This was further exacerbated by the loss of land birds and the collapse in seabird populations.
These habitats are home to many fish, marine mammal and seabird populations, including white sharks.
This led to political pressure for the closure of this fishery; the seabird populations subsequently improved.
Like the nearby islands it is the result of volcanic activity and has a substantial seabird population.
Assessment of the risk to seabird populations from New Zealand commercial fisheries.
The cay also supports a diverse seabird population.
Many studies have shown overwhelming effectiveness of individual eradication campaigns, including partial or complete recovery of seabird populations.
The study highlights six types of hazard affecting seabird populations: human exploitation, predation, fisheries, pollution, disturbance and habitat change.
The feral cats introduced to the island have had a devastating effect on the native seabird population, with an estimated 60,000 seabird deaths per year.
Other human factors have led to declines and even extinctions in seabird populations, colonies and species.