Chagos 2016 - Day 3

Scientists from TRCC and GTOPP are at sea in the Indian Ocean with the Bertarelli Foundation's Chagos Archipelago Science Expedition 2016.  Dr Heather Koldewey, Chief Scientist of the Expedition, wrote:
 

Day 3 highlights – 7th April 2016 , Peros Banhos

Turtle Team

• Today saw two good hawksbill turtle tracks:
  
• One at Ile Diamant
• One at Ile Yéyé (picture). This track was extremely fresh – either from last night or early morning
• Thanks Benoit and Lukas for continuing the turtle research! 
  

Coral Reef Team

• A busy day of surveys around Petit Coquillage in Peros Banhos and we enjoyed a turtle inspection and seeing reef and nurse sharks during the dives.
  
• Limited bleaching at present–only in occasional colonies. Water temperature is currently warm at 30- 31 degrees C.

Monitoring the reef ecosystem

• A newly designed automatic water sampler was deployed that collects water every 2 hours over a 24 hour period.
  
• The collected water will be sent back to Stanford University to precisely measure different forms of carbon.
  
• We will then quantify the calcification to net photosynthesis ratio to monitor ecosystem function.
  

Tagging & Array Team

• The array team continued to recover and redeploy receivers in the array, servicing 10 receivers and expanding our array at Speakers Bank.
  
• The expansion of the array at Speakers Bank included the first deployments of acoustic receivers set on acoustic releases, expanding our ability to monitor deep water habitats.

A nurse shark inspects a receiver

• The tagging team tagged one grey reef shark and caught and sampled a variety of pelagic fishes at Speakers Bank.
  
• The surprising abundance of pelagic fish at Speakers Bank led Dr Barbara Block to refer to it as a “tuna hotel”. 
  

Robbie with a yellowfin tuna at Speakers Bank. This fish was released. 

Thanks to all on Vava II, especially the Captain and crew, for a fantastic and productive day!