PIT 2011 Summary

2011 PIT Crew

June, 2011 saw the successful completion of the Sharklab’s 17th annual PIT mark-recapture census.  Beginning with the first night of fishing in the Sharkland nursery on May 26th, and ending with the final night in the North Sound on June 13th, the past month has been a very busy, productive, and tiring time here at the Sharklab.  In addition to our crackerjack crew of staff and volunteers, the lab hosted a Brazilian film team who were keen to film all the action.  Furthermore, the Sharklab was thrilled to welcome Wally Bell of Sundance Boats and his daughter Alexis.  None of our work here at the Sharklab would be possible if not for the extremely generous donation of Sundance boats by Mr. Bell and we are very grateful for his ongoing support.

  

Ornella and Steve take a blood sample from a juvenile lemon shark

This year, we collected two new important types of data – isotope samples and blood samples – which will provide us with even more information about the early life history of Bimini’s juvenile lemon shark population.

This year’s Sharkland catch, at 117 total, is the lowest in recent years (see Figure 2)  This year, neonates in Sharkland constituted 56.4% of the total catch, compared to last year’s 25.6%.  As expected, most individuals (80.3%) were captured within 100m of the shoreline, highlighting the high usage of the mangrove-fringed nursery area.

2011 saw the North Sound with a total catch of 92 sharks, including 69 neonates.  This is particularly interesting because, with the exception of 2005, it is the only year since 2003 with more neonates in the North Sound than in Sharkland.  Also notable is that both nurseries showed a male/female ratio of approximately 1:1, a trend that appears to be consistent over the past several years

And for more information on the BBFS PIT Tagging Program, Click Here.