The future of fish and fisheries in Australia: prioritisation of research needs through a horizon scanning approach

Participants

To establish a list of contacts who work in the field of Fish and Fisheries in Australia, a range of approaches were used including literature searches and collation of organisational mailing lists. Contact details for 354 individuals were collated, and they were sent emails with a link inviting them to participate in the horizon scanning online survey. The horizon scan was also promoted among organisational mailing lists such as the Australian Fisheries Management Forum to further maximise reach and uptake. All participants were notified that identifiable information such as participants names and institutions would not be disseminated or made available. This research was approved by the University of Queensland office of research ethics (permit # 20169002497).

Collating the initial list of questions

The horizon scanning approach was consistent with the methods developed by Sutherland et al. (2009), and later refined by Jarvis and Young (2019) to ensure comparability of results across studies. This approach included participants submitting research questions which aligned with a focus statement ‘informing the future direction of fish and fisheries science or management in Australia to ensure we can adequately conserve and manage our environments and resources’. It was also required that questions all met the following criteria, which were adapted from Jarvis and Young (2019): (1) be relevant to fishes (all taxa) and fisheries in Australia; (2) address an important gap in knowledge; (3) be formulated as a research question (rather than general topic or priority area); (4) be answerable through a realistic research design; and (5) be of a spatial and temporal scope that could be addressed by a research team.

The online survey was launched on 4 October 2019, and was open for 8 weeks. Once submissions were received, they were evaluated against the inclusion criteria, and similar entries were combined to avoid replication These questions were then classified into seven major ‘themes’ based on similarity of topics across the submitted questions and the ease of use of the final results. Themes were identified to ensure both consistency with relevant literature (Jarvis and Young 2019; Holder et al. 2020), and direct relevance to fish and fisheries science or management in Australia. Classification was undertaken through independent allocation of each question to a single theme by co-authors. For any questions that were not consistently classified among co-authors, their intent was first discussed before allocation to the theme deemed as most suitable. The full list of submitted questions is available as supplementary material.

Prioritising questions for the final list

Participants who submitted questions in the initial phase were invited to take part in the prioritisation phase. A survey for prioritisation of research questions was provided and allowed questions to be scored between zero priority (0), to highest priority (6). The survey was open for 4 weeks from 23 April 2020. The final prioritisation matrix was then averaged across participants to identify the 10 highest priority questions for each of the seven themes. The top 10 research questions presented for each theme are listed in priority order with the highest ranked question (highest average score) listed first.

Theme 1: biosecurity

Generally speaking, biosecurity is concerned with stopping introduced species from establishing and spreading into non-native habitats, or minimising their impact on other species and environments when they do. The overall impacts of invasive species are mediated through complex biotic and abiotic interactions that occur habitat-wide, often altering ecosystems and community assemblages irrecoverably (MDBC 2004; Harris 2013). Within aquatic environments, impacts by invasive species may include habitat destruction and localised extinctions of native plant and animal species, reductions in biodiversity, the introduction of disease and parasites, and economic changes to fishing and tourism industries. Recent research has indicated that the introduction of invasive species poses a higher risk to threatened species than other anthropogenic factors such as agricultural or human disturbance, ecosystem disturbance, pollution or even climate change (IPBES 2019; Kearney et al. 2019). Management of aquatic invasive species is particularly challenging due to constraints on effective detection, monitoring, and subsequent eradication activities in aquatic systems. Indeed, the detrimental effects of non-native species introductions have been cited as a contributing factor in 68% of North American fish extinctions in the past 100 years, and an instrumental factor in the threatened status of up to 55% of Australian endemic freshwater fishes (Miller et al. 1989; Wager and Jackson 1993; Lintermans 2013). The past 50 years has seen many new establishments of non-native fishes into Australian waters, especially in the warmer northern regions of Queensland, the Northern Territory and Western Australia (Millington et al. 2022). García-Díaz et al. (2018) attributed these primarily to the either deliberate or accidental release by ornamental fish keepers. In aquatic environments, once established in the wild, invasive fishes are very challenging to eradicate, with methods limited to applying pesticides to entire waterbodies and subsequently destroying all local fish and invertebrates in the process (Sandodden et al. 2018). Once an invasive fish has naturalised, there may also be larger ongoing costs associated with mitigating their spread, including funding alternative measures of containment (e.g. installing fish screens), conducting long term fish-down activities, and providing industry subsidisations. The environmental cost can rarely be quantified.

The ‘silent’ invasion of exotic parasites, diseases, and hitchhikers that both reside within the non-native species introductions, and those that arrive by other means (e.g. ship ballast water, fish feed, etc.) have the ability to cause widespread economic losses to Australian aquaculture faming revenue (McNamara et al. 2015). Many marine-based biosecurity pathways have been identified via imported feed product, such as Sardine Herpes Virus (through import of American sardines to feed tuna in South Australia (Whittington et al. 2008)), and White Spot Syndrome Virus (through the use of infected ‘retail’ prawns being used as bait (Knibb et al. 2018)). In addition to fishery and aquaculture economic losses, secondary impacts from the loss of basal species like pilchards and prawns has resulted in increased mortality of piscivorous seabirds like penguins (Dann et al. 2000) and Australasian gannets (Bunce and Norman 2000), causing significant food web disruptions. The key research questions identified under the biosecurity theme were:

Theme 2: resource management and stewardship

Resource management and stewardship is focused on the application of community-led or voluntary initiatives, rather than strict regulatory approaches to management. There has been increasing interest in habitat rehabilitation as a form of stewardship and management in Australia, with a focus on how different stakeholder groups or agencies can collaborate (Rogers et al. 2018; Emslie et al. 2020). The co-management of fisheries resources between stakeholders and government is one area where stewardship has advanced and resulted in a shift in governance and management of the resource (Zacharin et al. 2008). These community led co-management arrangements have been shown to provide mutual benefits such as greater flexibility to allow for adaptive management under changing environmental conditions and reduced regulatory burden (i.e. red tape) (Nursey-Bray et al. 2018). In addition to this, traditional forms of resource management and stewardship, such as voluntary codes of practice or regulatory management, continue to evolve in order to deal with new challenges (e.g. anthropogenic pressures from population growth and urbanisation). However, the lack of information on the effectiveness of different approaches at achieving their outcomes has continued to stifle some enterprises through inadequate community buy-in or lack of government investment in both small- and large-scale initiatives. The key research questions identified were:

Theme 3: ecosystem and biodiversity

In the Anthropocene age of decreasing biodiversity and continuing global changes, maintaining ecosystem function is seen as a means to both preserve biological diversity and secure the services that ecosystems provide to safeguard human wellbeing into the future (Jax 2010). The concept today is prominent in many fields of ecology and conservation biology, such as biodiversity research, ecosystem management, or restoration ecology (Jax 2010). Despite the accelerating loss of species and key ecosystems, research focused on experimental marine biodiversity and ecosystem function lags far behind other areas, and constitutes only a fraction of the total number of studies (Gustafsson and Boström 2011). The paucity of available research is the same in freshwater and estuarine ecosystems, many of which support critical juvenile fish habitat and are particularly vulnerable to anthropogenic impacts such as nutrient loading (including agricultural run-off), industrial and urban pollution, habitat fragmentation and mangrove clearing (urbanisation), amongst other pressures. In the marine environment, ecosystem based fisheries management approaches have been promoted since the turn of the century, yet despite the strong support for the concept, challenges associated with its implementation have restricted its uptake (Patrick and Link 2015; Lidström and Johnson 2020). There is currently an inadequate understanding of the consequences of these environmental changes and their interactions with other stressors, especially at the higher, multi-species, organisational levels (Belgrano et al. 2015). The key research questions identified under the ecosystem and biodiversity theme were:

Theme 4: fisheries management

Within Australia, fisheries resources are monitored, assessed and managed at the international, domestic, state and local level depending on the relevant area, species, stakeholders, habitats, ecological communities or impacts involved (Haward 1995; Vince 2018). These varying forms of governance each have different legislative and policy frameworks that align to their organisational objectives for meeting the principles of ecologically sustainable development (Vince 2018). This multi-layered system is complex, with a range of formal (e.g. offshore constitutional settlement arrangements between state and territory governments with the Commonwealth) and informal arrangements (e.g. plans for community level monitoring of resources by State and local Government) (Haward 1995). Australia also has a number of statutory authorities that are set up to perform functions related to complex interjurisdictional resources, which aim to integrate resource management across jurisdictions (e.g. the Murray Darlin Basin Authority) (Koehn 2015).

In the management of wild catch fisheries, regulating the commercial harvest of target species through the use of input and output controls has been a focal point. However, over recent decades there has been a growing emphasis on management approaches that consider the needs of all fishing sectors, and account for ecosystem-wide impacts. Some of the applied management outcomes that have come from future thinking include reducing incidental catches or impacts on non-target species through bycatch reduction technologies (Avery et al. 2017; Wakefield et al. 2017) and the future projection of environmental conditions to inform adaptive management boundaries (Hobday and Hartmann 2006; Hobday et al. 2011). Other areas of recent focus include broadening the scope of fisheries management to better achieve triple bottom-line outcomes (i.e. social, ecological and economic objectives) and recognising the issues that face all fishing interests (e.g. commercial, recreational, charter, conservation and traditional fishing) (Brownscombe et al. 2019; Dichmont et al. 2020). Underlying these complex challenges are the inherent complications associated with working at the political interface, and how alternative arrangements such as non-regulatory, co-management frameworks and harvest strategies can be used to generate better outcomes (Nursey-Bray et al. 2018). Despite some recent progress in the management of fisheries or species, considerable work remains in order to progress the key science that informs direct management outcomes across the diversity of Australia’s fishing landscape. The key research questions identified were:

Theme 5: monitoring and assessment

The effectiveness of fish and fisheries management is heavily reliant on the richness of available information (Carruthers et al. 2014). Given the difficulties of undertaking population surveys on aquatic fauna, it is critical that investment in monitoring and assessment aligns with efforts that will more accurately determine the status of a species or fishery. Traditional data collection in Australian fisheries has often focused on fishery-dependent sources (e.g. commercial fishing logbook data), with trends in catch rates used to inform changes in the abundance of species (Dichmont et al. 2021). In more complex assessments, these fisheries data are often complemented by biological information, and in some cases independent surveys on species of interest that are used to inform population models. This has also had a flow on effect of research projects more commonly being designed to focus on commercial wild catch fisheries, rather than data-limited recreational fisheries. The result of this is that research questions of highest importance to fisheries assessment may become lower priority due to their difficulty of implementation. To enhance the richness of data available to assess the health of fish populations within fisheries, monitoring of wild populations has expanded to survey additional forms of mortality (e.g. recreational fishing) or directly estimate biomass (Macaulay et al. 2013). Furthermore, there has been a growing emphasis on data collection and dissemination in near real time. The key research questions identified to highlight the further challenges, data needs and concepts that are focal for progressing monitoring and assessment of fish and fisheries in Australia were:

Theme 6: environment and climate

While implicitly linked with other major themes such as ecosystem and biodiversity, the impacts of climate change on aquatic ecosystems will include shifts in temperature, acidification, deoxygenation, changes in ocean currents and sea level rise. Given the increasing research dedicated to this field, it warrants its own thematic group. Inherently, changes to aquatic environments will significantly impact on fish and fisheries resources globally via influences not just at the ecosystem or habitat level, but also phenotypic changes that may occur as fish rapidly adapt to their new environments. Movement ecology is receiving particular attention, as researchers rush to understand the rapidly depleting biodiversity in the tropics (e.g. the coral triangle) and how species distributions are tracking towards historically cooler regions at higher latitudes in line with their thermal affinity (Burrows et al. 2019). Flow-on effects on these receiving ecosystems and their food webs remain unknown. Mendenhall et al. (2020) postulated that in addition to changes in fisheries productivity and distribution, human migration to and away from coastal areas, stresses on coastal fisheries infrastructure, and challenges to prevailing maritime boundaries will also ensue. As a result, an increase in fishery-driven disputes will occur, and thus new challenges for existing fisheries management institutions will emerge (Mendenhall et al. 2020). The key research questions identified under environment and climate were:

Theme 7: emerging technologies, tools and approaches

Many of the key advances in our understanding of fish and fisheries have been driven by leaps in technology and methodology. The rapid development of molecular tools, remote sensing and wildlife tracking technologies over the past decade are several examples of where improving technologies have progressed our understanding of aquatic systems, their users and inhabitants (Lennox et al. 2017). For example, the transition from genetic approaches to genome-wide assays has allowed investigation of functional adaptation, stock structure, population size estimation and environmental DNA that can inform the current and future management of fishes and fisheries (Bravington et al. 2016; Kumar and Kocour 2017; Hansen et al. 2018). The use of remotely operated vehicles and drones represent technological advances that allowed for low-cost visual fish surveys in otherwise inaccessible marine habitats (e.g. shallow mud flats or deep-water habitats) (Ventura et al. 2016; Chaloux et al. 2021). These emerging remote technologies are complemented by advances in mapping approaches and open access software (e.g. Google Earth), which have provided researchers with the ability to explore, analyse and communicate complex spatial data such as vessel movement or wildlife tracking (Campbell et al. 2012). The following key research questions are those that may be explored through the further enhancement, development or application of emerging technologies, tools and approaches:

Conclusion

Our horizon scan identified key questions for progressing fish and fisheries throughout Australia, as was also found in a broader marine science context in New Zealand by Jarvis and Young (2019). These knowledge gaps allow researchers to seek investment and target their skills around issues that are important for the future of our species, ecosystems and fisheries. It is hoped that future horizon scan activities are undertaken to allow for continual development and reflection in the issues that face research, academics, stakeholders and managers working in the field.