The nutrition of the fish depends on the type of fish. Let’s first look at the nutrients in fish.





Tooth and bone formation, nerve transmission, muscle contraction

Milk and other dairy products, bean curd, dark green vegetables


Bone development, transfer of energy in the cells

Most foods


Nerve transmission, muscle contraction

Meat, dairy products, salt


Formation of hydrochloric acid



Regulation of heartbeat, maintenance of water balance, nerve transmission

Fruits (especially bananas)


The catalyst for ATP formation

Nuts, grains, dark green vegetables, seafood, chocolate


Thyroid activity

Seafood, iodized salt


Hemoglobin formation

Meat, dark green vegetables, dried fruits

Mineral amount in Fish: -

Sodium: -

Picture: Red Pomfret

  • Sodium levels in the flesh of a 100 g edible marine fish range from 155.7 mg to 346.4 mg.
  • Sodium in freshwater fish ranges from 48.2 mg to 124.8 mg.
Calcium: -

Picture: Red snapper

  • Calcium in marine fish ranges from 89.0 mg to 376.5 mg.
  • Calcium in freshwater fish ranges from 4.4 mg to 233.0 mg.

The ratio of calcium and sodium in marine fish is higher than in freshwater fish.

Potassium: -

Picture: Snakehead fish

  • Potassium in freshwater fish ranges from 228.4 mg to 500.8 mg.
  • It ranges from 180.0 mg to 260.6 mg in marine fish.
The ratio of potassium in freshwater fish is higher than in marine fish.

Other Minerals: -

Picture: Climbing Perch

In the case of magnesium, iron, and zinc, the values are not very different between freshwater and marine fish. However, in the case of some freshwater fish, there was little variation in the values with some marine fish.

Magnesium: -

Magnesium in freshwater fish is 1.80 mg to 53.06 mg and in marine fish, it is 31.2 to 40.7 mg.

Zinc: -

Zinc is 0.21 to 4.53 mg in marine fish and 0.74 to 2.25 mg in freshwater fish.

Fish Oil:-

  • Fish oil is oil obtained from the tissues of oily fish.
  • Fish oils contain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
  • Studies have shown that pelagic fish contain more fish oil than fish that live in the deep sea or lakes.
  • These are called pelagic fish species.
  • Pelagic fishes are species that live away from the bottom of the oceans or lakes.
  • This water is called the pelagic zone, which is away from the shore at the bottom of the ocean or lake.
  • Pelagic varieties contain the highest levels of EPA and DHA.

Omega-3 fatty acids: -
  • One of the most important nutrients is omega-3.
  • Omega 3 is a type of polyunsaturated fat.
  • They play an important role in the functioning and health of various parts and processes in the human body.
  • These include, in particular, brain health and heart health.
  • In fact, a significant proportion of brain and heart tissue contains omega-3.
  • Protects your immune system.
  • This is important for many more health benefits.
  • Fatty acids include alpha-linolenic acid (ALA), ecosapentaenoic acid (EPA), and tocosahexaenoic acid (DHA).
Omega-3 benefits:
  • Omega3 lower cholesterol
  • Omega3 reduce blood pressure
  • Omega3 reduces the risk of heart diseases
  • Omega3 help to prevent diabetes
  • Omega3 soothe the symptoms of rheumatoid Arthritis
  • Omega3 protect your brain
  • Omega3 keep your skin healthy
  • Omega3 are great for your eyes
  • Omega3 help to prevent cancer
  • Omega3 reduce the symptoms of PMS

Types of fish high in omega-3 fatty acids: -




Indian Mackerel



These types of fish contain far more omega-3 fatty acids than freshwater fish (except catfish).

Reasons why marine fish have more omega 3s than freshwater fish: -

Marine fish get more omega 3 fatty acids than freshwater fish by eating marine small fish, oysters, shrimp, seaweed, and other small fish.

Nutritional Differences: -

Picture: Tilapia
  • Freshwater fish and saltwater fish are very similar when it comes to their nutritional content.
  • However, there may be a small additional benefit from freshwater fish.
  • Marine fish do not absorb the surrounding sodium from the water.
  • Lake fish are generally higher in calcium and monounsaturated and polyunsaturated fatty acids than marine fish.
  • For fresh and saltwater fish, freshwater species are high in vitamin A and folate.

Mercury Differences: -

Picture: Red snapper

  • Few freshwater fish particularly cold-water fish contain healthy omega-3 fatty acids, as like marine fish.

  • Many lakes, rivers, and some seafood are high in contaminants, such as dioxins and polychlorinated biphenyls, which are found in fish meat.

Many people have questions about the level of mercury in freshwater fish.
  • Freshwater contains more mercury than saltwater, so it is natural to assume that freshwater fish contain more mercury. But it is not like that. 
  • In freshwater, mercury is deposited on decomposed plants and animals. Sunlight breaks them easily. So even though water has some mercury content, it will not be present in fish.
Thorns: -

  • Marine fish have large spines.
  • Marine fish are less thorny and easier to eat.
Picture: Tilapia skeleton

Freshwater fish have a lot of small spines. (Except for the sardine) Patiently remove the thorns and eat them.

Both Marine fish and freshwater fish contain many important nutrients.

  • Eating fish is much healthier than eating mutton, beef, and chicken.
  • Can be eaten by all ages. Also, fish contains more protein, omega 3 fatty acids, and lots of minerals than other meats.