The Northern Agricultural Region (NAR) coastline is part of the West Coast Bioregion and is over 550km long. It includes both the ‘Turquoise Coast’ from Guilderton to Dongara and the ‘Batavia Coast’ from Dongara north to the remote Zuytdorp Cliffs near Kalbarri. There are many relatively pristine beaches, intact dune systems, and charming coastal towns along the coastline’s entire length. Impressive coastal cliffs dominate the northern portion. Long stretches of the coastline are protected in a network of nature reserves including Kalbarri and Nambung National Parks. Many of the 36 islands off the Turquoise Coast are protected within the Jurien Bay Marine Park and a network of smaller island reserves. The Houtman Abrolhos Islands, one of the largest temperate limestone reef systems in Australia, comprises 210 coral cays located off the coast of Geraldton. The islands are clustered into three main groups – Wallabi, Easter and Pelsaert – and were declared a national park in 2019 (see the Strategic Plan 2020-2024). Together, these features provide habitat for a fascinating mixture of temperate and tropical coastal and marine flora and fauna. The islands and coasts also support diverse ecological communities, including several threatened species.
The coastal and marine areas of the NAR are highly valued by the community for a combination of ecological, recreational, cultural and economic reasons. There is evidence of Noongar and Yamatji people occupying various parts of the coast for many thousands of years. Aboriginal people have a spiritual and physical connection to the marine environment. Many stories of Noongar and Yamatji people contain references to the sea and its inhabitants. Stone artefacts have been found in caves in the Jurien Bay region, and the area between Greenhead and Jurien Bay has the largest number of midden deposits in Southwest Australia. Throughout the region, coastal dunes were also used as burial sites, and skeletal remains have been exposed due to dune blowouts. River mouths and estuaries tend to be particularly significant (AHIS 2020). Underwater cultural landscapes, known as Sea Country, also hold a strong cultural and spiritual connection for many Indigenous Australians (Mamid 2020). Coastal and marine environments in the region are highly sought after housing, infrastructure development, and recreation locations. Changes in tenure, management, and development in the coastal zone should protect these areas’ environmental, cultural, spiritual and historical values.
You can download the Beachcombers Field Guide or the Beachcombers App for iPhone or Android to help you identify common finds on Western Australia’s southern and mid-west beaches and includes information on some pest species. You can search for wildflowers in the Chapman River area using the CRFWildflowers App for iPhone or Android, and the Coastal Plant Pocket Guide, also available for iPhone or Android, to identify common plants found along the Northern Agricultural Region’s coast from Kalbarri to Guilderton.
The Northern Agricultural Region (NAR) coastline is oriented more or less linearly south to north. It consists of sandy beaches backed by low dunes with intervening sand promontories, rocky headlands, caves and cliffs. The sandy beaches are generally underlain by a limestone platform, and reef systems protect much of the coast from the impacts of larger coastal storms. While there is little heavy industry along the coastline, most of the population of the region is concentrated in coastal settlements. Coastal areas, therefore, face substantial pressures from urban development.
The coastline falls within the Geraldton Sandplains and Swan Coastal Plain Interim Biogeographic (IBRA) Regions. The coastal wetlands and limestone areas support distinctive vegetation communities. Patches of the vulnerable Subtropical and Temperate Coastal Saltmarsh Threatened Ecological Community (DAWE 2020; Conservation Advice 2013) can be found throughout the region’s coast as well as on some of the offshore islands. Coastal saltmarsh is restricted to the upper intertidal environment and consists mainly of salt-tolerant vegetation (halophytes) including grasses, herbs, sedges, rushes and succulent shrubs. Vegetation is generally less than 0.5 m height (with the exception of some reeds and sedges). Many species of non-vascular plants are also found in saltmarsh, including epiphytic algae, diatoms and cyanobacterial mats.
Estuaries punctuate the NAR coastline and tend to be fairly small, a few km in length. They are generally blocked by sandbars for most of the year. The limited exchange between estuaries and the sea means that they are particularly vulnerable to the impacts of nutrient and sediment deposits on water quality. Estuarine biodiversity is high, and the region’s estuaries support at least 10 freshwater fish and several coastal fish species. Estuaries are particularly important habitat for both resident and migratory shorebirds and are highly valued cultural and recreational sites. Outside of estuaries, the coastal environment is important for the conservation of heath-dwelling mammals, including Dibblers and various dunnart species as well as many birds and reptiles.
For more information on regional fauna, visit the biodiversity page.
Species diversity of seagrass, macroalgea, fish, seabirds, invertebrates and other marine flora and fauna is very high. The combination of both temperate and tropical species in the region is particularly notable. Many migratory species, particularly Cetaceans (whales and dolphins) and seabirds utilise the Northern Agricultural Region’s (NAR) marine ecosystems. The Leeuwin Current (CSIRO 2011), one of the region’s most dominant natural features, is responsible for much of this diversity. The Leeuwin Current is a warm ocean current that flows strongly southwards along the region’s coast, transporting warm, low salinity waters from the tropical north to southern Western Australia. It influences the recruitment of the Western Rock Lobster Panulirus cygnus and is responsible for the presence of true corals at the Houtman Abrolhos Islands and the transport of tropical marine species down the west coast into the Great Australian Bight. The northward flowing Western Australian Current plays an important role bringing temperature species north. The Abrolhos Islands are very diverse, providing habitat for a unique mixture of tropical, temperate and Western Australian endemic marine species. The islands are the southernmost major coral reef development in the eastern Indian Ocean, one of the highest latitude coral reef systems globally and an important part of one of the world’s 18 hotspots of coral reef biodiversity.
The Central West Coast limestone reef system extends from Kalbarri to Perth, inside the 20m depth contour, and is one of Australia’s largest temperate limestone reef systems. It supports a mix of temperate and tropical marine fauna and flora, again due to the influence of the Leeuwin Current, and extremely high species diversity of seagrasses and seaweed. Extensive seagrass meadows provide shelter and nursery habitat for many fish and other marine creatures including Western Rock Lobster. The diversity of habitats and species in the Central West Coast bioregion is well-represented in the Jurien Bay Marine Park. The islands and coast of the Jurien Bay Marine Park, along with a few other nearby islands, are the only major breeding areas for the vulnerable Australian Sea Lion Neophoca cinerea along the west coast of Australia. Inshore fauna is predominantly temperate, with up to ~35% tropical species.
At least 10 species of cetacean (three toothed and seven baleen whales) and two species of turtles (Leatherback and Loggerhead – both endangered species) have been reported from waters off the NAR. Four of the whale species are listed under the EPBC Act as endangered and two are listed as vulnerable. Other specially protected species that can occur in the region include several species of sharks (critically endangered Grey Nurse Shark Carcharias taurus and vulnerable Great White Shark Carcharodon carcharias), sygnathids (seahorses and sea dragons) and dolphins. The Abrolhos Islands are globally significant nesting areas for seabirds, including the endangered Lesser Noddy Anous tenuirostri, the vulnerable Fairy Tern Sternula nereis and large numbers of Wedge-Tailed Shearwater Puffinus pacificus. Significant floral communities on the islands include mangroves Avicennia marina, Atriplex cinerea dwarf shrubland and saltbush flats.
Thirty islands in the NAR (22 in the Abrolhos and 8 in the Turquoise Coast Island Nature Reserves) have been identified as having significant values at risk from coastal hazards such as inundation and erosion (Coastal Hazard Assessment 2018). Sea level rise of almost 1m is expected by 2120, which will result in the majority of islands in the NAR being significantly inundated during storm surge events. Some smaller islands, such as Beacon Island and Tattler Island in the Abrolhos, could be vulnerable to complete erosion under these conditions.
Commercial and recreational ﬁshing are significant activities in the coastal and offshore environments of the NAR. In this region, the principal commercial fishery is the Western Rock Lobster fishery, which is Australia’s most valuable single-species wild capture fishery (Rock Lobster Report 2017).
Introduced marine species can become deadly pests and represent one of the greatest potential threats to the region’s oceans and biodiversity (DPIRD 2016). There are 60 known non-native marine species that have become established in Western Australian waters. Most of these are temperate species (only six are exclusively tropical) established in the south-west, around Perth, Albany and Bunbury. Within the NAR there are at least 7 introduced marine invertebrates of concern, including the south-eastern Australian Fan Scallop Scaeochlamys livida which has replaced the native south-western Australian Fan Scallop Mimachlamys asperrimus. Marine pests are usually introduced inadvertently, transported on the hulls and in the ballast water tanks of ocean-going ships. Commercial shipments of seafood, aquarium supplies and aquaculture products also provide a travel opportunity for marine species (DPIRD 2009; DPIRD 2016).
Unlike many other types of environmental impacts, invasions of introduced marine species can be irreversible, making their prevention or early detection the most important aspects of marine pest management (DPIRD 2020). An Aquatic Biosecurity Charter promotes the protection of Western Australia’s oceans and rivers from aquatic pest species. The early detection of thaid snails (Thais haemastoma floridana and Thais rustica) in the port of Geraldton prevented the establishment of these potential pests in the NAR (DPIRD 2016). The community has an important role to play reporting aquatic pest sightings or unusual species to the Department of Primary Industries and Regional Development’s FishWatch hotline 1800 815 507. Boat users can assist by keeping their boats and equipment clean and ensuring that all anti-fouling protections are up to date.
Climate change is regarded as one of the most serious long-term threats to coastal and marine environments in the NAR, with widespread changes already occurring (Marine Waters 2019). The West Coast Bioregion, of which the NAR’s coastal and marine environments form an important part, is exposed to a high risk of climate change impacts because it spans a transitional zone between tropical and temperature regions (DPIRD 2019). Expected climate change impacts include changes in water temperature, ocean currents, winds, rainfall, sea level, ocean chemistry and extreme weather conditions. Climate change is already causing oceans to warm and acidify, leading to coral bleaching and reduced growth rates (Coral Reef Watch 2020). Sea levels will continue to rise, increasing coastal erosion, and there are likely to be stronger and more frequent extreme weather events, including marine heatwaves and coastal storms (Caputi et al 2015, Caputi et al 2019).
Climate change can influence biological systems by modifying the timing of spawning, species range and distribution, composition and interactions within communities, exotic species invasions and impacts, and the structure and dynamics of communities, including changes in productivity (DPIRD 2017). Species distribution shifts are the most commonly reported changes and are often the easiest to recognise and measure. Changes in the distribution of marine species are monitored in a national citizen-science program (www.redmap.org.au). Responding to the impacts of climate change requires integrated planning responses. Coastal hazards, such as recession and inundation, need to be considered as part of land use planning decision-making, consistent with State Planning Policy 2.6 (DPLH 2006). Coastal Hazard Risk Management and Adaptation Planning (CHRMAP) guidance is available to help decision-makers develop and implement effective coastal hazard risk management and adaptation plans.
Many pressures in the coastal zone relate to land use and development, including a mix of residential, recreational, industrial and commercial uses (DPLH 2020). These often conflicting land uses can result in the direct loss of coastal habitat and indirect impacts on biodiversity via effects on soil salinity, contamination or erosion. Coastal infrastructure related to ports and marinas may also impact natural sand movements, resulting in changes to erosion and accretion patterns. The majority of the residential population of the NAR is concentrated along the coast, and coastal towns in the region are popular tourism destinations. Population growth exerts strong pressure on coastal land, increasing the need for housing and infrastructure. Consideration must be given to social amenity and public access, as well as the management of coastal hazards and the adequacy of coastal foreshore reserves.
State Planning Policy 2.6 (DPLH 2006) provides guidance on managing development and land-use change in the coastal zone, particularly via establishing and enforcing public coastal foreshore reserves. Development within the coastal zone should protect, conserve and enhance coastal biodiversity and ecosystem integrity as well as cultural significance. The policy requires that all coastal development proposals are considered in the context of coastal hazard risk management and adaption planning (CHRMAP), and that sites identified as vulnerable to coastal erosion and / or inundation should be avoided. New urban development should be concentrated in and around existing settlements and infrastructure, avoiding continuous linear urban development along the coast and significant or permanent negative impacts on the environment (DPLH 2006). The policy also discusses Planned or Managed Retreat (Dannenberg et al 2019), i.e., removing or relocating coastal assets in areas likely to be subject to intolerably high risk of damage.
In this region, the principal commercial fishery is the western rock lobster fishery, which is Australia’s most valuable single-species wild capture fishery (Rock Lobster Report 2017). When they are inappropriately managed, commercial and recreational fishing activities can deplete fish stocks and negatively impact marine environments and other non-target marine species. Western Australia monitors and manages fish numbers and the health of aquatic environments under a regional-level Ecosystem-based Fisheries Management Framework (Fletcher et al 2010). The region has an excellent reputation for sustainable fishing in both the commercial and recreational sectors and 95% of WA fish stocks are not at risk from fishing (DPIRD 2017). Adverse environmental conditions, such as warmer ocean temperatures as a result of climate change, pose the greatest risk to our coastal, marine and estuarine ecosystems and the fishery resources they support. There are also occasional conflicts between commercial fishers and a growing number of recreational anglers.
The Integrated Fisheries Management Government Policy (DPIRD 2009) determines how fish resources are sustainably shared between commercial, recreational and customary fishers and aquaculture. All coastal and marine areas less than 200m deep in the NAR have been closed to trawling since the 1970s, protecting marine benthic habitats including reefs and seagrasses (DPIRD 2020). Formal fish habitat protection areas have been established at the Houtman Abrolhos Islands and at Blue Holes near Kalbarri. A number of ongoing research programs monitor the health of coral communities at the Abrolhos Islands and the status of various fisheries (DPIRD 2019), including the Western Rock Lobster fishery. A recreational fishing guide (DPIRD 2019), supported by the recfishwest app, outlines fishing licence requirements, bag, size and other possession limits and closed season and protected areas. The department has also produced a species identification guide for recreational fishers (DPIRD 2020).
Water quality in the marine and coastal waters of the NAR is generally good, although estuaries can suffer eutrophication and sedimentation (see Water page). Water quality problems in estuarine environments are compounded by poor drainage and can result in algal blooms, lower oxygen levels in the water and adverse impacts on fish and other species (WA Coastal Strategy). Water quality problems in marine environments can be caused by:
Community-led beach clean-up days, plastic bag bans and recycling programs go a long way towards reducing marine debris. Recreational beach-goers and boaters can help by taking their rubbish home with them and disposing of it properly. Policies and technical guidance documents are in place to limit industrial, agricultural and urban sources of pollution. For example, the Environmental Protection Authority (2016) has produced a guidance document outlining how to assess and predict the extent, severity and duration of impacts to benthic habitats associated with significant dredging activities.
The coast is continuously in motion, moving with the tides, wind, waves and weather systems. The daily action of wind and waves result in erosion (removal) and accretion (depositing) of sand which changes the shape of dunes (WA Coastal Strategy). Tides and storms deposit water on land, and will do so more frequently as sea levels rise. These processes become hazards when they negatively impact life, property, infrastructure, or other assets. Erosion can undermine and damage infrastructure and houses. Storm surge and powerful winds can inundate low lying land and threaten lives and properties. There are twelve coastal erosion hotspots (high value coastal areas with high vulnerability to hazards) in the NAR. The highest priority of these are Drummond Cove in Geraldton, Grace Darling Park in Lancelin, Ledge Point and Seabird (DoT 2019). The City of Greater Geraldton has conducted several Coastal Erosion and Inundation Studies that describe the expected impacts of coastal erosion and inundation on the city. Climate change and sea-level rise are expected to accelerate shoreline retreat in affected areas.
Engineering interventions to control or minimise the impacts of natural processes only offer limited and temporary protection in specific locations. These protection works are expensive, require ongoing maintenance, and may cause unintended negative impacts to the adjacent coastline (WA Coastal Strategy). Other strategies for reducing coastal erosion and inundation impacts include integrated coastal planning (CHRMAP), building homes and infrastructure away from coastal reserves (DPLH 2006) and planting or maintaining native vegetation in coastal areas, estuaries and surrounding foredunes. Introduced plants have previously been used to stabilise naturally unstable foredunes and dunes. Revegetation and rehabilitation activities should use appropriate native plant species to minimise the risk of invasion from weed species (WA Coastal Strategy).
Maintaining and enhancing public access to the coast is a high priority for the NAR community. Still, uncontrolled or informal access to the coast for recreational activities can cause damage to coastal vegetation, disturb breeding shorebirds, introduce pests and weeds and result in dune destabilisation. Access to vulnerable areas including estuaries and offshore islands by boat and 4×4 vehicles can impact on coastal ecosystems, social amenity and safety through the destruction of habitat, collection of firewood and dumping of litter and rubbish. Even activities that are seemingly harmless, like boating, diving or reef walking, can contribute significantly to degradation, especially when local human populations swell during peak tourism periods. The most disturbed areas are close to coastal towns such as Geraldton, Dongara, Jurien Bay, Cervantes and Lancelin but even in remote areas, uncontrolled access to fishing, surfing and camping spots has caused significant degradation. Public access needs to be sustainable, controlled and managed to reduce the impact on coastal environments (WA Coastal Strategy).
Coastal and foreshore management plans are prepared by both the Department of Planning, Lands and Heritage and coastal local government authorities of the NAR (e.g. Northampton 2006; Greenough 2013). These include guidelines for access to coastal areas and the kinds of recreational activities that are allowed. For example, public access is prohibited or seasonally restricted on many of the Jurien Bay Marine Park islands. The adequacy of foreshore reserves and public access points may need to be reviewed in some locations, particularly as local populations continue to grow in coastal areas.
Vegetation loss has occurred on dunes, in saltmarsh and in and around the region’s estuaries. Actvities contributing to vegetation loss include uncontrolled 4×4 traffic, clearing for agriculture and human settlement or infrastructure, illegal waste disposal, fire (Lancelin, Cervantes), illegal residency, resource exploration (near Dongara) and firewood collection. The estuaries associated with all the major rivers of the NAR have lost riparian vegetation and ecological function as a consequence of recreational, agricultural and urban use.
Restoration and rehabilitation projects aim to alleviate the extent of erosion and vegetation loss through stabilising riverbanks and dunes. Brush packing (also known as brushing), planting native vegetation and fencing sensitive areas to exclude unsustainable vehicle movement and livestock are the most common activities (Coastal Planning and Management Manual 2003). Foreshore assessments have been developed for the Chapman, Greenough and Hutt rivers. These assessments identify the most degraded foreshore areas that can be targeted for urgent rehabilitation.
Coastal Planning and Management Manual: A community guide for protecting and conserving the Western Australian coast 2003 https://www.dplh.wa.gov.au/getmedia/39e8b4f7-a9a5-4d3d-83e2-64c04962ab6d/ML_Coastal_Planning_and_Mng_Manual
CoastWest grants https://www.dplh.wa.gov.au/coastwest
Department of Planning, Lands and Heritage – Coastal planning and management (including Coastal Management Plan Assistance Program) https://www.dplh.wa.gov.au/coastal-planning
Department of Primary Industries and Regional Development – Aquatic Biosecurity http://www.fish.wa.gov.au/Sustainability-and-Environment/Aquatic-Biosecurity/Pages/default.aspx
Department of Primary Industries and Regional Development – Aquatic Biosecurity Charter http://www.fish.wa.gov.au/Sustainability-and-Environment/Aquatic-Biosecurity/Pages/Biosecurity-Charter.aspx
Department of Primary Industries and Regional Development – Fisheries and aquatic resources scorecard 2016/17 http://www.fish.wa.gov.au/Documents/sustainability_scorecard/sustainability_scorecard_2016-17.pdf
Department of Primary Industries and Regional Development – Fisheries Resources http://www.fish.wa.gov.au/About-Us/Publications/Pages/default.aspx
Department of Primary Industries and Regional Development – Integrated Fisheries Management Plans http://www.fish.wa.gov.au/About-Us/Publications/Pages/Integrated-Fisheries-Management.aspx
Department of Primary Industries and Regional Development – Introduced Marine Species in Western Australia http://beachcombers-kit.fish.wa.gov.au/wp-content/uploads/2011/03/Introduced-marine-species-book.pdf
Department of Primary Industries and Regional Development – Introduced Marine Species Factsheet http://www.fish.wa.gov.au/Documents/recreational_fishing/fact_sheets/fact_sheet_introduced_marine_species.pdff
Department of Primary Industries and Regional Development – Status reports of the fisheries and aquatic resources 2018-19: West Coast Bioregion http://www.fish.wa.gov.au/Documents/sofar/status_reports_of_the_fisheries_and_aquatic_resources_2018-19.pdf
Department of Transport Coastal Erosion and Stability (including coastal adaptation and protection grants) https://www.transport.wa.gov.au/imarine/coastal-erosion-and-stability.asp
Marine Waters Fact Sheet: Climate Change https://marinewaters.fish.wa.gov.au/resource/fact-sheet-climate-change/
National Climate Change Adaptation Research Facility CoastAdapt
Range Extension Database & Mapping project http://www.redmap.org.au/
Western Australia Coastal Zone Strategy 2050 https://www.dplh.wa.gov.au/information-and-services/state-planning/coastal-planning-and-management/wa-coastal-zone-strategy