Explanation needeed for specific part

[ivan-zd]

Hi, I have suzuki df20a outboard and when i was changing oil filter i noticed that there is slight damage (hole) on one black pipe but before fixing it i wanted to check what is this pipe used for. Its black pipe right next to red one as you can see in attached image.
Can someone please help me point out what it is and how should i treat damages on such pipes. Thanks.