Tuatua

How to identify tuatua

• A smooth, triangular shell with no ribs and a sharply angled hinge.
• Lives in fine, clean sand on open surf beaches, not in sheltered harbours.
• Often sits only a few centimetres into the sand with the straight siphon end showing, stained green or brown by algae.
• The shell closes fully and has a sharp edge and a fairly flat base. Toheroa are much larger, rounder and gape at one end: leave those in the sand.

Tuatua belong to the surf clam family, along with pipi and toheroa. All have smooth, wedge-shaped shells with no ribs, which is the quickest way to tell them from a cockle.

To separate tuatua from pipi, look at the shape and the hinge. Tuatua are larger and more triangular, with the hinge (the point where the two halves join) sharply angled. A pipi shell is more evenly oval, with the hinge near the middle of the top edge. Where you find them also helps: tuatua live on open ocean beaches with surf, while pipi live in sandy banks near harbour and estuary mouths.

Toheroa are the one to watch for on surf beaches. They look like an oversized tuatua, but NIWA describes the toheroa shell as rounder, gaping at one end and with a lump at the base, while a tuatua shell closes fully, has a sharper edge and a fairly flat base. Adult toheroa can be twice the size of a tuatua and grow to over 150 mm. Toheroa are protected, so if you are unsure, put it back.

For the fishing rules, MPI counts southern or deepwater tuatua (Paphies donacina) as tuatua, so the same limit covers both species.

Where it lives in New Zealand

Tuatua need fine, clean sand on open ocean beaches with moderate surf. The densest beds are from the low-tide mark out to about 4 m deep, so you usually need a very low spring tide to reach them. They are found around the country but are most common around the North Island, with scattered beds in the northern South Island, Stewart Island and the Chathams.

Tuatua can be gathered year round. Low spring tides give the best access, and summer holidays are the busiest time on the beds. Some beaches are closed or have lower limits; see the limits by area below.

How to gather it

Wade out at the bottom of a very low tide and feel for tuatua with your feet, then pick them up by hand once you have found a patch, as gatherers have done for generations.

There is no minimum size for tuatua in most areas, but take only the bigger ones and leave the small ones to breed: they are the next few years' harvest. Count as you go: shellfish count towards your limit once they are in your bag, and see the limits by area below.

Leave toheroa where they are. It is an offence to take, possess or disturb them, and juveniles are easily killed by vehicles driving over the beds.

Respect rāhui and mātaitai. A rāhui is a customary ban on gathering, put in place by tangata whenua so a bed can recover or after a drowning; most people will respect a rāhui if they know about it. Some rāhui are also backed by an MPI temporary closure. Mātaitai reserves are managed by tangata whenua, and their bylaws can set lower limits or ban taking some species. Both are listed with the limits below, and MPI publishes the rules and maps for each customary management area.

Eating

Tuatua are sweet and tender. Most gatherers leave them in a bucket of clean seawater for a few hours so they spit out their sand before cooking.

Steam them open in a covered pot with a little water or white wine. Tuatua make good fritters and chowder, and Te Ara notes that cooks often use them in place of toheroa in soup, though they lack its green colour. Don't overcook them, or the meat turns rubbery.

Before you eat anything you have gathered, check MPI's shellfish biotoxin alerts for that stretch of coast. Tuatua are filter feeders, so they take up whatever is in the water, including algal toxins and sewage. Cooking does not destroy biotoxins. Stay away from beaches near stormwater drains and sewage outfalls, and don't gather after heavy rain. Your regional council's water-quality reports, such as LAWA's Can I swim here? or Auckland's Safeswim, show where water quality is poor.

Symptoms of shellfish poisoning usually start between 10 minutes and 3 hours after eating, and include tingling around the mouth and in the fingers and toes, dizziness and difficulty breathing or swallowing. If you feel unwell after eating shellfish, call Healthline on 0800 611 116 or get medical help straight away, and keep any leftovers for testing.

Good to know

Toheroa are a cautionary tale. Early last century they were canned as toheroa soup, which had a cult following. Canneries opened in Northland, Wellington and Southland, and Northland produced a record 77 tonnes of canned toheroa in 1940. Demand outstripped supply: commercial harvesting ended in 1969, recreational seasons were closed one by one through the 1970s, and the last open day was at Oreti Beach in 1993. Harvesting has been banned since. Decades later, toheroa have still not recovered, which suggests vehicles, sediment changes and other environmental pressures are holding them back. Toheroa are a taonga species and a prohibited shellfish. In MPI's words, "the only exception to collecting toheroa is a customary fishing permit", issued for a hui or tangi.

Tuatua have been gathered since the first people arrived. Middens around the coast are full of their shells, and the shells were used for scaling fish.

Gathering has fallen sharply. MPI's national panel survey estimated that recreational fishers took about 57,000 tuatua in 2022–23, against about 564,000 in 2017–18. The survey's authors put part of the fall down to closures and rāhui, and the shellfish estimates are uncertain because relatively few households gather them.

Tuatua spawn into the water, and their larvae drift for two to three weeks before settling. They reach 40 to 70 mm in about three years.

Questions

How many tuatua can I take?

It depends on where you are. The daily limit is lower in some areas and in some mātaitai and taiāpure, and some beaches are closed. See the limits by area and the closures below, checked against MPI.

How do I tell tuatua from toheroa?

Toheroa are much larger, with a rounder shell that gapes at one end and has a lump at the base. A tuatua shell closes fully, has a sharper edge and a fairly flat base. If you are unsure, put it back.

Can you take toheroa?

No. Under the Fisheries (Amateur Fishing) Regulations, you must not take, possess or disturb toheroa. Recreational harvesting ended in 1993 and the beds have not recovered.

What's the difference between tuatua and pipi?

Tuatua are bigger and more triangular, with a sharply angled hinge, and live on open surf beaches. Pipi have a smoother, more oval shell with the hinge near the middle, and live in sandy harbour and estuary channels. See <a href="/pipi/">pipi</a>.

Are tuatua safe to eat?

That depends on the water they came from. Check MPI's shellfish biotoxin alerts before you gather, avoid beaches near stormwater and sewage outfalls, and don't gather after heavy rain. Cooking does not destroy biotoxins.