Problem with requirement #4
Requirement #4 has a scout demonstrating various knots. The one in question is "bloop loop (barrel knot)"
These are two different knots. One is a "loop" formed in the middle of a line to attach additional lures, weights, bait, etc. to. The other is a "bend", joining two lines.
The more currently common name for the Blood Loop is the Drooper Loop. You'll find this designation all over the internet and a animatedknots.com.
The "Barrel Knot" is also called the "Blood Knot" which is where I think someone got confused, thinking "blood knot" and "bloop loop" were the same thing.
The other issue is, the Fishing MB book shows and describes the "barrel knot" yet they still call it a loop, which it doesn't have.
It seems like the MB requirement intended to have the "blood loop" since all other knots listed in Requirement 4 are loops. The blood loop is similar to the blood knot (which is also called the barrel knot) and somewhere down the line, the "typo" was made.
(Personally, I'd think joining two fishing lines might be a good fishing skill to have, but is beyond the basics of a Merit Badge course.)