SEA BLOOM 



sea bloom — See plankton bloom. 



seaboard — A general term for the rather extensive 

 coastal region bordering the sea. (68) 



sea bottom — See sea floor. 



sea breeze — A light wind blowing toward the 

 land caused by unequal heating of land and 

 water masses. (61) 



sea butterfly — See pteropod. 



sea cave — (or jnarine cave). A cave eroded in a 

 sea cliff' by wave action. It usually is at sea 

 level. 



seachannel — A long, narrow, U-shaped or V- 

 shaped shallow depression of the sea floor, 

 usually occurring on a gently sloping plain or 

 fan._ (62) 



sea cliff — A cliff situated at the seaward edge of 

 the coast. (61) (See figure for shore profile.) 



sea clutter — See sea return. 



sea cow — (or sirenian). An aquatic herbivorous 

 mammal of the order Sirenia which includes the 

 dugong, the manatee, and the allegedly extinct 

 Stellar sea cow. 



sea cucumber — (or holothurian) . One of a class 

 (Holothuroidea) of elongate, usually wormlike 

 echinoderms which have a flexible body wall 

 and creep over the bottom from shallow water 

 to great depths. They are eaten commonly in 

 the Orient as the trepang or beche-de-mer of the 

 Chinese. 



sea fan — Any of a group of fanlike sessile 

 anthozoans. 



sea feather — 1. Any of a group of featherlike 

 sessile anthozoans. 



2. Any of a group of featherlike sessile 

 crinoids. 



sea fir e^ — (or hurnmg of the sea). A brilliant 

 display of bioluminescence ; more commonly 

 described from tropical waters. 



sea floor — (or sea heel, sea 'bottom). The bottom 

 of the ocean where there is a generally smooth, 

 gentle gradient. In many uses depth is dis- 

 regarded and the term may be used to designate 

 areas in basins or plains or on the continental 

 shelf. 



sea fog — A type of advection fog formed when 

 air that has been lying over a warm water sur- 

 face is transported over a colder water surface, 

 resulting in cooling of the lower layer of air 

 below its dew point. (5) 



sea gate — A restricted passage leading to the sea. 

 (68) 



sea gooseberry — A luminescent ctenophore 

 {Pleurohrachia pileus) found in coastal waters. 

 Has the appearance of a transparent gooseberry. 



sea grape — A small ascidian, particularly of the 

 species MoJgula manhattensis. which grows in 

 large clusters on piles, rocks, and other under- 

 water objects. 



seagrass — 1. A member of either of two families 

 (Hydrocharitaceae and Zosteraceae) of usually 

 grasslike marine spermatophytes. Seagrasses 

 grow chiefly on sand or mud-sand bottoms and 



most abundantly in water less than 30 feet, but 

 some may grow on rock in the intertidal zone, 

 and others may range to depths of at least 200 

 feet. The eelgrass (Zostera marina) , the turtle- 

 grass ( Thalassia testudinum) , and the manatee- 

 grass {Sy ring odium fliforme^ are better known 

 members of these families. 

 2. Any grasslike marine alga. 



sea ice — 1. Specially, ice formed by the freezing 

 of sea water; opposed, principally to land ice. 

 In brief, it forms first as frazil crystals (lolly 

 ice), thickens into sludge, and coagulates into 

 sheet ice, pancake ice, or ice floes of various 

 shapes and sizes. Thereafter, sea ice may de- 

 velop into pack ice and/or become a form of 

 pressure ice. 



2. Generally, any ice floating in the sea. 

 (5) 



sea ice shelf — Sea ice floating in the vicinity of its 

 formation and separated from fast ice, of which 

 it may have been a part, by a tide crack, or a 

 family of such cracks. (68) 



seaknoll — See knoll. 



sea lettuce — One of either of two genera {Mono- 

 stroma and Viva) of membranous green algae. 



sea level — (or water level). The height of the 

 surface of the sea at any time. 



sea level datum — See mean sea level. 



sea lily — See crinoid. 



sea mat — See bryozoan. 



sea mist — See steam fog. 



sea moat — See moat. 



seamount — An elevation rising 500 fathoms 

 (1,000 meters) or more from the sea floor and of 

 limited extent across the summit. (62) 



seamount chain — Several seamounts in a line 

 with bases separated by a relatively flat sea floor. 

 (62) 



seamount group — Several closely spaced sea- 

 mounts not in a line. (62) 



seamount range — Several seamounts having 

 connected bases and aligned along a ridge or 

 rise. (62) 



sea mud — A rich saline deposit from salt marshes 

 and seashores. (2) 



seapeak — See seamount. 



sea pen — Any of a group of penlike or featherlike 

 sessile anthozoans. 



sea puss — A dangerous longshore current, a rip 

 current, caused by return flow, loosely the sub- 

 merged channel or inlet through a bar caused 

 by those currents. (61) 



sea reach — The straight section of the lower course 

 of a river between tJie last bend and the sea. 

 (68) 



sea return — (also called sea clutter). Radar 

 echoes reflected from the sea. (68) 



seascarp — See escarpment. 



seashore — The shore of a sea or ocean. (61) 



seashore lake — A body of water isolated from the 

 sea by sediment bars or banks. 



142 



