The Western Australian Government is committed to keeping the community as safe as possible when using our oceans. There is no one simple solution, shark encounters are rare and the following shark safety initiatives, operational responses and shark safety tips, allow the community to keep informed and help reduce the risk of a shark encounter.
Whale Carcass Management20 September 2018
Effective whale carcass management requires the collaboration of relevant government departments and land managers.
The Department of Biodiversity, Conservation and Attractions (DBCA) is responsible for the management of whales in Western Australia. As whale carcasses are a known shark attractant, the Department of Primary Industries and Regional Development (DPIRD) also has a role in their management.
After receiving a report of a floating or beached whale carcass, DBCA, DPIRD and the local government authority work collaboratively to make an assessment of the animal and manage the response. This may include issuing a public safety alert and removal of the whale carcass, where possible.
Removal of a whale carcass is the responsibility of the land manager, usually the relevant local government authority, or DBCA.
There are many considerations in assessing a carcass for removal including size, location of the animal, safety of the operation (includes sea conditions) and available resources.
DBCA have developed instructional material and provide assistance, advice and support to land managers on the removal of a carcass.
Frequently Asked Questions
Why are more whale carcasses washing ashore in Western Australia?
Populations of humpback whales that migrate annually along the Western Australian coast have recovered steadily since commercial whaling ended in 1978.
As whale numbers increase, there is an increase in natural mortalities. This naturally occurring cycle means there is a higher probability of whale carcasses washing ashore, particularly during the whale migration from March to November.
Carcasses of other whale species may also beach across the calendar year in much lower numbers. These species include sperm whales, pilot whales and other smaller whale species.
What happens when a whale carcass is located on land?
Decomposing carcasses are part of the natural cycle of life. When these events occur in remote locations along our extensive coastline, there is generally no need for humans to intervene. However, when they occur close to human population centres they can pose a number of issues, including public health concerns and an increased presence of sharks in coastal waters. In these cases, the relevant land manager will, where feasible, remove the carcass to landfill.
Who is responsible for the management of a whale carcass on land in Western Australia?
The Western Australian Government has a clearly defined policy position on the responsibilities for whale carcass management whereby the land manager, typically a local government authority or DBCA, is responsible for the carcass. DBCA provides instructional material, input, support and advice to land managers on removal procedures.
What should I do if I see a whale carcass?
If you see a whale carcass, report it to Water Police on 9442 8600 as soon as possible. Early reports may increase the options available for removal.
If you see a live cetacean (whale or dolphin) or turtle which has become stranded contact WILDCARE Helpline on 9474 9055.
What species of whale carcasses are most common in Western Australia?
The most common whale carcass in Western Australia is the humpback whale. At times, sperm, fin, and smaller toothed-whale carcasses are also reported.
How are whale carcasses removed?
Whale carcass removal is the responsibility of the land manager, generally a local government authority or DBCA. DBCA have developed instructional material and provide assistance, advice and support to land managers on the removal of a carcass.
Where removal from land is possible, the carcass is generally rolled onto a net by machinery and dragged to a safe access point for a crane. The carcass is then lifted into a truck for transportation to a disposal site. Where possible the carcasses are removed in one piece to minimise the amount of debris and fluids left on the beach.
Additional information regarding the removal of whale carcasses can be found on the DBCA, Parks and Wildlife Service website at www.dpaw.wa.gov.au
Why are some whale carcasses left to decompose naturally while others are removed?
The most efficient response to a whale carcass is to remove it for burial in a land fill site, where it is practical to do so. However, there are instances where carcasses are left to decompose naturally. This includes situations where the removal of a carcass is physically not possible due to inaccessible coastal terrain; where the carcass is in a remote area where little or no public activity occurs; or when removal would present safety concerns for staff or contractors.
Why don’t you use explosives to assist with whale carcass removal?
The use of explosives to assist with whale carcass removal on land is not a practical option. This has many associated risks to staff, as well as ongoing human health and safety risks from the decomposing biological matter.
At sea, the associated risks to staff are greater with the amount of explosives required and working in sea conditions. In addition, the potential impacts of explosives used on water would be detrimental to other marine mammals, fish and the environment. The currents off the Western Australia coast have the potential to spread a fragmented whale carcass over a larger area, which could impact on human health and may cause an increased shark risk, particularly if whale fragments make their way to coastal areas and beaches.
Why don’t you sink/anchor whale carcasses?
The only feasible point to attach an anchor is to the peduncle (part of the body to which the tail attaches).
Given the high energy of Western Australia’s coastline, anchoring in open water may not be an option, so it would be likely that a sheltered area would need to be found to achieve this.
When parts of decomposing anchored whales break off, they may spread and come to shore in a number of locations, causing an increased shark risk and other associated risks for relevant local authorities.
The sinking of carcasses has also been raised as an option. However, research shows that the amount of weight, or size of a hole, in the animal needed to cause it to become negatively buoyant makes this an unrealistic option.
Why aren’t all whale carcasses towed offshore?
There are a number of factors which limit the ability to tow a whale carcass offshore. Very few whale carcasses are sighted adrift in Western Australia and most are reported once they come ashore.
Whale carcasses may be large and there are challenges with towing a decomposing whale carcass by boat. These include, prevailing (and next 24 hours) weather conditions, sea state, size and condition of carcass, the availability of large-capacity vessels and suitably qualified staff. In addition, the eddying (swirling) nature of the Leeuwin current off the coast of Perth makes it likely that towed carcasses may return to land. It is possible the carcass originally made its way to shore by the effect of these same currents.
Why can’t you tow a whale from a beach?
Smaller whale carcasses in good condition (smaller than or equal to five metres) may be suitable for towing from beaches but only where they are in the wash zone. Any size carcass that is hard ashore is difficult to drag back into the water and the risk to staff undertaking this activity is considerable. Where this is done it is preferable to tow the whale carcass to a point of land where they can be efficiently removed for disposal in landfill.
Towing of smaller whales offshore may also be possible, but removal from the marine environment where they stop becoming a risk to re-landing, or becoming a navigational hazard is preferable.
Large whales like humpbacks, which are the most common whale carcasses in Western Australia, can weigh less than one tonne as a new born, up to 40 tonnes for adults measuring 12 to 16 metres. Towing these larger whale carcasses once they have made landfall is very problematic and potentially dangerous. If the carcass is in a state of advanced decomposition, towing from the beach is likely to fail.
Why aren’t all whale carcasses buried at the beach?
Beach burials remove the sight and smell of a carcass in the short term and are relatively cost effective, but the extent to which carcass burial alters beach groundwater and attracts sharks to the surf due to fluids from the decomposing whale dissipating is unknown.
In 2017 successive beach burial decisions of large (approximately 18 tonne) humpback carcasses in New South Wales were reversed due to community concern, leading to the exhumation and transport to waste management facilities, costing the local government authority significantly more.
Experience in Western Australia has shown that if insufficient burial depth is not achieved the carcass ‘floats’ to the surface as it decays, causing significant public health risk.
Why don’t you know when there is a whale carcass adrift?
Like any material floating in the ocean, a carcass can make its way to shore without being sighted beforehand, especially if it’s not within well used navigational pathways. Many whale carcasses come ashore in remote locations where there may be low levels of on-water activity and therefore are not sighted until they make landfall. Given Western Australia’s extensive coastline, some whale carcasses may be unreported.
If you see a whale carcass, report it to Water Police on 9442 8600.