Sledding for seagrass?

Today was a full day of sledding. The 'sled' was a contraption that looked a little like a sled and had curved edges that we dropped off the mothership, Velella. Attached to the sled was a GoPro and another camera that gave us a live feed of the sea floor. The sled looks like this:

sled2     longgrass

This was definitely a group task as there were many roles that needed to be covered:

1. Reader of the GPS co-ordinates, depth, time (there is a reason to know latitude and longitude!)

2. Dropper of the sled

3. Rope Technician (the assistant to the Dropper of the sled - the Master of Coil) 

4. Seagrass Identifier (the Farmer of the Sea)

5. Assistant to the Seagrass Identifier

6. Note-taker 

We literally cruised around the bay, dropping the sled at various locations. More often than not we would simply find sand or shells, but every so often we would hit gold (seagrass that is). This was a time of much joy and celebration. We then had to determine the type/s of seagrass and the extent of seagrass cover. Again, this was all about working out the distribution of seagrass. Sometimes it took only 2 minutes to drop the sled and identify the seagrass (or not). Other times it took up to 8 minutes due to the turbidity of the water and the swiftly moving current.

Our number one nemsis today was once again our old foe caulerpa, popping up at random times to confuse us with it's lush foilage and vivid greens. It finds weakness in the seagrass and attempts to take over. Caulerpa thrives in bare, low-light environments. This means that if there is too much sediment covering the seagrass (runoff from floods, urban development, etc.), then caulerpa jumps at the opportunity to extend. This 'weed' is actually native, however, due to it's toxic nature, it is not a habitat conducive to a flourishing life (apparently fish can starve in caulerpa meadows).

The day ended with a swim. This was my first chance to grab the GoPro that I took from school and jump in the water. I made a very dodgy video! Here are a couple of screen shots (yes, I found seagrass - halophila spinulosa):