I want to start a fish Rearing business. I understand that meat is tamasic and eating it effects the guna of human body. But isn't the soul same in case of whether if it is an animal or a plant. How is killing an animal not any different from killing a plant? Doesn't that make all farmers as plant-killers and Animal-killers? (Some farmers do rear goats and fish for meat)
Yes, it is but you might be surprised to know that an apparently harmless job like ploughing the field (for agriculture) is even a bigger sin. Because several organisms like worms are getting killed in the process.
- What sin a fisherman incurs in the course of one full year, — the same is incurred by the driver of a ploughshare made of iron in the course of a single day.
Parashara Smriti, Chapter 2; Verse 8
From the above it is clear that some amount of sin is incurred by the fisherman. Now, one owning the fishery business mustn't be doing the fishing himself but he still commits the same amount sin that a fisherman commits because the owner is approving the killing and he is also earning money by selling the fishes.
This will be clear from the following verse:
Manu Smriti 5.51. He who permits (the slaughter of an animal), he who cuts it up, he who kills it, he who buys or sells (meat), he who cooks it, he who serves it up, and he who eats it, (must all be considered as) the slayers (of the animal).
The idea that fish and meat are bad is a post-Buddhistic idea. A spiritual aspirant has the option of eating fish and meat if he wants. There is nothing wrong in rearing and selling fish.
He who thus knows this Yajnayajniya Saman, woven in the limbs of the body, is endowed with all the limbs, and is not crippled in any limb; he reaches the full length of life, lives gloriously, becomes great with offspring and cattle and great also with fame. His holy vow is that he should not eat fish and meat for a year, or rather, he should not eat fish and meat at all.
Chandogya Upanishad 2.19.2
There are other scriptures that reject the idea that meat eating is bad.
Are there no asses and the like to whom home and forest are the same and who wander about naked without shame? Do they become yogins thereby? If men could get liberated by coating themselves with mud and ashes, are all the country-folk who live in mud and ash, freed? Denizens of the forest like deer and other animals live only on grass, leaves and water; do they become yogins thereby? Frogs and fish live all their lives in rivers like the Ganges; do they acquire special merit thereby? Pigeons eat nothing but stone; the chataka bird does not partake of the water on earth; are they too yogins thereby? Truly, such privations and the self-denials are only for deceiving the world. The only means for liberation is the knowledge of the Truth, the Divine.
Kularnava Tantra, Human Birth and Life, Readings by M.P. Pandit