The idiom 大海捞针 ('fishing a needle from the ocean') is the Chinese equivalent of 'a needle in a haystack.' Also, 捞 is used colloquially to mean making money in shady ways - 捞一把 means 'to make a quick buck.'
culture
捞面 (lāomiàn) or 捞 in Cantonese cuisine refers to tossing noodles with sauce (as opposed to soup noodles), which is where the dish name 'lo mein' comes from.
Left hand radical - anchors 捞 as a hand action. The core sense is to scoop or fish out, especially from water; hence the modern usage 捞鱼 (catch fish) and the colloquial extension 捞钱 (rake in money). Same hand family: 打, 拉, 抓, 摸.
Right 劳 supplies the sound exactly (láo → lāo, just a tone shift to first tone). 劳 originally pictured a torch-lit night labor scene; here the laboring imagery reinforces the meaning, since fishing nets out of water is hard, repetitive work. Same phonetic in 唠 (chatter), 涝 (waterlogged).
