The Poor Knights are located 20 kms off-shore midway between the Bay of Islands and Whangarei Harbor. The Islands have been isolated from the mainland NZ for longer than any other group apart from the Three Kings Islands 60kms northwest of Cape Reinga.
What remains today are heavily eroded rims of a large volcano, which erupted some 10 million years ago. This volcano was possibly 1000meters high, measuring 15 – 25 kilometers in diameter.
Today the group consists of two main islands, Tawhiti Rahi (163ha) 191 meter high and Aorangi (110ha) and 216meters high. There are also several smaller islands and rock stacks. 6.5kms to the southwest lay the Pinnacles and the Sugarloaf. Collectively these islands form the Poor Knights Islands Nature Reserve. Rising vertically 100meters from the sea floor the many land and underwater features of caves and archways are the result of constant erosion during fluctuating sea levels.
The Poor Knights Islands are considered to be eroded ryolite from the remains of large lava domes, which rose up from a deep fracture running from the Commanded Peninsula north.
Even during the last ice age 15,000 years ago when sea levels receded joining the other northern islands and the Hauraki Gulf Islands to the mainland the Poor Knights Islands remained separated by the depth of water.
Guy & Sandra Bowden are owners of Tawapou Coastal Natives Plant Nursery on the Tutukaka Coast. Guy grew up on the Tutukaka Coast and has been passionate about NZ native plants all his life. His interest was kindled by his conservationist parents who began protecting sections of native bush and pohutukaka on the cliffs of the property over forty years ago. Below Guy talks about The Poor Knights Islands in relation to location & geology; history; plants and birds on the islands; reptiles, insects and snails on the islands; marine life and the 1996 weed eradication programme.