Seaweed production requires areas with sufficient nutrients and light for growth and salinity and temperatures that are not limiting to the species being cultivated. The mesotrophic boreal temperate coastal ocean is ideal for growing many species, of which large brown kelp species are most commonly grown. Seaweed has numerous qualities which make it ideal to not only support the growth of gardens and crops, but to condition the soil, as well. It usually contains a mixture of nitrogen, potassium, magnesium, phosphate and potash, among many other nutrients and minerals."Seaweed" is the common name for countless species of marine plants and algae that grow in the ocean as well as in rivers, lakes, and other water bodies. Once harvested, seaweed, also known as macroalgae, could potentially be turned into various forms of energy, such as biogas and ethanol, through different chemical processes. Because seaweeds live in the ocean, surrounded by water, they don't need and have none of the structures that plants use to obtain water and nutrients from the soil. Seaweeds lack the vascular system and roots of a plant; they can absorb the water and nutrients they need directly from the ocean surrounding them. Seaweeds are green, red, or brown plant-like organisms that grow in the ocean. Like land plants, seaweed produces oxygen, around 70% of the total oxygen on Earth, and is the basis of the ocean food chain. Seaweed planted in shallow water near the surface (30 to 50 centimeters) receives plenty of sunlight and its growth will be good. Seaweed planted in deep water (more than 1 meter from the sea surface) does not get enough sunlight and its growth will be poor.

To my knowledge, rivers are not included in the native habitats of seaweed. River and stream systems have some natural levels of substrate movement which process and transport fine and various degrees of coarse sediments. The substrate is or supports habitats to a variety of aquatic species. Overwhelming stream channels with seaweed or periphyton would reduce stream velocity due to added friction (Manning’s N) which could encourage sedimentation, aggradation, as well as marked oxygen shifts due to respiration which could saturate oxygen during daylight and deplete during night respiration. Added sediment and aggradation reduces channel capacity and makes flooding more frequent and higher magnitude. Transport with water craft and some water sports may be limited if seaweed were introduced and successfully grown in rivers. Iintroducing non-native organisms to native ecosystems often has unforeseen impacts and the results may not turn out well. Finding ways to identify, protect, maintain, sustainable harvest where appropriate, and improve or restore the natural seaweed habitats should be encouraged.

Seaweed actually refers to aquatic plants that grow in saltwater, like seas and oceans not freshwater lakes.Seaweed types grow floats, or air-filled pockets, that bring them closer to the surface for increased photosynthesis. Light requirements limit how deep seaweed can grow. Seaweed farmers can sell their crops to restaurants, markets, or processors for use in cosmetics, fertilizers, and animal feed. Prices for seaweed vary depending on the market demand and type of seaweed, but it is typically more profitable than traditional crops such as rice or wheat. Inorganic carbon, light and nutrients are required for seaweed photosynthesis and growth, and interactively regulate rates of seaweed production. Nitrogen is the element most frequently observed to limit growth, although in some cases phosphorus may be limiting. Seaweed" is the common name for countless species of marine plants and algae that grow in the ocean as well as in rivers, lakes, and other water bodies.Green seaweeds can be found in shallow waters in warm, tropical climates. Brown seaweeds are much bigger than the green seaweeds and live at greater depths. Red seaweeds can grow in cold water that is either shallow or deep. Seaweed, when it's farmed, provides benefits to the ecosystem, creates jobs in coastal communities, and develops highly nutritious and functional food products and feedstock for industry.