Mapping marine biodiversity in Bay of Islands


Building a publicly-available database from the results of a marine mapping survey of the Bay of Islands provides us with a stocktake of the local aquatic resource, in turn giving us valuable information on what areas we can better manage for the future. 


Like many areas around coastal New Zealand, marine life in the Bay of Islands is under increasing pressure from human activities such as aquaculture, fishing, tourism and land development. If we are to measure the extent of the impacts these activities are having on the marine environment, and find ways to manage it sustainably, we need to gather comprehensive data about the area’s seabed habitats.

With the completion of a two-year survey of the marine life of the Bay of Islands and eastern coastal Northland, and the development of an online database displaying the results, we now have a snapshot of the health of the region’s aquatic biodiversity.


Land Information New Zealand commissioned NIWA to carry out the study, which is part of the government-funded Ocean Survey 20/20 project.

The survey area was divided into two zones and conducted over two phases.

Visit the Ocean Survey 20/20 website 

Mapping biodiversity, oceanography and sediments

NIWA’s research vessels and personnel, along with a number of associated subcontractors, were used to conduct surveys of the ocean floor and collect data on:

  • bacterial biomass and activity
  • benthic and attached algae
  • benthic and demersal fish life
  • meiofauna, macrofauna and epifauna
  • sediment accumulation rates
  • oceanography
  • water quality and circulation patterns

Read our media release 'Download the seabed!'

Data collection methods

  • Multi-beam echosounders: collect information on water depth and seabed.
  • Side scan sonar: collects information on seabed.
  • Aerial photographs: provide coastal information.
  • Beam trawl: collects seafloor specimens.
  • Shipek (bottom) grab: samples sediment and benthic organisms.
  • Brenke sled: samples free-swimming macrofauna.
  • Conductivity temperature depth instrument: measures water salinity, temperature, pressure, depth and density.
  • Rock dredge: samples reef areas where it is too rough to use other devices.
  • Deep towed imaging system: remote camera system to take photos and film of seabed habitats.
  • Epibenthic seamount sled: samples large epibenthic fauna on rough terrain.
  • Core sampling: samples rock, sand and other varieties of sediment.


The information drawn from the survey presents a more complete picture of the issues facing the marine environment and supporting ecosystems of the Bay of Islands and coastal Northland than ever before. By interpreting the data, groups such as government agencies, iwi, local authorities, developers and environmentalists are provided with a basis from which to manage marine resources in more effective and sustainable ways.

The survey data and interpretations are freely available to the public through Ocean Survey 20/20.

Visit the Ocean Survey 20/20 website 

This web portal makes the data available in several ways:

  • interactive web maps linking information collected from sample sites to many different, user selectable, layers
  • downloadable photographs of seabed specimens
  • a searchable metadata catalogue from which data and reports can be downloaded or provides the contact from where information can be obtained.

NIWA Contacts

placeholder image
Principal Technician - GIS and Spatial Data Management
External people involved: 
Land Information New Zealand
SilverStripe Ltd
Ministry of Fisheries
Department of Conservation
Northland Regional Council
Ministry of Science and Innovation
Ministry for the Environment
Biosecurity New Zealand
Far North Distric Council
Te Runanga a Iwi o Ngapuhi
Bay of Islands Maritime Park
Page last updated: 
18 December 2017