:The second paragraph of that paper's introduction says: 
 Preliminary in situ observations on maerl grounds at several sites in Scotland revealed that large burrows of similar external appearance were common and important features of the habitat. Use of a range of remote sampling gear on maerl beds in the Clyde Sea area failed to capture the organism responsible but subsequent use of a diver-operated air-list, following methods developed on Irish maerl ground (Keegan & Könnecker, 1973), revealed that these burrows were occupied by the thalassinidean shrimp Upogebia deltaura (Leach). 
 :That seems to confirm that it commonly occurs in Scottish maerl beds. If that's not enough (or even if you're just interested), send me an email, and I'll gladly send you the whole paper as a PDF.