cultch
noun
ˈkəlch 
variants or less commonly culch
1
: material (such as oyster shells) laid down on oyster grounds to furnish points of attachment for the spat
2
chiefly New England : clutter, trash
Example Sentences
Recent Examples on the Web In the hatchery's case, this is recycled oyster shell, either whole or ground up into a sand-like texture called cultch. 
Julia Rentsch, baltimoresun.com, 18 Aug. 2019
Julia Rentsch, baltimoresun.com, 18 Aug. 2019 Word History
Etymology
perhaps from a French dialect form of French couche couch
First Known Use
1667, in the meaning defined at sense 1