An evaluation of the Emerald/Western Bank juvenile haddock closed area

Abstract

A juvenile haddock (Melanogrammus aeglefinus) closed area was established on the offshore banks (Emerald and Western) of the central Scotian Shelf (NAFO Div. 4W) in 1987. The management objective associated with this meausre was to protect incoming recruits and thereby allow the stock to rebuild. Our evaluation of the effectiveness of the closed area revealed that the management objective was not fully met. The expected trend of declining juvenile mortality after, and high mortality preceding its imposition, was not readily apparent. The lack of response may have been due to several factors: (i) the proportion of juveniles within the closed area steadily declined and a majority of year classes during the post-closure period remained unprotected; (ii) the closed area remained open to fishing by fixed gear whose catches inside the closed area and surrounding areas steadily increased; and (iii) the resident haddock stock deteriorated in terms of growth and condition due to a combination of historical over-exploitation and large-scale environmental changes. The closed area does appear to have had some benefit to other groundfish species in terms of increased abundance, notably American plaice (Hippoglossoides americanus) and winter flounder (Pseudopleuronectes americanus).