According to Buddhist scriptures, animal beings could have seeds of Buddhahood planted in mind just by hearing names of the Buddhas. Thus it is very important to offer them some Dharma recitations prior to their release. If you skip this step and release them in a rush, then they are just being saved from temporary sufferings, knowing they could be captured again and have no guarantees for their next life. A complete life releasing should include recitation prayers and refuge giving, so that the animals can receive blessings from the Three Jewels. We should also be aware that if we have truly arise compassion during this process. If the above conditions are all met, we can generate unimaginable amount of merits through group practice of life release.
Merits are founded on good hearts, our most important attitude while releasing captive animals is to treat them with compassion. By having compassion, even releasing a tinny fish would cultivate you huge merits. Additionally, other than doing this by ourselves, we should also actively introduce this virtuous deed to others, or rejoice when seeing others do it, in this way our mind will always abide in this virtuous intention - a great source of merit. As an attained master said:"a virtuous deed can shelter you from a hundred disasters." For those who rejoiced and participated in life releasing, fortunes will naturally come and disasters can be avoided. Therefore, life release is a way to accumulate merits and benefit self and others - in which, yourself is the biggest winner.
- Rigdzin Gawa Rinpoche