|Analysis of reef ecology and fisheries information for a small-scale fishery management in Diani-Chale, southern Kenya: a GIS and RDBMS application
Mwaura, J.M. (2007). Analysis of reef ecology and fisheries information for a small-scale fishery management in Diani-Chale, southern Kenya: a GIS and RDBMS application. MSc Thesis. Universiteit Antwerpen/Vrije Universiteit Brussel (ECOMAMA): Brussel. 59 pp.
|Document type: Dissertation
Fisheries > Marine fisheries > Reef fisheries
Information systems > GIS
Management > Resource management > Fishery management
ISW, Kenya, Coast, Diani; ISW, Kenya, Diani Chale
ECOMAMA, Kenya Belgium Project
The spatial complexity of coral reef's characteristics and site use by fishermen suggests that spatial mapping could be an important tool for assessment and support of reef fisheries management and conservation measures. Participatory reef monitoring surveys have generated enormous data sets that require effective handling. This thesis considered application of an integrative approach of a relational database management system (RDBMS) and geographical information systems (GIS), based on ArcGIS 9.1 (ArcView) as a model for assessment of coral reef fishery and support of management. The reef's point estimates of underwater ecological resources (benthic habitat cover, reef fish, and invertebrates) and fisheries use (catch per fisher (CPF), gear types, site use visits) were periodically collected at Diani-Chale reef lagoons between 2001 to 2006 through a collaborative approach between Government Fisheries Department and local fishing community with scientific support coming from Coral Reef Degradation in Indian Ocean program (CORDIO East Africa). The GIS representation of fishing site characteristics revealed differences among 47 sites of benthic composition, fish abundance, invertebrates as well as fish catch per fisherman (CPF) and site use preferences. Overall, most sites revealed degraded status of reefs as judged by high algal turf cover (46%), high coral rubble cover (14%), high sea urchins density (42/5m 2 ) and low hard coral cover (8%). The inshore reefs were dominated by Acanthuridae, Scaridae and Labridae (species that are generally less sought-after), while population densities of highly favorite target fish species, like Serranidae, Lutjnanidae and Lethrinidae were very low. Spear guns and basket traps had overall highest fish catch rates, suggesting that they are out-competing other gears. Amongst the common gear used, gillnet and hand line showed stable or increasing catch rates over time, while the other gears had inconsistent patterns. The high spatial overlap of gear use at most of the sites may be indicating competition for reduced fish resources. We suggest that management of complex tropical inshore fisheries can be made more effective if site-based controls are focused as key locations for management measures. The integrative approach used in this study can serve as a model for assessment and management of small-scale fishery.