BROWN ALGAE

Brown algae, or Phaeophyta, or Phaeophyceae.

a. Green chlorophylls, xanthophylls, carotenoids. Fucoxanthin gives the characteristic brown color to these plants.

b. Covered or suffused with algin, which minimizes desiccation at the surface and/or provides elasticity to the stipes of these tall plants. This chemical provides the major basis for the kelp harvesting industry (Kelco).

c. Heteromorphic alternation of generations, consisting of a huge sporophyte phase (the giant kelp plant we see) and an inconspicuous gametophyte phase.

d. Kelp plants.
1). Eisenia arborea, or sea oak, or southern sea palm, or palm kelp. Note the bifurcation at the top of the stipe, at the ends of each of those branches where the blades emerge.
2). Postelsia palmaeformis, or northern sea palm, or palm kelp. Looks similar to the southern sea palm except that the stipe does not bifurcate; the blades come out from the top
3). Pterygophora spp., palm kelp, looks much like the northern sea palm, except that it has a very prominent central rib on each blade. It is found in deeper water than the other two intertidal to shallow littoral genera.
4). Egregia menziesii, or ribbon kelp, or feather-boa kelp. The juvenile form of this plant is a single long blade attached to the bottom by a very small holdfast (haptera). The mature plant has a central stipe that is nearly 5-6 cm (2") wide, being about 1 cm (1/3") thick. Along this central stipe, there is a line of opposite blades that are thin, nearly 3 cm (1") wide, and 12 cm (5-6") long. At the base of each of these blades is a small bladder. The old plant, usually seen around the summer and fall months, still has the central stipe but the blades have all degenerated into hair-like filaments with no bladders. Even though these two forms of this plant look very different, they merely represent different stages.
5). Nereocystis spp., or bull kelp, or northern bull kelp. Looks similar to Pelagophycus except that the stipe does not bifurcate at the top so that the large, long leaves come out from the top center of this giant bladder.
6). Pelagophycus porra, or bull kelp, or staghorn kelp, or elk kelp. The stipe is attached to the bottom by a fairly small holdfast for a plant of this size. The stipe is pencil-sized along most of its length (up to 30 m or 100' long), gradually getting thicker toward the surface. At the distal end, the stipe bulges out and forms a giant bladder, with diameters of nearly 30 cm (1'). The stipe then bifurcates on the surface side of this bladder so that the giant, 1 m (3') wide and 7-8 m (20-25') long blades come off in series along these two "horn-like" parts. The bladder is full of gas, with carbon monoxide one of the common gases contained. The bladder is up to 3 cm (1") thick, and it is often used in the making of kelp candy.
7). Macrocystis pyrifera, or giant bladder kelp, or what I call "kelp kelp"
a). Growth rates up to 1/2 m (1.7') per 24 hours have been measured in nature; fastest rate of growth in the plant kingdom, exceeding that of the tropical giant bamboo. This kelp can get up to 70 m (more than 200') long within 5-6 months.
b). In the 1930s, the algin-extraction industry developed. Algin, a form of potassium compound, is a hydrophilic (water-loving), colloidal substance, making it an effective emulsifying and suspending agent. Algin is used extensively in the food (ice cream, chocolate milk, processed foods, salad dressings, cake icings), alcohol (beer foam), cosmetic (lipstick, lotions, creams), pharmaceutical (milk of magnesia, calamine lotion), construction (sizings, insulation), and clothing textiles, synthetics, water-soluble dyes) industries. Kelco, a San Diego based company (used to be a division of Merck Industries but in 1995/96 was sold) is the world's leading harvester of kelp and producer of algin (called Kelgin). c). Antitropical, shunning the warm waters, found locally off southern California in waters down to 40 m (125') and off the coast of Chile to more than 80 m (250').
d). Exploited during World War I as a fertilizer resource to replace potash which had come from Germany.
8). Petrospongium spp., or rock sponge, forms a lobes and convoluted encrustation over rocks in the intertidal zones. It is up to 10 cm/3" in diameter.
9). Colpomenia sinuosa is a small, yellowish-brown, hollow, bubble-like intertidal species.
10). Cystoseira spp/Halidrys spp are 2 fan-shaped plants that are similar in appearance. The vesicles in Cystoseira are spherical, giving the form of peas in a pod, whereas those in Halidrys are flattened but circular in shaape. These have a shape that remind me a bit of a fern, but a brown one.
11). Sargassum spp.
a). Name is derived from the Portugeuse word "sarga," meaning a kind of small grape; 15th century Portugeuse sailors named the Sargasso Sea, based on the grape-like air vesicles seen on these plants floating in the water in the western North Atlantic.
b). Tropical and subtropical distribution.
c). Primarily an attached, near-shore plant, but hurricanes and storms detach them and they are then borne by the Gulf Stream and deposited in the gyre in the western North Atlantic in the region called the Sargasso Sea. There they vegetate and flourish but do not reproduce, so that the extent of the Sargasso Sea fluctuates widely depending on the degree of renewal by storms.
d). The Sargasso Sea is a major biotope in the Atlantic, harboring many other plants and animals that either live permanently in this oceanic area or wander through this area in search of food or protection or reproductive sites. For example, the European Eel, Anguilla, that we have already run across, breeds in the Sargasso Sea. When the eggs hatch, the larvae drift across the North Atlantic to the coasts of western Europe, where the juveniles run up the rivers and spend most of their adult lives in the freshwaters of Europe. When they are mature, breeding adults, they migrate down river to the Atlantic, swim southward to the Canary Islands, and then ride or swim the Atlantic Equatorial Current to the western North Atlantic. Their last leg is in the Gulf Stream to the Sargasso Sea, where they spawn and die.
12). Fucus in northern waters and Pelvetia in southern California are some of the most common intertidal plants. At Bird Rock in La Jolla, there is a carpet of Pelvetia that covers the rocks of the mid to high intertidal zones. The gamestes from these plants are only found after a period of exposure at low tide. Fucoxanthin was initially isolated and described chemically from the genus, Fucus, with the work done at Berkeley and at the Hopkins Marine Station in Monterey.