Molly McCormley at UC Santa Cruz Long Marine Lab, CA--It’s official…Spot’s tags have been recovered!! Spot  has been wearing her tags for 8 months, picking up data that researchers are just now able to view!  

Here's Spot laying on the sand at Año Nuevo State Reserve!  Notice that the tags have already been taken off, what's let will naturally fall off during her catastrophic molt. Photo: Mike TIft

You see, satellite tags relay some data points back to the lab via the Argos satellite system. The rest of the data is stored within the tag, ready to be downloaded upon recovery. The time-depth-recorder tag however, does not relay any data back to the lab. Instead, this little tag MUST be recovered...or the data is lost.
How it works: This CTD tag records salinity and temperature data throughout the water column as the seal dives. This tag also connects to the satellite system with the seal surfaces at sea. Elephant seals only take short breaks between dives (an average of only two minutes) before they embark on their next dive. This tag must be quickly connect to the satellites to acquire location information, and then either store, or relay data back to the lab. Photo: Mike Tift

Spot is named after a very special phenomenon, HOTSPOTS!  There can be both prey and biodiversity hotspots!  Prey hotspots are locations in the oceans where there are large concentrations of prey species. They can be associated with currents or eddies, temperature, and/or the bathymetry (or contour of the ocean floor). Seals hit the jackpot when they come across one! Biologists have identified some hotspots in the North Pacific but they are still pretty mysterious and many hotspots haven’t even been identified.  

This is where Spots tags come in.  We know that seals like to feed in hotspot areas because the richness in prey diversity, so we attached a very special tag, called a CDT tag, to her head.  This special tag is like wooly mammoth of all tags!  It not only has a time-depth recorder and a tracking device on it, but it also can measure salinity!  This is awesome, because places like hotspots don’t always occur right on the oceans surface.  This means we must somehow get data from depths that we can’t very easily get to.  However, since Spot is an elephant seal, she can dive to depths of around one to two thousand feet!  This means that we can get samples from possible hotspots to learn more about how or why they exist. In addition to learning about the e seals themselves, we are able to also learn more about the ocean around us!  
While feeding in the prey hotspots Spot can become quite fat!  Gita is using an ultrasound to measure the blubber densiy on Spot's body.  E seals have the perfect body to measure fat because they are so round! By measuring the blubber depth, researchers can learn a lot about e seals energy gain and loss. Photo: Mike Tift

Cory is measuring Spot's lengths to see how much she has grown.  E seals grow throughout their lives, so even though she is an adult she still can grow larger! Photo: Molly McCormley

Spot and her pup lying on the beach at Año Nuevo State Reserve after the recovery. Photo: Molly McCormley