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Taro terraces in the Takuvaine valley

A wetland is a land area that is saturated with water, either permanently or seasonally. Wetlands around the world play a very important role in keeping our Earth healthy. They are a habitat for a number of plants and animals that have adapted to living in these watery environments. Wetlands also provide many services which people take for granted, some of which will be covered in this article.

The Cook Islands are fortunate to have four types of wetlands:

• Freshwater marshes and swamps: on Rarotonga, Mangaia, Atiu, Mitiaro and Mauke.

• Permanent freshwater lakes: Lake Tiriara on Mangaia, Lake Tiroto on Atiu, and Lake Rotonui and Lake Rotoiti on Mitiaro.

• Tidal salt marsh: at Ngatangiia Harbour on Rarotonga.

• Mountain streams: on Rarotonga.

The most common use of the freshwater swamps are for the cultivation of taro. Cultivation methods of taro in freshwater wetlands include raised taro beds (pa’i taro), taro swamp (repo tavari) or irrigated taro terraces (such as those found in the Takuvaine and Tupapa valley streams). The cultivation of taro in wetlands is very important to our food security in the Cook Islands, particularly in the outer islands.

Rarotonga also hosts the only remaining tidal salt marsh in the country – the Aroko Salt Marsh in Ngatangiia. This salt marsh is different to freshwater swamps where we grow our taro, as the area is covered by salt water during high tide. The Aroko Salt Marsh provides habitat to certain marine species found nowhere else in the Cook Islands such as the Koiti Raukura (Fiddler Crab), and provide shelter and safe hatchery conditions for important lagoon fish species.

Aside from providing food in the form of taro, and a habitat for a wide variety of animal species, wetlands provide a number of other benefits to people, here are some of them:

• Many people are unaware that wetlands are important natural filters for sediments and man-made pollution, by preventing pollution from entering the lagoon. (This service should be valued now more than ever due to current issues of lagoon pollution on Rarotonga).

• Wetlands also provide protection from natural disasters such as flooding from extreme rain events. The wetlands act as a natural buffer, soaking up large amounts of water and reducing the frequency and intensity of floods.

• A number of wetland plant species are used in traditional maori medicine, such as mauku vai (water grass), ta’uri’au and tamore.

• Other services include coloring and hardening of wooden artefacts.

Unfortunately, our Cook Island wetlands have been shrinking for decades due to development and conversion into agricultural land. Many businesses and landowners fill in swampland with soil and coral rocks so they can construct buildings on the land. It is not just filling up the wetland, but also building around them can block off the natural drainage flows, rendering the wetland useless.

A ra’ui to protect the filling in of wetlands would be ideal, just as ra’ui are placed on lagoon areas, wetland areas are also vitally important to the health of our islands and people. People need to be aware of the importance of these ancient wetlands and the role they play not only in providing food, but in filtering our pollution, providing a home for biodiversity and preventing flooding.

Wetlands should be utilized for their agricultural potential as taro plantations, however people should refrain from filling in wetlands or dumping rubbish or pouring chemicals into wetlands. As many of these chemicals will end up in our taro patches, the saying goes: you reap what you sow! Lets look after our wetlands so that future generations can benefit from them.

This article comes from Te Ipukarea Society’s weekly ‘environment column’ in the Cook Islands News

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One of the Hungrybin worm farms Te Ipukarea Society is providing to Cook Island schools

Wriggly worms play a vital role in our environment. They eat all day and can turn waste into compost. Today, all this useful service can now be contained in the form of a ‘worm farm’. Worm farms allow us to recycle our food scraps and significantly reduce the amount of organic waste being sent to landfills.

The worms used in worm farms are in fact compost worms, which are different to the regular earthworms found in garden soil. Compost worms are surface feeders and don’t burrow deep into the soil like garden earthworms do. If you want to find compost worms on Rarotonga, underneath old puru and pig pen sites are your best bet. Compost worms are capable of eating their own body weight in food each day. So a kilogram of worms will consume that much food daily! In comparison, garden earthworms only eat around half their body weight each day, so they aren’t as good at composting lots of material really quickly, as it take them twice as long.

The valuable compost produced by these special worms is made up of worm poo, also known as ‘castings’. There are two by-products from a worm farm, these are vermicasts, (a soil-like material) and a liquid being ‘worm tea’.

Vermicasts makes for high quality soil conditioner, and can be added to the garden or pot plants. Worm tea is the liquid waste from the worms (pee/mimi) and is usually separated out from the compost through a tap or outlet. Worm tea is liquid gold for your garden, it makes for great fertiliser and can be sprayed over the garden with a watering can.

Feeding these hungry worms is simple, but there are a few rules, for instance there are some things that compost worms just won’t eat, and there are other things that are just simply unhygienic to put into a worm farm.

Things you can put into your worm farm includes, most fruit & vegie scraps, Cooked food, tea leaves/bags and coffee grounds, egg shells as they are a great source of calcium which worms require in their diet to stay healthy, paper tissues, handy towels, toilet roll inners, shredded moist newspaper & cardboard.

Things not to put into your worm farms include citrus, acidic fruit skin, spicy foods, onion, garlic, leeks, capsicums, meat and dairy products, bread, pasta and processed wheat along with shiny paper and fats and oils.

Establishing and maintain a worm farm is not only environmentally-friendly, but is great fun and an excellent way to educate owners into getting in touch with the natural world along with providing a sense of responsibility for ones actions in the world we live in.

Te Ipukarea Society aims to spread this experience amongst all our school in the Cook Islands, by providing each of the schools with a portable worm farm to maintain and care for. How to build a portable worm farm along with what makes for a healthy worm farm will all be taught to each of the schools in order to start a sustainable waste management process that could improve our recycling habits. Araura College was the first school to receive their worm-farm, and Te Uki Ou School received theirs earlier this week, and will be keeping theirs next to their Rent-A-Plate stall at the Muri night market, in order to make the most of the food scraps people leave on their plates!

This article comes from Te Ipukarea Society’s weekly ‘environment column’ in the Cook Islands News

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