The Conservation Committee provides a forum for members of the IWC to report and share information on the measures being taken within their own countries to reduce and record incidences of ship strikes.  In addition, the Conservation Committee has established a dedicated Ship Strikes Working Group to develop detailed proposals for mitigation of ship strike events and to co-ordinate work between member governments. This group was founded by the late Commissioner for Belgium, Alexandre de Lichtervelde who died in 2011. Belgium remains committed to this issue and its new Commissioner, Frédéric Chemay, who is also the present Vice-Chair of the Commission, has taken on this role.

In 2010, the IWC’s Ship Strikes Working Group held a joint workshop with scientists and representatives from ACCOBAMS (the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic Area).  The workshop reviewed the available information on ship strikes including mitigation measures for reducing ship strikes.  The report of the workshop can be downloaded here. It developed a number of important recommendations and these form the basis of the IWC’s workplan to address this important issue. The latest report of the Conservation Committee, which includes its discussions on ship strikes, can be found here.

Evidence of ship strikes comes from a range of sources including direct observations from vessels and examination of whale carcasses found floating at sea or washed up on the beach for evidence of collision. In some cases, whales become lodged on the bulbous bows of large vessels and frequently the crew only become aware of this when the ship enters port. However, for every incident that is observed and reported there will be many others that are missed. This makes assessing the conservation implications of ship strikes very difficult.

For some populations, such as the North Atlantic right whale whose main habitat is the busy waters off the east coast of the USA and Canada, the mortality rate is particularly high compared to the overall population size. It is thought that mortality due to ship strikes may make the difference between extinction and survival for this species and mitigation measures have been developed as discussed below. There are also concerns about the high collision rates for the population of fin whales in the Mediterranean. Reported numbers will never give accurate estimates of the numbers of whales involved and so there is a need for estimates based on an understanding of risk and relating this to densities of ships and whales.

Separating whales from vessels is is not as easy as it sounds for both scientific and logistical reasons, but it has been achieved in some areas. In particular, it relies on good information and predictable patterns of whale (and vessel) distribution as well as a practicable alternative route for shipping.

For example, in the Bay of Fundy off the east coast of Canada, long-term data on North Atlantic whale distribution allowed a small adjustment to the shipping lane, adding minimal passage time to shipping, but achieving a substantial reduction in collision risk. A similar approach has been used for shipping lanes approaching the port of Boston on the east coast of the USA. Considerable progress has also been made in Panama and Spain, for example.

In other areas, there is no practicable alternative route for shipping and other potential solutions need to be considered. There is good evidence that ships travelling at slower speeds pose less of a collision risk and in areas where there is a particular concern, vessels have been requested to slow down. For example, there is an area in approaches to the Strait of Gibraltar that appears particularly important to sperm whales, but would be difficult for vessels to avoid.

Measures to regulate shipping, such as modifying mandatory shipping lanes or establishing areas to be avoided, are decided by the International Maritime Organization. In 2009, the Marine Environment Protection Committee of the IMO accepted a a guidance document on minimizing the risk of ship strikes with cetaceans into its work programme.

The database includes information on the whales (e.g., species, size, observed injuries) and on the vessels. In many cases there is evidence to suggest a ship strike but often the cause of death cannot be determined conclusively. It is important that the database clearly identifies the level of uncertainty in each case. The objectives of developing the database are to lead to more accurate estimates of the incidence of mortality and injuries, to help detect trends over time, to allow better modelling of risk factors (e.g., vessel type, speed, size), and to identify high risk or unsuspected problem areas.

It is essential that reported data are carefully checked (for example several people may report  the same incident) and the uncertainty carefully described. Events reported are therefore carefully checked by the IWC’s data review group.

You can also download a summary table of data entered up until October 2010. These data come mainly from reviews of historical sources including past national progress reports to IWC. Therefore the interpretation as to whether these incidents were indeed definite ship strikes relies on the provider of the data or authors of review papers. None of the data have therefore been subject to the review process currently being established by the IWC data review group. These records include reports of carcasses showing evidence of collisions with vessels as well as direct reports of collisions where the fate of the whale may not be known. For the majority of these records, the available information is limited. These data are provided subject to these caveats and particularly to allow potential data holders to check whether incidents are already in the database.
Shipstrikes Summary Data Table (xlsx) to download - Click Here