Science Centres: Aquatic Biodiversity and Biosecurity

Predicted fish species richness in the New Zealand EEZ.

Which parts of New Zealand’s EEZ hold the most species of bottom-dwelling fish?

To answer this question, a NIWA-led research team used data from 21 000 MFish research trawls to analyse the relationship between fish species richness and characteristics of the marine environment. From this, they calculated the expected number of fish species in trawlable parts of the EEZ (less than 2000 m depth), including areas not sampled.

This represents the first comprehensive description of species diversity patterns for bottom-dwelling fish in the New Zealand EEZ. Depth was the strongest predictor of variation in species richness. The highest number of species occurred in depths of around 900–1000 m.

In an extension of this work, distribution models for 122 bottom-dwelling species were analysed with software designed to plan protected areas. Results demonstrate the value of such systems in assessing the relative conservation benefits of proposed marine protected areas.

This research shows the value of large, high quality datasets built up over many years. The study was funded by the Foundation for Research, Science & Technology, DoC, MFish, and NIWA.