Mackerel Behind Bars

By guest blogger Merrill Singer, PhD

University of
In 2004, the government banned access to cigarettes among
inmates at federal prisons (although some tobacco is still smuggled in).  This change was not driven by health
issues alone.  Prior to the ban, in
addition to smoking them, inmates used cigarettes as currency to acquire goods
and services from other prisoners, including contraband items like drugs
(possession of cash having already been banned). 

In response, in some prisons around the country, inmates
turned to plastic-and-foil pouches of mackerel fillets (cans also are banned
because they can be made into weapons) as the new currency. Called “macks,”
they became the new coin of the realm. For example, a haircut from a fellow
prisoner cost two macks (the equivalent of two dollars); laundry services also
can be purchased with macks.  Why
mackerel packages? Few prisoners – even new ones who traditionally have been
known by the slang word “fish” – want to eat mackerel, claiming it is too oily
(and perhaps unaware that mackerel is an excellent source of omega-3 fatty
acids and other nutrients that have been linked to multiple health benefits).  Additionally, the packages are small, can
be easily transported inside a prisoner’s clothes, and have a standard
size.  In short, like printed money
they can readily serve as a medium of exchange and value inside the semi-closed
society of a prison.
The result has been a significant increase in the sale of packaged
mackerel to U.S. prisons.  To try
and control the underground economy, in some prisons an inmate caught by guards
with a lot of mackerel packets may be disciplined. 
One of the ironies here is that the word “mackerel” was used
in the past, particularly in England, to refer to prostitutes, madams, and
pimps (and suggesting someone who is smooth or slick), occupations that could
land you in prison.  Once behind
bars, use of drugs – available in the underground economy if you have enough
macks to spend – enables inmates to get “macked up or
macked out,” which the Urban Dictionary defines as seriously under the

Note from NAMA: if you are interested in more of a backstory on mackerel used in prisons, check out this Wall Street Journal story from 2008: