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🌊 Coastal Ecosystem Study

Te Taiao Takutai — Life at the Ocean's Edge

🏖️ Where Land Meets Sea

Aotearoa has over 15,000 km of coastline — one of the longest in the world for our land size! Coastal ecosystems are among the most productive and diverse, supporting countless species and providing food for both wildlife and people.

Coastal Zones

🏔️ Splash Zone

Above high tide — only gets wet from spray and storm waves.

Conditions: Extreme! Must survive heat, cold, drying out.

Species: Lichens, periwinkles, some crabs.

🌊 Intertidal Zone

Between high and low tide — covered and uncovered twice daily.

Conditions: Challenging — must survive both underwater and in air.

Species: Mussels, barnacles, sea stars, anemones, crabs.

🐟 Subtidal Zone

Always underwater — from low tide down to the continental shelf.

Conditions: Stable, but needs light for seaweed.

Species: Kelp forests, fish, crayfish, octopus, sea urchins.

🦀 NZ Coastal Species

🦞 Kōura

Crayfish

🐚 Pāua

Abalone

🦪 Kutai

Green-lipped mussel

Pātangaroa

Sea star

🐧 Kororā

Little blue penguin

🌿 Rimurimu

Kelp/seaweed

🕸️ Coastal Food Web

Energy Flow

  • Producers: Seaweed, phytoplankton (make energy from sunlight)
  • Primary consumers: Sea urchins, shellfish, small fish (eat plants)
  • Secondary consumers: Crayfish, octopus, larger fish (eat animals)
  • Top predators: Sharks, dolphins, seals, seabirds
  • Decomposers: Bacteria, worms (break down dead matter)

🌿 Kaimoana — Seafood

Traditional Coastal Mahinga Kai

Coastal gathering has always been central to Māori life:

  • Kaimoana — seafood as a taonga (treasure)
  • Rāhui — temporary fishing bans to let populations recover
  • Maramataka — lunar calendar for best gathering times
  • Mātaitai — customary fishing reserves today

Sustainable harvesting ensured kaimoana for future generations.

⚠️ Threats to Coastal Ecosystems

Human Impacts

  • Pollution — plastics, sewage, agricultural runoff
  • Overfishing — removing too many fish or shellfish
  • Climate change — warming water, ocean acidification
  • Coastal development — destroying habitats
  • Invasive species — like undaria seaweed

✏️ Activities

Activity: Rock Pool Investigation

If you visit a rocky shore, carefully observe a rock pool:

  1. What species can you identify?
  2. How are they adapted to survive in the zone?
  3. Draw a simple food web of what you find
  4. What threats might this ecosystem face?

Remember to leave everything as you found it!

Observations:

👩‍🏫 Teacher Notes

Curriculum Links

  • Science: Living World — ecosystems, adaptation
  • Geography: Coastal environments
  • Te Ao Māori: Kaitiakitanga, kaimoana