Home sweet home: identifying prime real estate for deep-water fish

Curtin University researchers have collaborated on a project which could pave the way for the long-term sustainable management of deep-water fish and their habitat across the Indian and Pacific oceans.

Researchers used predictive species distribution modelling to accurately map the distribution of commercially valuable Hawaiian bottomfish, a fishery which targets a group of deep-water species including snappers, groupers and jacks. These species are distributed, and fished commercially, across the Indo-Pacific including Australia.

The findings identified ‘core’ bottomfish habitat, where all species co-exist, which will allow fishing regulatory bodies to identify the most important areas for management.

The study’s lead author, Dr Cordelia Moore, Curtin’s Department of Environment and Agriculture, said ecosystem-based, or place-based, fisheries management is a new method being adopted globally, and provides a more holistic approach to managing and protecting our marine resources for the long-term.

“Currently there is a lack of detailed information on the spatial distribution of many marine species and the environmental conditions that shape them. This is particularly problematic for deep-water species that are hard to sample, meaning there is less data available to manage their populations,” Dr Moore said.

The study results showed each species responded to a unique combination of environmental conditions, with little overlap, suggesting that effective management of deep-water fisheries must take into account species-specific differences.

Dr Moore said the findings could support the sustainable management of the Hawaiian bottomfish fishery, and provide details for the future management of deep-water fish and their habitats in other parts of the world.

“Most of the species are long lived and can live up to 40 years, which means they have longer to successfully reproduce and maintain a healthy population,” Dr Moore said.

“This makes these populations particularly vulnerable to overfishing and in need of careful management,” Dr Moore said.

The research paper, titled Improving essential fish habitat designation to support sustainable ecosystem-based fisheries management, was published this month in the journal Marine Policy.

The project was a collaboration between Curtin University, the University of Hawaii Deep Sea Fish Ecology Lab, the Australian Institute of Marine Science and the Department of Land and Natural Resources Division of Aquatic Resources via the Sportfish Restoration program.

Can we rely on satellite data to monitor the Kimberley Marine Park?

Scientists from Curtin University and CSIRO have been investigating how data collected from satellites can help to provide the information needed to monitor the extensive waters of the Kimberley Marine Park.

The Kimberley region is vast and remote, making it difficult and expensive to access and monitor, but satellite remote sensing technologies are providing a cost effective method to gather historical and baseline data with broad spatial coverage and high repeat frequency at metre to kilometre scales of resolution.

A Western Australian Marine Science Institution project has focused on measurements of the turbidity of marine waters using NASA’s MODIS sensor on its Aqua satellite. 

“The murkiness or turbidity of waters directly impacts the amount of light reaching the seabed, so plays an important role in determining what organisms can exist and grow in these environments,” CSIRO’s Dr Nick Hardman-Mountford said.


To confidently monitor turbidity through time and quantify how it changes seasonally and between years, it is necessary to know the precision of the satellite-derived measurements. However, as with any derived data, there are uncertainties about how accurate a picture remotely sensing can provide and at what scale. These have not been determined previously for Kimberley waters.

To help remedy this, a key component of the research has been to analyse these uncertainties for remotely sensed turbidity ‘products’ by making comparisons with archived “in water” measurements, and by looking at what resolutions work best.

In situ data was obtained from a number of recent expeditions that occurred along the Kimberley and Pilbara coastline including sites in King Sound, Collier Bay, in the vicinity of King George River, and near Onslow on the Northwest Shelf. Data being used by the team includes specialised optical measurements, as well as measures of turbidity and vertical light attenuation.

The project is due to be completed in December 2016.

 Landsat image pan-sharpened to 15 m resolution. The town of Derby is clearly visible, as well as extensive mudflats exposed at low tide.


The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government’s Kimberley Science and Conservation Strategy co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley.


Kimberley Marine Research Program

Whales from space

By: Cassidy Newland (AIMS)

It’s as strange as it sounds… researchers are looking for whales in the Kimberley from a vantage point of 770 kilometres above sea level using the Worldview 2 Satellite.

The Satellite captures a spatial resolution of 0.46 metre pixels in the Panchromatic band and a spatial resolution of 1.6 metre pixels in the 8 band Multispectral image (Figure 1).


The Panchromatic band captures light across the visible spectrum in a single band and is often displayed as a grey scale image. It has a higher spatial resolution of up to 0.46m, but a lower spectral resolution than the multispectral. The multispectral has 8 bands extending from the far blue through the visible spectrum to the near infra-red providing higher spectral resolution but the spatial resolution is only up to 1.6m.

A number of surveys by different organisations had previously been carried out in the Kimberley by plane, boat and some from land and for the first stage I looked for an image in the World view 2 archive to match one of these.

Although there is a large archive of imagery since the satellite commenced operation in 2009, matching an exact date was difficult and we were lucky to find several images matching surveys conducted in August 2010. I acquired one image which I expected would have the most whales and began the task of looking for them.

At 12-16 metres long you might expect a Humpback whale to be relatively easy to distinguish, but in the multispectral image with 1.6m pixels, a whale seen fully surfaced will only be up to 10 pixels long. Figure 2 shows a simulation based on an actual aerial photo of what a whale might look like in a satellite image.


In actuality only a single fully surfaced whale was distinguishable, but with a lot of interpretation and a little imagination a range of whale related features were identified including partially surfaced whales, submerged whales, the foot print of recently surfaced whales, bubble rings from below and even what appears to be a bubble net.

These features are examined in each band to see where they can be best distinguished and determine what band or combination of bands will be used in the analysis to identify further features. There is also testing of the similarity of features within a type and testing of separability of each type. The result is a refined set of features which can then be used to train and verify success of the remote sensing techniques used.

The techniques used included thresholding where cut-off values are defined manually, supervised classifications using the features as training sites and unsupervised classifications where clusters are identified statistically. Of these, thresholding and unsupervised classification provided the best results.

Challenges were noise from shallow water, swell and turbidity, but it was possible to identify surfaced whales, whale footprints, some submerged whales and boats.


Related Links:

WAMSI Project 1.2.1 Humpback Whale Distribution project

ABC Kimberley’s Erin Parke talks to WAMSI/AIMS researcher Michele Thums about satellite tagging humpback whales:

The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government’s Kimberley Science and Conservation Strategy co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley.


Kimberley Marine Research Program