Fish: an expert guide, by Nathan Outlaw

In the case of shellfish, you will also need to check on their status. Molluscs need to be alive when you buy them. If clams, cockles, mussels or oysters have open shells, tap them firmly and if they don’t close readily, don’t buy them as this indicates that the shellfish are no longer alive.

One exception to the ‘live’ rule is scallops, which often come to the market ready prepared and cut from the shell. However, they should still smell ozony and sweet. Also, make sure they are firm and haven’t been left to soak.

To guarantee the freshness of lobsters and crabs, they should be alive. Check there are no bubbles coming from their mouths as this is a sign that they are stressed and it will affect the quality of their meat. Lobsters should have long antennae; short ones suggest the lobster has been stored for a long while and has either begun to eat itself or been eaten by others.

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Finally, cephalopods – squid, octopus and cuttlefish – really need to be eaten within a couple of days of being caught. For optimum freshness, they should be intact, with bright eyes and no signs of changing colour to pink, as this suggests they have seen better days.

Now you know how to buy your fish, here are our favourite easy fish recipes to cook at home:

26 best ever easy fish recipes

Storing seafood

If you’ve found a bargain or someone has brought you lots of freshly caught fish, don’t turn it away – most fish freezes well. Ideally, seafood should be eaten within 24 hours of being bought. Store it wrapped in a damp cloth in the coldest part of the fridge. Don’t let it sit in water, as this will impair the flavour.

The fridge should be between 0°C and 2°C. If you can, cover the wrapped fish with a layer of fresh ice – don’t let it touch the fish directly as this will cause ‘freezer burn’. Stored carefully, on the bone, most fish will be fine for several days.

If you know that you won’t be eating the fish within a few days, take it off the bone, make sure it’s completely dry, then wrap it tightly in clingfilm and put it in the freezer as soon as you can. It will keep quite happily for up to 2 months. In the case of lobster and crab, cook before freezing, cool and wrap securely before putting into the freezer. Always allow fish and seafood to defrost overnight in the fridge before cooking.

Now you know how to store seafood, why not make our fab seafood fideuà recipe...

The health benefits of fish

Fish is an excellent source of protein, vitamins and minerals. Oily fish has the significant added bonus of being rich in omega-3 fatty acids, which help to keep our heart, joints, skin and eyes healthy. And some of the smaller oily fish can be eaten whole, so they provide a particularly rich source of calcium and phosphorus.

For those who need to follow a low-fat diet, the obvious choice is white fish. Shellfish is also low in fat and a good source of zinc, iodine, copper and selenium. Mussels, oysters and crab provide a fair amount of omega-3 fatty acids too.

However, we need to set a few limits on the amount of oily fish we consume as they can contain low levels of pollutants, which can build up in the body. It is suggested that we should eat no more than four portions of oily fish per week. For anyone who is pregnant or breastfeeding, this reduces to two portions per week. Bream, bass, turbot and brown crabmeat may also contain low levels of pollutants, so it makes sense to eat these in moderation.

If you're in the market for a healthy fish recipe, we have plenty of low calorie fish recipes here.

A note on sustainability of fish

Sustainability is something we need be concerned about if we want to be able to eat fish in the future. Over-fishing has caused major depletion of some species and until consumers become more confident about eating alternatives to the old favourites, this is likely to remain the case. There are many delicious alternatives, so it’s a matter of trying them out. The Marine Conservation Society provide a updated list of what’s endangered and what isn’t.

In the UK, much of the fish and seafood found around our shores ends up on continental markets which is crazy both in terms of sustainability and from an economic point of view (think of the cost and pollution caused by the mileage to get it there).

The best way to shop sustainably is to find a good fishmonger, either locally or online (try hecornishfishmonger.com) and ask questions. Where did the fish come from? How was it caught? If they can’t give you the answer, don’t buy from them. The status of a fish can change quite quickly so check a sustainability guide such as the cornwallgoodseafoodguide.org.uk for up-to-the minute information and some recommendations for alternative fish to eat.