Frequently Asked Questions

FSANZ (Food Standards Australia New Zealand) has an online Food Composition Tables, listing the nutrient content of over 100 raw and prepared seafood products (including vitamins, minerals, fats and amino acids). They can help you determine which foods are the best sources of essential nutrients as well as which ones are major sources of nutrients you may want to limit (such as fat). And of course, there’s more than seafood, it contains data for over 2,600 foods (including common restaurant meals). 

When prawns are harvested, enzymes in their bodies continue to function, leading to oxidation which forms black spots within a few hours without refrigeration; a similar reaction to the browning of fruits and vegetables such as apples and potatoes. Low temperatures slow – but don’t stop – enzymatic reactions, and refrigerated raw prawns develop black heads within a day or two if they are untreated. Most prawns are therefore either cooked (which denatures the enzymes), snap frozen, or dipped in a weak solution of metabisulphite (to slow the enzymatic reaction) as soon as they’re harvested. Increasingly, citric acid-based alternatives are being used to cater for people who are sensitive to sulphur. Farmed prawns are occasionally sold without being frozen, cooked or sulphured, though they do often start to show signs of blackening around the heads. 

Eating fish has many nutritional benefits for pregnant women and young children. 

Fish are a valuable source of protein, minerals, vitamin B12 and iodine, are low in saturated fat and contain omega-3 fatty acids. Omega-3 fatty acids are important for the development of the nervous system in babies, before and after they are born.

But eating too much of a good thing when you are pregnant or breastfeeding can be bad, because some fish contain mercury levels that may harm an unborn baby or young child’s developing nervous system. It is also not advised to any eat raw fish while pregnant.

For more detailed information, please visit the NSW Food Authority website. 

Mercury occurs naturally in the environment and accumulates in the aquatic food chain, including in fish, as methyl-mercury. This means all fish contain some methyl-mercury.  The good news is that most fish in Australian waters have very low mercury levels.

It is important to note that mercury from fish is generally not a health consideration for most people, it is only an issue for women planning pregnancy, pregnant women, breastfeeding women and children under six. 

To find out more please contact the NSW Food Authority on 1300 552 406 or your health professional. 

Listeria is a group of bacteria found widely in nature e.g. in soil, water and the intestines of many domestic and wild animals, fish and birds. Listeria can survive for long periods of time in soil, leaf litter, sewage, silage, vegetation and water. Listeria is frequently found in food processing environments and has the ability to form biofilms and survive on apparently smooth surfaces. 

Listeria infection does not normally affect healthy adults and children. However, it can be very serious for pregnant women and their unborn children, new born babies, the elderly and persons whose immune systems have been weakened by disease or illness, such as those suffering from cancer, leukaemia, AIDS, diabetes, liver or kidney disease and anyone on medication that can suppress the immune system (e.g. corticosteroids such as prednisone or cortisone – but not topical creams and ointments), including organ transplant patients.

To find out more please contact the NSW Food Authority on 1300 552 406 or your health professional. 

All freshly cooked seafood is safe. Use immediately and store any leftovers in the fridge for consumption within one day. 
 
Fish and shellfish may be potential sources of Listeria, due to their harvest from natural environments where the bacteria can be found. However, it is more likely that Listeria may enter seafood products during and/or after processing through poor hygiene or manufacturing practices, or from subsequent handling of product. This is a special concern for those products that receive minimal or no heat treatment before consumption. 

Raw (uncooked) seafood. 
 
Smoked salmon and trout: Smoked salmon and smoked trout have a pH in excess of 6.0 and are usually salted to achieve an aqueous salt content of 3.5%. If Listeria is present in these products it is capable of significant growth, as they have a long shelf life. These products should be avoided by at-risk groups. 
 
Live oysters and mussels: Listeria is rarely isolated from fresh live oysters and mussels, however contamination can occur due to contaminated processing environments. Smoked mussels have been associated with cases of listeriosis in Australia and New Zealand. Pre-opened raw and smoked oysters and mussels should be avoided by at-risk groups. 
 
Peeled prawns (cooked): Peeled prawns (cooked) can be extensively handled both at retail and post-retail, thereby increasing the possibility of contamination. In addition, poor temperature control of retail chilling cabinets may allow the growth of Listeria if present. Cooked peeled prawns in prawn cocktails, as sandwich fillings, or in pre-made salad should be avoided, due to the extensive handling of these products and possible time/temperature abuse during storage. 

Ciguatera is a form of food poisoning associated with some tropical reef-feeding fish. Not all tropical reefs are affected however, and only some species of fish are susceptible. 

It is a naturally occurring marine toxin that accumulates in the food chain. It is passed from fish that feed on algae associated with some tropical reefs, to larger, predatory fish, which are in turn eaten by humans. 

While the chances of contracting Ciguatera poisoning are low, it is not uncommon, especially from tropical reef fish caught off the Queensland coast. Most cases of Ciguatera poisoning are a result of consuming recreational catch of large fish. 

To find out more contact your local doctor or local Area Health Service. 

Sydney Fish Market has strict guidelines in place to restrict potentially contaminated fish from being sold at the wholesale auction. The restrictions include rejection of potentially contaminated fish from prohibited supply regions and the introduction of maximum size limits for some tropical reef fish.  

Since implementing these guidelines, no known cases of Ciguatera from fish sold through Sydney Fish Market have been reported.  

To assist in controlling Ciguatera in commercial fish, the NSW Food Authority has provided the seafood industry with guidelines as part of their Food Safety Programs.

Fishers have been advised to avoid landing large Mackerel caught north of Cape Bryon. In addition, the NSW Food Authority has provided the same information to seafood processors.

The guidelines include: 

• Rejecting those species known to be associated with Ciguatera; 
• Rejecting other species based on the catch location and size. 

Dioxins are a group of chlorinated compounds produced unintentionally by industrial processes, as well as some natural processes, such as bushfires. 

Food Standards Australia and New Zealand (FSANZ) advises that Australian food supplies are safe.  

Studies have shown that the risk to Australians from eating foods, including fish and shellfish, containing dioxins is very low and it is not considered to be of public health concern. 

In February 2006, the NSW Government, following advice from an expert panel, banned commercial fishing in Sydney Harbour indefinitely due to high levels of dioxin found in Sydney Harbour Prawns and Bream. 

Sydney Fish Market supports the ban and does not sell for human consumption seafood caught in Sydney Harbour. 

Please contact the NSW Food Authority on 1300 552 406 or your health professional. 

• Scale, gut, gill and wipe out all fish before freezing. Place in an airtight freezer bag, extract as much air as possible, label and date. 

• Whole non-oily fish can be frozen for up to 6 months at -18°C or less.* 

• Whole oily fish, and all fish fillets, steaks and cutlets can be frozen for up to 3 months at -18°C or less.* 

• Meat from molluscs (such as Squid and Mussels) can be frozen for up to 3 months at -18°C or less.* Gut and clean Squid, Cuttlefish and Octopus or remove meat from shells. Place in an airtight freezer bag, extract as much air as possible, label and date. 

• Crustaceans can be frozen for up to 3 months at -18°C or less.* Place crustaceans (other than Prawns) in an airtight freezer bag, extract as much air as possible, label and date. 

• Place unpeeled Prawns in a plastic container appropriate to the volume of Prawns. Cover with water, seal and freeze. This forms a large iceblock, which insulates the Prawns. Do not add salt as it draws out the moisture. Label, date and freeze as above.  

* Note: many domestic freezers do not get as low as -18ºC, if in doubt check. 

Mussels taste creamier just before they spawn as they’re full of spat (roe). Just after they’ve spawned, they may taste stronger (some people say slightly bitter) due to the absence of the sweet creamy roe. Mussels tend to spawn in warmer weather, though the actual time varies from region to region and year to year. A Mussel that hasn’t spawned will look plumper and feel heavier than one that has, though that’s not much use when they’re closed tight in their shells. So, as with most seafood questions, it’s best to buy from a fishmonger you trust and to ask them! 

Sashimi is a Japanese dish of slices of raw seafood, usually served with soy sauce and wasabi. It’s not served with rice and therefore is considered an entrée rather than a meal by the Japanese. Sushi is raw seafood (and sometimes other ingredients) served with rice, and therefore considered a main course or complete meal. As the seafood is eaten raw, it must be very fresh and of exceptional quality, such seafood is called ‘sashimi-grade’. Sashimi-grade seafood is caught, handled and prepared in a special way to keep it as fresh as possible so that it looks, tastes and smells as if it’s just come out of the water. 

Very fresh seafood suitable for eating raw is called ‘sashimi-grade’. It’s caught and handled in such a way that peak freshness and quality are maintained. Sashimi-grade Tuna, and other large wild-caught fish, are line-caught, landed onto a mattress (to minimise bruising) and killed instantly by brain-spiking (ike jime). This prevents the fish from struggling and releasing stress hormones and helps keep the body temperature low. The fish is then bled immediately, removing heat and waste products, and put into an ice slurry to drop the body temperature as close to 0ºC as quickly as possible. Ideally sashimi-grade fish should be purchased on the day of consumption; after more than 24 hours in a domestic fridge, while it will still be premium quality, it won’t be at peak freshness and should be cooked rather than served raw. 

Rays and Skates are very similar fish, both have cartilage instead of bones and their pectoral (side) fins are greatly enlarged and attached to their heads forming a large disc-shaped ‘body’, to which a much smaller tail is attached. Rays usually have long whip-like tails (often with stinging barbs on them). Skates have shorter, slightly thicker, more developed tails without a stinger. It’s generally the pectoral fins (usually called ‘flaps’ or ‘wings’) that are eaten and there’s little, if any, differentiation between species in the market. 

Also known as Pacific dory, freshwater fillet or shark catfish, Basa are catfish farmed (and occasionally wild caught) in South East Asia. Frozen whole fish, fillets and cutlets (primarily Pangasius hypophthalmus) are imported, mainly from Vietnam and Thailand. 

Common deep-sea fish include: Orange Roughy, Shark, Billfish (Swordfish and Marlin). 

Whole fish can be cut in several different ways. A fillet is the whole side of a fish cut away from the central back bone and rib cage. You may need several fillets from a very small fish, such as Sand Whiting, to serve 1 person, while those from a larger fish, such as an 800g Snapper, may be an ideal portion size for 1 person. Fillets from very large fish, such as Swordfish or Tuna, are usually sliced vertically into steaks that are a suitable portion size for 1 person. Cutlets are a section sliced horizontally through the whole fish, leaving the bones in; Salmon and Blue-eye Trevalla are often seen as cutlets. 

True Lobsters, common in Europe and North America, have large edible front nippers and are only found in the Atlantic Ocean. Their Australian relations, with much smaller front claws, are Rock Lobsters, though they’re often mistakenly called ‘lobsters’ or ’crayfish, and are known as spiny lobsters in other parts of the world. Crayfish, the freshwater relatives of Lobsters and Rock Lobsters (called crawfish in the USA), are much smaller and found in rivers, dams and lakes. Yabby, Marron and Redclaw are the most common varieties. Slipper Lobster is another name for Balmain or Moreton Bay Bugs. 

Crustacean shells (prawns, crabs, rock lobsters, bugs) turn bright red when cooked. Their flesh, once removed from the shell, will be opaque rather than translucent — at that point it’s done. 

All oysters are one of two types: cupped or flat. There are only two main species of food oyster in Australia: Sydney rocks and Pacifics, both of which are cupped. Being filter feeders however, oysters gain a lot of taste from their environment, so flavours and textures vary greatly depending on where they’re grown and oysters are often sold by location rather than species. Sydney rocks are native to Australia and are grown right along the NSW coast, plus a few around Albany, WA. Pacifics are introduced and grow in the colder waters of Tasmania and SA as well as small pockets in Port Stephens and the Hawkesbury River. A third species, native (or angasi) oysters, a flat oyster native to the southern coast of NSW, is also occasionally seen, while meat from a fourth species, pearl oysters, is becoming more popular. 

Named for the popular Kumamoto Oysters of Japan (Crassostrea sikamea), these small Pacific Oyster’s are grown in conditions that simulate the rough oceans off Kumamoto, forcing them to grow deep in their shell as the new fragile layers of shell are constantly broken off. They’re popular for their good meat to shell ratio and rich flavour. Being in the rough water at the front of the Oyster leases means they get first pick of the nutrients that are washed into the lease, so despite their small shell size they have an intense flavour. Also called ‘virgin Pacific Oysters’, as they’re harvested before they’ve spawned, they’re a plump, creamy, briny little mouthful of sweet Oyster meat. 

Whitebait is the name given to tiny immature fish of various species, depending on the country. They’re generally 4-5cm long, translucent, so small that there are thousands per kilo, and eaten whole.

Australian whitebait are either young native trouts (members of the Galaxiidae family), or adults of an unrelated species called Tasmanian whitebait; but there’s no commercial whitebait fishery in Australia. 
 
Frozen whitebait is imported into Australia from New Zealand and Asia.

New Zealand whitebait is the young of native trout caught in the lower reaches of rivers during a short, strictly controlled, season. Most however is farmed in Asia. Whitebait is most commonly served as fritters and sometimes appears on menus under its Italian name nanatta or neonata (meaning ‘new born’). 
 
A larger, thicker fish, Sandy Sprat, around 5-6cm long, is also sometimes incorrectly sold as whitebait in Australia. 

Surimi (meaning ‘ground meat’ in Japanese) is the technical name for seafood extender. It’s made from inexpensive fish (typically pollock or hake) pounded into a thick paste then shaped and cooked. It’s been popular in Asia for hundreds of years, where its used to make products such as fish balls, a key ingredient in dishes like Laksa. It comes in various shapes and textures, is often coloured to resemble lobster or crab meat and is sometimes referred to as crab stick, though it can’t be labelled as such if it doesn’t contain any crab. In Australia it’s often used in inexpensive salads and sushi. 

Kosher foods are those that conform to Jewish dietary laws. In terms of seafood, this means only fish with fins and scales. Some common Australian kosher fish are: albacore, anchovies, barramundi, blue-eye trevalla, blue grenadier, bream, flathead, flounder, garfish, gemfish, mulloway, John dory, mackerel, morwong, mullet, mulloway, Murray cod, orange roughy, pike, red emperor, redfish, salmon, sardines, snapper, sole, trevally, trout, tuna, warehou (blue and silver), whiting and yellowtail kingfish. Some common species that are NOT kosher are: catfish, eel, shark (sometimes sold as flake), leatherjackets, ling, rays and skate, and swordfish. Skinless fillets are prohibited unless it can be certain they’re from a kosher species prepared with knives and boards thoroughly cleaned before cutting. 

Australian aquaculture dates back to the 1870s, when Sydney rock oysters were first cultivated in NSW. Since the 1980s it has really started to grow with blue mussels (in all states except Qld) and Atlantic salmon (from Tasmania), two of the first species to be farmed locally. Other popular aquaculture species are: barramundi (Queensland, NT and WA), eels (mainly Victoria and Queensland), freshwater crayfish (yabby, redclaw and marron), Murray cod (Victoria and NSW), oysters (Sydney rock, Pacific and native), prawns (especially banana and black tiger), silver perch (mainly NSW and Queensland), trout (mainly rainbow trout grown in freshwater, or in sea cages and marketed as ocean trout), and yellowtail kingfish and mulloway (mostly from Port Lincoln, SA). Also available in Australia is chinook salmon (farmed in New Zealand and marketed as king salmon). 

While overfishing has been a serious problem globally and continues to be an issue in some regions, since the turn of this century Australian fisheries have been internationally recognised as among the best-managed in the world. Both State and Commonwealth legislation requires that our fisheries be sustainable and that the environmental impacts of fishing activities be regularly assessed. Stocks of even previously overfished species continue to increase under careful supervision; recovery plans for such species are mandatory and have been proven to work. The best way to be sure you’re buying sustainable seafood is to buy Australian.  
 
Visit our Sustainability page for more information.