THE IMPORTANCE OF TAXONOMIC PROJECT OF ZOOPLANKTON TO SOCIETY

1. THE IMPORTANCE OF TAXONOMIC PROJECT OF ZOOPLANKTON TO SOCIETY Waya R.K. TANZANIA FISHERIES RESEARCH INSTITUTE

2. THE IMPORTANCE OF TAXONOMIC PROJECT TO SOCIETY Waya R.K. TANZANIA FISHERIES RESEARCH INSTITUTE

3. Introduction • Biodiversity in Lake Victoria is increasingly at risk from human activity such as pollution, overexploitation and widespread catchment deforestation resulting in excess sedimentation • In order to predict ecosystem responses to environmental perturbations, it is essential to have an enhanced understanding of the diversity of various key components of the lake ecosystem.

4. Introduction • Zooplankton is one of them having a potentially important function in aquatic food webs. • Zooplankton community of Lake Victoria consists of Copepoda, Cladocera and Rotifers but Copepoda comprised of 80 % of the community

5. What is a copepod ?

6. a forked tail: the caudal rami 5 pairs of bi-ramous swimming legs 5 pairs of mouthparts Eucyclops macruroides (Lilljeborg, 1901)

7. Cyclopoida

8. Importance of the study • Zooplankton as one of the important ecological factors governing production, abundance and sustainability of key commercial fisheries • evaluation of zooplankton occurrence, taxonomy, distribution and abundance patterns is of utmost importance • because to a great extent it can be used as a tool to interpret trends in fish spatial and temporal dynamics and for management decisions

9. Importance Cont.’ • In order to monitor and maintaining biodiversity, the knowledge on the taxonomy is necessary • when biodiversity is maintained the outcome will be a health ecosystem with sustainable resources.

10. Importance Cont.’ • Zooplankton are important to fisheries as they graze on phytoplankton and detritus converting it into animal protein for use by fishes • Fish larvae (baby fishes) regardless of species, are obligate zooplanktivores, ingesting zooplankton as the first external food.

11. Importance Cont.’ • Their presence in good amount will sustain the fish production, since the fishing communities are said to be dependent upon the fishery for their livelihood and well-being • millions of people will have enough fish as the major source of protein • and the fishery industry will provide employment to fishermen and people in secondary associated occupations • Eventually poverty will be alleviated.

12. THE INTRODUCTION OF ALIEN SPECIES • Detailed zooplankton taxonomic study will provide information on the introduction of alien species, for example Copepod parasites • They are found on the general body surface, fins, and gills, and obtain nourishment from the tissues of the host. • Under natural conditions parasitic copepods are rarely present in sufficient numbers to cause serious injury to the host.

13. In hatchery ponds, however, where fish are crowded in a limited area, there is much greater opportunity for the free-swimming immature stages to find a host, and, as a result, heavy and serious infections may break out. • When firmly establish copepod parasites are difficult to control, chiefly because the sclerotized exoskeleton of the adult is resistant to chemical solutions.

14. Newly attached larval parasites are relatively delicate, however, and sometimes it is feasible to combat infections by giving the fish frequent salt or acid baths. • In extreme cases there is no alternative but to get rid of the parasitized fish, clean the hatchery ponds, and start a new

15. Tapeworms • Fresh water cyclopoids play an important role as intermediary host in the development of tape worms. • When the copepod eats the free swimming larvae of the tape worm it become infected and the (planktonivorous) fish becomes infected by eating the cyclopoids. • Heavy infection of the tapeworm leads to dwarf growth of the host.

16. Other tapeworms (example Diphyllobothrium latum) remains as a plerocercoid in the mussels of the fish (which act as a second intermediary host) and develops further in the intestine only in fish eating mammals (examples: bears and humans).

17. Dibothriocephalus latus Coracidium Procercoid

18. Aquaculture production • Aquaculture is being promoted as an alternative income generating activity for those affected by declining open water resources. • It attempts to bridge the gap between supply and demand for fish • With greater emphasis on promoting aquaculture production on the region to bridge the shortfall in fish production, provision of high quality protein live fish feeds has come into the limelight.

19. Rearing and mass production of desirable zooplankton species will become increasingly important in hatchery operations. • Owing to that the gained taxonomic capacity will alleviate poverty in the way that, it will be possible to identify the required species of zooplankton required in the fish farms in order to control cannibalism. • Results will be high fish production in fish farms and the problem of over exploitation of fish in Lake Victoria will be solved

20. PLANKTON MANAGEMENT FOR FISH CULTURE PONDS • In the culture of larval fish of various species, management of the zooplankton forage base is critical to successful transition of larvae to the fingerling stage. • in most cases Cladocerans are desirable fish prey since they have high energetic caloric value and are readily consumed by most fry. • However, cladoceran populations usually decline rapidly when subjected to predation in culture ponds

21. On the other hand, copepods, because they are swift, powerful swimmers are better able to maintain their populations during the later stages of a culture season • Therefore the taxonomy study is important to the society because it will lead researchers to use particular fertilization techniques and species-specific zooplankton inoculations in culture ponds

22. These management techniques will maintain high densities of desirable zooplankton species in culture ponds until fish will be harvested or able to consume commercial feeds • and eventually the plankton management for fish culture ponds will be possible

23. Conclusion • Zooplankton taxonomic analyses will provide the society with practical applications to a range of policy issues such as climate change, biodiversity, the introduction of alien species, pollution and eutrophication in addition to fisheries.