Jozani biodiversity inventory report 2002 - Coastal Forests of Kenya ...

- places of great attraction of larger marine organisms, especially fishes in search of
good feeding areas
- good nursery grounds for juvenile stages of commercially important shrimps, crabs,
lobsters and fishes
- important feeding sites for adult fishes and birds.
In Chwaka Bay fishermen reported that mangroves and seagrass meadows were important
fish habitat and spawning areas. Mangroves were particularly important for prawn breeding; it
was reported that most prawns breed in the mangroves. Places reported to be important for
fish breeding in the estuarine included Mchenga/Kidimani, Vijawi, Kumvi and Haibari
"river". These breeding sites have special significance in Chwaka bay as they form an
important breeding area for fish because the corals which are usually good breeding sites for
fish are reported by fishermen to be on the edge of the bay where it joins the marine
environment. It is important to note here that seagrass farming is also actively practised by the
local people especially women in Chwaka Bay (FAO/Department of Environment Zanzibar,
1999). This has a positive effect on fishery as the seagrasses provide shade, feeding and
nursery grounds for fish.
4.2.11.5 Threatened species of fish (IUCN threat categories)
There are several factors which may lead to fish species to become threatened. The causative
agents of the threat are usually humans and human activities. It is commonly known that
some species of sharks, swordfish, Billfishes are threatened (Table 20). Many of these fish
occur in deep water sea or are benthic species so are not easily seen by the local people. These
fish are also not usually caught by artisanal fishermen hence are not locally reported, although
distribution maps show that they occur on Zanzibar (FAO, 1984a, 1984b, 1984c, 1984d;
Smith and Heemstra, 1991).
Table 20: Threatened fish species (IUCN) reported as occurring on Zanzibar (Source:
FAO, 1984a, 1984b, 1984c, 1984d; Smith and Heemstra, 1991,
http://www.redlist.org/info/links.html)
FAMILY SPECIES ENGLISH NAME IUCN
STATUS
SERRANIDAE Epinepheleus tukula Potato grouper LR
LABRIDAE Cheilinus undulatus Hampered wrasse LR
CARCHARHINIDAE Carharhinus plumbeus Sandbar shark LR
CARCHARHINIDAE Carharhinus taurus Grey nurse shark EN
CARCHARHINIDAE Carharhinus falciformis Silky shark LR
CARCHARHINIDAE Galeocerdo cuvier Tiger shark LR
SERRANIDAE Cromileptes altivelis Barramund grouper LR
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