National Marine 
Fisheries Service 
NOAA 
Fishery Bulletin 
fir established in 1881 
Spencer F. Baird 
First U S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Strong relationship between commercial catch of 
adult Atlantic halibut (Hippoglossus hippoglossus ) 
and availability of suitable habitat for juveniles in 
the Northwest Atlantic Ocean 
Email address for contact author: Nancy.Shackell@dfo-mpo.gc.ca 
Abstract-— Atlantic halibut (Hippo¬ 
glossus hippoglossus) is an increas¬ 
ingly valued commercial fish and 
its recent population growth has 
attracted the attention of fisheries 
scientists and managers both within 
and outside Canada. With renewed 
transnational interests in this spe¬ 
cies, fishery managers have relied 
on existing, but limited, ecological 
information for multilateral discus¬ 
sions on shared allocations of catch. 
To address this dearth of informa¬ 
tion, we modeled species distribu¬ 
tion using maximum entropy, where 
by survey catch data were related to 
environmental data to quantify habi¬ 
tat suitability. We then calculated 
the amount of suitable habitat for 
juvenile Atlantic halibut per North¬ 
west Atlantic Fisheries Organization 
(NAFO) divisions, within and out¬ 
side Canada’s Exclusive Economic 
Zone. Among NAFO divisions, we 
found a strong relationship between 
the availability of suitable habitat 
for juvenile Atlantic halibut, and 
both current and historical fisher¬ 
ies landings. Results are consistent 
with the nursery-size hypothesis 
which states that the amount of 
available juvenile habitat is related 
to the level of adult production. The 
majority of occupied suitable habitat 
is found on the southwestern half of 
Canada’s Scotian Shelf, whereas the 
U.S. and international waters off 
Newfoundland have ample suitable 
habitat to support larger popula¬ 
tions. Quantifying habitat suitability 
and linking this suitability to stock 
abundance and distribution is an 
important step toward an ecosystem 
approach for the management of At¬ 
lantic halibut. 
Manuscript submitted 11 May 2017. 
Manuscript accepted 24 November 2017. 
Fish. Bull. 116:111-125 (2018). 
Online publication date: 26 January 2018. 
doi: 10.7755/FB. 116.2.1 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
Kiyomi J. French 
Nancy L. Shacked (contact author) 
Cornelia E. den Heyer 
Bedford Institute of Oceanography 
Department of Fisheries and Oceans Canada 
P.O. Box 8 1006 
Dartmouth, Nova Scotia B2Y 4A2, Canada 
In the Northwest Atlantic Ocean, 
Atlantic halibut (Hippoglossus hip¬ 
poglossus) range from Greenland to 
Virginia, United States (Bigelow and 
Schroeder, 1953; Collette and Klein- 
MacPhee, 2002). In Canada, it is 
currently managed as 2 stocks. The 
larger stock, which is the subject of 
this article, extends from the South¬ 
ern Grand Banks of Newfoundland, 
across the Scotian Shelf, and into the 
Gulf of Maine (Fig. 1). The stock rang¬ 
es over multiple North Atlantic Fish¬ 
eries Organization (NAFO) divisions 
and, importantly, spills over interna¬ 
tional boundaries into the territorial 
waters of the United States, Over¬ 
seas France, and the international 
High Seas regulatory area. Despite a 
history of overfishing (Grasso, 2008), 
Canadian assessments show that the 
stock has rebounded in the last de¬ 
cade, is benefiting from a period of 
high recruitment (DF0 12 ;Trzcinski 
1 DFO (Department of Fisheries and Oceans 
Canada). 2015. 2014 assessment of 
Atlantic halibut on the Scotian Shelf 
and southern Grad Banks (NAFO Divi¬ 
sions 3NOPs4VWX5Zc). Can. Sci. Ad- 
vis. Seer. Sci. Advis. Rep. 2015/012, 16 
p. [Available from website.] 
2 DFO (Department of Fisheries and 
Oceans Canada). 2015. Stock Assess- 
and Bowen, 2016), and was the third 
most valuable groundfish in Canada 
in 2015 (Economic Analysis and Sta¬ 
tistics, Department of Fisheries and 
Oceans Canada, landings data, avail¬ 
able from website). The Canadian 
fishery is now certified “sustainable” 
by the Marine Stewardship Council 
(Marine Stewardship Council, Track 
a Fishery, website). In contrast, un¬ 
der the U.S. Endangered Species Act, 
Atlantic halibut is listed as a “Spe¬ 
cies of Concern” from Labrador, Can¬ 
ada, to southern New England (USA) 
(NOAA * * 3 ), and the 2015 results of the 
U.S. halibut assessment model were 
rejected owing to limited information 
(an action that has enforced the view 
that the stock is still in an overfis hed 
state) (Henne n 4 ). 
ment of Atlantic Halibut of the Gulf of 
St. Lawrence (NAFO Divisions 4RST) for 
2013 and 2014. Can. Sci. Advis. Seer. 
Sci. Advis. Rep. 2015/023, 15 p. [Avail¬ 
able from website.] 
3 NOAA. 2013. Species of concern: Atlan¬ 
tic halibut, 2 p. [Available from web¬ 
site.] 
4 Hennen, D. 2015. Atlantic halibut. 
In Operational assessment of 20 North¬ 
east groundfish stocks, updated through 
2014. U.S. Dep. Commer., Northeast. 
Fish. Sci. Cent. Ref. Doc. 15-14, p. 171- 
179. [Available at website.] 
