Ocean forest covers an area of more than 7 million square kilometers, and contributes to the production of the largest percentage of oxygen, as well as removing the largest amount of carbon gas from the atmosphere making It is the real lung of Earth.
Off the coast of nearly every continent are vast underwater forests of seagrass, providing habitats that support marine biodiversity and productive fisheries. These marine habitats are more important than forests on land, but they are vulnerable to climate change and human activities.
What are ocean forests?
Underwater forests are formed by seaweeds, which are types of algae. Like other plants, seaweeds grow by capturing the Sun’s energy and carbon dioxide through photosynthesis. The largest species grow tens of metres high, forming forest canopies that sway in a never-ending dance as swells move through. To swim through one is to see dappled light and shadow and a sense of constant movement.
Although seagrass varies in shape and size, larger species—such as Ecklonia maxima and giant kelp—remarkably resemble trees.
Some giant species have small gas-filled sacs that allow them to form flexible floating surface canopies. Unlike trees that can live for centuries, seagrass is relatively short-lived, only 25 years old, meaning that an entire kelp forest regularly overturns its permanent biomass.
How large are marine forests and where are they located?
According to a recent scientific study published in Global Ecology and Biogeography, the area of marine forests ranges between 6 and 7.2 million square kilometers, and covers about 25% of the world’s coasts.
The largest marine forests are concentrated in the cold regions near the poles and the temperate regions, near the western coasts of North and South America, South Africa and East Asia.
The most productive are the African marine forests and the forests around the coral reefs of southern Australia.
Most of the world’s forests are made up of kelp, a group of more than 30 genera of giant algae that can grow very rapidly in ideal conditions, at a rate of more than half a meter per day. Therefore, it has floating “leaves” that can reach tens of meters in length, forming a tangled forest that provides habitats for many marine creatures.
Among the most important are the great African marine forests dominated by giant sea bamboos. It extends along the western coast of South Africa and Namibia with a length of more than 1,000 km, and is characterized by being one of the few marine forests that is expanding in its area, and harbors thousands of species of unique organisms, so it has been classified as a major ecosystem for regeneration in the world’s oceans, according to the “Sea Change Project” website.
Why are ocean forests important?
Seagrass forests are critical to sustaining life on Earth and providing habitat and food for many living organisms, in addition to their essential role in mitigating the effects of climate change.
According to some scientific sources, nearly 70% of the world’s oxygen is produced by marine species, including seaweeds through photosynthesis, and their importance in this respect is greater than rainforests over land, whose contribution does not exceed 28%.
Seagrass provides a home for many different animal species, including fish, shellfish, sea urchins, snails, and sea otters. Large marine mammals, such as sea lions and harbor seals, use these habitats for feeding and protection from predators.
In addition, seaweed contributes to reducing pollution levels by absorbing excess toxins, such as organic chemicals and heavy metals, from the water. They also absorb carbon dioxide and convert it into biomass from seaweed in a process called carbon sequestration.
Although their area is only 0.1% of the ocean area, seaweeds store about 18% of the carbon that ocean water absorbs from the atmosphere.
Despite their importance, marine forests are exposed to many risks that have led to a worldwide decline in their area. Some estimates indicate that this decline is occurring at a rate of 1.5% of the area annually, and that 29% of seagrass meadows have been eliminated during the last century.
Human activities, which are mostly concentrated on the coasts, with harmful fishing practices and the disruption of the ecological balance, in addition to the rising temperatures in the ocean waters; One of the main reasons for this decline.
Sources:
https://onlinelibrary.wiley.com/doi/10.1111/geb.13515
Oxygen levels – https://ugc.berkeley.edu/background-content/oxygen-levels/