Assessing the freshness of seafood can be a little challenging, but with some knowledge and practice you’ll be able to tell whether or not your catch is truly fresh. Here are some simple guidelines that will help you make an informed decision without risking your health:

Smell it

One of the telltale signs of spoiled or old fish is a foul smell. This is caused by trimethylamine, released by rotting seafood. Although this odor may not always be detectable, if it’s too strong for your taste buds then you should probably steer clear from purchasing it.

Appearance

A freshly caught fish should appear shiny, firm and vibrant. Its skin should be metallic in color with no missing or broken scales. The gills should also be vibrant red while the flesh should spring back when gently squeezed.

Shellfish

When purchasing raw clams, oysters and mussels, look for tags with certification numbers on them. These should indicate that the seafood was harvested and processed according to FDA-approved standards.

When tapping them gently, the shells should remain closed. If they open slightly after being touched but again close tightly after tapping again, these aren’t fresh and should be discarded.

Live crabs, lobster and other shellfish should also be easy to tell if they’re fresh. Their tank water should be clear and they should be moving around; if not, then these animals have likely past their prime and should be discarded.

Smell it

Seafood should have a pleasant, fresh smell that recalls the ocean. This aroma is specific to where it was caught; so be wary of seafood with strong fishy, sour or ammonia-like smells.

Eyes

Fresh fish should have bright, clear eyes with black pupils that are easily visible. As fish age, their eyes become cloudy and dull – especially larger species like salmon but smaller varieties may also exhibit signs of aging.

Scales and Skin

Fish that have aged may start to lose their shine. You might notice darker spots or even no scales at all; these could indicate chemical exposure or storage in an unsanitary environment. If the skin of a fish appears pale, it could indicate exposure to chemicals or an unhygienic environment.

Fattyness

Fresh fish should have a smooth, fatty fat that’s not flaky or stringy. Bass, cod, flounder and red snapper all have naturally fatty flesh but salmon, mackerel, herring and anchovies tend to have leaner fillets due to their higher oil content.

Fatty doesn’t necessarily equal bad or overly oily. Just remember that some oils are necessary for flavor, so don’t let fish fat content be your only consideration when selecting a dish.

Another essential factor to consider when purchasing fish is how it feels when you bite into it. Stale or defrosted seafood will usually have a soft and loose texture, as well as an unappealing appearance; on the contrary, fresh seafood should be firm and resilient when touched.