Maziwi island officially, The Maziwe Island Marine Reserve (Kisiwa Hifadhi Akiba Bahari cha Maziwi in Swahili) is a unvegetated, protected island surrounded by coral reefs located about 8 kilometres (5.0 mi) south east of the town of Pangani off the northern coast of Tanga Region in Tanzania. The island is administered under Mwera ward of Pangani District. However, it is currently under the Tanga Marine Reserves System. It became a nature reserve in 1975. At one time the island was larger than its present area and was well-vegetated but with the loss of its coconut trees and scrub cover, it has suffered erosion and is now sometimes completely immersed at the time of the highest tides. Green sea turtlecontinue to nest every season on the island, and it is visited by numerous sea birds. The sea contains many species of coral and over two hundred species of fish. The reserve has received little active conservation work but management is now supported by levying a small fee on tourists which is used to compensate local fishermen for loss of income.

The Maziwe Island Marine Reserve, established in 1975, was Tanga's first MPA. The General Management Plan for this reserve is still being created for a number of reasons. The Tanga Coastal Zone Conservation and Development Programme (TCZCDP), which was started in July 1994 and ran until June 2007, helped Tanga coastal regions, including Maziwe Island Marine Reserve, to understand and apply the fundamentals of ICAM. Historical records indicate that this island used to be significantly larger and was vegetated with palm trees and other shrubs. Due to local fishermen cutting trees on the island possibly in combination with sea level rise, changing current or weather patterns, and tourist use of the island to snorkel or dive from, the island has experienced significant erosion.

There is a wide diversity of marine species found in and around the island reserves. This includes over 425 species of fish, 35 species of corals, many types of birds and a number of different sea grasses, algae and sponges. The island is also home to an endemic shrimp species named Tectopontonia maziwiae. The island used to be a nesting site for endangered green sea turtles. However, their eggs must be deposited above the high tide water line to survive and the entire island is covered with water at certain points because of the severe erosion. While no longer a nesting habitat, sea turtles are still commonly sighted in the surrounding reef.

Maziwe reef was set aside as a 'no use' conservation zone under the Pangani/Ushongo Community Conservation Program in 1994. Despite this little had changed with the actual management and use of the reef until recent effort from partners of the Dorobo Fund and community partners, notably local fishermen and tourist resorts known as Warafiki wa Maziwe (Friends of Maziwe). Under this program tourists are charged a small fee which goes to reimburse local fisherman for patrolling the reef and not fishing there. While monitoring programs are underway, the effects of this protection are currently unknown.