°29′6″N 118°36′12″E); TWN, Taiwan (22°45′24″N 121°09′02″E); TKT, Taketomi Island (24°21′36″N 123°44′60″E); CNB, Cone Bay (16°30′19″S 123°34′55″E); PRL, Pirlangimpi (11°15′07″S 130°20′53″E); MLK, Milikapiti (11°22′5″S 130°34′21″E); ANR, Anuru Bay (11°43′23″S 133°20′35″E); WGU, Wigu (11°38′49″S 133°25′23″E); MRN, Mooroongga Island (11°56′06″S 135°02′47″E); NHL, Nhulunbuy (12°14′14″S 136°40′30″E); BKD, Bukudal (13°00′40″S 136°37′41″E); UMB, Umbakumba (13°39′03″S 136°40′45″E); BWN, Bowen (19°56′54″S 148°08′55″E); NUM, Noumea (22°17′21″S, 166°26′36″E)