Whales: New Zealand Marine Mammals

Whales, including species like the orca, sperm whale, and humpback, play a vital role in marine ecosystems, from regulating food webs to storing carbon.

Whales are large marine mammals that belong to the cetacean family, which also includes dolphins and porpoises.

What Do Whales Look Like?

Whales have large, streamlined bodies adapted for life in the ocean. Baleen whales, which are filter feeders, tend to have smooth, dark skin and long flippers. They primarily consume small marine organisms like krill, copepods, and other tiny crustaceans. Toothed whales, which are whales like orcas and dolphins that hunt prey, may have more varied colours and body shapes. Most baleen whales have two blowholes, while toothed whales have one. Whale sizes vary widely, with the largest species, the blue whale, growing up to 30 metres long and weighing over 180 tonnes.

Where Do Whales Live?

Whales are found in oceans all over the world, from the icy waters of the Arctic and Antarctic to the warm tropical seas. Baleen whales often migrate between cold feeding grounds and warmer breeding areas, while many toothed whales stay in specific regions year-round.

What Species of Whales Inhabit New Zealand Waters Permanently or Seasonally?

Almost half of the world’s whale and dolphin species can be found in New Zealand. These include:

Bryde’s Whale (pronounced ‘Brooders’) – One of the most poorly understood baleen whales, Bryde’s Whales are nationally endangered in New Zealand and can be found in the Bay of Plenty, Hauraki Gulf, and the east coast of Northland with the majority of sightings in the Hauraki Gulf Marine Park.
Gray’s Beaked Whale – Aside from the Gray’s Beaked Whale, 11 other species of beaked whales live in or frequent the waters around Aotearoa.
Humpback Whale – New Zealand is a key location along the Humpback whales migration highway. In winter, they can be observed along the coast of New Zealand as they migrate to tropical breeding grounds. Later on, they return to their Antarctic feeding areas.
Minke Whale – There are two species of minke whales found in New Zealand waters. These are the dwarf minke whale, which has a complex and colourful pattern, and the larger Antarctic minke whale, which typically feeds on krill in the Antarctic Ocean.
Orca – Known as killer whales, orcas have been observed to hunt and prey on larger whale species. An estimated 150 to 200 orcas reside in New Zealand waters.
Pygmy Blue Whale – A slightly smaller subspecies of the Antarctic blue whale, pygmy blue whales can reach up to around 24 metres in length. In summer, this species can be found foraging offshore in the South Taranaki Bight.
Pygmy Sperm Whale – Known for their shark-like, underslung jaw, pygmy sperm whales have an average length of 3 metres.
Southern Right Whale – Occasionally seen around the mainland, southern right whales spend winter and spring near their breeding grounds in the subantarctic Auckland islands. To understand how the migration patterns of these whales are adapting to a changing climate, Live Ocean has supported Dr Emma Carroll’s Southern Right Whale research.
Sperm Whale – Sperm whales are the largest of the toothed whales. Semi-resident ‘bachelor’ sperm whale males are often observed in the underwater canyons around Kaikoura.

Do Whales Have Any Predators?

While adult whales have few natural predators due to their size, orcas or killer whales sometimes hunt smaller whales, calves, and injured individuals. Some shark species may also prey on young or vulnerable whales. However, humans have historically been the biggest threat through whaling and other human activities.

Are Whales Endangered?

Several whale species are classified as either endangered or vulnerable due to past and present whaling activities as well as ongoing threats. Conservation efforts have helped some populations recover, but many whale species remain at risk.

What Are the Biggest Threats to Whales Today?

Modern threats to whales include climate change, commercial whaling, ship strikes, entanglement in fishing equipment, and ocean noise pollution, which can disrupt whale communication and migration.

What Are the Common Conservation Efforts Aimed at Protecting Whales?

Conservation efforts to protect whale populations include:

Tracking whale populations, migration patterns, and health to guide conservation strategies.
Creating designated marine protected areas (MPAs) where human activity is restricted to create safe habitats for whales to feed, breed, and migrate.
Implementing quieter shipping and industrial practices to reduce noise and underwater disruptions.
Lowering ship speeds in whale migration routes to reduce the risk of collisions.
Developing and using whale-safe fishing gear to prevent entanglement.
Reducing plastic and chemical pollution in oceans to improve water quality and protect whale health.

One example of such a program is Dr. Emma Carol’s work on tracking New Zealand’s tohorā southern right whale population. The data from her team, which was collected between 2020 and 2022, contributed to a global study and helped inform policies on how to improve whale protection and prevent vessel strikes.

How is New Zealand Involved in Whale Consevation?

New Zealand has marine protection laws and conservation projects aimed at monitoring and safeguarding southern right whale populations, especially around the Auckland and Campbell Islands, where many whales breed.

What Is Blue Carbon, and How Do Whales Contribute to It?

Blue carbon refers to carbon stored in marine ecosystems which plays a vital role in climate change mitigation and the overall health of our planet. Whales help store and move carbon in two key ways:

Fertilising phytoplankton growth – Whale faeces are rich in iron and nitrogen, which are essential nutrients that support phytoplankton or microscopic marine algae. These microscopic plants contribute an estimated 50% of the world’s oxygen supply and absorb around 40% of the world’s carbon dioxide each year, and they play a critical role in reducing greenhouse gases.
Storing carbon in their bodies – Whales accumulate carbon in their massive bodies over their lifetimes. When they die, their bodies sink to the ocean floor, locking away carbon for centuries and preventing it from re-entering the atmosphere.

How Much Carbon Can Whales Lock Up?

Over its lifetime, a single whale can sequester around 33 tonnes of carbon dioxide, which is equivalent to the amount stored by 1,000 trees. This makes whales a vital part of the ocean’s ability to regulate carbon and mitigate climate change.

How Can People Help Protect Whales?

People can get behind conservation efforts by reporting whale sightings to researchers, supporting marine protection policies, and advocating for sustainable shipping practices to prevent ship strikes.