Survey Reveals Bay of Islands’ Marine Life
4 February 2010: Media release
A survey of the Bay of Islands' marine life and supporting ecosystems is making good progress, Land Information New Zealand (LINZ) said today.
Since August 2009 teams from the National Institute of Water and Atmospheric Research (NIWA) have been gathering field information from the Bay as part of a two-year Ocean Survey 20/20 project coordinated by LINZ.
This work continued through January, and NIWA project leader Dr Mark Morrison says a surprising amount of high quality data has been gathered about the area’s fish, marine invertebrates, marine algae, bacteria, sediments, water quality and circulation patterns.
“One of the key observations so far is that there is a higher diversity of plants on the sediment surface than we expected, particularly in soft sediment areas,” Dr Morrison says.
Diverse and colourful communities of marine algae have been found in many soft sediment areas, while kelp forests and other seaweeds such as sea rimu inhabit shallower rocky reefs.
Dr Morrison says good numbers of juvenile snapper have been observed in the inner, more sheltered areas of the bay.
“Snapper nursery grounds occur especially over habitats such as horse mussels, and a range of other fish species exist across the wider area. Leatherjackets and red mullet (goatfish) are especially common.”
Dr Morrison thanked residents for their interest in and support for the project so far. Information about the Bay’s marine biodiversity, water quality and sediments will be made publicly available via a web portal also being developed by NIWA as part of the project.
“The aim is to make the information as widely and publicly available as possible. The huge volume of data collected will serve future research for management of the Bay of Islands, as an important coastal system with a diverse range of habitats and species, and as an iconic tourist destination.”
The Bay of Islands project began in 2008 with a comprehensive seabed mapping exercise in the Bay and the eastern Northland coast between Mimiwhangata and Spirits Bay/North Cape. This work informed the biodiversity sampling phase which began in 2009.
The project, due to be completed in June 2010, is being carried out in conjunction with the Department of Conservation and Ministry of Fisheries, with input from local stakeholders including the Northland Regional and Far North District councils, tangata whenua and Bay of Islands Maritime Park Inc.
For more information on the project see:
Media contacts
For further information about the Bay of Islands project contact:
Mark Morrison
Project Leader, NIWA Auckland
Ph 09 375 2063, mobile 0274 290 507
Email m.morrison@niwa.co.nz
For further information about the Oceans Survey 20/20 project contact:
Dave Chowdhury
Senior Communications Advisor
Land Information New Zealand
Ph 04 496 5402, mobile 027 222 9566
Email media@linz.govt.nz
More information from NIWA’s fieldwork to date:
- Diverse red and green algal communities have been found in many areas where settlement surfaces such as stable cobbles, shell beds, and living bivalve (shellfish) communities (sometimes buried) were available.
- Rhodoliths (“stony” algae) and coralline algae have also been found at a number of sites, sometimes in conjunction with dense mats of tube worms. Horse mussel beds are also common in a number of areas. Shallower rocky reef systems have kelp forest covers of Carpophyllum (flap-jack) species and Ecklonia radiata, depending on where the reef is located, along with other species such as sea rimu (Caulerpra).
- In deeper reef areas, beyond the light levels required by kelps to survive, a diverse range of encrusting invertebrates dominate, including sponges, bryozoans, and hydroids. Fish are also common, with good numbers of juvenile snapper in the inner, more sheltered areas of the Bay. Nursery grounds occur over habitats such as horse mussels. There is a broad range of other fish species across a wider area: leatherjackets and red mullet (goatfish) are especially common.
- Measurements indicate that the soft sediments of the Bay are in the order of 10 to 40 metres thick in the middle and outer parts of the Bay of Islands.
- Sediment cores from sites in deeper water (greater than 25 metres) were collected throughout the Bay and on the continental shelf at over 20 key sites by the research vessel Kaharoa. These will be used to determine the distribution of sediment bacteria and animal life and to analyse the nature of the sediment itself: how fast it accumulates, where it comes from and what it is made of. They will also be used to validate previously collected multi-beam sonar data and maps.
- Water column information on physical stratification, the influence of freshwater flows, and plankton has been widely sampled using CTD (Conductivity-Temperature-Depth) samplers.
- Two oceanographic moorings have been deployed at 65 and 180 metre water depths in the entrance to the Bay, to measure temperature and currents over time.
