Marine mammal pathology reports

What is a necropsy?

A necropsy is an examination of a dead animal to try to determine the cause of death.

Who does a necropsy?

Necropsies require specialised veterinary skills. Wildbase Pathology based at Massey University undertakes necropsies for DOC.

When does DOC request a necropsy?

A necropsy is only performed with the support of iwi/hāpu. The condition of the animal must also be suitable to be able to carry out a necropsy. 

Necropsies are undertaken on dead Hector's and Māui dolphins and New Zealand sea lions to help identify cause of death and to collect important scientific data that may help us manage threats to these species. Sometimes necropsies are carried out on other species for various reasons, such as on a particularly rare species, an unusual event, or to investigate a compliance issue (breaches of the Marine Mammals Protection Act 1978). 

View Hector's and Māui dolphin necropsy reports. 

Seismic surveying

Many companies undertaking seismic surveying agree to consider covering the cost of necropsies for any dead whales or dolphins found in the broad vicinity of their operations. We get Massey University pathologists to carry out these independent assessments.

Find out more about seismic surveying in New Zealand.

Limitations

Whether a necropsy is undertaken is dependent upon many factors, including (but not limited to):

• Condition of the animal. Animals must be reasonably fresh and preferably unfrozen to get useful information about cause of death. Decomposition occurs quickly after death in marine mammals, and a necropsy is very unlikely to be able to identify cause of death unless it occurs within a day or two of death. Decomposition is accelerated in warmer summer months. Freezing and thawing can badly affect the condition of the carcass.
• Availability of suitably qualified veterinary pathologists: There are only a limited number of veterinary pathologists in New Zealand with appropriate training and experience to undertake a post-mortem examination of a marine mammal.
• Transportation and other logistical issues. Access to the stranding site is an important consideration.  Only relatively small carcasses can be shipped to Massey University and there are also constraints on how unfrozen carcasses may be shipped in New Zealand.  

Research requests

Scientific researchers may seek permission to carry out post-mortem examinations or take samples (e.g. body tissues or stomach contents) from dead animals. They must have a permit from DOC and consult with iwi/hāpu.

While DOC may facilitate such research requests, these investigations are independent from DOC and may not be for the purpose of examining cause of death, nor will they necessarily be conducted straight away.