Vamizi (49173)
Mozambique, Africa
Site overview
KBA status: confirmed
Global KBA criteria: D1b
Year of last assessment: 2020
National site name: Vamizi
Central coordinates: Latitude: -11.0003, Longitude: 40.7171
System: marine
Area of KBA (km2): 86.50026
KBA classification: Global
Legacy site: No
Site details
Site description: Vamizi is a tropical island situated at 11° S in the Northern Mozambique, the island has approximately 12 km long and 2 km wide stretching along an east–west axis. It is bounded to the north and south by deep canyons. Close to 500 m deep, these canyons supply cooler water to the reefs from the depths of the Mozambique Channel, which may offer protection from warm water events and thus avert coral bleaching (Davidson et al. 2006). The island is surrounded by a fringing reef with associated shallow lagoon where coral bommies are interspersed with sandy patches. At the northern edge of this platform, the reef slopes plunge steeply into the canyons, whereas the eastern edge is a vertical wall with numerous overhangs. The southern and western side of the island has a gentle slope in shallow lagoon with patchy seagrass meadows, macroalgae, coral bommies and coral reef patches. On the north side, the coral form a continuous barrier between live coverage of 30-60% and dominated by Acropora species (Davidson et al. 2006, Hill et al. 2009, Sola, Silva, et al. 2015). The island is situated where the South Equatorial Current splits into the north-flowing East African Current and south-flowing Mozambique Current and this Northern Mozambique Channel (NMC) area has been described as the second hotspot of Indo-Pacific marine biodiversity (Obura 2012, McClanahan et al. 2014). Vamizi Island is under influence of the northeast monsoon from October to March, which bring warm temperatures and seasonal rains while the southeast monsoon, from April to September is associated with the cooler dry season (Davidson et al. 2006). While Vamizi Island seats outside the boundaries of the Quirimbas National Park, it benefits from the protection of a community-based management regime.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs. This site is one of 10 largest aggregations of giant trevally, estimated at more than 1000 individuals by Silva et al. (2014). It is only second to the largest aggregation worldwide recorded by Daly et al. (2018) in Ponta do Ouro Partial Marine Reserve (PPMR) which provides the maximum estimate of 2 413 individuals. The record of Silva et al. (2014) at this site represented the first identified spawning location for giant trevally in the Western Indian Ocean. Establishing the occurrence of a vital process such as the spawning location of a large valuable teleost predator reinforce the no-take designation at this site (Silva et al. 2014) and highlights the importance of developing community co-fisheries management programs for protecting such processes (Silva et al. 2014). This is particularly important for giant trevally because spawning locations are considered to be highly predictable due to their stable occurrence over space and time (Silva et al. 2014). This site also hosts some of the most diverse and pristine coral reefs of East Africa (Garnier et al. 2008, Hill et al. 2009, McClanahan & Muthiga 2011, Obura 2012). Vamizi Island is situated at the latitudinal edge of the WIO coral reef biodiversity center (Obura 2012, McClanahan et al. 2014), which provide a mixture of environmental gradients and biological diversity. This results in a strong environmental spatial heterogeneity combining areas of high environmental variability with stable refugia, indicating the existence of a climate-adaptive center that promotes acclimatization, ecological reorganization, and natural selection. Such areas are thus of regional importance for preserving climate-sensitive biodiversity, particularly a number of coral taxa (McClanahan & Muthiga 2017). In addition, there are mass-spawning event occurring every year on the reefs of the Vamizi, and likely extending to adjacent islands of Metundo, Rongui and Tecomaji, which involves the synchronized reproduction of tens of coral of species (Sola et al. 2016). This phenomenon, results in massive peaks of larval supply promoting high rates of larval settlement and recruitment of juvenile corals (Sola et al. 2015), a key process for the resilience of coral reefs under global and local threats. Combined with the characteristics of biodiversity and oceanographic conditions, these reproductive dynamics make the region of fundamental importance for maintaining the region"s coral population (Obura 2012, Sola et al. 2016). Some 207 species of hard corals from 46 genera and 14 families, including over 40 species of Acropora, have been reported for Vamizi and coral maximum diversity estimated to be as high as 269 species (Davidson et al. 2006, Hill et al. 2009, Obura 2012, Sola, Silva, et al. 2015), of which at least 18 species are listed within threat categories of the IUCN Red List of Species. Furthermore, the coral reefs of Vamizi Island host thriving coral communities susceptible to thermal stress, i.e. composed of temperature-sensitive taxa, which reflects the existence of a thermal refugia (McClanahan & Muthiga 2017). In addition, about 400 species of reef-associated fishes (Davidson et al. 2006, Hill et al. 2009), such as Bolbometopon muricatum (VU), Epinephelus polyphekadion (VU), Epinephelus fuscoguttatus (VU) and Oxymonacanthus longirostri (VU), large individuals (>1m total-length) of Epinephelus lanceolatus (DD), Cheilinus undulatus (EN) and Epinephelus tukula (LC), the near threathened sharks Carcharhinus amblyrhynchos and C. melanopterus are common and abundant in Vamizi Island, while the island also harbors the highest regional density and diversity of Chaetodonidae fish(McClanahan et al. 2014). The island is also likely to act as a nursery ground for C. melanopterus as females and very small juveniles are often observed in certain sites (E.S. pers. comm). In Vamizi is in addition a confirmed rookery for green turtles Chelonia mydas (EN) and hawksbill turtles Eretmochelys imbricata (CR)(Pereira et al. 2009, 2014, Garnier et al. 2012), where the highest density of nests, countrywide, are recorded annually for the former species (Louro et al. 2006, Pereira et al. 2009). The ca. 50 females that nest annually in Vamizi represent the most important green turtle population in Mozambique (Trindade, 2012). Finally, a wide variety of ecosystem types, such the already mentioned coral reefs, deep channels, seagrass meadows, sandy and rocky shores and rag-mangrove, a rare type of mangrove stands that grow on bare coral rag and in the absence of riverine fresh water input, host a plethora of biodiversity, some yet to be assessed, from small invertebrates to marine mammals such as the bottle-nose dolphin, Tursiops truncatus (LC), the humpback dolphin, Sousa plumbea (EN) and the seasonal migrante humpack whale, Megaptera novaengliae (LC). In summary, the proposed site, in addition to triggering the threshold for a KBA criterion for an important fish species, contains a wide variety of marine biodiversity of regional and global importance and is the scene for key biological processes, which, combined with the existence of climate-adaptive center, make it a site where high biodiversity may persist in a changing climate, given that effective measures are implemented to manage for this resilience. Therefore, the site satands-out as an ideal and eligible for the designation as a KBA.
Delineation rationale: It was not necessary to draw new boundaries. The proposed KBA follows exactly the limits of the existing Vamizi Community Managed Sanctuary, which is designated as a no-take zone.
Habitats
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Marine Oceanic | 20 | |
| Marine Neritic | 10 |
Threats
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Biological resource use | Fishing & harvesting aquatic resources | Intentional use: large scale (species being assessed is the target) [harvest] | Ongoing |