Effects of reduced fish by catch and discards on abundance of Ciconiiformes at selected landing sites along lake albert, Kikuube district, Uganda.

Abstract

Fish discards have been reported as a source of food for birds by a number of publications; however, these publications are mostly related to industrial fishing and sea birds in oceanic areas. Little is known if the same occurs with artisanal fishing and more so in fresh water lakes like Lake Albert with its limnics and land species like Ciconiiformes. This study therefore aimed at determining the effects of reduced fish by catch and discards on the abundance of these Ciconiiformes bird species along L. Albert in Kikuube District, Uganda. Data of by catch and discard quantities was collected through onboard observer programs. The by catch was separated from the total landed catch using a fishing scoop and categorized by gear type and target species. The discards were categorized as discards by fish species along the selected landing sites of the study area. A social survey questionnaire was used in the study and included questions like respondents’ demographics, their fish species of interest, those they consider as by catches, their awareness on the effects of discarding on the abundance of Ciconiiformes, trends of Ciconiiformes in the past few years, the trend of total catches, by catches and trends in discarding at their landing site. Data on birds’ abundance was obtained using point count method along the two mentioned landing sites. The obtained data was summarized on a spreadsheet for further analysis. There was a positive correlation between Ciconiiformes abundance at the study sites with quantities of by catch and discards generated by the lampara and long line fishery. This trend indicates that any drastic changes in the fish by catch and discards negatively affects the abundance of these Ciconiiformes at the study sites since the birds depend on the fish discards and by catch for food. The marabou stork was the most abundant bird, followed by the Hammer kop and the Black headed heron being the least abundant in the current study. The lampara fishery was found to be generating more fish by catches than a long line fishery. Discards and fish by catch are thus important food sources to these birds and any reduction of these ready sources of food might cause greater reduced Ciconiiformes abundances at these landing sites leading to their total migration or extinction and also curtailing the food chain involving these bird species.