Effects of Hydrogen Sulfide (H2S) on Z. marina seedlings, seed germination and shoot density from 2013-01-16 to 2015-09-11 (NCEI Accession 0156588)

Various seed storage conditions included fridge storage vs sea table storage, storage in mud vs sandy sediment vs seawater, light vs dark conditions and anoxic vs oxygenated seawater. The objectives of a fourth experiment were to census the density of Z. marina shoots along a transect in Padilla bay. By manipulating sediment conditions among some of the plots, we measured how organic matter in sediment is converted to sulfide and how that sulfide affects eelgrass shoot density.

To do so blocks of agar and 100g of sucrose were prepared and each treatment plot received half of an agar block, placed beneath the sediment, every two weeks. Control plots had the sediment manipulated in the same way but without adding organic matter under the sediment. At each two week interval, pore water was sipped and measured for salinity, pH, and total sulfide content at each plot, the sediment temperature of each plot was taken, and the number of vegetative and flowering shoots at each plot was recorded.