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Rob Kyle’s Blog – Tagging trip to Benguerra island

By: Rob Kyle
Senior Aquarist – Collections
uShaka Sea World

I recently had an opportunity to accompany Ryan Daly of ORI on a field trip to Benguerra island with the intention of catching and tagging Giant Kingfish (GTs) with acoustic tracking tags. The project is a collaborative study between the South African Association For marine Biological Research and Oceans Without Borders and for the duration of our stay on Benguerra we were accommodated at the amazing “&Beyond” lodge on the Island which provided us luxury which I never dreamed I would experience on a work field trip.

 There has been a similar study done on the GTs off the KZN and Southern Mozambique coasts which found that our fish travel large distances up and down the coast according to the seasons, water temperature and to reach suitable spawning grounds in the North.  It will be very interesting to compare the movement patterns of these GTs tagged at a higher latitude where the sea temperatures are consistently warmer, to the fish tagged off the KZN and Southern Mozambique coasts. It is expected that the fish tagged around Benguerra and Bazaruto Islands will not have the necessity to move such large distances as our fish, but time will tell. The acoustic tags have a lifespan of around seven years so the tagged fish will be telling us their story for a while to come. As time passes, the picture will become clearer to reveal their movements more accurately. The goal is to tag different size fish from just mature animals around 60cm fork length up to as big as we can catch. The general pattern picked up from similar projects elsewhere is that the smaller fish will have shorter movements and a smaller home range while the bigger fish move greater distances.  Whether this will be true for this population remains to be seen.

I met up with Ryan and his wife Clare early on the Sunday morning in Salt Rock and we hooked up their boat at a nearby storage garage and started the trip. The beginning of the drive on a trip like this is always filled with excited chatter which makes time pass quickly. It wasn’t long before we were driving past the familiar landmarks in Northern Zululand that I know so well from growing up in the area.

We got to the Border post at Kosi Bay late morning. For a pleasant change, there was no line at the border and we were through in a matter of minutes and onto the new tar road that has been constructed. The last time I travelled in Southern Mozambique, the tar road ended at the border and you went straight onto a sand track. Nowadays however, the road on the Mozambique side is as good, if not better, than on the South African side and it was plain sailing straight up the coast past the elephant reserve. The next point of interest on the drive was the new bridge at Maputo which is a pretty impressive piece of engineering.

We stopped just outside Maputo to fill up with Diesel again and buy some airtime and data – which is much cheaper than in South Africa – before pressing on to our overnight stay at Chidenguele.  Monday morning, we were up before first light, keen to get the day’s driving behind us. The trip was broken by the regular appearance of traffic officials who would step out onto the road at a distance but as soon as we got close enough for them to see the foreign number plate they would retreat and wave us past. This must have happened well over twenty times. It was very clear that an instruction must have been issued which has stopped the imaginative fines that most of us consider synonymous with road travel in Mozambique. It certainly made for plain sailing, with the occasional pause to identify birds. It was depressing to see the massive amounts of charcoal being sold all along the sides of the road and we were passed by several logging trucks coming from the north, full of massive trunks of some indigenous trees.

We arrived in Vilanculos around lunch time and had a quick bite to eat while Ryan caught up with one of his friends from the area who had assisted by arranging the necessary paperwork for launching the boat

I have been on my fair share of field trips, and the accommodation has varied from pretty much non-existent to fair and even sometimes pretty darn good. I never in my wildest dreams imagined that I would be part of a field trip based out of somewhere like the &Beyond lodge on Benguerra. Their hospitality extended to us for the duration of the trip was on a very special level.

On arrival at Benguerra, we met up with Tessa Hempson from Oceans Without Borders and the team was finally together. The first afternoon was spent getting all the tackle and tagging equipment ready and making sure we were totally ready for an early getaway in the morning.

The weather for the first few days of the trip was spectacular with next to no wind for three days. While this was fantastic from a comfort point of view, it wasn’t the greatest for the fishing.  The water surface of the ocean was glassy and there was next to no current offshore which made the fishing conditions very hard. The first day, we concentrated our efforts on the channel between Bazaruto and Benguerra. There is a relatively narrow gap between the islands which has a reef running across half of it which creates the most ideal scenario for a hunting GT during the pushing and dropping tide. This area is called the “Gap” and is a legendary place to catch GTs.  Unfortunately, we didn’t see a sign of a GT on this first day and for that matter, we did not get a single bite from a GT in the gap for the entire duration of my time there despite regular sessions there under all different conditions and tides. 

The following day, we were on the water at first light again and set off across the bay with the sun just about to rise off the starboard bow and the moon still above the horizon behind us. We went further afield on the second day and headed up to 9mile reef which is situated off the eastern side of Bazaruto about halfway up the island.  When we arrived on the reef, we sounded around a bit to work out the profile of the reef and located a shoal of fusiliers that were looking a bit nervous on the surface. On my second cast over them with the Sox popper, a GT came up and sipped the popper off the surface with a swirl more resembling a trout taking a dry fly than the infamous explosion associated with GTs. A short but hard tug of war ensued which ultimately resulted in the fish flapping on the surface next to the boat. The stretcher was hurriedly assembled and filled with water and the fish was lifted and placed in it.

After this early success at 9 mile reef, spirits were high. Ryan had a big fish come up on his popper minutes after getting back to the mark and we really though that we had found the honey-hole. Sadly, as is so often the case with fishing, this was the last bite from a GT that we got for the spot and pretty much for the day.

Thursday, we were on the water just after 9, following a spectacular lodge breakfast. The intention was to stay out the whole day and fish until dark.  With the whole day at our disposal, we planned on fishing our way up to 9 mile reef and back slowly and thoroughly. On the way up, Ryan was driving the boat watching for freak waves and with the really settled sea, I was able to throw a popper almost onto the reef that comes out of the water on low tide at 5 mile. I was throwing into the white water up against the rocks which looked absolutely epic for a GT to be hiding in. The first turn past the ledge, we saw a big GT lift up on the popper but didn’t actually have a swipe at it. We did a second turn along the ledge and at almost the exact same spot as we’d seen the GT, my popper disappeared in an explosion and I hit a few times to set the hook on what I was convinced was a big GT. As soon as the fish ate the popper, Ryan immediately started driving out from the ledge to try and get to deeper water and I wedged myself against the pontoon and the back hatch holding the spool and trying not to get pulled over the pontoons. Fishing with that type of drag setting off a rubber-duck with no solid gunnels to brace against provides many opportunities to disappear overboard. The fish was surprisingly willing to get dragged away from the reef and after the first 30 seconds I started doubting that it was a GT I had hooked. A short while later, the disappointing brown shape of a blacktip shark of around 25kg came into view under the boat and all our hearts sank.  It had eaten the popper off the surface and had the back single hook firmly in the side of its mouth. There was a bit of tricky manoeuvring over the side of the pontoons to remove the hook from the shark without either getting the hooks stuck in the pontoon or have the shark bite the pontoon.  It all ended well ultimately. The shark swam off, I got my popper back and the pontoons stayed inflated. 

After the shark episode in the morning, the rest of the day was really quiet with basically no action. Late that afternoon, we were fishing a ledge that dropped from around 12 to 22m which had a lot of fusilier and salad fish shoals up on the surface. We had seen a few impressive chases on the salad fish by what we could only assume were GTs, judging by the size of the splashes but despite throwing the lures into the middle of the action on one occasion we had raised nothing.  We tried a slightly deeper line on the drift than what we had been doing and towards the end I had a fish eat the popper just behind the boat. I knew that it was a big fish from the head shakes but fishing with a screwed down drag on a Stella 20k and 100lb braid means that fish fight a bit different to what I’m used to. I knew it wasn’t a GT and it wasn’t really able to take more than a few meters of line at a time but it had a strange head shake. I was pretty convinced that it was going to turn into another shark and I was super excited to see a big silver flank turn under the boat after about a minute or so of tussling. One more circle, and a big couta was ready to be released. We didn’t get a measurement or a weight on the fish but I would have put it around the 25kg mark. On a normal holiday, a fish like that would have made the trip but seeing as we were there with the sole intention of tagging GTs, it almost felt like a bit of a disappointment that it wasn’t a GT. It was a special fish to catch on top water however and I was super stoked with it.

The next day we did a double session with a small break over mid-day for Ryan to get some work done on the laptop while I serviced my reel, retied leaders and re-sharpened hooks. During the morning session, we had a few bites, but frustratingly, really battled to stick to a decent fish. Both Ryan and myself had two fish on that despite hard setting of the hook and driving away with the boat just fell off. Ultimately, Ryan got one young GT that we were able to tag. The afternoon saw us having similar luck with a few more missed opportunities. 

I eventually managed to stick to a small GT of 75cm FL which brought our total tagged fish for the day up to two. This was a frustrating score considering that we had at least 6 other fish come up on the lures between us

Saturday was  a very long,  very quiet day on the water with no GTs landed and then on Sunday the Southerly wind came through very strong. We took the opportunity to meet up with another scientist on the island who plans to do some telemetry work on other species in the area. That afternoon, despite the weather, we went out to the Gap, to brave the elements and see if the ocean would reward us for our dedication. Shortly after arriving, I had a fish eat the popper which I was convinced was a smallish GT, right up to the point that it surfaced near the boat and we saw that it was in fact a big yellowspot king fish. This was another cool fish, but another disappointment from a project point of view that it wasn’t a GT.  

This brought us to my departure day on Monday where I had to fly home and leave Ryan and team on the island for another week to hopefully make up the numbers on the GTs. We went out for a quick three hour session in the morning before I had to leave the Island at 10 to be at the airport in Vilanculos to catch my 13:45 flight back to JHB and down to Durban. This session proved to be totally unproductive despite throwing lures in some of the most amazing GT water you could ever imagine. We got back to the lodge with just enough time for me to appreciate one last five star breakfast before starting my journey back to reality.

It was a fantastic trip and an amazing opportunity to see a very beautiful part of Africa. It did however have sad side to it as from the moment you enter Mozambique, you start seeing charcoal for sale. This just gets more and more as you drive north and once passed Chidengeule, you start to see more and more hard wood timber for sale. The trucks that we passed with massive logs on them coming from some northern forest were a sad glimpse at what is happening.  On first look at the Bay off Vilanculos and around the Islands, it appears to be a pristine tropical paradise of blue waters and seagrass beds. Once you have spent some time there however, you realize that it is more of a tropical desert that gets netted to the point that there are almost no fish left in the bay. The crabs and sea cucumbers get collected in commercial quantities and speaking to the locals, their numbers have crashed as well as pretty much anything else that has a value. The reefs around the islands are still spectacular with amazing tropical fish. There was however a very obvious lack of fish that can be caught on rod and line with the majority of larger species left on the reef being grazers or filter feeders. I think that we were unlucky with the cold water that we experienced while we were there (between 22 and 24 degrees Celsius) and that under normal conditions we would definitely have seen and caught more pelagic gamefish. The undeniable reality is however that the area is under immense pressure and currently most people have limited options other than to try and survive off the dwindling marine resources.