Nomination to Have Death Or Injury to Marine Species As a Result of Boat Strikes Listed

Nomination for listing a key threatening process under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

Name of the threatening process:

Death or injury to marine species as a direct result of boat strike on the east coast of Australia.

A description of the threatening process that distinguishes it from any other threatening process:

Within eastern Australian waters, boat strikes are responsible for injuries and death to marine turtles, dugongs, whales and sharks to differing degrees. Boat strike not only impacts marine species in Australian waters, but all over the world, with research being conducted in the U.S. Gulf of Mexico and Atlantic coasts as well as Puerto Rico and the Virgin Islands. Data from these areas indicate vessel traffic to be an important cause of mortality, particularly amongst sea turtles (Lutz, 1996).

Boat strikes cause direct and indirect disturbance to marine wildlife. Direct contact with propellers may sever tissue and/or organs causing immediate death, debilitating the animal, or transmitting infection leading to a slower distressing death. Feeding and breeding grounds may also be disturbed as a result of boat access within a region. Populations may be restricted to feeding areas, which do not correspond with high vessel traffic in order to evade threat and disturbance, limiting their habitat and increasing competition for limited resources.

The Environmental Protection Agency (EPA) of Queensland keeps a stranding and mortality database for dugong, cetaceans and pinnipeds and turtles which indicates the mortality of each group and species due to boatstrike. 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.

Boat strike is a contributing factor in the depletion of marine turtle and dugong populations in Australia, along with hunting by Indigenous communities, predation of marine turtle nesting sites by introduced species such as foxes and pigs; and commercial fishing practices. Now that Turtle Exclusion Devices (TEDs) are included in commercial trawl nets, the mortality to loggerhead turtles due to trawling bycatch has significantly declined, leaving boat strike, together with ingestion of marine debris and entanglement in fishing tackle as the key threats to its recovery (XXXXXXXX, pers. comm.). Boat strike can be fatal to the largest marine mammals such as sperm whales – a large whales was struck and washed up in Newcastle in August 2006 with deep cuts through the length of its body, likely caused by the propeller of a large commercial vessel.

Marine animals are most at risk in areas of sizeable urban coastal populations, such as the Gold and SunshineCoasts.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 GBRMarinePark over the last four decades, with a rapid post-war expansion of visitors to the GBR through 1970’s and 1980’s. According to data compiled by Queensland Transport in 2003, there has been a steady increase in the number of motorboats registered in Queensland waters. As of December 2003, 180,304 vessels were registered in these waters, an increase of 4.88% on last year, and 6.02% on 2002. Visitor days have increased from 1,100,000 in 1985 to 1,600,000 in 2000 (Harriot, 2002).

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. A noted increase in the number of both cruise ships and super yachts, which measure between 35 and 70m in length, on the reef also have an impact in increasing boat strikes in the region, although at present, cruise ships are not permitted within 500m of reef and/or coastline within the GBR Marine Park.

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 inMoretonBay 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 (eg. Great Barrier Reef, GreatSandyBay, MoretonBay), this does not ensure the protection of marine mammals from boat strike. Within the last few years, 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. This includes 5 ‘go-slow’ zoned areas within the park at Moreton Banks, Amity Banks, Peel Island, Prices Anchorage and Lamb Island (QPWS, 2001). However, no binding mechanism limits boat traffic and speed limits. The voluntary speed limits that are set are ineffective - in the ‘go-slow’ areas of Moreton Bay, for example, many users travel at planing speeds, resulting in often fatal injuries to various mammals – in 2005 more than 38 turtles were killed (Queensland EPA/PWS 2006). The impact of the protected status of a marine park on boat strike for dugongs is illustrated by the fact that of the five dugongs struck by boats in Queensland in 2004, four were in MoretonBayMarinePark (Greenland and Limpus 2005). The urban growth in islands off Townsville and MoretonBay leads to increasing marine traffic, with water taxis and commuter traffic.

HSI understands the QueenslandParks and Wildlife Service is working in cooperation with the Department of Transport, the water police and Queensland Seafood Industry Association to consider options to decrease mortality from boating but we are unable to provide further details.

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 area.

Name any species listed as threatened under the EPBC Act that are considered to be adversely affected by the threatening process:

Name any species, other than those that are listed under the EPBC Act, that could become eligible for listing in one of those categories because of the threatening process:

Dugong dugon

Orcaella breviceps

Sousa chinensis

Although these species are not listed as endangered or vulnerable under the EPBC Act, their conservation value is recognised in that the dugong is listed as a marine species, while the dolphins are protected as Cetaceans, and all are listed as migratory species.

Justification for this nomination

(a) evidence that the threatening process could cause a native species or ecological community to become eligible for listing in any category, other than conservation dependant:

1. DUGONG – Dugong dugon

Vulnerable – QLD - Nature Conservation Act 1992

Vulnerable – Worldwide - IUCN Red Book 2006

Endangered – NSW - Threatened Species Conservation Act 1995

Listed Marine and Migratory Species – Commonwealth – EPBC Act 1999

Appendix II – Convention on Migratory Species (CMS)

Appendix I – Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES)

Although dugongs are found in over 40 countries worldwide, they are nearing extinction in many parts of this range. The recognition of this species as a listed Marine Species and Migratory Species under the EPBC Act, and as a threatened species under NSW and QLD law, as well as international obligations with the species listed on Appendix I of CITES and Appendix II of the CMS, clearly illustrates the high sensitivity of this species and the resulting need for a proactive and vigorous management approach.

Although there remains large uncertainty about accurate population figures, a decline in dugong numbers since the 1970s is apparent (Preen 2000). This follows on from recent findings of significant decline in population in the Great Barrier Reef particularly between Cooktown and HerveyBay. Populations in HerveyBay declined from 2200 in 1988 to 800 by 1994(Queensland Museum 2006). Population decline measured in Queensland waters between the 1960’s and mid-1990’s would, if robust and extrapolated to the entire population, qualify the dugong for listing as “Critically Endangered” worldwide (Marsh 2006).

Marsh (2006) reports on four decades of decline in dugong abundance in Queensland waters. A 40-year assessment of dugong catch per unit effort (CPUE) data in Queensland’s shark control nets found that the CPUE in 1999 was only 3% of that in 1962 (Marsh 2006), which indicates a large decline in dugong populations over that period. The shark controls are considered to be a fairly reliable passive source of population data for the coastal species they entrap.

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). Mammals with these life history parameters (long-lived, low reproductive rate, long generation time and large 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 that 5% per year, with sustainability relying on high levels of adult survivorship. This model was simulated using optimal 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. Seagrass beds occur in shallow coastal waters, and therefore, in close proximity to coastal populations and consequently coastal recreational activities including boating. There are also concerns that frequent boat activity can displace dugongs from their preferred habitats.

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 the areas in which they commonly aggregate has decreased (Preen 2000). In Florida there has been a tight correlation between the increase in boat traffic and the increase in manatee deaths (Illidge 1996). Boat traffic in the Hinchinbrook region 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).

The incidence of boat strike on dugong is most prevalent in MoretonBay, Hervey Bay – SandyStrait and Whitsunday regions and is a major anthropogenic cause of mortality and/or injury to the dugong population.

MoretonBay is home to the southern most 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 (population 1.5 million) leaves this dugong population especially vulnerable to continued anthropogenic effects. An increase in popularity of coastal recreation, including boating activities may be the cause of further death and debilitating injury to dugong.

A tri-agency (QueenslandParks and Wildlife Service, Department of Primary Industries and Fisheries, GBRMPA) approach is enabling close examination of dugong carcasses to establish the causes of mortality and obtain further information. The Environmental Protection Agency (EPA) of Queensland keeps a stranding and mortality database for dugong, cetaceans and pinnipeds and turtles which indicates the mortality of each group and species due to boatstrike. This database shows the known level of dugong mortality as a result of boat strike since 1996 (Table 1). We can assume the actual mortality rate to be an order of magnitude higher.

Table 1: Confirmed mortalities of dugong due to boat strike in Queensland waters for the period 1996-2005 (Greenland and Limpus 2006, Greenland et al. 2005).

Injuries to dugongs as a result of a boat strike may vary depending on the circumstance of the strike. The propeller causing lacerations to tissues may directly strike the mammal and organs resulting in prompt death, or otherwise injury susceptible to infection and/or delayed death. Dugongs have also been victim to cranial and vertebral damage due to high-speed boat strikes. Physical injury to ribs and organs occurs following being crushed by boats in shallow waters. 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.

Data collected from carcasses in MoretonBay suggest that the majority of boats involved in strikes on dugongs are not small recreational boats powered with outboard motors, but rather larger recreational and commercial vessels with twin propeller configurations (Limpus 2002).

The Recovery Plan for the conservation of the Dugong (D. dugon) in Queensland 1999-2004 proposes three main management approaches. These include prohibiting high speed boat races in areas which coincide with dugong habitat; restricting vessel operation in particular regions such as Moreton Bay Marine Park; and monitoring boat traffic in areas such as these and restricting vessel speed limits where necessary in conjunction with the Department of Transport. The plan also identifies boat strike as a significant threat to the species, particularly in shallow waters and where fast boats are used (Queensland EPA 1999).

Future management of this region must focus on the reduction of boat strike incidence by creating additional “go slow” zones. Five “go slow” zones were introduced in MoretonBay in 1997 whereby regulated speeds are prescribed for recreational vessels. Currently it appears that these zones are ineffective, with four out of five dugongs struck by boats in 2004 within the MoretonBayMarinePark (Greenland and Limpus 2005). A six-fold increase in the population of the southern MoretonBayIslands is predicted in the next few decades (Limpus et al. 2002), which will lead to an increase in coastal recreational activity as well as water taxi and vehicle barge demand. As urban and tourism development continues in the areas around Townsville and MoretonBay the increased boat traffic will correspondingly increase the threat to dugongs.

Vessel transit lanes have been installed in MissionaryBay with the use of 3 beacons and 3 navigation buoys. Speed limits of 10 knots over seagrass beds and 25 knots within these transit lanes are encouraged. This aims to create speed regulated lanes in deeper waters, away from shallow water feeding grounds, and in turn reduce incidence of boat strike. Again, it is unclear how these aims will be policed and enforced.

The above demonstrates that the threat posed by boatstrike to Australia’s dugong population could be a significant contributing threat causing it to become eligible for listing under the EPBC Act as vulnerable or endangered. Not only is the current known rate of boat strikes on dugong a cause for concern, but also the projection of that rate into the future, as boat traffic increases due to the growth in coastal human populations in key areas.

2 i) IRRAWADDY DOLPHIN - Orcaella brevirostris,

AUSTRALIAN SNUBFIN DOLPHIN – Orcaella heinsohni

Rare ~ Nature Conservation Act 1992

Appendix I ~ Worldwide ~ CITES.

In 2005 the Irrawaddy dolphin was discovered to be two separate species, differing genetically, in colour, and shape of the nose. The new species has been named Orcaella heinsohni, and the common name suggested as ‘Australian Snubfin dolphin’ (Beasley et al. 2005). It is restricted to Australian and southern New Guinea waters. National and international conservation agreements and legislation have yet to catch up with the new classification, so the old conservation status stands. It is clear however, that when a rare, endangered population is split into two, the status of the remaining populations must become even more critical and vulnerable to anthropogenic threats. Both populations are found within the same region, although the Australian snubfin may be more limited in distribution than the Irrawaddy. (As an aside, the nominee recommends that the TSSC review the conservation status of both Irrawaddy dolphin and Australian snubfin dolphin.)