DOI: 10.6084/m9.figshare.24769041.v1
title: <b>DMSP Induction and Responses to Short-term Stress in Intertidal </b><b><i>Ulva fenestrata</i></b>

description: This Excel file contains data from experiments that looked at responses of an intertidal seaweed (<i>Ulva fenestrata</i>) to short periods of exposure to hyposaline water and emersion. In these experiments, we emersed pieces of <i>U. fenestrata</i> or exposed them to hyposaline water (7.5 PSU) for 3 hours in summer and winter. We then measured the palatability of the algae to <i>Lacuna vincta</i> snails, seaweed growth, and dimethylsulfoniopropionate (DMSP) concentrations two days later. After the grazing measurements, the remaining seaweeds were allowed to recover in an incubator in culture medium for 7 days, and their DMSP concentrations were measured. A follow-up summer desiccation experiment was conducted in which maximum quantum yields (MQYs) and DMSP concentrations were measured after 0, 15, 30, 45, and 60 mins of emersion at low tide. This study is described in the manuscript “Seasonal effects of short-term stress on susceptibility to herbivores and DMSP induction in the intertidal green alga <i>Ulva fenestrata</i> (Chlorophyta)” by K.L. Van Alstyne and N. Borgen, which has been submitted to <i>Marine Biology</i>. When citing this data set, please also cite the <i>Marine Biology</i> paper, which contains additional information about the experiments conducted.Information about column headings in the data set:<br><b>Page 1) Size and Mass Change</b><br><b>Season:</b> Time of the year when the experiments were done (winter = January, summer = July)<b>Salinity (PSU):</b> Seawater salinity in PSU (7.5 or 30)<b>Emersion Time (h)</b>: Time in hours that <i>U. fenestrata</i> were emersed in the field (0 or 3)<b>Individual: </b>Replicate number for the piece of <i>U. fenestrata</i> (1-10)<b>Lacuna?:</b> Indicates whether the piece of <i>U. fenestrata</i> was placed in a container with <i>Lacuna vincta</i> (Yes or No = control)<b>D2 SA:</b> Surface area (in cm<sup>2</sup>) on day 2 after two days of grazing<b>D2 Growth: </b>Growth of seaweed pieces from day 0 to day 2 (%/day)<b>Herbivory:</b><b> </b>Loss of surface area due to grazing (in cm<sup>2</sup>); calculated as the change in surface of grazed seaweeds minus the change in surface area of control seaweeds<b>D9 SA:</b> Surface area (in cm<sup>2</sup>) on day 9 after 7 days of recovery in an incubator<b>D9 Growth: </b>Growth of seaweed pieces from day 0 to day 9 (%/day)<br><b>Page 2) DMSP Day 2</b><br><b>Season:</b> Time of the year when the experiments were done (winter = January, summer = July)<b>Salinity (PSU):</b> Seawater salinity in PSU (7.5 or 30)<b>Emersion Time (h)</b>: Time in hours that <i>U. fenestrata</i> were emersed in the field (0 or 3)<b>Individual #: </b>Replicate number for the piece of <i>U. fenestrata</i> (1-10)<b>[DMSP] umol/g DM: </b>Concentration of dimethylsulfoniopropionate (DMSP) (in µmol DMSP<sup>.</sup> g<sup>-1</sup> dry mass of <i>U. fenestrata</i>) on day 2<br><b>Page 3) DMSP Day 9</b><br><b>Season:</b> Time of the year when the experiments were done (winter = January, summer = July)<b>Salinity (PSU):</b> Seawater salinity in PSU (7.5 or 30)<b>Emersion Time (h)</b>: Time in hours that <i>U. fenestrata</i> were emersed in the field (0 or 3)<b>Individual #: </b>Replicate number for the piece of <i>U. fenestrata</i> (1-10)<b>[DMSP] umol/g DM: </b>Concentration of dimethylsulfoniopropionate (DMSP) (in µmol DMSP<sup>.</sup> g<sup>-1</sup> dry mass of <i>U. fenestrata</i>) on day 9<br><b>Page 4) Follow-Up Field Data</b><br><b>Individual: </b>Replicate number for the piece of <i>U. fenestrata</i> (1-10)<b>Desiccated: </b>Indicates whether the piece of <i>U. fenestrata</i> was emersed in the field (Yes or No)<b>Exposure Time (min)</b>: Time in minutes that <i>U. fenestrata</i> were emersed (0, 15, 30, 45, or 60)<b>DAY 0 Fv/Fm</b>: Maximum quantum yield (F<sub>V</sub>/F<sub>M</sub>) on day 0 after emersion treatments were conducted<b>DAY 7 Fv/Fm</b>: Maximum quantum yield (F<sub>V</sub>/F<sub>M</sub>) after 7 days of recovery in an incubator<b>DAY 0 [DMSP] umol/g DM:</b> Concentration of DMSP (in µmol DMSP<sup>.</sup> g<sup>-1</sup> dry mass of <i>U. fenestrata</i>) on day 0 after emersion treatments were conducted<b>DAY 7 [DMSP] umol/g DM: </b>Concentration of DMSP (in µmol DMSP<sup>.</sup> g<sup>-1</sup> dry mass of <i>U. fenestrata</i>) after 7 days of recovery in an incubator<b>DAY 7 Surface Area (cm2):</b> Surface area (in cm<sup>2</sup>) on day 7 after 7 days of recovery in an incubator