GRANT
NUMBER:
NA76FD0102
NMFS NUMBER:
96-NER-106
REPORT
TITLE:
Bleach-Dipped Lobster Detection Technique
AUTHOR:
Dr. Francis X. Smith
PUBLISH
DATE:
January 25, 1999
AVAILABLE
FROM:
National Marine Fisheries Service, Northeast Region, One
Blackburn Drive, Gloucester, Massachusetts 01930-2298.
TELEPHONE: (978) 281-9117
ABSTRACT

Bleach dipping
is a widely used technique for illegal removal of eggs
from female lobsters. A simple, non-invasive technique
was developed for detecting the presence of small amounts
of bleach on lobsters. Cotton swabs dipped in a starch/iodide
solution turned blue when rubbed on the tails of bleach-dipped
lobsters. Swabs rubbed on non-bleached control lobster
tails did not change color. The illegal removal of eggs
from female lobster is a significant problem in the lobster
industry. One of the most common techniques for egg removal
is to dip the tail of the lobster in a chlorine bleach
solution. Since there are no obvious external signs of
the bleach treatment, these scrubbed lobsters can then
be sold. Previous methods for detecting bleach treatment
involved removing the pleopods or swimmerettes for 200x
microscopic evaluation or potassium iodide solution color
detection, compromising the health of the lobster. The
method described in this paper can be done without harming
or damaging the lobster, and is quick, simple and precise.