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13 Facts about Sea Lettuce

by Fitriani

The sea lettuce is a type of green algae found in the ocean. As for its scientific name, it’s Ulva lactuca. Rich in chlorophyll, many marine creatures like to feed on it. The manatees and the sea slugs are some of the common ones.

The sea lettuce have even been used in the medical field, the food industry as well. Here are more 13 Facts about Sea Lettuce that you should know. The sea lettuce is an interesting algae with its positive and negative traits.

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1. It’s Edible for Humans

Sea lettuce is safe to eat. In fact, people all over the world eat it in various ways. In Japan, the sea lettuce is commonly known as aosa. The sea lettuce is a part of the Venetian and Neapolitan dish called as ‘sea zeppolelle’ in Italy. Scandinavia and Ireland are other places where sea lettuce is also consumed. The sea lettuce can be eaten raw in salads but it can also be cooked into soups. It may also be dried and sprinkled on food.

2. Rich in Vitamins and Minerals

The sea lettuce might be thin, but it’s packed with loads of vitamins and minerals. It contains a high amount of vitamin C, iron, protein and fiber. There’s also calcium which helps with metabolism, potassium that maintains the nervous system and Omega-3 which is good for the heart. It would be beneficial to include sea lettuce into the daily diet due to all of its micronutrients.

3. It Looks Like a Lettuce Leaf

Here’s another fact about sea lettuce. Just like its name, the sea lettuce does resemble a lettuce leaf. In its best condition, it’s green. But once it dries up in the sun, the colour will turn to white or black. Other than that, the lettuce leaf is translucent. The edges are ruffled and wrinkled. The sea lettuce is thin but it’s actually pretty tough. Under a microscope, the sea lettuce is seen to have 2 layers.

4. Decomposing Sea Lettuce Can be Toxic

There have been some cases where decomposing sea lettuce released a toxic gas. In August 2009, a large amount of sea lettuce ended up on the beaches in France. They decomposed and released hydrogen sulfide. People who have come into contact with decomposed sea lettuce often lose their consciousness. As for animals, breathing in the fumes may result in death.

See also: Types of Ocean Habitats

5. It Varies in Size

The size of the sea lettuce widely varies, depending on where it’s growing. It can be as short as 8 centimetres. But it can also be as long as 40 centimetres. The average width is around 30 centimetres. The sea lettuce tends to grow better where the water is rich in nutrients.

6. It Has No Stalk Nor Root

The sea lettuce has no stalk and no root. Most of the time, it floats freely in the ocean water. You may even find it at the mouths of rivers or marshes. It grows in the intertidal zones, carried by the tides to stick on rocks.Here are the Characteristics of Ocean Intertidal Zone to know more about it.

7. It Holds on Other Things as Anchors

Even though the sea lettuce can freely float, they may hold on to other things as anchors. For instance, it can attach itself on shells or small rocks. That’s why they’re often found in shallow tide pools. But there have been records where the sea lettuce is found in the deep water. The sea lettuce was found at the depths of 22 metres.

8. It Can Regrow

Another interesting fact about the sea lettuce is that it can grow quickly under the right condition. In any case, if a part of it becomes detached, it will continue to grow. The growth of the sea lettuce can be massive and create large colonies floating on the water.

9. Acts as an Indicator for Pollution

Apparently, the sea lettuce thrives in areas where the pollution level is high. The sea lettuce is strong and can tolerate toxic waste. Most sea lettuce prefer to grow where the region is loaded with sewage runoff. That’s why it can be used as an indicator for pollution in that particular area.

10. It Can Prevent Photosynthesis for Other Marine Vegetations

The sea lettuce can be found all year round but its biggest bloom happens during the summer. When that happens, the sea lettuce covers most surface of the ocean. This will prevent sunlight from penetrating through the water. It won’t be able to reach marine vegetations that grow in the deeper part of the water, such as the eelgrass. The eelgrass will find it difficult to carry out photosynthesis. Learn more about the different Types of Ocean Vegetation.

11. It Depletes Oxygen

This next fact about the sea lettuce is related to oxygen. Dissolved oxygen in the ocean is important. Marine organisms, such as fish, need oxygen for respiration. However, fungi and bacteria do need oxygen as well. When sea lettuce dies in the ocean, the bacteria takes up the oxygen to decompose it. Depending on the amount of decomposing sea lettuce, most of the oxygen could be taken away. Other organisms would have to move to other places or they’ll die from suffocation.

12. Disrupt Human Activities in the Ocean

Sea lettuce can disrupt human activities in the ocean. For instance, it may cause difficulty for swimmers to move around the water. Furthermore, the sea lettuce could get attached to fishing nets, hampering fish harvest.

13. It is Used in Aquarium Trade

Sea lettuce is often used in aquarium trade due its useful properties. It can take in high nutrients and serve as food for herbivorous fish. The sea lettuce can also last for a very long time and easy to manage. It has a high tolerance for temperature and light.

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It’s important to protect sea lettuce in the ocean. Despite its downsides, it’s still needed as food source for marine creatures. The sea lettuce has a significant part in the marine ecosystem.

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