Introduction

Marine macro algae and sea grasses have had a long history of importance throughout the world, with their use dating back to ancient times. Today, many species have important economic and commercial value. Marine algae is used in thousands of products including fertilizer, bio-fuel, ice cream and even cosmetics. In several cultures it's highly prized as a food item and is a major part of some island diets. Its appearance in the aquarium industry began with a few species of Caulerpa used mainly as tank decorations.

With the many innovations over the past several decades in marine reef keeping, marine plants have increased in popularity among saltwater aquarists and even large scale commercial aquariums. Adding various species of marine plants in the aquarium is a natural approach that can improve the health of fish and invertebrates. It also serves as a powerful and effective filtration method, effectively removing nitrates and phosphates to very low levels. Another added benefit is the food value of many species of macro algae. In their natural environment, herbivorous fish and invertebrates feed continuously during the day, consuming large amounts of micro and macro algae from the ocean.

A fairly new trend in the marine aquarium hobby is creating macro algae and sea grass dominated aquariums. These systems are gaining popularity as a change from the normal "reef" setup. They're very popular with marine aquarists that are interested in keeping peaceful fish and invertebrates, such as seahorses, pipefish and dragonets. Just like a freshwater planted aquarium, there's something alluring and beautiful about the undersea forests that can be created with the combination of algae, sea grass and coral. The ocean is filled with a fascinating array of marine plants, but not all are available today to the hobbyist and some simply don't do well in captivity. As the marine aquarium hobby progresses, hopefully more species will become available for the aquarist to observe and enjoy in the home aquarium.