12.1 TOPIC OVERVIEW AND LEARNING OBJECTIVES

This section presents a detailed description of the Mekong River fish and fisheries, and explains importance of their relationship to the environment and ecology of the Mekong River. In this section an interactive model is provided so that the users can explore the important relationships between the physical, biological and human systems of the Mekong basin using fish and the fisheries to demonstrate the integration between the natural ecological systems and human ecology. The section focuses on fish but notes that similar principles apply to other kinds of aquatic animals such as crustaceans, molluscs, that are also form an important part of the fishery.

Through the use of the interactive model the user is introduced to the concept that river ecology determines fish ecology and explains the relationship between the great diversity of habitats in the Mekong River ecosystem and the great diversity of fish species that are found in the river. It includes explanations of why fish look the way they do; how all aspects of river ecology influence the behaviour and life histories of fishes; why and how fish migrations are a response to river form, function and ecology.

Fish migrations are explained in terms of how they are responses to river form, function and ecology.
The importance of the flood-pulse on the nature of fish and fisheries is described, including the relationship between the flood-pulse and biological production. This is followed by explanations of how river ecology influences the demand, supply and price of fish and fishery products, as well as human livelihoods and food security.

The importance of the flood-pulse on the nature of fish and fisheries is described, including the relationship between the flood-pulse and biological production. The section provides explanations of how river ecology influences the demand, supply and price of fish and fishery products, as well as human livelihoods and food security. The vulnerability of fisheries to major, as well as minor, changes in river ecology and the environment is discussed. The linkages between biodiversity, livelihoods, gender and socio-economic values of fisheries are stressed.

After completing this Section, the user should be able to:

• Describe at least three factors that may contribute to the high diversity of the Mekong fish fauna;

• Describe the typical life cycles of at least two major groups of freshwater fish and give examples of how life cycles differ between them;

• Describe, with examples, at least three different migration patterns of Mekong River fish species - two different patterns within freshwaters and another near the estuary or sea;

• Describe at least three ways in which river ecology and fish ecology influence the nature of fishing gears and fishing methods;

• Provide at least five different examples of ways in which people depend on the Mekong River fishery;

• Explain the basic relationships between river ecology/environment, biodiversity, and dependency of people on fisheries and sustainable development;

• Describe at least three ways in which human activities can have an impact upon fish and fisheries and explain the basic ecological processes through which those impacts occur;

• Describe, with examples, how maintaining connectivity between different parts of the river is important to maintaining fish stocks and the fishery;

• Describe at least two potential impacts of altering mainstream flows (and the natural) flood pulse on fisheries resources;

• Describe, giving at least two examples, the ways in which river ecology influences the lifestyles of people through fish and fisheries. Provide another example of how changes in river ecology brought about through human disturbances can impact men, women and children differently; and

• Excluding the cash value of the fishery, provide at least two examples of the way in which fisheries benefit people and contribute to food security.