Just found a very interesting RECENT work (Dec. 2005) from Chingis Nigmatullin that says that bottom and near-bottom species periodically are scavengers also.
Furthermore, this author informs us that died organisms, ship´s discards and offal can be a source of food to some bottom octopods (e.g. Enteroctopus dofleini) and to a less degree sepiids and near bottom squids (e.g. Berryteuthis magister). They could be died fish, shrimps, crabs and cephalopods.
Sorry for being a grey literature (but it is in English) but here it goes:
Nigmatullin, Ch. M. (2005). Towards the correct methology of cephalopod feeding study: review of some neglected problems. Libro de resumenes III Simposio Internacional sobre clalamares del Pacifico y II Taller Internacional sobre calamares (28 Noviembre-2 Diciembre, Lima, Peru). Resumen No 34- IMARPE, Callao, Peru