What would Buck eat for his daily rations?

In this book, Buck and the other sled dogs seem to subsist
solely on fish.  This was a kind of food that would have been easy to get up in that
area during this time and it would have been relatively light.  It would have been light
because, as we are told in Chapter 2, what they were eating was sun-dried
salmon.

In Chapter 2, at least, when Buck is working for
Francois and Perrault, his ration for each day is a pound and a half of the sun-dried
salmon.  There will be times in the book where he gets more or less than that, but he
always seems to be eating fish.