Key Threatening Process Nomination Form

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Description of the key threatening process
4. DESCRIPTION

Describe the threatening process in a way that distinguishes it from any other threatening process, by reference to:

a. its biological and non-biological components;

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Within Australian waters, boat strikes are responsible for injuries and death to marine turtles, dugongs, whales and sharks to differing degrees. Direct contact with propellers or hulls of boats may sever tissue and/or organs causing immediate death, debilitating the animal, or transmitting infection leading to a slower and more distressing death. Feeding and breeding grounds may also be disturbed as a result of boat access within a region (Hodgson & Marsh,

2007). Populations may be restricted to feeding areas with high vessel traffic, limiting their habitat and increasing competition for limited resources (Hazel et al., 2007).
The Department of Environment and Resource Management (DERM) of Queensland keeps a Stranding and Mortality Database for dugongs, cetaceans and pinnipeds, and marine turtles, with data published in Annual Reports indicating the proportion of mortality of each group and species due to boat strike. However, exact mortality figures from boat strikes of marine species are unknown. Many carcasses do not wash ashore and are therefore not accounted for on the mortality database. Many carcasses are also unidentifiable at time of finding, or the cause of death unable to be determined. It can therefore be expected that a greater incidence of fatalities occurs, than is recorded, but the true extent is unknown.
Marine animals are most at risk in areas of sizeable urban coastal populations, such as the Gold Coast and Sunshine Coast in Queensland. These areas contain the most frequent and abundant amount of boat traffic, including both commercial and recreational craft. There has also been a high level of boat activity in the Great Barrier Reef Marine Park over the last four decades, with a rapid post-war expansion of visitors to the Great Barrier Reef through 1970s and

1980s. According to data compiled by Queensland Transport in 2003, there has been a steady increase in the number of motorboats registered in Queensland waters. Additionally, visitor days have increased from 1,100,000 in 1985 to

^1,600,000ⁱⁿ²⁰⁰⁰^(H^a^rrio^t^,²⁰⁰²⁾^.
Boat ownership in Perth waters grew from 27,997 to 48,468 between the years of 1990 and 2007 with 10.4% of vessels being greater than 7.5m in length. Forward predictions for 2025 are 84,857 with 12.5% of vessels greater than 7.5m, indicating that not only is boat ownership growing rapidly, but that boat size is increasing. (DPI Technical Report #445

Feb 2008 -attached). This trend is similar to that of the Peel region (the fastest growing regional area in WA) with the

8,733 licensed boats (7.26% >7.5m) in December 2009, projected to grow to 18,438 by 2031 (14.75% >7.5m) (WA Department of Transport, 2010). It is expected that boat strike incidences will rise proportionally with these projected increased.
Both commercial and recreational boats have been responsible for striking marine animals. Recreational vessels, however, account for 96.9% and commercial vessels only 0.001% of registered vessels in Queensland in 2003 (MSIAR,

2003). Small sailing boats (carrying <20 people) pose little threat to marine animals due to their slow speed, and allow evasive responses in marine animals (Preen, 2000). Recreational windsurfers, speed boats, as well as large catamarans, which can hold more than 400 people, operate at faster speeds and leave lesser time for the animal to react and are therefore most likely to strike marine mammals.

Boat type and the circumstance of the strike can be estimated, given the measurements of propeller depth, length, distance between and number of cuts to the carcass. This information assists in recognizing which category of boat has been most inclined to strike marine animals. Data collected from dugong carcasses in Moreton Bay suggest that the majority of boats involved in strikes are not small recreational boats powered with outboard motors, but rather larger recreational and commercial vessels in twin propeller configurations (Limpus, 2002). Strikes by small recreational vessels including jet skis have also been recorded.
Despite much of Queensland’s coastal waters being protected in marine parks of some form (e.g. Great Barrier Reef, Great Sandy Bay, Moreton Bay), this does not ensure the protection of marine mammals from boat strike. Within the last decade, Queensland Parks and Wildlife Service together with Queensland Transport have installed 18 ‘go-slow’ signs within Moreton Bay Marine Park as a response to high mortality figures of turtles and dugongs from boat strikes. However, no binding mechanism limits boat traffic and speed limits and as a result the voluntary speed limits that are

^se^t^areⁱ^ne^f^f^e^ctⁱ^v^e^(H^a^z^e^l^e^t^a^l^.^,^2007).
Within the Townsville-Cardwell (Hinchinbrook Channel/ Missionary Bay) region, inhabited by large populations of turtles and dugongs, speedboats and other large planing vessels make up a total of 76% and 84% respectively of all boat movement in the area (Preen, 2000). Small to large speedboats make up 80% of boat traffic in the Hinchinbrook region (Preen, 2000). With the predicted construction of the two marinas in the Hinchinbrook area, (Oyster Point and Dungeness), boat traffic and consequently boat strikes are also expected to increase, with an escalating interest in vessel numbers and boating activity in the region.

Indigenous Values
5. INDIGENOUS CULTURAL SIGNIFICANCE

Is the key threatening process known to have an impact on species or country culturally significant to Indigenous groups within Australia? If so, to which groups? Provide information on the nature of this significance if publicly available. Species impacted upon by the nominated key threatening process, such as marine turtles and dugongs, are culturally significant to coastal Indigenous groups throughout Australia.

Criterion A: non-EPBC act listed species/ecological communities
6. SPECIES THAT COULD BECOME ELIGIBLE FOR LISTING AND JUSTIFICATION

Provide details and justification of non-EPBC Act listed species that, due to the impact of the key threatening process, could become eligible for listing in any category, other than conservation dependent. For each species please include:

a. the scientific name, common name (if appropriate), category it could become eligible for listing in;

b. data on the current status in relation to the criteria for listing;

c. specific information on how the threatening process threatens this species; and

^d^.ⁱⁿ^f^orma^t^ion^oⁿ^th^e^extent^to^w^h^ich^t^h^e^th^r^e^at^c^ou^ld^c^h^aⁿ^ge^th^e^sta^tu^s^o^f^th^e^s^p^e^cⁱ^e^sⁱⁿ^r^e^la^t^ion^t^o^th^e^cri^t^e^ria

for listing.

Dugong (Dugong dugon)

Could become eligible for listing as Vulnerable.

^A^u^s^tr^a^lian^c^on^se^r^v^a^t^ion^sta^t^u^s^:

National: Listed as a Marine and Migratory species under the Environment Protection and Biodiversity Conservation Act,

^1999.

New South Wales: Listed as Vulnerable under the Threatened Species Conservation Act, 1995.

Northern Territory: Listed as Protected Wildlife under the Territory Parks and Wildlife Conservation Act, 2001.

Queensland: Listed as Vulnerable under the Nature Conservation Act, 1992.

^We^s^t^e^rn^A^u^s^tr^a^lia:^Lⁱ^s^ted^a^s^S^p^e^cially^P^r^o^tect^e^d^und^e^r^t^h^e^Wil^d^li^f^e^Coⁿ^s^e^r^v^a^ti^oⁿ^A^c^t,¹⁹⁵⁰
International conservation status:

^{- Li}^s^ted^oⁿ^A^pp^e^nd^ix^I^o^f^th^e^C^oⁿ^v^en^ti^oⁿ^o^f^In^t^e^r^na^ti^ona^l^Tr^a^d^eⁱⁿ^E^ndaⁿ^ge^r^e^d^S^p^e^c^ies^o^f^F^aun^a^an^d^Fl^o^r^a⁽^C^I^T^E^S).

- Listed as Vulnerable on the International Union for Conservation of Nature and Natural Resources (IUCN) Red

List of Threatened Species.

- Listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS).

Although there remains large uncertainty about accurate population figures, a decline in dugong numbers since the

1970s is apparent (Preen, 2000). Marsh et al. (2005) reports on four decades of decline in dugong abundance in Queensland waters through a 40-year assessment of dugong catch per unit effort (CPUE) data in Queensland’s shark control nets, which found that the CPUE in 1999 was only 3% of that in 1962, which indicating a large decline in dugong populations over that period. Population decline measured in Queensland waters between the 1960s and mid-1990s would, if robust and extrapolated to the entire population, qualify the dugong for listing as “Critically Endangered” worldwide (Marsh, 2008).

The dugong is a long-lived mammal with a lifespan of 50-60 years and a low reproductive rate, the minimum pre- reproductive period for the dugong is roughly 9-10 years for both sexes, with one calf every 3-7 years (Marsh et al.

¹⁹⁸⁴^).^M^a^mm^a^l^s^with^the^s^e^lⁱ^f^e^hⁱ^s^t^o^ry^p^aram^e^t^e^rs^(loⁿ^g^-^lⁱ^v^e^d^,^l^o^w^r^e^p^r^odu^cti^v^e^ra^t^e^,^l^on^g^geⁿ^e^rati^oⁿ^tⁱ^m^e^an^d^l^a^rge

investment in each offspring) must sustain a high survival rate to maintain population numbers and are vulnerable to human induced mortality. Population simulations suggest that dugong populations are unlikely to increase by more

^t^h^an^5%^p^e^r^y^e^ar,^with^sustaⁱⁿ^a^b^ility^r^e^l^yⁱⁿ^g^oⁿ^h^igh^l^eve^ls^of^adu^lt^s^u^r^vⁱ^v^o^r^s^hⁱ^p^.^T^hⁱ^s^m^o^d^e^l^was^sⁱ^m^u^la^t^e^d^u^sⁱⁿ^g^op^timal

life history parameters including low natural mortality rates and no human-induced mortality. Therefore, the slightest decline of adult dugong survivorship may see a population crash (Marsh e. al. 1984).

Boat strikes pose a direct threat to dugong populations. The shallow water habitat of the dugong subjects the species to high contact with human populations, and further constrains dugongs ability to avoid boats by diving (Hodgson & Marsh,

2007; Maitland et al., 2006). There are also concerns that frequent boat activity can displace dugongs from their preferred habitats (Hodgson & Marsh, 2007). Hodgson (2004) showed that it's likely dugongs initiate their response to approaching vessels appears as a function of distance rather than speed, meaning that when a boat approaches quickly the response may be too slow to avoid an impact.

One of the largest populations and feeding grounds of dugongs in Australia is found in the Townsville/Cardwell area. The Hinchinbrook region provides habitat for approximately half of all dugongs in the Great Barrier Reef south of Cooktown. Oyster Point is sheltered by the Hinchinbrook Channel and retains the world’s largest dugong population. As boat traffic in this area has increased since the 1970’s, the incidence of boat strike on dugongs has also increased and

^t^h^e^a^r^e^asⁱⁿ^w^h^ich^t^h^e^y^c^omm^oⁿ^ly^a^ggr^e^ga^t^e^h^as^d^e^c^r^e^a^s^e^d^(Pre^eⁿ^,²⁰⁰^0).^Bo^a^t^tr^a^f^f^icⁱⁿ^th^e^Hⁱⁿ^c^hⁱ^nb^r^o^ok^r^e^gion^is

increasing due to development and increasing tourist activities, and is likely to continue to grow. This predicted increase in boat traffic can be expected to result in an increase in boat strikes (Preen, 2000).

Moreton Bay is home to the southernmost distribution of dugong on east coast of Australia. It is also an area of high boat usage adjacent to Brisbane and a region of high tourism activity. Dugong population size has increased in this area since the cessation of hunting for oil to a most recent estimate of 500 mammals. This small population size, combined with seagrass beds in close proximity to Brisbane leaves this dugong population especially vulnerable to continued anthropogenic effects.
The Department of Environment and Resource Management (DERM) of Queensland formerly kept an annual stranding and mortality database for dugongs, which included data on mortality due to boat strike. These annual reports, the most recent of which is Biddle et al. (2011), show the known level of dugong mortality as a result of boat strike between the years of 1996-2010, with a summary of this data being shown in the following table (Table 1). It can be reasonably

assumed that the actual mortality rate is significantly higher, due to not all incidences being detected, further incidences not being reported, and many instances not being able to be officially assessed and have cause of mortality confirmed .

Table 1: Dugong mortalities caused by boat strike in Queensland waters for the period 1996-2010

Year

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

Mortalities

Directory: system -> files -> pages -> 87ef6ac7-da62-4a45-90ec-0d473863f3e6 -> files
pages -> Grey-headed Flying-fox Management Strategy for the Lower Hunter Grey-headed Flying-fox
pages -> Marine bioregional plan for the North Marine Region prepared under the
files -> Key Threatening Process Nomination Form
pages -> List of cites species for the Purposes of the Act as amended
pages -> Offshore pelagic shark and teleost surveys Objectives
pages -> Approved Green Army Projects to begin in the 2015/16 financial year
pages -> Australian Government
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