Marine permaculture for Tai Tokerau?

Tai Tokerau is a slim peninsula about 320 km long. The Northland Region has 3200 kms of coastline and harbour shoreline, including the Kaipara Harbour, which has the longest shoreline of any harbour in the world. Our marine ecosystems range from the pristine Poor Knights Islands, to the degraded waterways in our harbours. 700,000 tonnes of sediment flow into the Kaipara harbour annually.

We know we can regenerate soils; Can we regenerate oceans too? Regeneration infers dynamic systems that can either regenerate or degenerate. Daniel Wahl’s model positions regeneration as a virtuous spiral where we learn from nature and work more humbly with her.

Figure 1: Daniel Wahls model of regeneration

When we achieve this virtuous circle, nature confers generous co-benefits. Soils become richer, they infiltrate and store water leading to benefits for plants, animals, humans and the wider ecosystem. But what of the oceans? Our degenerating land practices create excessive loads of sediment, nutrients and pollutants that degrade rivers, estuaries, harbours and the sea. Marine vegetation is covered in sediments and is choked of light. Excessive carbon dioxide in the air is absorbed by oceans leading to acidification of sea water, and global warming is precipitating marine heat waves, that degrade coral reefs and other ocean ecosystems.

Although in Tai Tokerau, we are surrounded by the sea and none of us live further than 40 km away, what do we know of the potential of the ocean in mitigating and adapting to climate change? Dr Brian von Herzen tells us that kelp forests sequester more carbon than tropical rain forests. The ocean produces from 50 to 80% of the world’s oxygen. Phytoplankton nucleate rainfall. So when we disrupt the food chains in the ocean, we are further disrupting hydrological cycles. Oceanic warming disrupts the thermocycling where cool nutrient rich water cycles from the deep to cool and feed ocean ecosystems. When this cycle stops food chains are disrupted.   

What does marine permaculture look like?

Seaweed is provides the living infrastructure for marine permaculture.

Marine permaculture offers a solution to transform the way we harvest our food from the sea. It begins with growing the marine vegetation that is at the base of the food chain. Kelps grow rapidly.

Brian Von Herzen is working to promote marine permaculture in Australia, the U.S. and South Asia. Alongside the kelp’s vegetative framework, fish and shellfish thrice in the ecosystem. Kaimoana (seafood) can be harvested sustainably.

The value proposition for marine farming is compelling, especially for Tai Tokerau with our 3,200 kms of ocean and harbour shoreline.

  • Kelp forests sequester more carbon than rain forest, largely because of its rapid growth rate. Kelp surplus to needs can be sunk to the sea bottom where it sequesters carbon for decades.
  • They create new marine habitat that supports a sustainable harvest of kaimoana.
  • Kelp has uses as super nutritious food, fertiliser and stock food. Brian states that flowering crops especially benefit from foliar applications.
  • Kelp sequesters nutrients – so can remove excess nitrogen and phosphorus.

As marine farming creates new habitat, a case could be made for excluding the kaimoana from the quota management scheme increasing the profitability for fishers and reducing the cost of fish. This would incentivise investment and shift fishing away from the destructive extractive fishing practice.

Hopefully we can get Dr. Brian von Herzen here to explore this potential. He is an Edmund Hillary Fellow. His presentation begins at 23.45 in this video.

This video explores the many uses of algae and its huge economic potential.

Questions:

Where does kelp grow in Tai Tokerau and what are the main species?

What kelp species have most potential here?

How do we regenerate seagrass?

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