Links between humans and seagrasses—an example from tropical East Africa

The concept of ecosystem goods and services and the approach of a linked social–ecological system were used to identify and describe the interactions between humans and seagrasses in a rural tropical economy in the East Coast of Zanzibar (Chwaka village). The main stakeholders in the population are fishermen and seaweed farmers. Through in-depth and semi-structured interviews, questionnaires, market data analysis and participant observation, we found a diversity of social–ecological links that are important for the welfare of the local population. Fishing grounds for finfish and invertebrates, substrate for seaweed cultivation and sites for bait collection were among the most important ecological support areas for fishermen and farmers. Seagrass-associated fisheries in the form of trap fisheries (“dema”) provided the highest daily average income per fisherman. Furthermore, seagrass-associated fish constituted the primary source of animal protein for the local people. Seagrasses were also used as traditional medicine and fertilizers. They provided a wide range of ecological services including aesthetical, instrumental, spiritual and religious. The amount of local ecological knowledge (LEK) among fishermen was substantial. No institution directly dealing with seagrasses in the area was identified. The use of a seascape management approach is recommended to improve and develop social–ecological resilience.