Awlright, I�ll take a stab, if anything else, y�all can tell me how far off base I am and sorry about the questions on questions.
Fish Kill?
If he�s concerned about his fish dying, what options does he have? Does he have the resources to seine and move to another pond somewhere? Does he have a supplemental water source? What happened last year? It sounds like he thinks the pond will completely dry out.
Survivors and population dynamic?
Depends on management goals and resources. If you are managing for maximum carrying capacity, and you have a pond in a Mediterranean climate, you better have supplemental water. My (limited) experience with warm Mediterranean climate ponds that lose significant volume over summer, but maintain enough capacity for survivability, is that the surviving populations really blossom when the pond fills back up. If one doesn�t care about maxing out the pounds per acre, droughts are a good way of keeping your surviving fish from stunting. Overall much lower populations, but high quality fish. The strongest have made it through the summer, and with the winter and spring rains, full pool, everybody is happy, active, and ready to re-populate, kind of a mixed blessing.
Water Quality?
Hard to answer without some knowledge of watershed (water and soil chemistry). Iow, seems it would depend a lot on what type of water there is to begin with (and what kind of soil it interacts with). My water quality has stayed really nice this summer despite the toll of evaporation. Does he or can he aerate?
Where to put dirt?
What would I do? Re-use the pond soil.
The ideal scenario would be 3 pieces of equipment. Track hoe the dirt, wheel loader (or dump truck) to spreading site, dozer to spread. Long pushes with a dozer aren�t efficient. Pond soil is good stuff, people pay a lot of money for topsoil (around this area anyway).
