Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/24812
Title: Transplanting of the seagrasses Halodule Wrightii, Syringodium Filiforme and Thalassia Testudinum for sediment stabilization and habitat development in the southeast region of the United States
Authors: Fonseca, Mark S.
Kenworthy, W. Judson
Thayer, Gordon W.
Keywords: Seagrasses
Soil stabilization
Sediment control
Publisher: Environmental Laboratory (U.S.)
U.S. Army Engineer Waterways Experiment Station.
Series/Report no.: Technical Report;EL-87-8
Abstract: Little information is available on the population growth and areal coverage rates of the tropical and subtropical seagrasses shoalgrass, manatee grass, and turtlegrass. However, such data are needed to manage restoration of these systems. In this study, seagrass transplants were conducted at sites across a broad geograph1c area in order to assess seagrass shoot generation and coverage rates under different environmental conditions. The environmental factors considered were temperature; salinity; light attenuation; water depth; hydraulic regime; sediment type, fluctuation, and depth; and biotic disturbance. Of these factors, temperature, sediment fluctuation, sediment depth, and biotic disturbance were seen to affect transplants. Biotic factors were probably most influential in transplant survival and coverage through shading, temperature increases due to reduced circulation, excavation, and grazing. Shoot generation and coverage rates were determined for south Florida and the northeast Gulf of Mexico. Shoot generation rates varied as a function of species, planting season, and geographic (latitudinal) location. Shoot generation rates for the three species were ranked as shoalgrass > manatee grass > turtlegrass, although differences were less pronounced in the northeast Gulf sites than in the south Florida sites. These data are expected to be transferable at similar latitudes within the distribution of the species. Transplant stock for shoalgrass and manatee grass should contain rhizome apical meristems and can be dug from donor meadows in areas protected from waves and strong currents. These species also sometimes exhibit a stoloniferous-like growth which, when removed from the parent plant, is highly suitable for transplanting. Wrack-line collections of planting stock are also reconm1ended. Transplanting stock for turtlegrass should be either sprigs with rhizome apical meristems (taken from meadov1s salvaged from dredging or filling) or seeds and seedlings. Natural turtlegrass meadows should be used for sprig collection only as a last resort. Shoalgrass and manatee grass should be established first and followed with sprigs or seedlings of turtlegrass after the first seagrasses have coalesced. Attempting to use the slower growing turtlegrass as the primary transplant species could be 30 to 90 times more costly than using the other species over the same time span. Plantings should be considered successful if surviving planting units exhibit a coverage rate similar to data presented here, if the coverage generated equals or exceeds the impacted meadow acreage, and if that coverage persists through time.
URI: http://hdl.handle.net/11681/24812
Appears in Collections:Technical Report

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