Chapter 1Introduction
1.1On 5 September 2022, the Senate referred an inquiry into the spread of climate‑related marine invasive species (the inquiry) to the Senate Environment and Communications References Committee (the committee) to inquire into:
The spread of climate-related marine invasive species, particularly long spined sea urchins (Centrostephanus rodgersii) along the Great Southern Reef, with particular reference to:
(a)the existing body of research and knowledge on the risks for and damage to marine biodiversity, habitat and fisheries caused by the proliferation and range shifting of non-endemic long spined sea urchins;
(b)management options, challenges and opportunities to better mitigate or adapt to these threats, and governance measures that are inclusive of First Nations communities;
(c)funding requirements, responsibility, and pathways to better manage and co-ordinate stopping the spread of climate-related marine invasive species;
(d)the importance of tackling the spread of invasive urchin 'barrens' to help facilitate marine ecosystem restoration efforts (such as for Tasmanian Giant Kelp Macrocystis pyrifera); and
(e)any other related matters.
1.2The Senate originally set a reporting date of 1March2023. After several extensions, the final reporting date for the inquiry was 3 November 2023.
Scope of this inquiry
1.3This inquiry was established to consider the range spread of the native long-spined sea urchin (Centrostephanus rodgersii)—commonly called 'Centro'—which is an endemic species to New South Wales (NSW) waters. In particular, the inquiry considered the range extension of Centro into new areas of the GreatSouthern Reef (GSR) region, including the eastern coast of Victoria and Tasmania.
1.4The inquiry was also established to consider where the Commonwealth could lead, support and collaborate on Centro management strategies. This included current and future actions undertaken by the states and industries individually and collaboratively, and where there are opportunities to draw on the knowledge of First Nations communities and their involvement in commercial or restoration programs.
1.5A particular focus was leveraging the opportunities available in the management of Centro to develop industry and markets for commercial harvesting as a premium food product, including in Australia and overseas.
Background
1.6Centro is an echinoderm, which means it is one of a family of marine invertebrates with spiky skin that includes starfish or sea stars, sea cucumbers, and other kinds of sea urchins. In Centro's case, it has very long, black moveable spines that contain an irritant toxin, used not only for its protection, but also sensing and locomotion.
1.7In a healthy and balanced ecosystem, populations of Centro are kept under control by natural predators, such as lobster and some large fish species, which can penetrate the urchin's spiny shell with their teeth, pincers and claws. Centro has been described as an 'integral component of the sea scape' in NSW, where it is a native marine species.
1.8However, where populations of Centro are left unchecked by predators, they can become overabundant and overgraze vast areas known as 'urchin barrens' (areas devoid of marine plant life, see Figure 1.1 and Figure 1.2). Centro are well known for their ability to alter habitat structure through their grazing activity and have been described as an 'ecosystem engineer'. Urchin barren formation transforms healthy kelp bed ecosystems into low productivity rocky ecosystems, and impacts the biodiversity dependent on these ecosystems. Barrens can span vast marine ecosystems, with individual barrens measuring up to hundreds of hectares.
Figure 1.1Centro barren forming within a giant kelp forest (Schouten Island, Tasmania, 2010)
Source: Dr Scott Ling (via the Institute for Marine and Antarctic Studies, Submission 38, p. 13.)
Figure 1.2Fully established urchin barren
Source: IMAS, Long-Spined Sea Urchin (Centrostephanus rodgersii) (accessed 2 November 2023).
1.9The transformation from kelp forests to urchin-barren rocky reefs also alters ecosystem services such as wave buffering and nutrient cycling, which affects the overall inshore ecosystem.
1.10Kelp forests provide critical habitats for both the juvenile and adult stages of some of 'Australia's most economically, socially and culturally valuable species and fishery resources'. Kelp forests provide:
a primary food source for abalone and lobsters;
shelter from predation for post-larval juvenile fish that have newly recruited from pelagic larval stages;
a chemical cue that allows planktonic larvae of lobster and finfish species to locate suitable habitat to recruit into;
critical habitat for prey species of higher order predators, including reef fish and lobsters, seabirds, dolphins and Australian sea lions, and multiple shark species; and
a means to capture nutrient flows from anthropogenic sources on land, potentially reducing the occurrence of negative environmental effects including algal blooms that impact fishery productivity and amenity values.
Range expansion
1.11Due to the impacts of climate change, Centro has significantly expanded its endemic range, spreading south through the GSR in Victorian and Tasmanian waters, and across to New Zealand (see Figure 1.3). The species spread is not only a result of warming oceans, but also a climate change-induced strengthening of the East Australian Current, which flows from around the Great Barrier Reef off the coast of Queensland, and down to the ocean south‑east of Tasmania.
1.12The Tasmanian Government summarised this change in its submission:
Coastal waters off the south-eastern coast of Australia are changing rapidly due to increasing ocean temperatures. Ocean temperatures off eastern Tasmania are estimated to have increased by 2°C in the past 100 years—three times the change in global average ocean temperature. The increasing frequency of marine heatwaves in recent years is compounded by a steady rise in the temperature of the EAC [East Australia Current], which together are increasingly impacting marine habitats and species, resulting in depleted kelp forests and sea grasses, a poleward shift in some marine species, and increased occurrence of disease.
Figure 1.3Range shift of Centro
Source: IMAS, Submission 38, p. 5.
1.13The spread of Centro outside its natural range represents a significant threat to the health of rocky reef ecosystems along the south-eastern coast of the Australian mainland and Tasmania. Urchin barrens have expanded rapidly along Tasmania's east coast, increasing from a total cover of 3 per cent in 1978 to 15 per cent in 2018. Over the same time period, it is estimated that the number of Centro off the Tasmanian coast grew from two positively identified individuals in 1978, to around 11 million in 2002, and an estimated 20million in 2018.
1.14Given the potential for similar exponential growth in NSW and Victoria, as well as in off-shore populations that are difficult to measure accurately, current urchin numbers in the Australian marine environment are potentially in the billions.
1.15Despite the sheer size of urchin populations, and the devastating ecological and economic crisis this immense growth represents, many Australians remain unaware of the problem. In part, this could be due to marine invasive species being less visible than other, terrestrial invasive and feral pest species, which attract public interest and government funding for programs. This was argued by Dr Ian Dutton, the General Manager—Marine Resources, Department of Natural Resources and Environment Tasmania, who told the committee:
… this is an issue that's occurring on the doorstep of more than half of Australia's population yet it's one that's not reached the level of national prominence that other comparable issues like crown-of-thorns starfish or if there is a terrestrial equivalent that had taken out 15 per cent of our terrestrial habitats in one state alone and significant areas of other states that are of great cultural and economic importance, we would have already reached some level of national focus.
1.16Centro also represents a significant economic threat, as the flow-on implications for businesses and industry dependent on these ecosystems and species decline are substantial. For example, it has been noted that the GSR contributes over $10billion per annum to the Australian economy and underpins marine-based industry and businesses across NSW, Victoria and Tasmania.
1.17Centro management is an issue that exists across all the three states with Centro populations. However, the sheer scale of the challenge is perhaps best demonstrated by the available figures for Tasmania. Regionally, the loss of species, including over 150 species that live in Tasmanian kelp ecosystems, threatens parts of the fisheries for Blacklip Abalone and Southern Rock Lobster, which have an annual gross value of production of $50million and $100 million respectively. Moreover, the Centro problem also poses a serious problem for a healthy recreational fishing sector, which contributes around $270million a year to gross state product and supports 2670 full time jobs.
1.18These figures are substantially increased when the threat to fisheries in NSW and Victoria are considered, as the combined value of the fishing industry in all three states is collectively between $200 and $250million—before other sectors including recreational fishing, tourism and other blue economy businesses are factored in.
1.19The Institute for Marine and Antarctic Studies (IMAS) noted that 'of the approximately 77 marine range-extending species recently documented to have undergone climate-driven extension across Australia … the Longspined Sea Urchin is the most ecologically important due to its ability to overgraze kelp habitats and maintain an alternative and hyper-stable barren grounds'. In its analysis of the current outlook, IMAS noted that:
The urchin represents the single largest and most immediate marine environmental threat to kelp-dominated reef ecosystems in south-eastern Australia. Extensive barrens threaten reef ecosystems from [around] 2–40 [metres] depth with local loss of hundreds of kelp-associated species, including lucrative fishery species such as abalone and lobster, plus the iconic weedy seadragon, as well as downgrading social, economic and cultural values.
Opportunities for management
1.20However, unlike many other pest and invasive species, the management of Centro also offers substantial opportunities for industry, as it is a culinary delicacy and also has potential use for other products. This was summed up by Dr Cayne Layton, IMAS Fellow and the Co‑Founder and Director of Blue Carbon Services, in his evidence to the committee:
I think the core point that we really want to make is that this is really an incredible opportunity for south-east Australia and for Australia in general, and it really is one of those rare opportunities where there is such massive potential for significant win-win-win opportunities against the triple bottom lines of environment, economics and also social and cultural benefits. That's obviously rural and regional economies across south-east Australia, Indigenous communities and organisations, fisheries, high-value seafood products, and our globally unique and absolutely remarkable Great Southern Reef and the threatened kelp forests that are the foundation of that system.
1.21Additionally, the benefits of reef and kelp forest rehabilitation and management programs have already been shown to provide impressive returns of from modest investments, not only from revived stocks for fisheries damaged by Centro populations, but also from increased biodiversity, and nitrogen and carbon values.
1.22These will be discussed further later in this report.
Condition of Australia's broader marine environment
1.23One of the recurring themes of this inquiry was the general condition of Australia's marine environment, in particular the warming of oceans caused by climate change.
1.24This issue was comprehensively laid out in the Commonwealth's State of the Environment Report 2021 (SOE), released in July 2022. On the impact of climate change on the marine environment, the SOE stated that 'the physical characteristics of the ocean, such as temperature, salinity, oxygen content and pH, are clearly changing in Australia's oceans as a result of climate change', and that:
Pressures associated with climate change and associated extremes have high to very high impact on the Australian marine environment and are generally worsening. No pressures are assessed as improving.
1.25Further, the SOE reports that the south-east and south-west of Australia are global warming hotspots.
1.26The SOE particularly highlighted the danger posed to rocky reefs and kelp beds, specifically citing the risk of overgrazing by urchins as an impact of climate change, alongside several other factors:
climate change, through rising temperatures and heatwaves, and nutrient and pH variation associated with changing current systems;
overgrazing by sea urchins and other species, resulting from range extensions and removal of top predators by fishing; and
decreasing water quality from coastal run-off.
1.27More generally, the SOE noted that 'extensive species redistributions are projected to occur around the Australian coastline for the foreseeable future' because of changing climate conditions. This has also been noted in other research. For example, authors Gervais, Champion, and Pecl highlighted that 'marine species are shifting their distributions poleward on average six times faster than terrestrial species, as well as displaying nearly double the rate of extirpations [local extinctions]'. Their paper continued:
Extensive climate-driven environmental change is now apparent throughout Australian marine systems. The East Australian Current has extended a further 350 km southwards over the last 70 years, and both the south-east and south-west regions of Australia are recognized as ocean warming 'hotspots', in the top 10% for rates of temperate increase globally. Moreover, the rate of ocean warming around Australia has accelerated in recent decades, with the greatest increases in sea surface temperature (SST) occurring off the south-eastern coastline.
1.28The Intergovernmental Panel on Climate Change (IPCC), in their sixth assessment report noted the continued impact of greenhouse gas emissions on global warming and indicated that global warming is more likely than not to reach 1.5 degrees Celsius, even under a very low greenhouse gas emission (GHG) scenario. Further, the IPCC stated that many climate-related risks are projected to become increasingly severe with every increment of global warming (very high confidence).
1.29Concerningly, the SOE noted that 'detailed explorations' of the impacts of the range shifts caused by climate-related ocean changes are 'under‑represented', leading to a lack of knowledge regarding the implications of widespread changes in species distributions, which may well have significant ecological impacts, as well as threatening the viability of some aquaculture and tourism industries.
1.30On funding, the committee understands that the Commonwealth has historically invested far more heavily in the management of tropical reefs, particularly the Great Barrier Reef, than it has in temperate reefs, such as the Great Southern Reef. For example, Dr Scott Bennett of the Great Southern Reef Foundation told the committee:
… if we look at Australian Research Council funding to the Great Barrier Reef versus temperate reefs in Australia that we did in that 2016 study—those values are up until 2015 or 2014, I think—temperate reefs received fourper cent of the funding that was allocated to coral reefs.
… Since then, 2016 to 2020, the last five years or so, that increased slightly to around 21 per cent, but that was because of the end of the funding cycle for the Centre of Excellence for Coral Reef Studies. If you also consider the federal government investment directly to the Great Barrier Reef … the $535million package in 2018 and all the additional funding the Great Barrier Reef has received in the last five years—temperate reefs have received less than one per cent of funding.
Centro Task Force 2023
1.31In February 2023, a National Centrostephanus Management Task Force (Centro Task Force or Task Force) was formed to look into:
cross-jurisdictional relationships and priorities in addressing the range expansion of Centro;
maintenance of marine ecosystem health;
interventions to manage levels of threatened species;
strategies to rehabilitate damaged ecosystems;
identification of potential new markets for sea urchins as a food product; and
the productive utilisation of waste from food processing.
1.32The Task Force comprised of members of state fishery agencies, the Commonwealth, and Commonwealth agencies the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and Fisheries Research and Development Corporation (FRDC). It met with more than 30stakeholders over June and July 2023, and completed its work in the form of a five-year business plan for the collaborative management of Centro, published in early September 2023.
1.33The plan makes three key recommendations, namely:
1) An immediate national investment of $55 million [over five years] into Centro control, guided by this Plan's action areas and priorities.
2) Continuation of the national Task Force to govern the national investment delivery, coordination, implementation and reporting (via a small secretariat hosted by a Task Force member).
3) Establishment of a National Centro Advisory Group including Traditional Owners, industry, researchers, commercial dive, processing and recreational dive sector representatives, to provide guidance, co-design, coordination and delivery of actions at a State and regional level.
1.34The Task Force also identified several action areas and priorities to manage Centro, and four 'pillars for success'—principles that should underpin actions and priorities, as well as environmental and industry outcomes.
1.35The Task Force's Five Year Plan is discussed in greater detail in chapter 4 of this report.
Structure of the report
1.36This report comprises 4 chapters, as follows:
Chapter 1 provides an introduction and background to the inquiry;
Chapter 2 provides an overview of the challenges faced by the range extension, environmental and economic impacts of Centro, as well as the approach of the states and Commonwealth to its management;
Chapter 3 discusses evidence on potential opportunities offered by an effective Centro management strategy, including export opportunities as a premium foodstuff resource;
Chapter 4 sets out evidence that supports a national strategic approach to coordinate and collaborate Centro management and environmental restoration programs, as well as the Task Force's proposed Five Year Business Plan. This chapter also includes the committee's view and recommendations.
Conduct of the inquiry
1.37In accordance with its usual practice, the committee advertised the inquiry on its website and wrote to individuals and organisations inviting submissions by 13 October 2022. The committee continued to accept submissions received after this date.
1.38The committee received 44 submissions, which are listed at Appendix 1. It also held three public hearings in: Hobart on 3 February 2023; Melbourne on 6June 2023; and Sydney on 7 June 2023. A list of witnesses who participated in the hearings is at Appendix 2.
1.39In February 2023, a National Centro Workshop was organised to inform the committee of the latest Centro research and management opportunities. It brought together 140 representatives from industry, government, research, First Nations communities, and other community members. The committee also received a private briefing from three representatives of the related Centro Task Force on 2 August 2023 at Parliament House, Canberra.
1.40Public submissions, documents providing additional information,Hansard transcripts of the hearings and tabled documents are all available on the committee's website.
Acknowledgement
1.41The committee would like to thank all the individuals and organisations who contributed their time and expertise to the inquiry.
1.42The committee also acknowledges the work undertaken by the Centro Task Force. The Task Force's work informed this inquiry, as it was able to engage in wide-ranging consultations with a very diverse range of stakeholders, and provided a proposal for a Five Year Business Plan for Centro management to the committee in mid-September 2023.