Seaweed Belongs To Which Of Earth’s Spheres?

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Flowing, green seaweed may not seem important, especially when it ruins the image of a perfect beach. However, it is deceptively important to ecosystems after analyzing its impact on the Earth’s spheres. Discover where seaweed belongs and how climate change’s influence changes how it interacts with the planet.

What Are the Earth’s Spheres?

Earth has four spheres, or subsystems, categorizing everything on the planet. Each sphere has unique characteristics based on what thrives within it. Where does seaweed play a role in ecosystems?

Hydrosphere

The hydrosphere is every water system regardless whether it’s fresh or salty, including the water in the air, and in all states of matter — solid, liquid, and gas. This is seaweed’s home. It flourishes in the hydrosphere because it has the right balance of nutrients to encourage healthy growth cycles. 

Seaweed takes other nutrients and gasses out of the water to let other plants and animals have access to what they need. Also, as with any plant and alga, they are crucial for creating oxygen through photosynthesis — around 70% of the planet’s oxygen is from seaweed alone, and it sequesters 175 million tons of carbon annually.

Lithosphere

The lithosphere, or geosphere, refers to the land. It is the most solid subsystem, consisting of the structures on the Earth’s crust and mantle. This is where tectonic plates move, natural wonders form, and organic components grow and foster plants and animals. 

Seaweed isn’t a part of this sphere, but it’s helped it for over 1.6 billion years. For example, coastal areas suffer erosion after major storms or high quantities of pollution washing ashore. Seaweed is a barrier against negative influences. If seaweed didn’t exist anymore, many species would be without food and most of the oxygen on the planet would disappear. This is a modern concern, as invasive species, deforestation, and pollution threaten seaweed.

Biosphere

The biosphere refers to all living things, including plants, microorganisms, humans, and all other animals. This includes algae like seaweed, even though it’s in the hydrosphere.

Seaweed is critical to the biosphere because it’s an essential part of the food chain, feeding crustaceans, seabirds, and Arctic foxes, among many others. Seaweed also greatly influences humanity, primarily as people become more sustainability focused. It’s a food for biodiversity and a contributor to countless consumer goods, including:

• Pharmaceuticals
• Cosmetics
• Biofuel and green energy
• Textiles and fibers
• Food and beverage
• Art and décor

Atmosphere

The atmosphere is the Earth’s air. It’s divided into many layers. The troposphere is the one closest to the lithosphere, and it is where most of the biosphere lives. Seaweed impacts the atmosphere by storing carbon, but it also releases methane and carbon dioxide when it decomposes. 

What Is the Difference Between Kelp and Seaweed?

Seaweed and kelp are often confused with one another because of their appearance. What is the difference? 

Designation

Kelp and seaweed are both types of algae. However, kelp is a subcategory of the seaweed family. They aren’t standard plants because they lack stems and roots, but they do undergo photosynthesis. There are over 650 seaweed varieties, and these are some of the most prominent and impactful:

• Sugar kelp
• Bladderwrack
• Spiral wrack
• Thongweed
• Wakame
• Harpoon weed
• Bonnemaison’s hook weed

Characteristics

Kelp is extremely long, potentially extending to hundreds of feet. This is what forms iconic kelp forests under the ocean. They are also thicker and leafier than seaweed, which is typically thinner and more delicate. Finally, seaweed is more colorful, ranging from bright reds and greens, whereas kelp is generally on the browner side.

Habitat

Seaweed is a more versatile algae, growing in more regions than kelp. The latter demands nutrient-dense waters, where seaweed can grow in a warm lake or cold ocean. Kelp forests also provide habitats for many aquatic wildlife, whereas seaweed doesn’t have that same role.

How Does Water Pollution Affect Seaweed?

All types of seaweed are under threat from pollution. One polluter is wastewater, and around 80% of it goes into natural systems without regulation or treatment. Other major deterrents include cigarettes, plastic bottles and bags, and food packaging. 

Non-native influences like these change the water’s temperatures, nutrient density, acidity, and more. This transforms the ecosystem to something that can’t support seaweed anymore, making it toxic. Pollution also boosts sedimentation, which buries new growth.

Pollution’s impact on seaweed transfers to other living things, inevitably impacting every sphere on the planet. Everything from heavy metals to chemicals get into seaweed, get eaten by other fish, then get consumed by humans. Contaminants spread so easily, leading to more climate concerns and public health crises.

Seaweed’s Sustainability Impact

Many may not understand how important seaweed is to every one of the Earth’s spheres, but it’s important to spread awareness. Without education, seaweed species will continue to perish, and biodiversity and habitats will be at risk.