Algae, or alga (singular), include a diverse array of mainly aquatic organisms that create oxygen through photosynthesis. Some algae—like kelp—are large (called macroalgae) and others are microscopic (called microalgae) and cannot be seen by the naked eye. Some algae, such as seaweeds, look like plants, but algae are actually neither plants nor animals. They lack true roots, stems, and leaves. Algae produce about 70% of oxygen in the Earth's atmosphere! Sea vegetables are a type of algae.

Aquaculture is the aquatic (water-based) equivalent of agriculture—or farming on land. Aquaculture is the cultivation of aquatic organisms (e.g., animals, plants, and algae) in controlled freshwater or saltwater environments. Bivalves and sea vegetables can be cultivated through aquaculture.

Aquatic foods are foods derived from animals, plants, and algae that are caught or cultivated in freshwater and saltwater. Bivalves and sea vegetables are aquatic foods.

Bivalves are a category of aquatic mollusks (and a type of shellfish) that have bodies enclosed within a hinged shell. This category includes clams, mussels, oysters, and scallops. Bivalves are a type of shellfish, but they are different from crustaceans. There are believed to be over 9,000 bivalve species.

Blue foods is an alternative term for aquatic foods. This term has been brought into wide usage by the authors of the Blue Foods Assessment. Bivalves and sea vegetables are blue foods.

Crustacean is a category of shellfish invertebrates characterized by exoskeletons, segmented bodies, and jointed appendages. Crustaceans include shrimp, crayfish, crab, and lobster. Bivalves and crustaceans are types of shellfish. Bivalves are not crustaceans.

Marine ecosystems are any water environment where saltwater is present (oceans, coastal habitats like mangroves, estuaries, etc.).

Mollusks are soft-bodied invertebrates that usually have a hard, protective shell, or exoskeleton. There are nearly 100,000 species of mollusks. Mollusks are found in nearly all freshwater and marine environments, and some are found also on land. Mollusks are soft-bodied invertebrates that usually have a hard, protective shell, or exoskeleton. There are nearly 100,000 species of mollusks. Mollusks are found in nearly all freshwater and marine environments, and some are found also on land. Bivalves are mollusks.

Regenerative ocean farming is a climate-friendly aquaculture method of growing bivalves and seaweed that does not require any inputs such as freshwater, feed, or fertilizer.

Seafood is a term commonly used to categorize all foods from the sea (i.e. saltwater). Most bivalves and sea vegetables are seafood (some grow in freshwater).

Sea vegetables are all edible varieties of seaweeds, such as kelp, Irish moss, sea lettuce, dulse, and nori that most often grow in or near an ocean. This is also the term Food for Climate League’s research found to be most appealing to U.S. eaters.

Seaweed refers to roughly 11,000 species of plant-like macroalgae and microscopic phytoplankton that grow in freshwater and saltwater ecosystems. Seaweed forms the base of the marine food chain and provides food and habitat. They are commonly classified by three main colors: green, red, and brown. Not all seaweeds are edible. Sea vegetables are edible seaweeds.

Shellfish is a common term that refers to aquatic invertebrate animals. There are two categories of shellfish: crustaceans and mollusks. Bivalves are a type of shellfish.

Note: Not all shellfish are bivalves. Bivalves are a type of mollusk shellfish. Shrimp, crabs, and lobsters, for example, are crustacean shellfish, but not bivalves.