Marine Environment

Our Marine Environment - What do we want to do?

As a region and council we actually know too little about our marine environment so we want to kick start a programme of marine research. We will need the support of recreational, customary and commercial fishers to find out more and how we can better manage our marine environment.

Goals to reduce the amount of sediment and contaminants in our estuaries and low land streams will also help improve breeding habitats and the Regional Council has developed fish passage ramps so ocean-going fish and eels can migrate naturally in and out of streams and wetlands.in the bay.

Our work so far

• Hydrodynamic Model of Hawke’s Bay
• Key Ecological Areas Report
• Glider missions
• River Input Model for Hawke Bay
• Mapping Wairoa Hard and Clive Hard
• Exploring subtidal habitats with ROV
• Coastal Bird Survey

For more information on any of these programmes see below.

You can contact us for further information here coastal@hbrc.govt.nz.

Hydrodynamic Model of Hawke’s Bay

HBRC is currently supporting a PhD student at the University of Waikato to create a hydrodynamic model of Hawke’s Bay.  This model will provide insight into the types, transport, and fate of sediment into the coastal environment.  This model will incorporate data from several different programmes within HBRC including (but not limited to): SedNetNZ, ISCO samplers, coastal water quality, freshwater water quality, and nearshore sediment sampling (see photo).

Key Ecological Areas Report

NIWA combined information from HBRC and national sources (DOC, NIWA, academic literature, etc.) to assess Key Ecological Areas for Hawke’s Bay.  The review highlighted that the existing marine significant conservation areas (SCAs) satisfy some of the national criteria for key ecological areas (e.g., rarity/endemism, importance for life history stages, threatened species habitats), but are lacking in representation for biological productivity, ecosystem services, ecological function and/or naturalness.  A pilot test with Zonation software showcased that existing data could identify additional areas of significant conservation in Hawke’s Bay.

See report for more information.

Glider missions

NIWA’s glider ‘Betty’ (see photo) operated in Hawke’s Bay for 4 weeks in Autumn 2019 collecting data on water temperature, salinity, and dissolved oxygen levels in the Bay.  It recorded above average sea surface temperatures as well as low dissolved oxygen at the surface off the Mohaka River and adjacent to Cape Kidnappers headland.  Depleted oxygen can be explained by both land and ocean processes.  See report for more information.

River Input Model for Hawke Bay

NIWA has modelled the inputs of rivers and ocean outfalls on the water quality in Hawke Bay.  The Mohaka River and Wairoa River are the two biggest contributors of freshwater to the bay.  However, the offshore ocean and Tukituki River are the two biggest contributors of nutrient concentrations in Hawke Bay.  They are using data from freshwater water quality programme.

See report for more information: Modelling the effect of river inputs on coastal water quality in Hawke Bay

Animation of freshwater dispersal

This animation is a model of the dispersal and transport of freshwater from ten rivers and two wastewater outfalls into Hawke Bay from January -December 2017.  It shows that the freshwater is transported north and south along the coast by alongshore currents.

http://vimeo.com/645029185

Mapping Wairoa Hard and Clive Hard

Both the Wairoa Hard and Clive Hard have been mapped through a joint project with HBRC and NIWA.  This mapping helps identify important areas for biodiversity habitat.  The bathymetric maps from this project provide detailed information on the structure, depth and composition of the seafloor (e.g., physical habitats).  The backscatter information identifies structures in the water column (e.g., kelp beds).  Analysis of the spatial extent of different habitat types will provide insight into whether or not this area has been affected by stressors like sedimentation.

Exploring subtidal habitats with ROV

Currently, a research and investigations programme from HBRC is underway to look at subtidal habitats in the CMA. We used a Remotely Operated Vehicle (ROV) to capture the video below. It was taken in March 2020 at 25 m of the Wairoa Hard, off the coast of Hawke’s Bay between the Waikare river mouth and Waihua. This area is unique in that it is hard bottomed (cobbles, gravels, boulders) compared to the majority of the soft sediment (mud, muddy sand, sandy mud) seafloor in Hawke’s Bay. This difference in habitat structure influences species abundance and diversity, the more complex the habitat (e.g. cobbles, boulders, algae, sponges, gravel, sand, shellhash) the more niches there are for different species to occupy.

Coastal Bird Survey

The Regional Council has commissioned a region wide coastal bird survey because the diverse Hawke’s Bay coast supports a vast array of coastal bird species. 

Key findings include:

• 79 bird species and two marine mammal species were detected. 
• 57 bird species (72%) are native or endemic to New Zealand, and 28 of these species (35%) are ranked as either Nationally Threatened or At Risk under the New Zealand Threat Classification System. 
• Local indigenous species diversity was highest at estuaries, river mouths and coastal lagoons, on inshore islands and along sections of coastline with mixed rocky shore and sandy beach habitats.

This survey provides an up-to-date picture of indigenous bird diversity, abundance and distributions along Hawke’s Bay coast and will help inform coastal management decisions in the future.  See report for more information -  A baseline survey of the indigenous bird valuesof the Hawke's Bay coastline.