Species group report card
– sharks and sawfishes
Supporting the marine bioregional plan
for the North-west Marine Region
prepared under the Environment Protection and Biodiversity Conservation Act 1999
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© Commonwealth of Australia 2012
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CONTENTS
Species group report card – sharks and sawfishes ..................................................................
1. Sharks and sawfishes of the North-west Marine Region ............................................................
2. Vulnerabilities and pressures .......................................................................................................
3. Current protection measures ........................................................................................................
References .......................................................................................................................................
Attachment 1: Sharks and sawfishes occurring in the North-west Marine Region ..............
SPECIES GROUP REPORT CARD –
SHARKS AND SAWFISHES
Supporting the marine bioregional plan for the North-west Marine Region prepared under the Environment Protection
and Biodiversity Conservation Act 1999
Report cards
The primary objective of the report cards is to provide accessible information on the conservation
values found in Commonwealth marine regions. This information is maintained by the Department of
Sustainability, Environment, Water, Population and Communities and is available online through the
department’s website (www.environment.gov.au). A glossary of terms relevant to marine
bioregional planning is located at www.environment.gov.au/marineplans.
Reflecting the categories of conservation values, there are three types of
report cards:
 species group report cards
 marine environment report cards
 heritage places report cards.
While the focus of these report cards is the Commonwealth marine environment, in some instances
pressures and ecological processes occurring in state waters are referred to where there is
connectivity between pressures and ecological processes in state and Commonwealth waters.
Species group report cards
Species group report cards are prepared for large taxonomic groups that include species identified as
conservation values in a region; that is, species that are listed under Part 13 of the Environment
Protection and Biodiversity Conservation Act 1999 (EPBC Act) and live in the Commonwealth marine
area for all or part of their lifecycle. All listed threatened, migratory and marine species and all
cetaceans occurring in Commonwealth waters are protected under the EPBC Act and are identified in
the relevant marine bioregional plans as conservation values.
Species group report cards focus on species for which the region is important from a conservation
perspective; for example, species of which a significant proportion of the population or an important life
stage occurs in the region’s waters.
For these species, the report cards:
 outline the conservation status of the species and the current state of knowledge about its ecology
in the region
 define biologically important areas; that is, areas where aggregations of individuals of a species
display biologically important behaviours
 assess the level of concern in relation to different pressures.
1. Sharks and sawfishes of the North-west Marine Region
The North-west Marine Region has a rich fauna of cartilaginous fish (sharks and rays) owing to the diversity of marine
environments found across its waters. Of the approximately 500 shark species found worldwide, 94 are found in the
region—19 per cent of the world’s shark species (DEWHA 2008).
Four species of cartilaginous fish listed under the EPBC Act are known to occur in the
North-west Marine Region: grey nurse shark, white shark, whale shark and green sawfish.
Two other species of listed cartilaginous fish may infrequently occur in the region
(Attachment 1). Of the cartilaginous fishes known to occur in the North-west Marine Region, this report card focuses on
the six species listed in Table 1. These species were selected following consideration of their conservation status,
distribution and population structure within the region, life history characteristics and the potential for the populations in
the region to be genetically distinct from populations elsewhere.
Sawfishes
North-western Australia probably represents some of the last relatively healthy populations of sawfish in the world
(Stevens et al. 2008). The dwarf sawfish, Pristis clavata, freshwater sawfish, Pristis microdon, and green sawfish, Pristis
zijsron, occur mainly in inshore coastal waters and riverine environments of tropical northern Australia (Pillans et al.
2010).
The freshwater sawfish and green sawfish are wider-ranging in the Indo-west Pacific, while the dwarf sawfish has been
confirmed only from northern Australian waters. Given considerable declines in the global (and Australian range) of
sawfishes, northern and north-west Australia may contain the last significant populations of these sawfishes.
Important areas for sawfishes adjacent to the North-west Marine Region include the Pilbara coast, King Sound, and
lower reaches of the Fitzroy, May and Robinson rivers for the dwarf sawfish; King Sound, and the Fitzroy, Durack,
Robinson and Ord rivers for the freshwater sawfish; and Cape Keraudren for the green sawfish (Stevens et al. 2008;
Thorburn et al. 2003, 2007, 2008).
Sawfishes generally inhabit inshore coastal, estuarine and riverine environments. The dwarf sawfish is primarily a coastal
and estuarine species and juveniles appear to use estuarine waters only (Thorburn et al. 2008). There is, however, a
single record from a riverine environment, more than 100 kilometres from the estuary (Thorburn et al. 2003). The
freshwater sawfish has been recorded in north-west Australia from rivers (including isolated water holes), estuaries and
marine environments (Stevens et al. 2005). Newborns and juveniles primarily occur in the freshwater reaches of rivers
and in estuaries, while most adult freshwater sawfish have been recorded in marine and estuarine environments
(Peverell 2005; Thorburn et al. 2007). It is believed that mature freshwater sawfish enter less saline waters during the
wet season to give birth (Peverell 2005) and freshwater river reaches play an important role as nursery areas. The green
sawfish has predominantly been recorded in inshore coastal areas, including estuaries and river mouths with a soft
substrate, although there have been records of sawfish offshore in depths up to 70 metres (Stevens et al. 2005). This
species does not occupy freshwater habitats.
Short-term tracking of movement patterns has shown that dwarf sawfish occupy a range within the coastal fringe of only
a few square kilometres and show site fidelity (Stevens et al. 2008). The species spends slack high tide resting in
mangrove areas and becomes active on mud and sand flats during tidal movement, presumably feeding (Stevens et al.
2008). Short‑ term tracking has shown that green sawfish appear to have limited movements that are tidally influenced,
and they are likely to occupy a restricted range of only a few square kilometres within the coastal fringe, with a strong
association with mangroves and adjacent mudflats (Stevens et al. 2008). Sawfishes feed close to the benthos on a
variety of teleost fishes and benthic invertebrates, including cephalopods, crustaceans and molluscs (Compagno & Last
1999; Last & Stevens 2009; Pogonoski et al. 2002; Thorburn et al. 2007, 2008).
Grey nurse shark
Grey nurse sharks (Carcharias taurus) are listed as separate populations under the EPBC Act. The west coast
population is listed as vulnerable and the east coast population is listed as critically endangered. The western
subpopulation has been recorded from the North West Shelf in the north, to Cocklebiddy in the south (RB McAuley,
unpublished data). Grey nurse sharks are most commonly found on, or close to, the bottom of the continental shelf, from
close inshore to depths of about 200 metres (McAuley 2004). The grey nurse shark is more commonly found in
temperate waters. The North-west Marine Region represents the northern limit of the west coast population. Grey nurse
sharks feed primarily on a variety of teleost and elasmobranch fishes and some cephalopods (Gelsleichter et al. 1999;
Smale 2005). Reef-associated benthic and deeper shelf fishes are all consumed (Smale 2005). Details of movement
patterns of the western subpopulation are unclear (McAuley 2004), but the eastern subpopulation undergoes north–
south seasonal movements related to breeding, forming aggregations at critical rocky reef sites (Bansemer & Bennett
2009). Although aggregation sites have not been formally identified off the west coast (Chidlow et al. 2006), a reliable,
but unconfirmed, account of at least one aggregation in the North-west Marine Region has been reported (RB McAuley,
unpublished data).
Whale shark
Whale sharks (Rhincodon typus) are listed as vulnerable under the EPBC Act. They have a widespread distribution in
tropical and warm temperate seas, both oceanic and coastal (Last & Stevens 2009). The species is widely distributed in
Australian waters, most commonly at Ningaloo Marine Park in Western Australia and to a lesser extent at Christmas
Island and in the Coral Sea. The species is generally encountered close to or at the surface, as single individuals or
occasionally in schools or aggregations of up to hundreds of sharks. Whale sharks also dive to great depths (at least
980 metres) (Wilson et al. 2006). Whale sharks are migratory and undergo seasonal movements that have been
associated with productivity pulses, ocean circulation and water temperatures, and they regularly appear where seasonal
food pulses are known to occur.
Ningaloo Reef is the main known aggregation site for whale sharks in Australian waters and has the largest density of
whale sharks per kilometre in the world (Martin 2007). Whale sharks aggregate at Ningaloo between March and June each
year to feed on krill and baitfishes (Wilson et al. 2006). The North-west Marine Region is therefore important to whale
sharks for foraging.
Whale sharks tracked by satellite from north-west Australia have been shown to move in a northerly, north-easterly or
north-westerly direction towards or into Indonesian waters (Sleeman et al. 2010; Wilson et al. 2006). There appears to be
spatial and seasonal segregation of whale shark populations according to size and sex. For example, coastal
aggregations such as at Ningaloo Reef contain a high frequency of immature males (Meekan et al. 2006). Whale sharks
are one of three species of planktivorous sharks and feed on a variety of plankton and nekton (Last & Stevens 2009). It is
unknown when and where whale sharks breed.
White shark
White sharks (Carcharodon carcharias) are listed as vulnerable under the EPBC Act. The species is primarily temperate
with northern ranges off north-west Australia (CMAR 2011; Last & Stevens 2009). There are no known aggregation sites
for white sharks in the North-west Marine Region, and this species is most likely to be found south of North West Cape,
probably in low densities (Environment Australia 2002b). However, recent research is providing new insight into seasonal
movement patterns along the west coast of Australia into the North-west Marine Region (CMAR 2011). White sharks
have been recorded travelling northwards during spring and appear to return to southern waters during the summer
(CMAR 2011). Sharks travelling up the west coast probably live in the Great Australian Bight for some of the year
(CMAR 2011). International mixing of populations has also been demonstrated, with one white shark making a
transoceanic migration from South Africa to the North-west Marine Region (Bonfil et al. 2005).
Smaller white sharks (less than 3 metres in length) feed primarily on teleost and elasmobranch fishes, broadening
their diet as larger sharks to include marine mammals (Last & Stevens 2009). The exact diet in north -west Australia
is unknown, but movements into the region may be related to prey availability (CMAR 2011). Sharks that have been
tracked moving up the west coast of Australia have been subadults (CMAR 2011), and there is little information on
reproductive activities in Australian waters (pupping grounds have not been id entified in Australia).
Biologically important areas
Biologically important areas are areas that are particularly important for the conservation of the protected species and
where aggregations of individuals display biologically important behaviours such as breeding, foraging, resting or
migration. The presence of the observed behaviour is assumed to indicate that the habitat required for the behaviour is
also present. Biologically important areas have been identified for some EPBC Act listed species found in the North-west
Marine Region, using expert scientific knowledge about species’ distribution, abundance and behaviour in the region.
The selection of species was informed by the availability of scientific information, the conservation status of listed species
and the importance of the region for the species. The range of species for which biologically important areas are
identified will continue to expand as reliable spatial and scientific information becomes available.
Biologically important areas have been identified for four species of shark and sawfish: whale shark, freshwater sawfish,
green sawfish and dwarf sawfish. Behaviours used to identify biologically important areas for shark and sawfishes
include foraging, nursing and pupping. Biologically important areas are included in the North-west Marine Conservation
Values Atlas (www.environment.gov.au/cva).
2. Vulnerabilities and pressures
Vulnerabilities
Cartilaginous fish as a group are characterised by their ‘limited’ life history (late age at maturity, slow growth rate, low
fecundity, longevity, low rate of natural mortality), which results in restricted productivity. Subsequently, they have a
limited capacity to recover from population depletion. White sharks, grey nurse sharks and sawfishes are all viviparous,
giving birth to well-developed live young, but there are many gaps in our knowledge of population dynamics, particularly
of sawfishes. This precludes assessment of the species’ reproductive capacity and hence resilience to depletion. The
grey nurse shark has one of the lowest reproductive rates known among the chondrichthyans, giving birth to a maximum
of two pups every second or third year (Bansemer & Bennett 2009). In white sharks, the development of young is slow,
with a gestation period estimated to be 18 months; the 2–17 young are large when born (around 1.3 metres in length)
(Last & Stevens 2009). Only a single pregnant whale shark has ever been examined, and she contained about 300 pups
(Joung et al. 1996). Litter size is not known for dwarf and freshwater sawfish. Freshwater environments have been
identified as important nursery habitats for sawfish (Peverell 2005; Pillans et al. 2010; Thorburn et al. 2007). This
physically restrictive environment limits their ability to evade exploitation and the alteration of their habitat (Compagno &
Cook 1995) and therefore makes freshwater sawfish more susceptible to the impacts of human pressures.
Occurring in freshwater environments (identified as important nursery habitat; Peverell 2005; Pillans et al. 2010;
Thorburn et al. 2007) adds to the susceptibility of freshwater sawfish to the impacts of human pressures; this
physically restricted environment limits their ability to evade exploitation and the alteration of their habitat (Compagno
& Cook 1995). Repeated use of small areas of habitat has been demonstrated in dwarf sawfish and green sawfish
(Stevens et al. 2008) and renders these species susceptible to localised depletion. In the case of the freshwater
sawfish, dry season riverine habitat can retract into a series of pools, reducing available habitat, and increasing
susceptibility to pressures. A recent study found that populations of green, freshwater and possibly dwarf sawfish in
north-west Australia may have different maternal populations to those occurring in the Gulf of Carpentaria (Phillips et
al. 2011). This would make local populations more vulnerable to decline as females would not be replenished from
stocks elsewhere.
Analysis of pressures
On the basis of current information, pressures have been analysed for the six cartilaginous species discussed in this
report card. A summary of the pressure analysis for sharks and sawfishes is provided in Table 1. Only those pressures
identified as of concern or of potential concern are discussed in further detail below. An explanation of the pressure
analysis
process, including the definition of substantial impact used in this analysis, is provided in
Part 3 and Section 1.1 of Schedule 1 of the plan.
Table 1: Outputs of the shark and sawfish species pressure analysis for the North-west Marine Region
Species
Pressure
Source
Sea level rise
Climate change
Changes in sea
Climate change
Sawfishes
(3 species)
Grey nurse shark
(west coast population)
Whale shark
White shark
temperature
Chemical pollution/
Urban development
contaminants
Agricultural activities
Nutrient pollution
Urban development
Agricultural activities
Marine debris
Shipping
Fishing vessels
Land-based activities
Noise pollution
Seismic exploration vessels
(other)
Physical habitat
Dredging
modification
Dredge spoil
Urban/coastal development
Offshore construction and
installation of infrastructure
Human presence at
Tourism
sensitive sites
Recreation and charter
fishing (burleying)
Research
Legend
of concern
of potential concern
of less concern
not of concern
data deficient
or not assessed
Table 1: Outputs of the shark and sawfish species pressure analysis for the North-west Marine Region
Species
Pressure
Source
Extraction of living
Illegal, unregulated and
resources
unreported fishing
Sawfishes
(3 species)
Grey nurse shark
(west coast population)
Whale shark
White shark
Commercial fishing
(non-domestic)
Commercial fishing
(domestic)
Recreational fishing
Indigenous
Commercial fishing
(prey depletion)
Bycatch
Commercial fishing
(domestic)
Recreational fishing
Collision with vessels
Shipping
Tourism
Fishing
Invasive species
Shipping
Fishing vessels
Land-based activities
Changes in
Land-based activities
hydrological regimes
Legend
of concern
of potential concern
of less concern
not of concern
data deficient
or not assessed
Sawfishes
Sea level rise—climate change
Sea level rise as a result of climate change is of potential concern for sawfishes in the North‑ west Marine Region. Sea
level has been rising at approximately 7.1 millimetres per year in the North-west Marine Region since the 1990s, the
largest increase in Australia (National Tidal Centre 2010). Global sea levels have risen by 20 centimetres between 1870
and 2004 and predictions estimate a further rise of 5–15 centimetres by 2030, relative to 1990 levels (Church et al.
2009). Longer term predictions estimate increases of 0.5 to 1.0 metre by 2100, relative to 2000 levels (Climate
Commission 2011). The main concern with sea level rise is the potential consequences when sea level rise is combined
with increasing cyclone frequency (Climate Commission 2011; DCC 2009). Predictions for the North-west Marine Region
in 2100 are for a hundred-fold increase in extreme sea level events in the Pilbara and up to a thousand-fold increase
in the Kimberley (DCC 2009).
Predicting the consequences of climate change for sawfishes is difficult. Very little is known about the species; basic
population information is lacking, and their adaptive capacity is unknown. However, rising sea level will have significant
effects on coastal habitats, including increasing salinity in estuaries and the lower reaches of creeks and rivers, and
altering geophysical processes of erosion and deposition along the coastal zone. Mangroves may decline in some areas
but expand in others by replacing salt marsh and freshwater wetland habitats (Chin & Kyne 2007). Sawfish species use
estuarine and freshwater habitats for key life stages (Pillans et al. 2010; Stevens et al. 2008) and some sawfishes are
known to use mangrove habitat (Stevens et al. 2008). There is evidence that salinity influences species distributions of
northern Australian estuarine sharks (Thorburn et al. 2003). Given the fairly restrictive habitat ranges of sawfish species,
it is likely that changes in key habitats will have adverse impacts on these species. In an analysis for the Great Barrier
Reef region, sawfishes were ranked as moderately vulnerable overall to climate change, with high exposure to the
effects of rising sea levels (Chin et al. 2010).
Marine debris—shipping; fishing boats; other vessels; land-based activities
Marine debris from shipping, fishing boats, other vessels and land-based activities is of potential concern for
sawfishes in the North-west Marine Region. Northern Australia is vulnerable to marine debris given the proximity of
intensive fishing operations, difficulties in surveillance and enforcement of existing management arrangements, and
ocean circulation patterns that are likely to concentrate floating debris before dumping it on coastlines and beaches
(Kiessling 2003). The North-west Marine Region is susceptible to marine debris
due to the illegal, unregulated and unreported fishing that occurs adjacent to the region. Large amounts of fishing net
are discarded or lost from the fisheries of the Arafura Sea (Limpus 2009).
Because of their saw-like rostrum, sawfishes are particularly susceptible to entanglement in marine debris (Seitz &
Poulakis 2006). Such entanglement can cause serious or fatal injury. The occurrence of sawfish species in popular
recreational fishing locations may expose them to discarded fishing line and other debris. Offshore, they may interact
with larger marine debris. The overall impact of marine debris on sawfish populations is unknown. However, there are
records of fatal impacts on individual sawfishes outside the region (Ceccarelli 2009) and management measures have
not been successful in significantly reducing marine debris in other areas.
Bycatch—commercial and recreational fishing
Bycatch from commercial and recreational fishing is of concern for sawfishes in the North-west Marine Region. Capture
of sawfish species is generally prohibited in Western Australian and Commonwealth waters. However, commercial
fishing has been identified as the major threat to sawfish species (Pillans 2007; Stevens et al. 2005; Stevens et al. 2008)
and substantial declines in several species have been attributed to this pressure (Stevens et al. 2005).
Entanglement in commercial fishing nets is considered the main threat to sawfish populations in northern Australia
(Stevens et al. 2008). Some species, including dwarf sawfish and green sawfish, have limited tidally influenced
movements and are particularly vulnerable to any net fishing operations when they are actively feeding on mud and sand
flats (Stevens et al. 2008). The rostrum of sawfish makes them particularly susceptible to capture in all forms of net
fishing gear (Stevens et al. 2008). Within Western Australia, there is commercial gillnetting for barramundi and king
salmon at King Sound, Cambridge Gulf, Eighty Mile Beach and the Joseph Bonaparte Gulf. While incidental capture
rates in commercial fisheries are generally low, sawfish mortality from bycatch in gillnets has been about 50 per cent of
captured individuals (Field et al. 2008). Such mortality is considered unacceptable for sawfishes, given their conservation
status. Post-release mortality can also occur as a result of capture and handling, although post-release survival rates will
be higher for larger, safely released sawfishes (FSERC 2009; Salini et al. 2007). A number of management measures
have been implemented but without population data, it is unknown whether these measures have been effective in
contributing to any recovery of populations.
Despite the protected status of sawfish species, there is potential for mortality from recreational fishing. Recreational
fishing is a popular activity in the North-west Marine Region, although most effort tends to be concentrated in waters
adjacent to population centres. Recreational fishing continues to grow in popularity, and with a growing population in this
region due to expansion of the resource sector, improvements in technology, and larger recreational boats giving greater
access to the coast, more remote areas are now becoming more accessible. This will result in increased overlap
between recreational fishing activities and the distribution of sawfish, which will increase the potential mortality from
incidental catches. Observations of dead, discarded sawfish from recreational fishing highlight that mortality occurs as a
direct result of capture and discarding (Stevens et al. 2005; Thorburn et al. 2003). Given the suspected small population
sizes and restricted habitats (for example, dwarf sawfish and green sawfish have been shown to repeatedly use
restricted areas of habitat; Stevens et al. 2008), these species are all vulnerable to localised depletion from incidental
mortality. Elsewhere, post-release mortality has been suggested to be the largest source of recreational fishing mortality
of elasmobranchs (Lynch et al. 2009), and damage from capture and handling or
from retained fishing line and hooks may cause post-release mortality in sawfishes.
Changes in hydrological regimes—land-based activities
Changes in hydrological regimes as a result of land-based activities are of concern for sawfishes in the North-west
Marine Region. Neonate and juvenile sawfish species use estuarine and/or freshwater environments, and the latter is an
important nursery area for freshwater sawfish. It is thought that pupping in all northern Australian sawfish species
coincides with the monsoonal wet season (Peverell 2005; Pillans et al. 2010; Whitty et al. 2008). Wet season freshwater
flows are thought to be the cue for sawfishes entering less saline water to give birth (Peverell 2005). Whitty et al. (2008)
demonstrated that the number of new recruits of freshwater sawfish captured in the dry season of each year is
significantly correlated to higher water levels during the late wet season. Alteration of flow could change
the timing of reproduction and the numbers of recruits.
Australian tropical rivers have highly energetic, episodic flows related to the monsoonal wet season that transport
sediments downstream with little trapping of materials in waterways (Brodie & Mitchell 2005). Barriers and
impoundments on rivers can cause siltation and a reduction in saltwater intrusion, and restrict upstream and downstream
movements of sawfish. Riverine habitat of freshwater sawfish is often restricted to isolated pools during the dry season,
reducing available habitat. Any further reduction of dry season flows would further restrict habitat availability. An
additional future threat is the proposed damming of tidal creeks for tidally generated electricity (DEWHA 2009).
Whale shark
Changes in sea temperature—climate change
Changes in sea temperature as a result of climate change are of potential concern for whale shark in the North-west
Marine Region. Climate change has the potential to change water temperature and oceanographic currents, thereby
significantly affecting the availability of prey and consequently the distribution of whale sharks. Sea temperatures have
warmed by 0.7 ºC between 1910–1929 and 1989–2008, and current projections estimate ocean temperatures will be 1
ºC warmer by 2030 (Lough 2009). Although there is little empirical data on effects of climate change on whale sharks,
there is some evidence to suggest that the abundance of whale sharks at Ningaloo is correlated to various climatic
conditions; therefore changes in climate could potentially alter this relationship. Wilson et al. (2001) suggest there is a
positive, but complex correlation between the Southern Oscillation Index, strength of the Leeuwin Current, coastal water
temperature, and abundance of whale sharks off Ningaloo Reef. Larger numbers of whale sharks are present during La
Niña years than El Niño years. It is possible that changes in oceanographic processes and temperature as a result of
climate change could magnify the climate-related seasonal abundance of whale sharks at Ningaloo.
Productivity at Ningaloo Reef is influenced by the southward-flowing Leeuwin Current and northerly flowing Ningaloo
Current. The Leeuwin Current flows stronger and closer to shore during autumn and winter—the peak sighting period for
whale sharks at Ningaloo Marine Park. It is suggested that the Ningaloo Current circulates the waters in the region of
Ningaloo Reef and drives productivity in the region at this time (Taylor & Pearce 1999). This circulation of nutrients,
combined with localised upwellings and the synchronised timing of spawning events for species such as coral on the
Ningaloo Reef, contributes to the influx of whale sharks to the region. Any modification of currents as a result of climate
change would likely have implications for not only whale sharks but the whole Ningaloo ecosystem.
Whale sharks are usually encountered in waters where the surface temperature is between 21 °C and 25 °C with
upwellings of colder water and a salinity range of 34 to 34.5 parts per thousand (Colman 1997). These conditions may
produce local concentrations of the plankton and nekton on which whale sharks feed (Colman 1997). Climate change
modelling predicts that ocean warming will cause large southward shifts in the distribution of many tropical and
subtropical zooplankton, displacing many local species, as well as earlier annual appearance of many groups (Hobday et
al. 2006). As zooplankton are such a critical food source for higher trophic levels, both these impacts will alter trophic and
competitive relationships among species and disrupt food webs (Hobday et al. 2006). Alterations in the seasonal
abundance and distribution of plankton at Ningaloo Reef could influence the abundance of whale sharks and the timing
of their annual migration.
Extraction of living resources—commercial fishing (non-domestic)
Extraction of living resources by non-domestic commercial fishing is of potential concern for whale shark in the North-
west Marine Region. Recent evidence indicates that overseas fishing pressure may be the primary cause of perceived
recent declines in whale shark numbers (Bradshaw et al. 2007; Bradshaw et al. 2008). Fishery data for whale shark,
although scarce, points to a decline in seasonal catches, with the declines occurring in a limited time period since the
establishment of directed commercial fisheries in, for example, the Philippines (DEH 2005b). Indonesia has the largest
chondrichthyan fishery in the world; however, chondrichthyan catches are largely under-reported or unreported and, as a
result, the total landings probably far exceed those reported by Indonesia (White & Cavanagh 2007). Trade in whale
shark products is largely driven by demand in Asia for meat and fins. Whale sharks are fully protected in Australian
waters, but because whale sharks roam internationally, apparent declines in seasonal sightings may be due to
unsustainable fishing in other parts of the whale sharks’ range. It is unclear how successful current protective legislation
is due to under-reporting of catches and illegal poaching in range states (i.e. Taiwan, Philippines, Indonesia, the
Maldives, Pakistan). The rapid change in population composition over a decade (less than one whale shark generation)
supports the hypothesis of unsustainable mortality in other parts of their range (e.g. through overfishing), rather than the
alternative of long-term abiotic or biotic shifts in the Australian marine environment (Bradshaw et al. 2008).
Consequently, the continued direct and illegal, unregulated and unreported take of whale sharks in other range states is
likely to negatively affect the Australian population. Whale sharks are easy to capture and have a widespread distribution
in small highly mobile populations, which increases their susceptibility to overexploitation. Slow growth rates, late
maturity and delayed infrequent reproduction means that population reduction due to overfishing is likely, and that
recovery will be slow (Meekan et al. 2006; Stewart & Wilson 2005).
3. Relevant protection measures
Dwarf sawfish, freshwater sawfish, green sawfish, grey nurse shark, whale shark and white shark are listed as vulnerable
under the EPBC Act. Under the Act it is generally an offence to kill, injure, take, trade, keep or move listed marine,
migratory or threatened species on Australian Government land or in Commonwealth waters without a permit.
The dwarf and green sawfish species are listed on Appendix I of the Convention on International Trade in Endangered
Species (CITES). The freshwater sawfish, whale shark and white shark are listed on Appendix II, which regulates and
monitors any international trade in the species.
Alongside the EPBC Act, a broad range of sector-specific management measures to address environmental issues and
mitigate impacts apply to activities that take place in Commonwealth marine areas. These measures give effect to
regulatory and administrative requirements under Commonwealth and state legislation for activities such as commercial
and recreational fishing, oil and gas exploration and production, ports activities and maritime transport. In some
instances, as in the case of shipping, these measures also fulfil Australia’s obligations under a number of international
conventions for the protection of the marine environment from pollution and environmental harm.
Protection and conservation measures administered under the EPBC Act and relevant to the conservation values
described in this report card are listed below.
EPBC Act conservation plans and action plans
 Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine
Fishes (Pogonoski, Pollard & Paxton 2002)
International measures
Australia is a signatory to the following international agreements for the conservation of sharks and sawfishes:
 Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)—www.cites.org
 International Plan of Action for the Conservation and Management of Sharks (IPOA – Sharks)—
ftp://ftp.fao.org/docrep/fao/006/x3170e/X3170E00.pdf
 Memorandum of Understanding on the Conservation of Migratory Sharks—
www.cms.int/species/sharks/MoU/Migratory_Shark_MoU_Eng.pdf
For more information on conservation listings under the EPBC Act, and related management objectives and protection
measures, visit the following sites:
 www.environment.gov.au/epbc/protect/species-communities.html (listed
threatened species)
 www.environment.gov.au/epbc/protect/migratory.html (listed migratory species)
 www.environment.gov.au/cgi-bin/sprat/public/sprat.pl (species profile and
threats database).
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ATTACHMENT 1: SHARK
AND SAWFISH SPECIES OCCURRING
IN THE NORTH-WEST MARINE
REGION
Table A1: Listed shark and sawfish species known to occur in the North-west Marine Region
Species (common name/scientific name)
Conservation status
Sawfishes
Green sawfish (Pristis zijsron)
Vulnerable
Sharks
Grey nurse shark (west coast population) (Carcharias taurus)
Vulnerable
Longfin mako (Isurus paucus)
Migratory
Shortfin mako (Isurus oxyrinchus)
Migratory
Whale shark (Rhincodon typus)
Vulnerable, migratory
White shark (Carcharodon carcharias)
Vulnerable, migratory
Table A2: Sawfish species known to occur in the North-west Marine Region on an infrequent basis
Species (common/scientific name)
Conservation status
Freshwater sawfish (Pristis microdon)
Vulnerable
Dwarf sawfish (Pristis clavata)
Vulnerable