The largest, richest and most complex ecosystem on land is the forest. The oceans, which occupy more than 70% of the earth's surface, are home to countless marine organisms, so could there be forests in the oceans as well? The answer is yes.
What Are Kelp Forests
Kelp forests are underwater forests composed of a variety of large brown algae such as laminariales. Most of the world's kelp forests grow in seasonally varying seas, mainly along the west coast of North America, south America, Antarctica, South Africa, Australia and New Zealand. The world's largest kelp forests can cover more than 8,000 square kilometers, and this underwater forest is located in the Pacific Ocean of North America.
Off the coast of California, you'll find what may be the world's most iconic ocean forest, a forest of giant seaweeds that grow to 12 inches in length. When conditions are right, the giant seaweed dominates the ecology of the California coastline and create habitat for a large number of local marine organisms.
Why Ocean Forests Can Transform the Earth
With the rich nutrient salt nourishment of the surge current, the giant seaweed in the ocean forest can grow to more than 60 meters, and the air sacs at the base of the leaves enable the seaweed to extend to the surface, forming a huge underwater forest landscape. Kelp forests not only purify seawater and help maintain ecological stability, but also provide oxygen, food and living space for fish. Kelp forests are considered to be one of the most productive and dynamic ecosystems on earth, providing a safe haven for hundreds of creatures (including mollusks, crustaceans, echinoderms, fish and marine mammals), as well as a productive fishing ground for humans.
Mitigating Climate Change
Although ocean forests, like forests on land, can photosynthesize and fix carbon dioxide from the atmosphere to synthesize organic matter. But the Earth's major biomass is concentrated on land, and ocean phytoplankton biomass accounts for only 1% of that of above-ground forest. So do underwater forests and terrestrial forests do the same thing? The answer is yes.
According to the observation data in recent years, the Earth's biosphere absorbs 52% of the carbon, and the ocean accounts for 45% to 50%, which is basically equal. Although seaweed is small, the turnover rate of reproduction and death is faster than that of terrestrial plants, with only one week for each generations, while the average generations of terrestrial plants takes 20 years. Therefore, the contribution of ocean forests is at the same level as terrestrial forests in the Earth's surface carbon cycle. It has been estimated that if the planktonic algae in the oceans were eliminated, the concentration of carbon dioxide in the atmosphere would have to increase by a factor of 1.5 after 100 years.
Hard Times for Ocean Forests
Almost all of the extra heat trapped by the 2,400 gigatonnes of greenhouse gases we have emitted so far has gone into our oceans.
This means ocean forests are facing very difficult conditions. Large expanses of ocean forests have recently disappeared off Western Australia, eastern Canada and California, resulting in the loss of habitat and carbon sequestration potential.
Conversely, as sea ice melts and water temperatures warm, some Arctic regions are expected to see expansion of their ocean forests.
These overlooked forests play an crucial, largely unseen role off our coasts. The majority of the world’s underwater forests are unrecognised, unexplored and uncharted.
We should take immediate action to reduce our dependence on fossil products such as plastic, for example by using reusable coffee cups made from biodegradable bamboo fibers in our lives.
If the growing environmental problems are further ignored, it will be impossible to ensure that ocean forests are protected and conserved - let alone harness the full potential of the many opportunities they provide.