Beyond the Backcountry

One of the many rewards working for a great organization such as Corkscrew is their partnership with other conservation groups! Through the sanctuary's relationship with Rookery Bay Reserve a few other interns and myself had the opportunity to go shark tagging as well as trawling with the reserves fisheries biologist. Shark tagging involved going out about two and a half hours before sunset to get into the bay were we would be setting up our longlines and gill net. The first photo below is a gill net, a large net hanging from a line with buoys on each end and smaller floats along the length of the net to keep it at the surface of the water. The longlines are pretty much the same except instead of a net hanging from the line there are baited hooks. The deployment of these two devices is very similar. From the back end of the boat you set the anchor located on one side of the line, as the boat moves forwards you slowly let out the line or gill net making sure they are not twisted.  We set the gill net between two baited longlines. 

Once your survey equipment is all set up you sit and wait, constantly checking to see if any of the floats are bobbing or underwater. This means that something is either caught in the net or on the line. We wanted to be able to know exactly when a fish got caught so that our reaction time was quick and they wouldn't be struggling on the line or net too long helping to prevent injury and stress. After seeing a float go under, we approach a few floats away and grab the line on top of the water, slowly lifting each portion slightly out of the water to check and see if we had anything caught. Not 10 minutes after being out there we caught a smalltooth sawfish! Now, we had to be very careful when bringing this endangered species on board because they could cause injury easily with their rostrum. The sawfish was placed into a kiddie pool on the boat that was prefilled with saltwater. This is so the gills can be kept underwater allowing them to breathe. A few measurements were taken and a tag was inserted just below the dorsal fin, then the 6 foot sawfish was released back into the water a little ways away from the gill net and longlines to avoid recapture.  

After processing a captured fish the protocol is to recheck the gill net starting at the end and lifting the net up out of the water working your way through the entire length. This is to make sure no other animals were captured while processing your previous catch. Nothing was found in the gill net and none of the longline floats were down so we went back to waiting. About a half an hour before it was time to start bringing in all the equipment excitement struck! One of the floats on the gill net was frequently moving up and down. As we checked the net we found a juvenile lemon shark! This catch was exciting because after we got him into the pool we were able to see he still had his umbilical cord scar, meaning this little was only a few months old! Due to the presence of the pool this lemon shark was able to swim around in circles keeping water moving over its gills reducing the stress of processing. Again, the shark was measured and tagged before being set free and bringing an end to our evening! but not before posing for a quick snap shot :)