Around 1900, fishermen in the Chesapeake Bay area landed mor

[AsadA969]

Around 1900, fishermen in the Chesapeake Bay area landed more than seventeen million pounds of shad in a single year, but by 1920, over-fishing and the proliferation of milldams and culverts that blocked shad from migrating up their spawning streams had reduced landings to less than four million pounds.

Q:
Which one blocked shad migrations up their spawning streams? Is it ''over-fishing and the proliferation of milldams and culverts'' or ''milldams and culverts'' or ''the proliferation'' only? Thanks

[Whit Garner]

Around 1900, fishermen in the Chesapeake Bay area landed more than seventeen million pounds of shad in a single year, but by 1920, over-fishing and the proliferation of milldams and culverts that blocked shad from migrating up their spawning streams had reduced landings to less than four million pounds.

Q:
Which one blocked shad migrations up their spawning streams? Is it ''over-fishing and the proliferation of milldams and culverts'' or ''milldams and culverts'' or ''the proliferation'' only? Thanks

The use of "that" means that the modifier is touching the noun it is modifying. In this context, it is likely modifying the pair "milldams and culverts" not just culverts.

[AsadA969]

Around 1900, fishermen in the Chesapeake Bay area landed more than seventeen million pounds of shad in a single year, but by 1920, over-fishing and the proliferation of milldams and culverts that blocked shad from migrating up their spawning streams had reduced landings to less than four million pounds.

Q:
Which one blocked shad migrations up their spawning streams? Is it ''over-fishing and the proliferation of milldams and culverts'' or ''milldams and culverts'' or ''the proliferation'' only? Thanks

The use of "that" means that the modifier is touching the noun it is modifying. In this context, it is likely modifying the pair "milldams and culverts" not just culverts.

So you are saying that 'that' did not modify 'over-fishing and the proliferation' anyways, right? Thanks. I got it. It helps.

[Whit Garner]

Glad to help!