Ocean News

Lots of bulls with tags!

13th February 2009

Every single day we would encounter between 20 and 30 bull sharks in Shark Reef Marine Reserve. Some of the large females that were not seen for weeks returned to the site with mating scars. We will see if some of them become visibly pregnant during the course of this year.

Starting on the first day, we put out a total of two pop-up satellite tags and 20 acoustic tags this time. One of the satellite tags was attached to a female bull shark that was already equipped with an acoustic tag from last year. This will hopefully be helpful when it comes to geolocation and reconstructing the track. Another male bull shark was double tagged with an external and internal acoustic transmitter, so I hopefully get some more precise information on stomach tag retention times. One of the pop-up tags is programmed to pop off soon and I will of course let you know how it goes!

Another major part of work to be done was retrieving and downloading acoustic receivers I have placed on various reefs along the coast. The data from the receiver will allow us to see where the bull sharks hang out when we don’t see them on Shark Reef.

And last but not least, my colleagues John Earle and Rob Whitton from the Bishop Museum in Honolulu added more fishes to the Shark Reef Marine Reserve fish list. We are now standing at around 420 species of fish, some of them probably not yet discribed and definitely some impressive range extensions!