Coastal management is diverse and uses a variety of approaches, each with its own motivations, theoretical background and history of implementation. Approaches covered in this chapter are integrated management, Indigenous management, climate adaptation, cumulative impacts management, threatened species management, and restoration and recovery.
Traditional Owners and Custodians are trying to build the foundational platform for their views and aspirations and ensure it is included in the full delivery agenda, which involves strategic directions, policy development, implementation planning, regulatory compliance power and resourcing. Indigenous people are aware of the range of levers to pull, but are often not in positions to influence change across all elements.
However, governance doors that were once closed to Indigenous people are starting to open. For example, the Great Barrier Reef Foundation established a Traditional Owner Advisory Group to provide strategic advice until the Reef 2050 Traditional Owner Alliance is formalised. However, substantive involvement remains the exception, with very few statutory arrangements for mandatory Traditional Owner involvement in decision-making for marine research and management.
Management approaches are either ineffective or partially effective, but, with the exception of threatened species management, most are improving.
Related to United Nations Sustainable Development Goal target 15.3
National coastal management legislation or policy is absent.
Resourcing for adequate co-management approaches is absent. Indigenous practitioners need empowerment to implement the necessary changes.
Generally, where Indigenous communities and organisations are enabled to enact management, there is success with limited resources.
Coastal adaptation to climate change impacts, occurs primarily at the local level following general guidelines provided by states.
New policies and guidelines have been developed, and decision-makers understand the need for cumulative effects assessment and management.
Threatened species management is uncoordinated and mostly relies on habitat protection, but protection is inadequate.
Coastal restoration is an emerging management action. However, for most habitats, restoration is still done at scales too small to address degradation.
Integrated management
Coastal management in Australia has long been noted for a lack of national coordination and integration, largely because of complex governance structures and blocking mechanisms (Harvey 2016).There is no national coastal management legislation or policy in the Australian governance system. Previous attempts to implement a national approach to integrated coastal ‘zone’ management in Australia have failed (Clarke & Harvey 2013), but there has been some success in developing a national response to assess coastal management risks associated with climate change (DCCEE 2009, SCCCWEA 2009, DCCEE 2011).
The key elements of integrated coastal management are:
- intergovernmental (vertical) integration
- intersectoral (horizontal) integration
- community integration with government
- spatial integration (land, coast, ocean)
- integration between science and management.
These have proved difficult to achieve in Australia, where the constitutional responsibility for the coast and the nearshore ocean (up to 3 nautical miles offshore) rests largely with individual states rather than the national government. Half of the Australian states and territories have their own coastal management legislation, policies and strategies, while others incorporate coastal management into their planning and development control legislation.
Integration is also hindered by the variety of players that influence coastal management reform; in addition to the 3 tiers of Australian government, there are local community, industry and nongovernment advocacy groups. The timing and alignment of such influences is often critical in reaching agreed coastal policy outcomes. It has been argued that this ‘combination-lock effect’ (Harvey 2016) is partly responsible for blocking integration in Australian coastal management.
The most recent national coastal management inquiry (SCCCWEA 2009) recognised the need for better integration and effective adaptation to climate change in coastal management. It remains the case that prospects for a national integrated coastal management approach depend on collaboration between federal, state and local governments together with material support for implementation.
It is also essential that Traditional Owners are recognised and supported to achieve co-management benefits. Indigenous practitioners have the leadership and vision for transformative change, and combining this with organisational willingness and resourcing can support equity in sustainable management and development. This catalysing opportunity remains largely dormant in Australia and means the full potential of Indigenous inclusivity is not unlocked.
It is important that all user groups are given opportunities to evaluate the management of Australia’s marine estate. There is a critical need to create new arrangements and structures that can build a holistic understanding of both the problem and potential solutions.
Coastal management reform
Failure to support a national approach to integrated coastal management has resulted in some individual states introducing their own coastal reforms. These reforms include responses to the need for climate change adaptation; better integration of management across catchment, coast and the marine environment; and recognition of the importance of defined geomorphic compartments and sediment supply in coastal planning.
Three eastern states (New South Wales, Queensland and Victoria) introduced coastal management reform through dedicated coastal legislation and policies, while Western Australia introduced coastal management reform through planning legislation (Harvey & Clarke 2019). The goal of integration is clearly stated in the objects and guidelines of new pieces of coastal legislation in New South Wales and Victoria, albeit with different mechanisms for achieving integration in each state.
The objects of the New South Wales Coastal Management Act 2016 include a sustainable and integrated approach to coastal management to mitigate risks from coastal hazards, including the effects of climate change. Another object supports the Marine Estate Management Act 2014 in a push to provide better integration across the coastal and marine continuum.
The Coastal Management Act defines 4 coastal areas that are linked to specific development controls in the State Environmental Planning Policy (Coastal Management) 2018. The NSW coastal management manual (2018) also has mandatory requirements for preparation and monitoring of coastal management plans linked to an integrated planning system. One of the more innovative planning reforms is the inclusion of sediment compartments as part of a national framework (Thom et al. 2018).
The Victorian Marine and Coastal Act 2018 is aimed at integration across the coastal and marine environment. The Act contains guiding principles that include the need for integrated and ecosystem-based management. Key reforms directed at better integration include establishing an independent Marine and Coastal Council; abolition of regional coastal boards and strengthening the role of Catchment Management Authorities; and the creation of a marine and coastal policy and a 5-yearly action-oriented strategy, both to be signed off by all relevant ministers.
The Act’s companion, the Marine and Coastal Policy 2020, includes a planning and decision pathway that guides how to apply the principles of the Act to decision-making in the marine and coastal environment. The Act requires the development of a marine spatial planning framework, as part of the Policy, and environmental, coastal and marine management plans. To complement the Act and the Policy, a marine and coastal strategy is being developed and is due for completion in 2022.
Apart from these state-led attempts for integrated management, Future Earth Australia has developed a 10-year national strategy to ensure that our marine and coastal environments remain healthy and resilient. The Sustainable Oceans and Coasts National Strategy 2021–2030 (Future Earth Australia 2021) was released in June 2021 (see the Marine chapter).
Indigenous management
Traditional Custodians have cultural obligations and cultural responsibility for this Country. They are actively involved in many aspects of the holistic management of sea Country (Figure 35). Around Australia, coastline Indigenous communities are at different stages of advancing each of these holistic components (e.g. Torres Strait Regional Authority 2017 Ranger Achievement Book; Northern Land Council; Carpentaria Land Council). Indigenous communities have been developing their own strategies through initiatives such as sea Country plans, Healthy Country plans, Working on Country plans and management plans for Indigenous Protected Areas. These strategies take time to build and are often supported by funding from the Australian Government, state and territory governments, and agencies.
The current increases in Indigenous Protected Areas within sea Country (see the Indigenous chapter) should be matched by increased opportunities to be part of the wider breadth of strategic leadership and governance body responsibilities (see Co-management with Traditional Custodians). It is important to recognise the achievements of Traditional Owner groups while allowing Indigenous leadership to define the measures of success and set the height of their advancement.
Continuous growth in Indigenous management of sea Country needs ongoing resourcing. Over recent years, new resourcing models are emerging in which a significant proportion of the funds within a program are quarantined for Indigenous-led initiatives and projects. In the Great Barrier Reef, 10% of Reef Trust Partnership funds (totalling $51.8 million) was provided to Traditional Owner Reef Protection to deliver on the aspirations of Traditional Owners.
Resourcing also allows communities to shift from aspirational goals to developing and designing monitoring and reporting systems (see the Indigenous and Marine chapters). Currently, the monitoring information collected by Traditional Custodians does not always inform government planning and management. There can also be disagreements or misunderstandings about where provided monitoring information from Traditional Custodians is stored and how it is used. Mismatched expectations can occur between government managers and Traditional Owners when monitoring and reporting practices are designed without both parties being continuously involved in the negotiations and sense-making. Evaluations of, and reflective learnings from, management and monitoring practices would help to identify ways to strengthen the holistic management landscape.
Local report cards on coastal species have been determined by some Traditional Owners groups (e.g. Torres Strait Regional Authority (TSRA 2016), Yawuru Indigenous Protected Area Monitoring, Evaluation, Reporting and Improvement plan (Nyamba Buru Yawuru 2020) (see case study: Torres Strait 2021 state of environment report card, in the Indigenous-led monitoring and evaluation section in the Indigenous chapter). Each community has their own ways of detecting and recognising change in the health of species. Management of coastal species would be strengthened by opportunities for Traditional Owners, with consent and safeguards over their information, to actively shape their own narrative to inform others about species’ importance and abundance changes.
Co-management with Traditional Custodians
Many authors have outlined the long process and ongoing struggles of Traditional Owners to secure better recognition of their rights and responsibilities in the management of sea Country (Dale et al. 2018, Schnierer et al. 2018, Rist et al. 2019). Co-management arrangements that support Traditional Owners to be involved in broader management plans are infrequent (outside of Indigenous Protected Areas and Traditional Use of Marine Resources Agreements). Such management plans deal with, for example, the mixing of diverse values in a multiuse area or across the marine ecosystem. This means Australia is missing the opportunity to be a world leader in marine co-management and co-governance with Traditional Custodians who have unique and holistic knowledge and diverse skills (see Indigenous knowledge and research), and who have upheld responsibilities for protecting Country over many thousands of years.
While management approaches such as integrated management and ecosystem-based management might be building in regions across Australia, Traditional Owners are still largely left out of designing the management approach. For example, Indigenous leadership is often highly distanced from shaping and developing the sustainable harvest strategy for many commercially harvested species. Traditional Owners are asserting their voice for stronger recognition and inclusivity of their knowledge and leadership within regulatory approaches. Also, cultural values are still being considered retrospectively – for example, when marine park management planning has processes that inherently give more consideration to scientific and ecological contexts than cultural considerations.
The assertion of Indigenous sea Country rights and aspirations is creating shifts towards new governance structures (e.g. the new Great Barrier Reef Foundation Traditional Owner Advisory Group), new partnerships and joint arrangements (e.g. the Proposed Bardi Jawi Marine Park indicative joint management plan 2020), new Indigenous-identified roles within management structures (e.g. an Indigenous Knowledge Broker role in the National Environmental Science Program), new ways of operating through co-design with Traditional Owners (see case study: Traditional Owner-led integrated monitoring and reporting using the Strong Peoples – Strong Country framework, in the Management and data agreements with Traditional Custodians section in the Marine chapter) and more Indigenous Protected Areas. Growing the supportive structures and genuine opportunities for active Indigenous governance and leadership is helping to bring about the achievement of Indigenous sea management aspirations (see the Indigenous inclusivity section in the Marine chapter). The transition from passive to active involvement will see a major growth in the testing and expansion of Indigenous sea Country rights over the coming decade (Dale et al. 2018). There is a critical need for more investment into understanding Traditional Owner views on best practices of co-management. Gaps will persist if there is no willingness to invest in allowing Traditional Owners to honestly voice their reflections about the success metrics of co-management and co-design programs.
Historically the voice hasn't been there for Aboriginal and Torres Strait Islander people in agency management, we are seeing a change in the tide for that to start to happen. (Participant, Traditional Owner online yarning circle)
Ensuring cultural integrity within the agenda of marine management planning is seeing Indigenous leadership and agency evolve in both ocean governance and sea management. Active Indigenous governance within high-level structures and hierarchies helps to ensure that Indigenous sea Country aspirations are actively incorporated rather than passively considered within multisector management plans.
However, progress across the nation in collaborations between government and Traditional Owner groups is fragmented, with various stop-and-start opportunities and policies with limited ongoing coordination and support. Progress towards formal joint management for marine parks has generally been slower than for terrestrial parks (see table 8 in the National and international frameworks that support caring for Country section in the Indigenous chapter). In sea Country, there is often either an absence of joint management or the joint initiative is still in its infancy. For example, in the Great Barrier Reef, Traditional Owner organisations have had very few resources with which to sustain the approaches necessary for negotiating genuine co-governance and co-management (Dale et al. 2018). However, on the western coast of Australia, new investment into the joint management of 3 new marine parks through co-design between Traditional Owners and the government is a positive sign that governments are willing to share responsibilities and strengthen co-benefits.
While the co-management journey comes with inherent challenges, there has been little strategy documentation by government agencies to signify that considered thought has been given to the transition phases for co-management or successful co-management examples. Another complexity with co-management is that there needs to be a connection between terrestrial and marine co-management through cultural landscape management.
It is important to strengthen structures to ensure the full involvement of Indigenous people in shared decision-making, embedding their ownership, responsibility and expertise into sustainable management. The link between sea Country plans and integrated management planning is largely missing around the Australian coastline and will remain so if there is no awareness of their overlap. An important question needs to be asked around how often Indigenous planning (e.g Sea Country Plans) is considered alongside government planning (e.g. a state government marine estate management plan). Overlooking this means Traditional Owners miss opportunities for joint management around the coastline. Australia is lacking examples of good or world-leading co-management in the marine estate that can demonstrate a track record (i.e. more than 5 years) of sustained co-management between government agencies and Traditional Owners.
Many Traditional Owners remain unhappy with their ability to leverage their native title, or human and cultural rights for their benefit (Figure 38). Cultural authority is often weakly enforceable, and a lack of regulatory power of Traditional Owners, and of penalties for noncompliance, allows abuse of the system (Dale et al. 2018). Indigenous involvement in marine management needs to establish Indigenous authority or recognition of Indigenous governance by mobilising approaches for co-governance and co-management.
Creating the structures for a deliberative democratic approach has been a key component in delivering the foundational elements of integrated management in New South Wales (Brooks et al. 2020). This democracy involves decision-makers transparently justifying their decisions and effectively responding to the voices, needs, inputs, concerns and options of the communities to which they are responsible. Putting this into practice has challenges, but the willingness and resourcing to create constructive dialogues is important in transparently weighing up the choices and consequences involved in balancing the use of our marine resources with environmental stewardship.
Climate adaptation
Climate adaptation on our coasts involves adjustments to account for the actual or anticipated effects of climate change. It includes adjustments to the built environment (e.g. coastal infrastructure and housing), changes in industry practices, and adaptation of coastal biodiversity. It may also include socio-economic tools such as disaster risk management regimes (e.g. emergency evacuation plans) and insurance. Coastal adaptation may be spontaneous or planned, in response to observed impacts, or in anticipation of future effects.
In the context of the built environment, climate adaptation can involve:
- retreat or protection, where houses or infrastructure are moved out of the impact zone
- accommodation, such as raising floor levels or improving drainage
- protection, which includes hard engineering structures, such as seawalls and groynes; soft engineering, such as beach nourishment and replenishment, beach scraping and dune management; non-engineering, nature-based options, such as use of greenspace; and nature-based coastal defence, achieved through construction of structured habitats such as mangrove forests or shellfish reefs.
Coastal adaptation is in its infancy in Australia (Ramm et al. 2017), particularly in regards to sea level rise, though some programs and guides have emerged in recent years. The National Climate Change Adaptation Research Facility (NCCARF) produced CoastAdapt, which provides online interactive access to several national datasets and a compendium of adaptation case studies. CoastAdapt has enabled exchange of ideas about the adaptive capacity of particular coastal systems, including both natural capacity for adjustment and adjustments made by society, and the integration of Indigenous knowledge in natural resource management.
CoastAdapt provides guidelines to avoid maladaptation, whereby an initial management action sets in place procedures that lock in an ultimately unsustainable course of action (e.g. where the cost of maintenance of a structure in future far exceeds the value of assets being protected). For example, current coastal management actions undertaken by local governments, such as dune fencing or erosion monitoring, can be considered as adaptations against future impacts, but local studies indicate these adjustments may not adequately protect natural or built resources against longer-term trends. A more systematic and nationally consistent response that includes appropriate strategic planning is required.
Since NCCARF ended in 2019, CoastAdapt has remained accessible but is no longer updated, and adaptation is now driven primarily by the states. In conjunction with local councils, states are addressing how erosion and inundation will affect coastlines, and are considering both short-term impacts of individual storms, and longer-term trends such as coastal recession in response to sea level rise.
NCCARF also supported the development of a national coastal sediment compartment framework (Thom et al. 2018, Short 2020). Processes operate differently in each coastal compartment. Several states have mapped compartments in detail, identifying areas that are prone to erosion or vulnerable to inundation (e.g. Tasmania). Sediment compartments enable identification of regional trends in shoreline behaviour. They have been used in Western Australia (where they are called cells) as a basis for considering current risk of erosion, historical shoreline movement, and future impacts of sea level rise, as well as storm-surge inundation, in some cases recommending trigger-based pathways (Grace & Thompson 2020). Coastal compartments form the basis for coastal management programs in New South Wales (as stipulated in the Coastal Management Act 2016), and provide a framework for modelling spatial variability in erosion potential (Kinsela et al. 2017).
Most states have provided guidelines and support for local councils on how to undertake coastal hazard assessments, develop appropriate adaptation strategies, and consider nature-based options such as restoring coastal wetlands. For example, Queensland has instigated the QCoast2100 program, and South Australia released coastal adaptation guidelines in November 2019. Victoria is developing guidance material in its coastal adaptation framework, consistent with its statewide marine and coastal policy.
However, some argue that local governments, who do the majority of local planning and implementation, are not well supported by or coordinated with their state governments, such that in some local government areas (LGAs) there is little or no adaptation planning (Dedekorkut-Howes et al. 2021). In other cases, attempts by a local government to implement a no-development zoning rule are overruled by their state government in favour of developers. Moreover, because adjacent LGAs are subject to similar erosion and deposition processes, variation in planning between jurisdictions means that protection infrastructure in one LGA can intensify erosional forces in a neighbouring LGA (Dedekorkut-Howes et al. 2021). There is also high variability between states in the effectiveness of their coastal management policies, largely because the federal government is only minimally involved in coastal management. In addition to governmental barriers, a significant proportion of coastal citizens oppose the implementation of adaptation measures, such that many attempts at climate adaptation by LGAs are blocked in their early stages (Mallette et al. 2021).
Human interventions can also facilitate adaptation of coastal biodiversity. For example, assisted evolution is being applied to coral reef restoration (van Oppen et al. 2015). There is also adaptation within marine industries. Increasingly, aquaculture industries are turning to selective breeding that targets not only disease resistance, but also resilience to warming and ocean acidification.
Cumulative impacts management
Cumulative impacts are the changes to the environment that are caused by a pressure in combination with other past, present and future pressures. Pressures interact with each other to produce additive, synergistic or antagonistic effects; however, there remains much uncertainty in how to define and predict ecological interactions (Côté et al. 2016).
Cumulative impact assessments (CIAs) systematically analyse and evaluate cumulative environmental change to inform decision-making and identify management actions. Ideally, management decisions incorporate uncertainties in both ecological responses and pressure interaction types. However, the outlook for cumulative impact management in the short and long term remains poor unless policies, guidelines and monitoring are further expanded across all levels of government and along the coast.
CIAs can be stipulated as a required component of environmental impact assessments at both state and federal levels. However, project-based approaches are limited in scope because they do not consider the impact of pressures external to the proposed action, or the cumulative impact of past and future pressures.
The Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) enables strategic environmental assessments (SEAs) to evaluate cumulative effects and develop management and planning outcomes at a broader scale. SEAs assess cumulative impacts on Matters of National Environmental Significance, with a collaborative assessment process undertaken by the Australian Government in conjunction with state and local governments and resource users (e.g. developers and mining companies).
SEAs are very useful for cumulative effects assessment and decision-making in coastal waters, but are rarely implemented. The most recent coastal SEAs were published in 2014 to support the streamlining of offshore petroleum environmental approvals (NOPSEMA 2014) and the management of the Great Barrier Reef World Heritage Area and adjacent coastal zone (GBRMPA 2014). A key recommendation of the Great Barrier Reef assessment was the development of the Cumulative Impact Management Policy (GBRMPA 2018) to provide a framework to mitigate or reduce cumulative impacts in the region. The policy was supported by several National Environmental Science Program reports, including Dunstan et al. (2019), which detail guidelines on how to assess cumulative risks and impacts in the Great Barrier Reef.
Despite the increase in policies and guidelines, several conceptual and methodological challenges remain that inhibit the effective management of cumulative effects in coastal waters, including inconsistent definitions and prediction of cumulative effects, lack of a systems perspective, and conflict between scientific and planning-based approaches. Long-term monitoring across coastal ecosystems is also needed to measure and assess pressure interactions and inform adaptive management processes that respond to changing conditions (i.e. adaptive monitoring).
Decision-makers at state and local levels seek advice to inform their understanding of potential impacts of current pressures and future activities (e.g. Exmouth Gulf proposals to be subject of cumulative impact study (2020)), yet the capacity for departments and proponents to achieve this is limited. Cumulative impacts are considered by some programs, such as the New South Wales Marine Estate Threat And Risk Assessment, but these are uncommon nationally. Challenges for cumulative effects management at state and local levels include a lack of regulation to effectively reconcile the scale and scope of CIAs, and the absence of guidelines on what approach best fits the environmental context.
Threatened species management
Management of threatened species in Australia is carried out using various approaches by several levels of government. Most management of threatened species habitat is done by local councils and state and territory governments; however, management of most issues, including native vegetation, is not coordinated between levels of government.
Recent analysis of human pressures along the coastline shows that very few areas of the coastline can be considered ‘intact’ or devoid of human pressure (Figure 40) (Williams et al. 2021). Only the north-west of the mainland, the southern coast and south-western Tasmania have coastlines with little human footprint. Even in areas where there is low human density, there is considerable human pressure.
Some of the pressures affecting species along the coast are national in scale (e.g. climate change), but others are caused by local activities such as land clearing for urban development. As much as 545,000 hectares (ha) of threatened species habitat was lost between 2000 and 2017 (Ward et al. 2019). Species that lost the most coastal habitat include the swift parrot (Lathamus discolor; 225,000 ha), the Australasian bittern (Botaurus poiciloptilus; 195,000 ha) and the Tasmanian wedge-tailed eagle (Aquila audax fleayi; 153,000 ha).
The scale of management needs to match the scales at which pressures and processes operate, but this is not currently happening across the ranges of many species.
The EPBC Act provides national protection for coastal biodiversity, and much of the available threatened species habitat should be protected under the Act. A major tool used to manage and conserve threatened species is the establishment of protected areas.
The Collaborative Australian Protected Area Database (CAPAD) compiles information on protected areas, including those in the coastal zone. Levels of protection range from 1 (highest) to 6, corresponding to the 6 International Union for Conservation of Nature protected area categories. Included in CAPAD are Indigenous Protected Areas (IPAs), which are identified land and sea Country dedicated to protection by Indigenous people (Figure 41). The Australian Government has recently committed $11.6 million for expansion of IPAs into sea Country and to establish new sea Country IPAs. Approximately 27,868,769 million ha of Australia’s coastline (defined as 50 kilometres from the coast) is protected, representing around 30% of the whole coastline.
The environmental values of all protected areas, including their value as habitats, vary widely and depend on each area’s ‘intactness’ (Figure 40). Environmental value also depends on the area’s vegetation coverage, which again varies considerably in protected areas across the whole coast (Figure 42).
Restoration and recovery
Australia’s coastlines are dominated by critically important habitats that include seagrass meadows, saltmarshes, mangroves, seaweed forests, oyster reefs and coral reefs. These habitats drive coastal productivity, protect shorelines from erosion, underpin biodiversity, and support many of Australia’s most valuable fisheries and tourism industries. Multiple human stressors including coastal development, pollution and climate change have led to extensive losses of seagrass meadows (around 300,000 ha lost since the 1930s (McLeod et al. 2019)), saltmarshes (50–100% losses (Duke & et al. 2003, Sinclair & Boon 2012)), tropical mangrove forests (Duke 2017, Lovelock et al. 2017), temperate seaweed forests (up to 98% declines in some species (Johnson et al. 2011, Layton et al. 2020)), oyster reefs (90–99% declines (Gillies et al. 2018)) and coral reefs (>50% loss in many regions (De'ath et al. 2012, Hughes et al. 2017)). In response to these declines and continuing threats, the Australian Government has listed many of these habitats and the ecological communities they underpin as Endangered (e.g. giant kelp – Macrocystis pyrifera; New South Wales seagrass meadows – Posidonia australis) or Vulnerable (e.g. subtropical and temperate saltmarshes) under the EPBC Act.
Coastal restoration is emerging as an increasingly important management tool aiming to recover and secure the ecosystem functions and services provided by these habitats. However, the history and current state of restoration varies greatly among habitats (McLeod et al. 2019). Seagrass restoration started in Australia in the 1970s, with efforts peaking in the 1990s and declining subsequently (Statton et al. 2018, Statton & Kendrick 2019). Most seagrass restoration efforts have been small-scale experimental tests – less than 100 square metres (m2) – with low (less than 25%) and highly variable survival rates (Statton et al. 2018, Statton & Kendrick 2019). However, recent innovations and improvements in tools and techniques are leading to improved success rates, and some examples of highly successful seagrass plantings are starting to emerge (Tan et al. 2020).
Saltmarsh restoration is the most advanced component of coastal restoration in Australia, with restoration success now documented at the scale of hundreds of hectares, and expansion projects to thousands of hectares planned for the near future (McLeod et al. 2019). Saltmarsh restoration efforts generally involve reinstating water-flow conditions to enable natural regeneration, and fencing to remove cattle grazing (Laegdsgaard 2006, Saunders et al. 2020).
While mangroves are protected from coastal development in Australia and their abundances vary temporally, having experienced both expansions and contractions in recent decades (Lymburner et al. 2020), restoration trials to minimise footprints of coastal development have involved seeding, transplanting seedlings and ameliorating environmental conditions, with success greatly determined by hydrology (Hurst et al. 2015, Erftemeijer et al. 2018).
Seaweed restoration has only been attempted a handful of times in Australia. A pioneering project to restore giant kelp in Tasmania in the early 2000s led to highly variable results, with short-term success at one location (Sanderson 2003). In recent years, giant kelp restoration efforts have focused on selecting low-nutrient- and thermally-tolerant genotypes to future-proof these forests against continued climate change (Layton et al. 2020). Other seaweed restoration efforts have successfully reversed the local extinction of Phyllospora comosa (crayweed) within the Sydney metropolitan coastline (Vergés et al. 2020). In south-eastern Australia, a major hurdle is the strong grazing pressure by herbivores such as sea urchins on the most dominant kelp species in Australia, the golden kelp (Ecklonia radiata) (Layton et al. 2020, Morris et al. 2020). There is currently growing interest in developing a market-based approach to restoring kelp forests via removal of urchins, which can be sold or ranched for human consumption (Eger et al. 2020a).
Shellfish reef restoration, mostly oyster focused, only started in Australia in 2014, but is rapidly being scaled up. Two projects are currently underway on tens of hectares in South Australia and Victoria (McLeod et al. 2019), and 13 shellfish reef restoration projects have been funded by the Australian Government’s $20 million Reef Builder program (TNC 2020). Because oyster restoration projects are very recent, there is limited information available about outcomes (Gilby et al. 2021, McAfee et al. 2021).
Coral reef restoration efforts have greatly accelerated in recent years, following extensive coral decline – particularly in the Great Barrier Reef – associated with bleaching due to more frequent warming events (Hughes et al. 2017). Restoration often involves transplantation of fragments from either extant populations or nurseries, or larval enhancement techniques to increase coral fertilisation, larval survival and recruitment. While survival of restored fragments tends to be high (60–70%), most coral restoration projects in Australia and internationally are short term (less than 18 months) and small in scale (around 100 m2) (Boström-Einarsson et al. 2020). Research is also underway to genetically enhance coral reef resilience to increased warming, through assisted evolution techniques focused on the coral host as well as on their microbial symbionts (van Oppen et al. 2015, Buerger et al. 2020).
Interest in coastal restoration has grown substantially both in Australia and internationally, with initiatives such as the UN declaration of 2021–30 as the ‘Decade on Ecosystem Restoration’ providing important momentum. The growing recognition of coastal habitats as critically important for carbon sequestration and climate change mitigation is also providing new incentives for restoration (Duarte et al. 2020). However, a fundamental issue for most habitats is the mismatch between the spatial (and temporal) scale of degradation and that of restoration. Saltmarshes and oyster reefs are 2 exceptions where restoration is being done at appropriate scales, underpinned by substantial financial and institutional support. Such support is critical for scaling up habitat restoration in Australia and globally (Eger et al. 2020b).