converted to Von Stosch algal culture medium. The culture technique elimi- 

 nated much of the loss due to dieback of leaf tissue and made possible in- 

 creases in fresh weight of 3 to 30 percent in a 4-week period for the five 

 species. Optimal growth for all species was observed at light intensities of 

 200 to 450 foot-candles. By contrast, growth was much slower at light inten- 

 sities of less than 200 and greater than 450 foot-candles. 



59. LOT, A., "General Status of Research on Seagrass Ecosystems in Mexico," 

 Seagvass Eaosystems: A Saientific Ferspectivet C.P. McRoy and 

 C. Helfferich, eds.. Marcel Dekker, Inc., New York, 1977, pp. 233-245. 



This is a discussion on the reasons for the sparse data on Mexico's coast, 

 the different coastal seagrasses {Thalassia, Zosteva, Ealophi,ta, Halodule, 

 Syvingodium) found in the area, and the state of seagrass ecosystems research, 

 especially in Veracruz, Mexico. Also included is an assessment of the effects 

 of human activity on seagrass ecosystems, and suggestions of priority areas in 

 Mexico for future seagrass research. 



60. MANN, K.H., "Ecological Energetics of the Seaweed Zone in the Marine Bay 

 on the Atlantic Coast of Canada, Part I. Zonation and Biomass of Sea- 

 weeds," Marine Biology, Vol. 12, No. 1, 1972, pp. 1-10. 



A survey of the zonation of seaweed in St. Margaret's Bay, Nova Scotia, 

 Canada, showed eight major zones: (1) Fuaus and Asaophyltian, (2) Chorda with 

 filamentous browns, (3) Chondrus ariepus, (4) Zostera marirux, (5) Laminaria 

 digitata with L. longiaruris, (6) Laminaria longioruris, (7) L. longiaruris 

 with Agarum sribrosum, and (8) Agarum eribrosum with Ptilota serrata. Zostera 

 marina occurred at the same level as C. orispus but replaced it in sheltered 

 water. 



61. MARINE EDUCATION CENTER, "The Seagrasses and Marine Algae of Mississippi 

 Sound," Marine Educational Leaflet No. 7, Marine Educational Center, Gulf 

 Coast Research Laboratory, Biloxi, Miss., Nov. 1976. 



This leaflet includes a general discussion and listing of the seagrasses 

 and marine algae in Mississippi Sound. 



62. MARSH, G.A., "The Zostera Epifaunal Community in the York River, 

 Virginia," Chesapeahe Saienae, Vol. 14, No. 2, June 1973, pp. 87-91. 



The invertebrates on Zostera marina in the lower York River, Virginia, 

 were sampled for 14 consecutive months at three different water depths within 

 a single bed. The five most abundant noncolonial species {Bittiim variion, 

 Paraaeraeis aaudata, Crepiduta aonvexa, Ampithoe longimana, and Eriahsonetla 

 attenuata) accounted for approximately 59 percent of the total fauna. These 

 species dominated the epifauna. Several other species, including Batanus 

 impovisus, Molgula manhattensis, Polydora ligni, and Erootania fuscata, were 

 abundant for only brief periods. An average index of affinity (58 percent) 

 between all synchronous sample pairs indicated a generally homogeneous fauna, 

 although several species were differentially distributed with depth. Exfolia- 

 tion of Z. marina after June caused a decline in plant biomass, but the abun- 

 dance of epifauna continued to increase in the summer and fall. Lowest total 

 numbers and species counts occurred in February and early March. Diversity 

 value (H') ranged from 1.92 to 3.90 bits per individual and averaged 3.04 



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