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Light penetration Is probably one of the factors limiting seagrass distribution in turbid
waters, such as Ihat found along the mainland shore in Mississippi. Seagrassesin Mississippi
Sound are not generally found growing in water greater than 3 meters in depth (MLW).
Phillips (1960) and Taylor (1928) Indicates thai In Cuban waters the greatest depth was about
24 meters (80 feet). However, even in these clear waters, maximum growth occurred in
shallow waters of 7-16 meters (23-52 feet). Buesa(1975) also Indicates that blue light may
favor Ihe growth of Syrlngodlum flliforme and red light for Thalatsla lestudinum. II is Inter
esting Io note Ihat T. lestudinum is very abundant on the soulheaslein Cuban shelf, whereas
in Mississippi Sound, Halodulewrightii Isthe most abundant species. A combination of water
depth, wave energy and an array of related ecological factors affect seagrass distribution
productivity and reproduction at different locations.
Concluding Remarks
It Isextremely important that techniques ofculluring seagrasses, including tissue culture,
be developed as soon as possible in view of declining and disappearing populations, well
adapted to geographical areai. Such a siluation exists in Mississippi Sound loday. where
Thahssia tcuudinum, Syrtngodium flliforme and Haloduleengelmannii have practically dis
appeared, primarily because of Hurricane Elena and several other storms and hurricanes ihat
occurred here in I98S. Restocking from an Innovative seagrass nearby nursery may save these
especially adopted ecotypes and genotypes from extinction. Hopefully, it is not too late.
Acknowledgments
I wish to thank my associate and friend. Mr. John Caldwell of the Botany Section.
GCRL, for his help in various ways during Ihe preparation of this manuscript. Thanks are
also due Mr. Michael Chambers for his assistance and interest In seagrasses. Mrs. Cindy
Dickens and Mrs. Mereau Tacon prepared the manuscript and final camera-ready copy,
respectively.
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