J.H. Merino
S.L. Merino
J. Carter
2009
<p><span>Estimates of submerged aquatic vegetative (SAV) along the U.S. Gulf of Mexico (Gulf) generally focus on seagrasses. In 2000, we attempted a synoptic survey of SAV in the mesohaline (5–20 ppt) zone of estuarine and nearshore areas of the northeastern Gulf. Areas with SAV were identified from existing aerial 1992 photography, and a literature review was used to select those areas that were likely to experience mesohaline conditions during the growing season. In 2000, a drought year, we visited 217 randomly selected SAV beds and collected data on species composition and environmental conditions. In general, sites were either clearly polyhaline (≥ 20 ppt) or oligohaline (≤ 5 ppt), with only five sites measuring between 5 and 20 ppt. </span><i>Ruppia maritima</i><span> L. (13–35 ppt, n = 28) was the only species that occurred in mesohaline salinities. </span><i>Halodule wrightii</i><span> Asch. occurred in 73% of the beds. The nonindigenous </span><i>Myriophyllum spicatum</i><span> L. was present in four locations with salinities below 3 ppt. No nonindigenous macroalgae were identified, and no nonindigenous angiosperms occurred in salinities above 3 ppt. Selecting sample locations based on historical salinity data was not a successful strategy for surveying SAV in mesohaline systems, particularly during a drought year. Our ability to locate SAV beds within 50 m of their aerially located position 8 yr later demonstrates some SAV stability in the highly variable conditions of the study area.</span></p>
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10.18785/goms.2701.01
en
Dauphin Island Sea Lab
Mesohaline submerged aquatic vegetation survey along the U.S. gulf of Mexico coast, 2000: A stratified random approach
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