91. ORTH, R.J., "The Demise and Recovery of Eelgrass, Zosteva rmrina, in the 

 Chesapeake Bay, Virginia," Aquatic Botanyt Vol. 2, No. 2, June 1976, 

 pp. 141-159. 



From 1971-74 eelgrass (Zosteva mavtrux) declined 36 percent. Evidence 

 indicating the loss was determined from aerial photos and ground-truth recon- 

 naissance. The decline is attributed to the cownose ray, human disturbance, 

 and a rise in water temperature. 



92. ORTH, R.J., "Effect of Nutrient Enrichment on Growth of the Eelgrass, 

 Zosteva mavina, in the Chesapeake Bay, Virginia, USA," Mavine Biology, 

 Vol. 44, No. 2, 1977, pp. 187-194. 



The addition of two commercial fertilizers had a positive effect on the 

 growth of Zosteva mavina in the Chesapeake Bay. There was a significant 

 increase in the length, biomass, and total number of turions in fertilized 

 plots compared with controls. This short-term field experiment suggests that 

 Zostera beds in the Chesapeake Bay are nutrient-limited, that the growth form 

 of Zostera may be related to the sediment nutrient supply, and that Zostera 

 may competitively exclude Ruppia mavitima by the shading of the light. 



93. ORTH, R.J., "The Importance of Sediment Stability in Seagrass Communi- 

 ties," Ecology of Mavine Benthos, B.C. Coull, ed. , University of South 

 Carolina Press, Columbia, S.C, 1977, pp. 281-300. 



Dense seagrass beds, such as Zostera in the Chesapeake Bay, stabilize sed- 

 iments, promote diverse and abundant benthic fauna, and protect fauna from 

 predation from blue crabs. 



94. PATRIQUIN, D.G., "Estimation of Growth Rate, Production and Age of the 

 Marine Angiosperm Thalassia testudinwn Konig.," Cavibbean Journal of 

 Science, Vol. 13, No. 1-2, Institute of Marine Science, University of 

 Puerto Rico, Mayaguez, June 1973, pp. 111-123. 



There is a linear relation between average growth rate and the average 

 maximum leaf length of Thalassia. The ratio production-to-standing crop (wet 

 weight including epiphytes) tends to be constant. New foliage is developed at 

 intervals of about 15 days. The age, growth rate, and production of under- 

 ground parts can be estimated by counting leaf scars. 



95. PATRIQUIN, D.G., "Migration of Blowouts in Seagrass Beds at Barbados and 

 Carriacou West Indies and its Ecological and Geological Implications," 

 Aquatic Botany, Vol. 1, Elsevier Scientific Publishing Company, Amsterdam, 

 The Netherlands, 1975, pp. 163-189. 



Blowouts are grass-free depressions within seagrass beds at Barbados and 

 Carriacou and reported in the literature to be common elsewhere in the 

 Caribbean region. They are typically crescent-shaped in plan view with the 

 convex side seaward, and are characteristic of elevated seagrass beds in 

 regions of moderate to strong wave action. The seaward edge is steep and 

 exposes rhizomes of Thalassia; the leeward edge slopes gently upward to the 

 seagrass plateau and is usually colonized by Syringodium. The general mor- 

 phology of the blowouts, the zonation of organisms across them, and the exist- 

 ence at some blowouts of a lag deposit of cobble-sized material at the scarp 

 base continuous with a rubble layer below the seagrass carpet suggest that the 

 blowouts "migrate" seaward. Measurements of scarp erosion and of the advance 



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