The title of Susannah Grant's 2006 film refers to the practice of catching a fish for sport then releasing it (rather than frying, broiling, or sauteeing it). The central character Gray (played most fetchingly by Jennifer Garner) is coming to terms with the death of her fiancé and in the process learning a good deal more about him than she thought there was to know. Loosening up about two-thirds through the film "in the company of his friends: lighthearted and comic Sam, hyper-responsible Dennis, and, oddly enough, his old childhood buddy Fritz, an irresponsible playboy whom she'd previously pegged as one of the least reliable people in the world" (as it's put at imdb.com), she admits that though she never told her fiancé or his friends, she abhors their practice of catching and releasing fish for sport. "If you're going to put a poor fish through the agony of being caught, you ought to have the decency to eat it" (that's a paraphrase).
"Catch and release" seems intended as a symbol of the coming to terms with the loss not only on the part of Gray, but also on the part of the fiancé's friends and mother (played effectively by Fiona Shaw). All of them have significant adjustments to make. But the association of this mental and emotional process with the abhorrent act of torturing a fish doesn't seem to me to work. The psychic process emphasizes the person dealing with loss (the fisherman, as it were), while the sport seems to emphasize the poor fish (which suffers in the catching, while the fisherman invests no psychic effort whatsoever in releasing it).
Though the film invites viewers to reflect on the patience that a significant loss demands of us that we may release and let go, it doesn't really drive the point home. Like the fishing metaphor, the film seems to be more about the catching of the next fish (a new love interest).