| || || Nainoca, Fulori Vakalutusau|
| || || The role of locally managed marine areas in the protection of herbivorous fish and their ability to control algal overgrowth in Fiji |
Author:Nainoca, Fulori Vakalutusau
Institution: University of the South Pacific.
Award: M.Sc. Marine Science
Subject: Fiji Locally Managed Marine Area Network, Fishery mangement -- Fiji, Marine resources conservation -- Fiji, Marine parks and reserves -- Fiji
Call No.: pac SH 329 .M35 N352 2014
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Many coral reefs around the world, including Fiji, are experiencing coral-algal phase shifts. There are two main reasons often given to explain why this shift occurs; nutrient enrichment and removal of herbivores. The latter is the result of overfishing, which drastically reduces the natural processes of maintaining algal growth on reefs. This research assessed the role of four locally managed marine areas in Fiji in protecting herbivorous fish populations and in turn the role of management in controlling the amount of nuisance brown algae. Collection of data included the use of Underwater Visual Census, Point Intercept Transect, algal biomass calculation and algal consumption assays. The results of this research found that (1) herbivorous fish biomass which was dominated by species of the families Acanthuridae and Scaridae; and herbivorous species diversity was significantly greater within the protected area than the adjacent fished area throughout all sites; (2) a significantly higher level of grazing (>50% consumption) of three common brown algal species (Dictyota, Padina and Sargassum) was observed inside the protected area compared to the fished area (<25% consumption); (3) a lower biomass of all four brown algal groups (Dictyota, Padina, Sargassum and Turbinaria) was observed within the protected area compared to the fished area; (4) there were significant positive correlations between fish biomass versus algal grazing; (5) there were significant negative correlations between algal grazing versus algal biomass; and algal biomass versus live hard coral cover. From this research we conclude that small scale locally managed marine areas in Fiji are effective in protecting herbivores and controlling potentially harmful algal overgrowth. It is recommended that species protection of key herbivores such as Naso unicornis, Naso literatus and Siganus spinus be managed through harvest bans to aid in stock replenishment.