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Biodiversity in the Bay of Plenty

Biodiversity is short for biological diversity. It refers to the number and variety of living things (animals, plants or microorganisms) found within a particular area. There are complex relationships between this variety of life. Marine biodiversity specifically refers to the variety of life in coastal and ocean environments.

The Earth and various species illustrating biodiversity.

Biodiversity

Biodiversity refers to the number and variety of living things (animals, plants or microorganisms) found within a particular area and the complex relationships between them.

Rights: ZeitNews

Biodiversity includes:

  • genetic diversity – the different genetic make-up among individuals of one species

  • species diversity – the different species within a habitat such as the birds, worms, fish, bacteria, insects and molluscs that live within an estuary

  • ecological diversity – the different ecosystem types (estuaries, oceans, forests, wetlands, grasslands, streams) and the communities within them.

Marine biodiversity

Marine species make up almost one-third of New Zealand’s total number of described native species. However, about seven new marine species are identified each fortnight – many more are yet to be discovered. Scientists estimate there could be as much as 80% of New Zealand’s biodiversity living in the sea.

A species inventory for New Zealand was developed over the last decade through a project called Species 2000: New Zealand. This project formally identified about 12,000 marine species in New Zealand’s waters, with another 3,550 known but not yet described. It is estimated that, at the present rate of description, it would take another 100 years to describe the remaining marine species.

Described species include:

  • seabirds

  • marine mammals

  • fish

  • molluscs (snails, shellfish and squid)

  • sponges

  • echinoderms (kina, sea stars (starfish))

  • seaweeds (rimurimu)

  • microalgae.

Examples of all of these are found in various Bay of Plenty habitats.

Life in the estuaries

The soft estuary bottom (consisting of sand and mud, including sediment carried down by rivers) supports a range of burrowing fauna such as worms, cockles and pipi. Most of these animals feed on accumulated debris and bacteria and algae films on the mud surface. Estuaries are ideal refuges for juvenile fish of many species and wading birds in search of fish and crustacea.

Little pied cormorants on a log in the Pukehina estuary, NZ.

Life in the estuary

Little pied cormorants enjoying life in the Pukehina estuary. They usually dive for food in relatively shallow water, consuming flounder, other small flatfish, eels and insect larvae.

Rights: Steve Clancy

Life in the beach zone

Bay of Plenty beach zones support abundant species such as shellfish – pipi, tuatua, biscuit shell, dog cockle and triangle shell. Sandhoppers can often be found jumping around in the debris left by an outgoing tide, called the wrack line. Terns and gulls often pick through debris. Pieces of driftwood often contain oyster borers and other insects. Fragments of dead seaweed such as sea lettuce and kelp are also common in this area.

Life on the rocky shore

The rocky shores support a huge diversity of life. Life here is not easy. Salinity, water, wave action, competition and predation are all factors affecting survival chances of life on the rocky shore. However, examples of many marine organism groups can be found there. Some examples are sea anemone, kina, sea cucumber, sea slugs, sea stars, pāua, crabs, chitons, sponges, worms, shrimp, barnacles, sea squirts, seaweeds, crayfish, octopus, fish, oysters and mussels.

Life around the offshore islands

These mostly volcanic rocky shores exposed to warm ocean currents support a unique diversity of subtropical marine life. In addition to species found on most New Zealand rocky shores, these habitats include long-finned boarfish, clown toado, crimson cleanerfish, the colourful splendid perch, Sandagers wrasse, copper moki and, in the summer, turtles.

Synoicum stewartense: sea squirts (ascidians) NZ's coastal water

NIWA explores marine biodiversity hotspots

NIWA explores new marine biodiversity hotspots – habitats that haven’t been explored before. They are hoping to discover new species, learn about them and how to manage them.

The importance of biodiversity

New Zealand’s marine biodiversity is ecologically important because it is unique and of international importance – many of our species are not found anywhere else on Earth. Biodiversity also has intrinsic value – the value of the variety of life itself – and creates ecosystems that allow organisms to flourish in an interdependent web of life. Some of these species have commercial value to us as food and sources of potential medicines. Our relatively unspoiled marine environment also has economic value for tourism and our fishing industry. Finally, of cultural significance is that Māori have a special affinity with the oceans in a non-material way, and this is recognised in the Treaty of Waitangi.

Nature of science

Science knowledge changes over time. As science and technology allows greater exploration of the ocean, more species are being discovered. New species are being discovered and identified all the time. With new discoveries come new possibilities – discoveries of medicines and other valuable compounds (biodiscoveries).

Related content

Use these Building Science Concepts articles to explore the science concepts that underpin knowledge and understanding about:

The Hub also has curations of resources that support learning about:

Biodiversity – estuaries and marine ecosystems is a collection of resources and notes for those teaching in primary school classrooms. You are welcome to copy the collection to your own profile, where you can edit and curate additional resources. Find out more about our easy to use collection tool.

These series of interactives features many of the Department of Conservation's marine infographics.

Activity ideas

These two student activities explore the two key science concepts of habitat and biodiversity:

  • Where do I live? looks at why and how marine animals and plants are best suited to particular habitats. The activity is ideal for rocky shore and estuary studies.

  • With Introducing biodiversity, students make models of a marine ecosystem and then explore ways humans might impact on that ecosystem.

Useful link

The New Zealand Inventory of Biodiversity 2012 (in three volumes) is an up-to-date inventory of biodiversity in New Zealand. It lists and describes all known species. Find out more on the Univeristy of Canterbury's website.

Published:11 January 2012