From a cursory search, I think the largest cluster of eels corresponds to the Fens, a now mostly-drained marshland [0]. And the "Bishop of Ely" who's overrepres

From a cursory search, I think the largest cluster of eels corresponds to the Fens, a now mostly-drained marshland [0]. And the "Bishop of Ely" who's overrepresented in that eel cluster, apparently that seat of power is named for the eels [1,2]. [0] https://en.wikipedia.org/wiki/The_Fens https://en.wikipedia.org/wiki/The_Fens [1] http://news.bbc.co.uk/cbbcnews/hi/newsid_6600000/newsid_6605400/6605443.stm http://news.bbc.co.uk/cbbcnews/hi/newsid_6600000/newsid_6605... - "Once a year, people from all over the country come to Ely, Cambridgeshire, to celebrate the city's namesake - the eel - at Ely's Eel Day." [2] https://epns.nottingham.ac.uk/browse/id/5328736fb47fc40c4f0007a6 https://epns.nottingham.ac.uk/browse/id/5328736fb47fc40c4f00... ("Survey of English Place-Names") - "OE ǣl -gē , ēl -gē , 'eel-district,' as already suggested by Skeat and Ekwall... Rents of eels were a fruitful source of income for the abbots and bishops of Ely."