Mudlarking is the term used to describe “collecting” by scavenging from rivers, usually at low tide. I’ve done a very small amount of it, even on “The Thames”, mostly around “New Tate”.
Maiklem’s book is an account of the why, how and what of her experiences which she very cleverly and astutely inter-leaves with her own history and that of mudlarking itself, “The Thames” and England. I’m a lot interested in the subject, mudlarking, but found her account of the “history” just as interesting. I did know about the migration of eels from and to the Sargasso Sea, I had no idea “the Thames” was once a tributary to “the Rhine”.
I didn’t much enjoy her “imaginings”: the way in which the found object may have gotten “there” because, I think, the fact of the object is much more interesting than the conjecture*.
The joy of exploring is that it opens more places that are new and challenges one’s understandings of the old and Maiklem passes on a number of references many of which I’ve already followed up by putting holds on books through the “one card system” or, where necessary, ordering books (I mostly use Book Depository, I’ve found them prompt and very reliable in the past. Some others? Not so much). Once  started, never ending?
*Late in the book Maiklem introduces her partner, Sarah, as her wife. I got a bit distracted by the idea that in heterosexual relationships it’s now more acceptable to refer to one’s partner as one’s partner, where-as, in homosexual relationships, it’s de riguer to refer to one’s partner as wife or husband, depending etc. “Vive la…”? Or “not”. Again “as the case…”etc.
https://en.wikipedia.org/wiki/Mudlark
https://en.wikipedia.org/wiki/Ivor_No%C3%ABl_Hume
“London in fragments : a mudlark’s treasures.” / Ted Sandling
“All the Best Rubbish : The Classic Ode to Collecting.”/ Ivor Noel Hume