Details

Autor(en) / Beteiligte

• Bwathondi, G
• Kadula, E
• Kaweme, K
• Lukwesa, C
• Muhoza, S
• Wakafumbe, R
• Zulu, I
• Kirika, A
• Wiltshire, N J
• Bailey-Watts, A E
• Williams, WD

Titel

Phytoplankton size and species diversity in two very contrasting waters: Lake Tanganyika and Loch Leven

Ist Teil von

• Verhandlungen. Internationale Vereinigung fur theoretische und angewandte Limnologie/Proceedings. International Association of Theoretical and Applied Limnology/Travaux. Association internationale de Limnologie theorique et appliquee, 2002, Vol.27 (7), p.4021-4026

Erscheinungsjahr

2002

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This paper compares size ranges, frequency distributions and species diversity of phytoplankton in the large, oligotrophic, meromictic Lake Tanganyika and the very different shallow, 13 km super(2), eutrophic Loch Leven, Scotland. In addition to improving our understanding of Loch Leven phytoplankton ecology, the work also involves training African nationals in limnology to assess pollution effects on the biodiversity of Lake Tanganyika (Bailey-Watts et al. 1996). Both lakes are well documented (Cooulter 1991, Bailey-Watts and Kirika 1996, Bailey-Watts 1998). The African system is a major cradle of biodiversity. The Scottish loch is associated with dense algal blooms, macrophyte die-backs and reduced angling successes, which are all features that imply a relatively restricted planktonic flora. The great age, size and spatial habitat variation of Lake Tanganyika has resulted in the presence of many thousands of aquatic species and apparently more endemic organisms than almost any other lake. Compared with mollusc and cichlid fish species diversity, the phytoplankton assemblage may be less special. Van Meel (1954) and Coulter (1991) list ca. 1,500 and 760 algal species, respectively, but both lists are dominated by benthic types, especially diatoms. This might explain the comparatively modest list of 103 planktonic species, including many nanoplankters, recorded in open water by Hecky and Kling (1981). Notwithstanding, Hecky and Kling (1981, 1987) and Kalff and Watson (1986) suggest that the chrysophyte flora is more diverse and abundant than that of any other large, tropical, African lake. In comparison with Lake Tanganyika, approximately 300 species of planktonic algae have been recorded from weekly/fortnightly sampling over the last 30 years at Loch Leven. This suggests that its phytoplankton is at least as diverse as the large lake, perhaps reflecting the very variable oceanic weather regime impinging on this shallow system. This view is in keeping with theories on species diversity enhancement by temporal changeability in environments (e.g. Williams 1964, Hutchinson 1978, Reynolds 1984, 1997, Shorrocks and Swingland 1990) and the impact of 'shock periods' (Round 1971). Species lists abound, but few are supplemented with information on sample size. As a consequence the actual phytoplankton species diversity is far from well known for either lake, hence the quantitative, systematic and thus repeatable procedures proposed here.