Bycatch of protected species: Hector’s and Māui dolphins
New Zealand's Environment Reporting Series: The Ministry for the Environment and Statistics New Zealand
The South Island Hector’s and Māui dolphins are among the world’s smallest marine dolphins. Both are subspecies of the Hector’s dolphin Cephalorhynchus hectori. These coastal dolphins are endemic to New Zealand, which means that they are not found anywhere else. The Māui dolphin is found in the inshore waters of the west coast of the North Island, most often from Maunganui Bluff, north of Dargaville, to New Plymouth. The South Island Hector’s dolphin (hereafter referred to as ‘Hector’s dolphin’) is mostly found in the inshore waters around the South Island. Both subspecies are threatened with extinction: Hector’s dolphins have a population estimated at 15,000 and are classified as nationally vulnerable, while Māui dolphins have a population estimated at 63 individuals over one year old and are classified as nationally critical (Baker et al, 2019; MacKenzie & Clement, 2016; Baker et al, 2016).
Dolphins can become entangled in fishing gear used by both commercial and recreational fishers, with set nets posing a particularly high risk. The accidental capture of marine life in fishing gear is typically referred to as bycatch. Reporting the causes of death of protected species and specifically identifying the number of animals killed as a result of fishing activities helps us understand the pressures our protected marine species face from fishing.
DOC’s Hector’s and Māui dolphin incident database 1921-2018 provides data on reported deaths of Hector’s and Māui dolphins.
This indicator measures the number of reported Hector’s and Māui dolphin deaths from entanglement, categorised by type of fishing gear where possible, since 1998. The number of entanglements is compared to the total number of reported deaths.
More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.