When we eventually got out on the water looking for the algal mats that were the source of material on the strand line became a priority. This coastline was a problem to navigate in; whereas elsewhere the lagoons were wide and extensive, here there were several rocky barriers that meant we had to use either different boats in each section or transport the boat by road from ramp to ramp to obtain full access. Even so, one or two of the smaller lagoons at the southern end were inaccessible by any boat. Also, the prevailing wind direction for Mauritius was from the south east at this time of year, which impacted strongly on the Belle Mare area; whereas Grand Baie had been sheltered, the outer reef was bashed by high waves almost continually, and where the reef was broken up by deep water gaps called passe, the currents rushed in causing a significant hazard for a small open boat.
Again we were lucky to use glass bottom boats, and had a charming Creole captain who was much more courageous and lagoon-savvy than his Grand Baie counterpart. We were afraid we were going to find the whole lagoon smothered in a green algal covering, choking the reef to death. On the satellite imagery I had interpreted there were large dark green areas throughout the lagoon and the characteristic colours and textures of reef were rarely present.
The nearshore area was sandy bottom, with the occasional rocky substrate, as we expected. When we reached the first of these dark green areas, we were astounded. Yes there was algae tangled around the reef but the reef itself was very much alive, and if anything expanding. On the staghorn coral, at the ends of lots of little yellow branches appeared almost fluorescent blue patches of recent growth, and there were not just the large ancient stands of coral heads, but plenty of tiny baby corals starting to branch out. In fact, it was the liveliest and most densely packed area of coral organisms I had seen anywhere in Mauritius. Tangled up amongst it was all this algae, though.
We trawled extensively over the lagoon trying to pick up clues on the original source of the algae and the impact on the reef but we continually saw that the reef and other habitats here were generally in broad health, despite the slimy covering. Then the boat engines cut. The captain had underestimated the amount of running around we were going to do and the boat’s fuel tank was empty. The boat started to drift northwards along the lagoon parallel to the beach. Fortunately when the power was lost, the boat was less than thirty metres from the shore, and given our captain was local he spotted a friend on the beach. It happened to be a Sunday and the beach was busy enough. Although he spoke in Creole, we got the Captain’s drift; he was asking his friend to fetch some more fuel from a nearby resort. As in many places the water was shallow and our helper splashed out with some more outboard motor fuel in a large water bottle. Our captain gave him a grubby rupee note and then looked at the water bottle – he looked at us all in the boat waiting for him to start again and smiled. He handed the bottle to me and reached below the outboard motor to release the fuel intake pipe. He dipped it in the open bottle, then fired up the outboard. He took back the bottle and settled it on the seat beside him then with a huge grin on his face recommenced the trip.