Historical Perspectives and Trends in Fisheries Research in Tanzania

This chapter traces the history and trends in fisheries research for the Tanzanian part of Lake Victoria and its basin back to the late nineteenth century when the haplochromine species were scientifically identified for the first time. Past studies in the early to mid-twentieth century were mainly designed to address issues related to the introduced species and the abundant haplochromines. Subsequent studies in the late twentieth to early twenty-first centuries integrated multiple disciplines such as fish biology, ecology, biodiversity, limnology, socio-economics and aquaculture. In the late 1990s and early 2000s, lake-wide research projects played a key role in further understanding of the lake-basin flora, fauna and related fisheries. Over the last half century, Lake Victoria has undergone dramatic ecosystem changes, partly driven by the introduction of the predatory Nile perch and the non-indigenous tilapiine species in the 1950s and early 1960s. The profound ecosystem transformation of the lake has also been attributed to cultural eutrophication, climatic variability and over-fishing. In the mid-1950s, the lake had a diverse fish fauna, which was thought to comprise about 29 genera and more than 650 species, with the haplochromines forming about 80% of the demersal fish stocks. Later discoveries in the early 1970s to the late 1990s confirmed that the haplochromine group alone consisted of over 500 endemic species. The introduction of the Nile perch was meant to utilize the abundant haplochromines that were considered commercially unimportant, and to extend fishing operations from the inshore to deeper offshore waters.