Estimating Total Fishing Effort over Tidal to Annual Periods in the Diani- Chale-Gazi Reef Fishery in Kenya.

Abstract

The Diani-Chale area of the southern Kenya coast has been the subject of considerable fisheries research and management for over 2 decades, however a detailed estimate of fishing effort is not yet available. A seasonal census of fishers and activity patterns was held from 2003 to 2006, to capture variability by tide, lunar phase and season in fishing effort by all local gear types. The confluence of religious and lunar/tidal calendars results in a very strong cyclical pattern in fishing, with low tides during the full moon spring phase in the northeast monsoon being the preferred time for fishing and half moon neap phase in the southeast monsoon the least preferred. On average, daily fishing effort was 27.3±8.9 to 42.3±6.6 fishers at each landing site, in the SEM and NEM, respectively. Over a full year this exerts a pressure of 85,551 fisherdays in Diani-Gazi. The total fisher population is estimated at 570 fishers, and the total annual catch, based on gear-specific catch rates is estimated at 403 tons. Both spearguns and beach seines are illegal gears in Kenya but between them they support 37% of fishers in the NEM and 57% in the SEM in the study area. Spearguns alone account for 33% of the total fishery. Based on their importance and current knowledge on impacts of these gears it is recommended that beach seine regulation be strengthened and rationalized, but that the social importance and limited evidence for damaging effects of spearguns will require softer regulations to reduce their prevalence but not eliminate them totally. Extrapolated to the national level, recognizing many limitations in doing this, these results from Diani- Gazi suggest the national artisanal fishery employs almost 23,000 fishers catching over 16,000 tons of fish annually. Both figures are 2-3 times higher than officially reported levels of 10,000 fishers and 5-7,000 tons/year, respectively.