On 3 September we took a drive up Mahe’s west coast. Unlike the east coast road, which is extremely busy and bordered by a wide variety of industries, showrooms, the airport and heavily populated villages, the west coast road remains relatively quiet and passes through attractive woodland and villages, and provides stunning views of the sea, rocky prominences, offshore islands and beautiful bays backed by verdant mountains.
We stopped in each bay to look for seabirds and migrant shorebirds on the foreshore, finding 2-3 Crested Terns, Grey Plovers and Whimbrels at nearly every stop. Anse Boileau proved different, however, with a minimum of 38 Crested Terns (most were sitting on a sand bank, probably with full stomachs, but others were flying, rendering counting difficult) and early arrivals of 2 Lesser Crested Terns and 2 Common Terns.
Further along the beach from our observation point, we heard the characteristic hooting sound of a conch shell being blown, indicating that fish had just been landed and were available for sale. We drove to the sound’s origin to find two fishing boats offloading their catches. The fishermen had clearly struck it rich as their nets were full of mackerel and they were busy unravelling the nets and extracting hundreds of glistening fish.
The unloaded fish were being sorted into packets of 5-7 fish, tied together through the gills and sold at the roadside at the top of the beach.
We bought a packet and Christine prepared them Seychelles style, cutting slits in the sides and filling them with garlic, ginger and spices in oil, and then barbecuing them that evening: fresh fish at its best!
We wonder if there was a connection between the mackerel catch and the unusually large number of Crested Terns at Anse Boileau. Predatory fish like mackerel drive smaller prey fish to the sea surface in order to concentrate the prey and increase their chance of catching them. Crested Terns, and the smaller tern species that we saw, make shallow dives to catch their prey and may have used the abundance of feeding mackerel to help with their own fishing abilities.
Fish-eating seabirds frequently forage over shoals of predatory fish. This relationship is so strong that I have been told by a tuna fisherman in Seychelles that, despite modern fishing vessels brimming with all kinds of electronic wizardry to help them to locate tuna shoals, skippers still use flocks of feeding seabirds to guide the boats to promising waters!