We administer a database containing information from reports received relating to incidents of Hector’s and Māui dolphin. Get a summary of information from database.


Reports may be of dolphins:

  • alive stranded on the beach
  • washed up dead on beach
  • found floating dead at sea or 
  • caught during commercial or recreational fishing (bycatch; may be dead or released alive).

Spreadsheet of Hector's and Māui dolphin incidents: July 2008 - 30 April 2018 (XLS, 76K) 

Note: Haplotypes are portions of DNA that are only passed on by females, so each dolphin has the same haplotype as its mother. Haplotypes are assigned letters of the alphabet. There are 20 haplotypes in Hector's dolphins, and one that is unique to Māui dolphins (G).

Quarterly incident update reports - includes pathology reports

Quarterly updates are posted about Māui and Hector's dolphin incidents in early May, August, November and February each year. Individual updates are current as at the date of publication, results that are pending at that time will be updated as they are received. Incidents are now grouped per year but will still be updated every quarter.

In order to align reporting and maintain the integrity of government fishery observer programmes, data on observed captures will generally be reported here only in the quarterly report after the quarter that the incident occurred in. You can provide constructive feedback to

Hector’s and Māui dolphin data

DOC is working to improve how we collect, manage, and report on Hector’s and Māui dolphin data. As a part of this process we are developing a new geospatial database. Some fields have changed and the old data has been converted to match the new fields. The differences are:

  • replacing date DOC notified with date event reported;
  • for cases when an observation or reporting date was unknown, the data have been replaced with the use of 1/11/1111 or part thereof
  • age class has been restricted to the use of adult or juvenile
  • encounter type has been changed to observation type and is restricted to a list of predetermined options
  • evidence of human interaction has been changed to gear type but the information is the same;
  • whether or not a necropsy has been completed is now represented by necropsy status
  • possible cause of death is represented by the cause of death as determined by necropsy, or suspected primary cause of death if a necropsy was not performed, and
  • cause of death is now also restricted to a list of succinct options and the full pathologist notes can be viewed in the necropsy report.

Where reports come from

The database relies on reports from the public of dead dolphins they have found. It is biased to areas visited frequently by people and so tends to have more reports from areas that have higher visitor numbers. The database also relies on reports from fishing vessels that may have caught dolphins during their fishing activity.

The earliest record in the database is from 1921. Some reports are historical records from museums or universities, but much of the information in the database is from reports investigated by DOC.

Currently, investigation of all Māui and Hector’s dolphin mortality includes:

  • photographing the dolphin as it was found
  • taking samples and measurements
  • necropsy by veterinarians (the animal equivalent of an autopsy or post-mortem) to determine the cause of death and collect additional scientific samples and information.

What the database contains

The database contains a variety of information about each dolphin, including its sex, size, where it was found, any background information about the incident and information collected during the necropsy.

In some cases, dolphins may not have been assessed for a cause of death as the carcass may have been too decomposed to find out how the dolphin died. In some cases, there may be clear evidence for a dolphin’s cause of death (for example, a specific wound), although in others there may be no clear evidence at all.

Ranger measuring dead dolphin calf.
Trainee Ranger Guy Brannigan measures a dead Hectors calf washed ashore at Warrington Beach near Dunedin in December 2012

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