Pacific oysters

Maori name: tio repe
Scientific name: Crassostrea gigas
Availability: April to November
Weight:
Length: 10–12cm, reaching 18cm

Pacific oysters

Maori name: tio repe
Scientific name: Crassostrea gigas
Availability: April to November
Length: 10–12cm, reaching 18cm
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Location

Widely distributed around the world, it has provided a foundation for oyster aquaculture and was probably an accidental import to New Zealand. The species is found largely around the north of the North Island, where it is now the main oyster farmed by aquaculture. It has spread by natural processes all around the North Island and across Cook Strait to the northern part of the South Island.

Attributes

Off-white shell with bands of yellow, brown, or purple. The flesh is light-coloured and has a black mantle margin.

Family

The Pacific oyster belongs to the Ostreidae family (oysters).

Spawning

Pacific oysters spawn annually with spat settling in brackish, estuarine water. Growth is rapid and, in good conditions, the oyster can reach a meat weight of 20 grams in 15 to 18 months. This, as well as the dense spat settlement, makes the Pacific oyster suitable for aquaculture.

Sustainability

New Zealand Pacific oysters are widely recognised as a highly sustainable seafood. Farmed at intertidal and sub tidal sites around New Zealand, using both naturally settling and commercially produced spat, they reach market size in 12 - 20 months, feeding on naturally occurring plankton. Every oyster farm must operate in accordance with a resource consent that sets strict conditions determined and enforced by the local council. The consent is in effect a licence that tightly controls, among other things, the size of the farm, activities permitted and required monitoring. The Quota Management System does not apply to Pacific oysters; it is instead governed by provisions within the Resource Management Act and the Aquaculture Act.

Fishing methods

The species is harvested throughout the year except in the breeding season (from December to March).

Nutrition

Pacific oysters are a good source

To quality for a 'good source' claim the food must contain at least 25% of the RDI.
The Recommended Dietary Intake (RDI) is considered to be the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97–98 per cent) healthy individuals in a particular life stage and gender group.

of Vitamin C

Vitamin C is necessary for nomal connective tissue and blood vessel structure and normal neurological function

, Vitamin B12

Vitamin B12 is necessary for normal neurological function and it contributes to blood formation, energy metabolism and to the growth and development in children

, Copper

Copper is necessary for nomal energy production and normal immune system function and it contributes to the transport and metabolism of iron

, Magnesium

Magnesium is necessary for normal nerve and muscle function and for teeth and bone structure and it contributes to normal energy metabolism

, Iron

Iron is necessary for the transport oxygen, for normal immune system function and for normal neurological development in the foetus, and it contributes to energy production and the reduction of tiredness and fatigue

, Selenium

Selenium is necessary for normal immune system function and for the production of thyroid hormones and it contributes to the maintenance of hair and nails

, Zinc

Zinc is necessary for normal immune system function, contributes to normal skin structure and the healing of wounds, the maintenance of bones, hair and nails

and Iodine

Iodine is necessary for the production of thyroid hormones, for normal neurological function and for normal energy metabolism, and it contributes to the growth and development in children

; and a source

To quality for a 'source' claim the food must contain at least 10% of the RDI.
The Recommended Dietary Intake (RDI) is considered to be the average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97–98 per cent) healthy individuals in a particular life stage and gender group.

of Manganese

Manganese is contributes to normal bone formation, energy metabolism and to the growth and development in children

, Phosphorus

Phosphorus is necessary for normal teeth, bone and cell membrane structure and for energy metabolism

, Riboflavin (vitamin B2)

Riboflavin (vitamin B2) is contributes to the transport and metabolism of iron, to the release of energy from food and to the maintenance of normal vision

, Vitamin D

Vitamin D is necessary for normal bone structure and the utilisation of calcium and phosphorus and it contributes to the maintenance of normal teeth

and Niacin (vitamin B3)

Niacin (vitamin B3) is necessary for the release of energy from food and for the normal structure and function of skin and mucous membranes, and contributes to the reduction of tiredness and fatigue

.

Seafood is a highly nutritious food and is a great source of protein

Protein is necessary for tissue building and repair, normal growth and development of bone in children and adolescents aged 4 years and over, and contributes to growth and maintenance of muscle mass

. Many species are low in saturated fat and a number of them are a good source of Omega 3

Omega 3 is a group of fatty acids that contribute to heart health

.

Tips

Pacific oysters are arguably best eaten fresh, raw and straight from the shell, however they can also be baked, barbequed, fried, poached, smoked, steamed, or used in a soup/chowder. Shuck fresh oysters an hour before you want to eat them and put them on ice - this will chill the oysters down and plump them up. They require very little cooking time (about 5 minutes on a barbeque or in the oven) and should be heated slowly to avoid a rubbery texture. Regardless of which cooking method you choose, the oysters are ready when the mantle starts to curl.

Buying & Storage Tips

Shuck fresh oysters an hour before you want to eat them and put them on ice - this will chill the oysters down and plump them up.

Frozen oysters should be thawed in the refrigerator. Store raw or thawed oysters in the refrigerator.