A series of postglacial shorelines and dunes backed by a former sea cliff,[1] they was originally covered with wetland and lowland forest, including numerous nīkau palms (the southern limit of this species on the West Coast).

[3] The most significant remnant of the flats' original vegetation is Nikau Scenic Reserve, a 20 ha block stretching from the coast to the post-glacial cliff.

Towards the hills it consists of forest dominated by northern rātā (Metrosideros robusta) and rimu (Dacrydium cupressinum), along with kamahi (Weinmannia racemosa), toro (Myrsine salicina), and nīkau (Rhopalostylis sapida).

The younger coastal ridges contain totara, kōwhai (Sophora microphylla) and akeake (Olearia avicenniifolia), and on their seaward side gorse, flax (Phormium spp.)

[2] In 2008, 80 ha of Barrytown Flats land owned by Rio Tinto, previously earmarked for ilmenite mining, was designated Te Ara Taiko Nature reserve.

[8] When early European explorer Charles Heaphy visited the area in 1846 he described it as an uninhabited strip of swampy flat land covered in rātā, flax, and bush.

[9] Later gold dredging centred on the small settlement of Seventeen Mile Beach, later renamed Fosbery and in 1881 Barrytown, of which the "All Nations Hotel", a cemetery, and a few dozen houses remain.

The trees on the coastal plain were too small and twisted for good timber, so podocarp forest in the hills was logged – these supplied planks for flumes, which carried water for gold sluicing.

[16] Barrytown JV Ltd then changed its name to TiGa Minerals and Metals and in January 2023 announced they would be lodging a new but largely unchanged application, claiming the mine would have no impact on flora, fauna, or the water table.

[17] The company applied for resource consents in April, claiming that when the mine was in full operation there would be $63m in export revenue, and up to $34 million in wages and local expenditure annually.