Don't grab your line. Bring a big dip net. Keep the line tight and dip up the fish. Also, if you do English subtitles so we could understand what your saying you might get a lot more subs.
Most canals, streams or rivers around Taipei are heavily polluted and you can not eat the fishes you catch. I attended university in Taipei and most fresh-water fishes we ate were from ponds in the country. You should use a net. That fish was catchable.