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.

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.

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

Kimberley Marine Research Program