Field Day - Settlement Trays and Fiddler Crab Burrows

            On 11/9/13 we finished our field sampling which included pulling up the settlement trays and completing the fiddler crab burrow transects. We learned how to process the settlement trays in the field which was a very involved and messy process. It definitely required all 4 group members and Dr. Smith at times, but we got better at it with practice. We emptied the contents of the tray into a set-up of layers of trays and mesh.

Sifting through the contents of the settlement trays
Courtesy of Dr. Smith

            Once all the contents were emptied out of the settlement tray we had to rinse the oyster shells with water and sift through to separate the benthic organisms into a labeled bucket which were then later collected into Whirl pak bags for further identification in the lab. Two species of shrimp that were identified from the samples taken from the settlement trays were Palaemonetes pugio (shore shrimp) and Alpheus heterochelis (big-clawed snapping shrimp).

Alpheus heterochelis (top)
Palaemonetes pugio (bottom)

            While Collin and Kierstin were measuring and sorting through the benthic organisms collected, Julianne and I started to measure out the transects for counting the fiddler crab burrows. One 12 m transect was measured out behind each settlement tray in each site (3 per site). 0.25 m² quadrats were placed at 0 m, 4 m, 8 m, and 12 m along the transect and each fiddler crab burrow that fell within the quadrat was counted.

Julianne and I counting fiddler crab burrows
Courtesy of Dr. Smith

            After a long day of sampling we brought back a lot of samples that need to be worked-up including analysis of spat settlement on the oyster shells that were attached to the bricks in the settlement trays. This will be done by using a 4 cm x 4 cm grid and placing it on the oyster shell while looking under a dissection microscope.
    Overall, there is still a lot of identification to do, but I'm excited to see what kinds of organisms we were able to collect.