Most New Zealanders ignore seaweed as food, apart perhaps from the odd bit of nori rolled round sushi or slivers of seaweed in rice biscuits.
These days you might also find a little karengo or a couple of kelp chips nestling against pikopiko (baby fern scrolls) on dishes by trendy chefs promoting New Zealand cuisine.
Seaweed is used widely in Asian cuisines, especially those of Japan, Korea and parts of China, but most of us don't realise it is also an ingredient in many processed foods, from beer to ice cream and salad dressing, as well as pharmaceuticals, paints, soaps, toothpastes and beauty products. It is also used in animal feed and as a fertiliser.
Off the coast of North America, they harvest seaweed with barges and mowers, according to Sally Carson, programme director at the University of Otago's New Zealand Marine Studies centre and Aquarium at Portobello. She regularly cooks seaweed chips, sprinkles chopped fresh seaweed on crackers and in salads, soups and stews, and uses dried, crumbled seaweed as a seasoning or flour.
"I grew up on the east coast of Canada where we ate dulse as an after-school snack," she said.
(Dulse is a North Atlantic species of red seaweed not found here.) Her interest in seaweed developed when she worked with a woman who farmed kelp off the west coast of Vancouver Island.
The good thing about foraging for seaweed, as opposed to mushrooms, is that almost all are edible.
Some are good to eat, with crunchy or chewy textures and salty flavours reminiscent of the ocean, but the taste and texture of others may be unpleasant, she says.
Bladder kelp
Fronds can be cut off without damaging the plant, she says.
Rinse it in fresh water to wash off sand, any marine organisms and some of the salt and hang it on the clothesline to dry. Then chop the blades (leaves) into bite-sized pieces with scissors and store them in an airtight container.
Ms Carson uses these to make her seaweed chips, lightly tossing them in a little hot olive or sesame oil and sprinkling them with sesame seeds. They have a distinctive, slightly fishy, salty flavour and are very good with beer, she says. They were certainly popular with her colleagues at the aquarium.
She also makes her own kelp pepper and kelp flour by further drying the fronds in the oven for about 10 minutes and crumbling them in her hands. Commercial gourmet kelp peppers are made like this and can be added to stir-fries, rice, fish and many other dishes. Kelp flakes are a good substitute for salt.
Grinding the flakes in a mortar and pestle produces kelp flour.
She often substitutes a third of a cup for ordinary flour in many recipes, such as pie crust, or cookies.
She also pickles the thick stipe or stem like gherkins or cucumbers.
Sea lettuce
Sea lettuce (Ulva latuca) is bright green and found on beaches where there are plenty of nutrients 7 be careful as they thrive around sewage seepages. They can be eaten fresh in salads or dried and powdered to add to stews and other dishes as a seasoning.
Bull kelp
The tender young fronds of bull kelp, which is common off the outer coast, can be eaten throughout the year. Maori used it to make pouches for storing preserved muttonbirds, and it is eaten by native people in Chile. Use it like bladder kelp to make kelp chips, or dry, roast and crumble for kelp seasoning.
Wakame (Undaria) is a frilly fronded seaweed that is prized in Japan and Korea, and was accidentally introduced to New Zealand waters in the 1980s.
There is a campaign to get rid of it because it could smother native seaweeds.
However, it is one of the most palatable seaweeds, good eaten raw in salads, cooked in soups, or baked or boiled. It is an essential ingredient of dashi, Japanese stock. It can be used in the same way as bladder kelp.
Gracilaria is a reddish brown, spaghetti-like plant that often grows from a small holdfast on a shell or piece of wood under sand. It is best harvested in spring or summer. It is also a good source of agar, and good eaten freshly chopped in salads or blanched, or in pickles. It can be cooked and used to thicken stews.
Karengo (Porphyra species or purple laver), a purplish green seaweed with a tough, silky texture that grows off the outer coast, was a favourite with Maori.
They gathered it in late winter and early spring and steamed it in a hangi.
During World War 2, karengo was sent to Maori fighting in the Middle East because it was reported to be more thirst quenching than chewing gum. It's the seaweed used to make nori. It can be dried and eaten as a snack or crumbled and used in salads, soups and other dishes. Roasting it gently crisps it and brings out a nutty flavour.
Neptune's necklace
Neptune's necklace (Hormosira banksii) grows in rock pools between high and low water. Like the bladders at the base of the blades on bladder kelp, the tender tips of fresh Neptune's necklace can be sliced and added to salads or sprinkled on cream cheese on crackers to give a pickle-like crunch.
Carrageen
It has a fleshy texture and narrow branching, feathery fronds and some are wider with little knobbly bits. It can be harvested throughout the year. Agar, a gel-forming substance, is extracted from it commercially. Ms Carson puts the dried seaweed in a cheesecloth bag and immerses it in boiling milk for 5-10 minutes, then adds flavourings to make a blancmange. It can also be eaten raw, made into jellies or used to thicken soups.
Many other seaweeds can be eaten - branching velvet weed ( Codium sp), which is best in spring and has a nut-like taste; green grape seaweed ( Caulerpa sp), which is best used fresh and is said t
Stipes and blades
Instead of roots, seaweeds have a holdfast, which holds them to the rocks.
The stem is called a stipe, and the leaves are called blades and the stem and group of leaves are fronds.
Many have little bladders filled with air, allowing them to float near the surface so they can use sunlight for photosynthesis.
Unlike terrestrial plants, seaweeds absorb their nutrients from seawater rather than through roots.
Don't harvest them from areas polluted by sewage or industrial waste. Seaweed washed up on the beach will be starting to decay - don't eat it, although it makes good compost or liquid fertiliser for the garden.
Seaweeds are full of nutrients and minerals which vary from variety to variety, where it grows and time of year, but in general they are a valuable source of nutrients, high in vitamin C, iodine, calcium, iron, potassium, other minerals and fibre, and also contain high quality protein, Ms Carson says.
Although they may be high in salt, some sources claim seaweeds actually help eliminate salt from the body. It is also promoted as a good diet food, and to help regulate blood sugar levels. Kelp tablets and other seaweed products are sold in health food shops.
Harvest carefully
Harvest seaweed at low tide. It's best to check tide tables for a particularly low tide.
Different types grow in different places, sheltered or exposed. Some die off in winter or in summer, and some are better at certain times of the year.
However, as we know little about the diversity and ecology of New Zealand seaweeds, it is important to harvest carefully, and leave holdfasts so the plants can regrow - apart from wakame ( Undaria) which is regarded as a pest in New Zealand.
Buy your own
If you don't want to harvest your own, you can buy dried seaweeds in the international sections of good supermarkets, and Asian groceries.
Some, like nori, are imported but two New Zealand companies harvest and process local seaweeds.
Valere on Banks Peninsula, which also farms mussels, harvests bladder kelp, dries and flakes it and produces a kelp pepper.
Pacific Harvest, in Auckland, produces produces karengo in bite-sized pieces, flakes and granules, and kelp granules and powder. It also produces lemon, chilli, lime and smoked kelp seasonings, smoked salt and karengo and tamarillo chutney, and New Zealand agar powder, a seaweed extract. Because it does not yet have permission to harvest wakame and sea lettuce, it imports these.
Goes well with fish
Not surprisingly, seaweeds go well with fish dishes.
Sprinkle on kelp flakes as seasoning or top cooked fish with kelp or karengo chips - bite-sized pieces of seaweed that have been tossed in hot oil.
Crumbled or flaked seaweed can be sprinkled on baked potatoes or roasted vegetables.
Seaweed flakes can be rolled in pastry to make savoury nibbles. A quarter or half cup of seaweed flour (dried, toasted and ground seaweed) can be substituted for plain flour in recipes for pastry or biscuits.
Pieces of fresh or dried seaweed can be added to many savoury dishes, from stews, stir-fries, soups to pasta sauces.
