| dc.description.abstract | Fish predation on cage fish farms can have significant ecological and economic consequences. The controlled environment of cage fish farms introduces a unique interaction between predators and the captive fish populations. This dissertation explores the impact of fish predation on cage fish farms and the implications for aquaculture production. Interaction between the predators and farmed species can lead to stock losses, disease transmission, reduced growth rates and increased stress levels among the farmed fish. Additionally, predation can alter the natural balance of the aquatic ecosystem by favouring certain predator species and disrupting the trophic dynamics. Management strategies such as predator exclusion nets and habitat modification are often employed to mitigate predation risks. However, these strategies may introduce additional complexities and trade-offs.
Research was carried out to identify the different fish predators on the cage fish farms and its associated effects which result from the vice of predation. Buikwe district comprises several cage fish farms situated on Lake Victoria, making it a suitable study area for research. Some of the fish cage farms include Ugachick fish farm, Agro fish farm, Yalelo fish farm, Rocksprings fish
farm limited, Premier harvest fish farm limited, Rottek fish farm limited and others. Due to resource constraints, research was undertaken in Ngogwe sub county Buikwe district and involved four farms namely Rocksprings fish farm limited, Premier harvest fish farm, Rottek fish farm and Agro fish farm. Questionnaires were delivered to the different technical personnel responsible for the day-to-day management of the fish cage farms such as the managers, nursery fish feeders, and supervisors in four-selected cage fish farms located in Ngogwe Sub County, Buikwe district. The questionnaires assessed constraints, management of related challenges, and type of predators, stage of fish mostly fed on and extent of predation experienced by the fish
farmers. Different predators were observed on the cage fish farms, their numbers noted and the stage of fish consumed by the fish predators.Results suggest that birds are the main fish predators on the cage fish farms. Some of the bird
species observed include Microcarbo africanus, Ardea intermedia, Threskiornis molucca and Ceryle rudis. The fish growth stage which suffered the highest rates of predation was the fingerling, consumed by Ardea intermedia and Ceryle rudis. While the Threskiornis molucca commonly fed on the juvenile and adult stages in comparatively lower quantities. The cormorants were present and abundant in the different farms that were involved in the study. The reptiles and mammals were the least observed predators. Ordinary methods such as use of cover nets and predator nets were commonly used to prevent the intrusion of the fish predators into the culture units. Overall, the correspondents reported minimal economic losses from the fish predation.
A comprehensive understanding of the dynamics of fish predation on cage fish farms is crucial for sustainable aquaculture practices and maintaining the health of farmed and wild fish populations. | en_US |
