Is There a Shark Nursery in the Rewa River?

Guest Blog
By Kelly Thomas Brown

Bula Shark Defenders!

It’s been a long time. My research is on-going with some set-backs experienced, but you learn to develop even more patience and/or pick up the pieces and move on.

Fiji experienced major flooding on our main island, Viti Levu, in late January and again in March, with thousands of people being displaced from their homes. The rain and flooding were caused by a series of low pressure weather systems, fortunately not developing into cyclones. Some towns were inundated more than once in a span of two weeks. Bad weather saw it unsafe to launch our boat for field research for a while.

Then my place was broken into! Taken were the video camera for the BRUVS research, laptop, and external hard drives. My raw data was on the one hard drive that wasn’t taken, so all that work wasn’t for nothing. I am slowly reanalysing data, replacing the stolen equipment and trying to get funding for another camera. Lesson: as soon as I back-up my data, copies are moved and kept everywhere.

With the BRUVS study on hold until the camera is replaced, the shark nursery portion of my research has started and this is keeping my team busy. The objective of the this study is to find out if the estuary of the Rewa River (Fiji’s largest river system) is a nursery for the scalloped hammerhead shark (Sphyrna lewini) and we’re in the process of collecting data.

Releasing juvenile scalloped hammerheads back into the estuary after taking length, weight, and other measurements.  Photo Credit: Kelly T. Brown

As these photos can attest, the initial data collection seems to point to YES!  This is a significant discovery.  The IUCN Red List of Threatened Species assesses the scalloped hammerhead as Endangered globally.

It is amazing to handle a juvenile shark of only 50 centimeters in length and realise that this beautiful animal can grow up to 4 meters. The study will continue for a couple months. I’ll let you know what we find. 

Volunteer and fellow graduate study Jerome release one of the juvenile scalloped hammerhead back into the estuary.  Notice the shape of the head (the shark's not Jerome's!)  That's where the scalloped hammerhead gets its name.  Photo Credit: Kelly T. Brown

Special thanks to my volunteers for the great work done – even in the rain and until midnight!  Until my next post, moce mada!

Kelly Thomas Brown is a Masters candidate at the University of South Pacific and is the Manager of Fiji Shark Defenders.