Marine ecosystems: coral reefs and sea grasses

Coral reefs are among the most productive and biologically diverse ecosystems. They provide goods such as seafood and reef mining, and services like recreational possibilities, coastal protection, as well as aesthetic and cultural benefits. Coral reefs serve as physical buffer for oceanic currents and waves, creating a suitable environment for seagrass beds and mangroves. Sea grasses serve as breeding, nursery and feeding areas for many invertebrates and vertebrate species; they are a source of food for herbivorous invertebrates, fish and turtles; they trap and bind sediments thereby reducing particulate pollutants over coral reefs; and they provide protection to shorelines by dissipating wave energy (NEMC 2006). A marine ecosystem of great importance in Tanzania is the reef system close to Zanzibar. For example, the Menai Bay Conservation Area, situated in the southwest coast of Unguja Island, extends 470 sq km and attracts tourism associated with diving and snorkelling around coral reefs and sand banks in Fumba, and with dolphins and whales watching in Kizimkazi.