Research  /  Fisheries Ecology

Fisheries Ecology

Biopixel Oceans Foundation collaborates with James Cook University and Queensland’s Department of Agriculture and Fisheries (DAF) to provide ecological information to complement traditional fisheries methods. Studies range from understanding the ecology of fisheries species to determining how broader ecosystem ecology is linked to the sustainable management of fish stocks. This includes a focus on habitats that are essential to sustain healthy fish populations.

BOF is proud to showcase the work of its research collaborators. Current projects and publications of our research collaborators include the works featured on this page.

Population biology and stock structure of the black jewfish in Queensland waters

Movement behaviour of sailfish in Queensland waters

Movement patterns of dolphinfish around fish aggregating devices (FADs)

Ecological and environmental characteristics of coastal snapper nurseries and implications for the management of critical fish habitats

Where do the crabs go? Investigating movement patterns and habitat use of the giant mud crab

Essential Habitats

Fisheries management traditionally focused on the exploited component of fish populations. More recently, it has been recognised the need for an ‘ecosystem-based management’, the focuses on fish populations as holistic units. A key component of holistic management approaches involves identifying and characterising essential habitats.

Essential habitats are areas required to support specific functions for a species, as for example areas used as foraging grounds, for shelter or for reproductive purposes (ie. mating, pupping and spawning).

These habitats can be different for the different life history stages. For mobile aquatic species that move throughout numerous components of the seascape, identifying essential habitats within a species’ broader distribution range is central to understanding their ecology and to provide the information needed to underpin effective management.

Marine Protected Areas

Understanding species habitat use patterns can guide marine protected area planning or test the effectiveness of current marine protected areas.


Population biology and stock structure of the black jewfish (Protonibea diacanthus) in Queensland waters

Research led by Queensland’s Department of Agriculture and Fisheries

Since 2017, there has been a rapid increase in targeted commercial fishing effort for black jewfish in Queensland (and other states and territories) following a rise in market demand for their swim bladders, which are sold fresh or dried in South-East Asia (considered a delicacy, medicinal value and for cosmetics in some countries).

This market demand has seen Queensland commercial catch increase from ~20 tonnes to over 120 tonnes in just two years, as well as an increase in black market trade of black jewfish.

Concerns for the welfare of jewfish populations are further exasperated because jewfish form large aggregations (probably for reproduction) in coastal areas, meaning that they can be easily targeted by fishing.

Fisheries that target reproductive aggregations can significantly impact recruitment (juveniles entering the population), resulting in populations collapsing before we detect any problems. This is called hyperstability (when a fishery’s catch rate stays stable while the actual fish population declines drastically), and is an Achilles heel of data poor fisheries, such as the black jewfish fishery in Queensland.


Figure 1. Commercial fishing harvest of Protonibea diacanthus from within the Queensland east coast inshore fishery showing an increase in catches from 2016 to 2018, followed by a sharp reduction in catch after management intervention in 2019

In 2018, black jewfish in Queensland were assessed as “undefined” under the Status of Australian Fish Stocks (SAFS) reporting framework. This assessment was primarily based on insufficient information available to confidently classify the stock.

Given the high value of black jewfish bladders (up to $500 – $750 per bladder), their vulnerability as aggregating species and the absence of a stock assessment to inform how many populations need to be managed, updated biological/ecological information (including stock structure) are needed for assessment of black jewfish stock(s) in Queensland.

Information on the connectivity among stocks within- and between state jurisdictions is fundamental to ensuring better management and protection measures where needed for jewfish on the East Coast of Australia.

Further, understanding the mortality rate of fish released under a new reduced recreational in-possession limit (1 per person) in Queensland is critical to estimating the level of fishing mortality from the recreational sector.

Normally changes to a fishery will occur after they have been heavily fished, whereas with jewfish we are at the beginning of the fishery, and therefore, management can be implemented prior to over exploitation. This is a rare opportunity to maintain healthy populations of a species (and fishery) instead of trying to recover an over exploited species.

The specific objectives of the project were to:

1) Assess the age structure, fecundity, and size-at-maturity for black jewfish  populations on the East Coast of Queensland.

2) Determine the stock structure and connectivity of black jewfish throughout Queensland.

To date: The research was able to characterise key aspects of the species population biology and population structure which have been used to directly inform the stock assessment and fishery management in Queensland waters.

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