Shark Tagging with Westminster Christian School

By Hannah Calich, RJD Graduate Student

Last Friday the RJD team was joined by the fabulous students and teachers from Westminster Christian School for another day of shark tagging!

The Westminster students, teachers, and the RJD team after a great day on the water

The RJD team met at Crandon Marina at 8 am to begin loading up Divers Paradise. Despite the hurricane over the Bahamas, Miami’s coastal waters were calm and the weather was great, so we were eager to get out on the water. Once everyone was on the boat the RJD team introduced themselves, our trip leader, Emily Nelson gave everyone a briefing, and we set off!

Once we got to the site, the RJD team deployed a baited fish trap as part of a new project we’re working on to learn more about the fish communities at our tagging sites. Once the trap was deployed we set 10 drumlines, took some environmental data, and had some lunch while we let the lines soak. After the hour-long soak we began checking our lines. Our first line came up empty, but when we got to drum # 2 we felt a familiar tug on the line and everyone sprang into action. Our first shark of the day was a 171 cm male blacktip shark!

A Westminster student gives the bait a kiss for good luck!

Once we tagged and released him we headed over to drum # 3 where once again we felt a familiar tug on the line. Our second shark of the day was a 174 cm female blacktip shark! What was particularly interesting about this girl was that she was a recapture! We checked our records and determined that we originally tagged her back on November 1^st, 2013! Back in 2013 she was 169 cm and has grown to 174 cm since then. We get really excited about recaptures because they are relatively rare and give us a lot of interesting data about how these animals are growing, where they are living, and what they are eating!

A Westminster student helping collect a fin clip from one of the blacktips

Once we re-tagged and released her we went to drum # 4, where once again there was a shark on the line! On drum # 4 we caught another 174 cm female blacktip! She had only been on the line for a few minutes so we decided to surgically implant an acoustic tag in her abdomen as part of our Urban Shark Project, which is studying how sharks use highly urbanized environments.

Once she was tagged and released we went back to checking and rebaiting our lines. Unfortunately, the next 16 lines came up empty. However, something was clearly eating our bait and since the first few lines had been so busy we knew it was only a matter of time until we caught another shark, so we decided to set 5 more lines.

While we were waiting for those lines to soak we decided to pull up our fish trap and work-up the fish we caught. We ended up catching about 25 fish from approximately 6 species! Once the fish trap was back on the boat we went to check on our drumlines and found that we’d caught one last shark! This time we had caught a large (240 cm) male nurse shark! The RJD team secured him while the students went to work collecting data. Within a few minutes the workup was complete and he was on his way again.

RJD intern Julia Whidden takes measurements of a fish caught in our fish trap

In the end it was a very successful day because we caught 4 sharks! We caught 3 similarly sized blacktips (one of which was a recapture!) and a large male nurse shark. In addition to doing our usual work-up we also deployed an acoustic tag and gained new data on the local fish communities! Thanks again for all your hard work Westminster, it is always a pleasure to go out with you guys. I can’t wait until the next trip!

Our last shark of the day, a 240 cm male nurse shark!