The second half of our expedition was extremely exciting. We returned to the field from Doha port once the weather gave us a break. The wind and subsequent wavers were both too high to get in the water on the day we returned, so we decided to utilize the time by deploying our new acoustic array. We deployed 15 acoustic receivers around the study area which took us most of the day. The receivers are deployed in 60m of water and so we needed to attach floats and acoustic releases (which can be activated from a boat) to each receiver so that we can retrieve them later in the year when the whale shark season ends.
The acoustic release deployment took up much of the day and due to the high winds we didn’t see or receive any reports about whale sharks in the area. On the Friday morning, we received a report from one of the platforms that they were seeing large numbers of whale sharks in the area and so we headed over. Upon reaching the location there were indeed many whale sharks aggregating just like the time before. Once in the water we managed to deploy three further MK10-Fs and many more acoustic tags. We also took SPOT IDs, and laser measurements from all the sharks encountered and as many tissue samples as possible. The wind was still relatively strong on this morning and the waves were high which meant that we had to work a lot harder than on day 1. By 13:30 and four hours in the water, the captain called us in as the waves were getting too high and the wind was quickly picking up. We managed to sneak in a quick feeding plankton sample from the rib before getting back on the research boat.
We then headed back towards the mainland as the wind was forecast to reach 40 knots over night. The wind certainly picked up and we were all glad the captain brought us back, as even close to shore the wind was strong and the waves were extremely high. We utilised the time well by analysing our collected data and setting up more equipment for our return into the field.
The wind stayed high for two days and then started to drop. The forecast gave us two flat calm days at the end of the expedition but the whale sharks were nowhere to be found. The GPS capable tags showed the sharks south-east of the study area, could the storm have caused them to move away? Even though we didn’t encounter any more sharks on our trip, we had two amazing days with large aggregations, deployed lots of tags and collected a lot of vital information about the sharks we encountered to build on the information collected last season. It was a fantastic trip enjoyed by all…