Seaweeds / Cha'guan Tasi

Sea grapes / Ado' / Caulerpa racemosa

The terms "seaweed" or "cha'guan tåsi" as they are called in Chamoru, are popularly applied to any plant-like organism living in the ocean. In fact, most of these marine plants are quite diffferent from plants found on land. Only the seagrasses are true flowering plants similar in structure and lifestyle to most of the land plants we are familiar with. There are only three kinds of seagrasses on Guam. One of them grows in extensive beds which form a very important habitat for juvenile fishes (see Marine Habitats).

Chaiguan / Sargassum cristaefolium

Unlike seagrasses, seaweeds are algae which are much simpler in structure and lack true roots, stems and leaves. Some kinds of algae are single-celled organisms that live freely or form colonies of brown to green slime. Others are larger and have visible structures reminiscent of higher plants such as blades which resemble leaves, holdfasts or rhizoids which resemble roots, and stipes that resemble stems. Seaweeds absorb nutrients through their entire outer surface rather than through roots and their holdfasts are used only for attachment. Seaweeds do not have flowers or seeds, but reproduce either asexually by means of spores or fragmentation and sexually by means of gametes. All marine plants are found only in water shallow enough for sunlight to reach them. Like land plants, they form the basis of the food chain.

Lumot / Enteromorpha clathrata

There are over 220 kinds of algae on Guam. They are classified into four divisions based on pigmentation and lifestyles. The blue-greens (Cyanophyta) are primarily single-celled or colonial froms that may form slimes and small clumps. The greens (Chlorophyta), browns (Phaeophyta), and reds (Rhodophyta) are generally larger typical seaweeds and are usually the color closest to their namesakes. Some of the greens and reds incorporate a great deal of calcium to give them a hard, segmented structure. Some reds, the coralline algae, form hard coral-like crusts or clumps and help "cement" dead coral, rubble, and sand into larger and harder structures.

Padina

Several kinds of algae have traditional uses. Some are edible while others are used as bait. The most common edible kind is ado' or sea grapes, a green algae so named because of its small clusters of grape-like spheres. Recently, several people died from ingesting an extremely toxic poison associated with the red algae Polycavernosa tsudai, a species that was commonly harvested and even sold in stores. Despite extensive scientific study, the origin and identity of the poison remains a mystery, and this seaweed should no longer be eaten. Many kinds of seaweeds have toxic properties and only those properly identified and with a long history of safety should be eaten. Some kinds of seaweeds are attached to hook and line as bait for certain fishes. The slimy stringy green "lumot" is used to catch adult hiteng and sesyon (rabbitfishes) and the hard, leafy brown "chaiguan" is used to catch tataga' (bluespine unicornfish).