Bay of Islands Coastal Survey Project

The Bay of Islands project was a coastal survey under the Ocean Survey 20/20 programme. It was the first Ocean Survey 20/20 project to address a coastal area. The previous surveys focused on offshore, deepwater locations. The Bay of Islands survey was also the first survey of its scope and intensity in the coastal waters of New Zealand.

The project was coordinated by Land Information New Zealand (LINZ), and was carried out in conjunction with the Ministry of Fisheries (MFish), the Department of Conservation (DoC), the Northland Regional Council, Ministry of Research, Science and Technology (MoRST), Ministry for the Environment (MfE), MAF Biosecurity NZ, Far North District Council, Te Runanga a Iwi o Ngapuhi and Bay of Islands Maritime Park Inc (BOIMP). The National Institute of Water and Atmospheric Research (NIWA) were contracted to deliver the project.

The project took place over 2008-2010 and was completed in June 2010.

Data collected during the project is freely available via the Ocean Survey 20/20 web portal, including high-resolution seabed maps and images.

An environment under pressure

As a marine environment, the Bay of Islands coast is under increasing pressure from competing interests, including aquaculture, fisheries, tourism and recreation. Land-based human activities are also having an impact. The project collected data about Bay of Islands seabed habitats and biodiversity to provide quality baseline data for the future, and a snapshot of the current state of biodiversity. This information can be used by government agencies, the regional and district councils and local groups to develop and manage the Bay of Islands coastal resources in a more effective and sustainable way.

Survey zones

The survey area was divided into two zones:

  1. the area within the Bay of Islands from mean high water springs to a line from Cape Brett, including Motukokako Island, across the Bay to Cape Wiwiki
  2. the area outside this, extending south to Mimiwhangata and north to North Cape / Spirits Bay, down to a 200 metre water depth.

Zone one was the main area of focus, while zone two was less intensively surveyed.

Zone 1: Bathymetric map of Bay of Islands survey area showing seabed gradient from shallow inshore areas to water up to 50 metres deep. Greyed areas are very shallow areas surveyed using side-scan sonar. Source: NIWA

Bay of Islands Survey Zone 1.

Zone 2: Bathymetric map of outer coastal survey area showing seabed gradient from 50 metres depth to 200 metres depth. Source: NIWA

Bay of Islands Survey Zone 2.

Download high resolution maps here.

Project structure

The project has two phases:

  1. bathymetry / acoustic survey
  2. biological survey.

Phase one

The first phase of the project ran from 12 October to 22 November 2008.

Three vessels carried out Phase 1, at different water depths across the two survey zones.

The RV Tangaroa covered the area with depths from 200 metres to 50 metres.

The RV Pelorus surveyed the area with depths from 50 metres to around 10 metres.

A third craft with side scan sonar was used for the area with depths from 10 metres to around two metres.

High resolution aerial photography will be used at very low tide for the area shallower than two metres deep.

Phase two

Data collected during Phase 1 was used to design the project's second phase, a biological survey.

Phase two started on 1 July 2009 with the RV Tangaroa undertaking biological sampling at 30 stations within zone 2 until late July. This was followed by RV Kaharoa undertaking fish surveys and recording video and still footage of fish and underwater reefs in both zones 1 and 2 until mid August 2009.

Inshore surveying from the Rangatahi III took place from August to November 2009 while current meters were deployed in July in the Bay to take oceanographic measurements. This last activity was completed in April 2010.

What datasets were collected?

The focus of the Bay of Islands project is on mapping biodiversity. However, the project also collected sediment and water quality data. Datasets include:

  • bacterial biomass and activity
  • benthic and attached algae
  • meiofauna, macro-fauna and epifauna
  • benthic and demersal fish rocky reef assemblages
  • sediment accumulation rates (coring, forensics, sources and analysis);
  • physical oceanography data (tidal and wind driven changes in sea level, salinity measures to determine the timing of freshwater inputs, variability of Bay of Island currents)
  • water quality data (eg chlorophyll a, salinity, oxygen, metals, pollutants, suspended sediment, etc)
  • opportunistic data (wild life such as seabirds, cetaceans, cartilaginous (e.g. white sharks), breeding colonies, marine mammal sighting or aggregation areas, biogenic reefs etc).

It is intended that the data from both phases of the project will be able to be successfully accessed and utilised by a wide range of different users from government agencies to members of the general public.

Access survey data

Data collected in the survey is available to the general public through the Ocean Survey 20/20 web portal. The data is available at a range of viewing scales, which feature interactive connections between locations and the representative photos and video footage.

Find out more about the Ocean Survey 20/20 programme and previous projects.

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