Pan-Arctic suitable habitat model for Greenland halibut

Journal of Northwest Atlantic Fishery Science, 2003

The variation in population structure of Greenland halibut (Reinhardtius hippoglossoides Walbaum) in the Northeast Arctic is analysed using data from three different surveys using trawl, longline and gillnet gears, in the slope area of the western Barents Sea in the period 19922000. The design of the longline and gillnet survey had limitations in that they were set to simulate the commercial fisheries, but the vessels were forced to cover the most important part of the slope area. Greenland halibut was the dominant species both in numbers and weight and was usually caught in the range of 515 years old, but the catch was dominated by ages 612. The data showed differences in sex composition and age composition both by area and by depth, and catches from trawl showed the most evident pattern. Greenland halibut caught by gillnet were larger and older than fish caught by trawl and the results from longline were in between. In most of the age groups, males were significantly smaller than females and this general trend was shown for all gears. Males also dominated the younger age groups in all gears and Greenland halibut older than 10 years were virtually all females. Fish from the earliest cohorts in the years investigated were generally smaller than fish from later ones.

ICES Journal of Marine Science, 2012

Morgan, M. J., Garabana, D., Rideout, R. M., Román, E., Pérez-Rodriguez, A. and Saborido-Rey, F. 2013. Changes in distribution of Greenland halibut in a varying environment. – ICES Journal of Marine Science, 70: 352–361. Fish are expected to respond to changing oceanographic temperature by altering their distribution. Off the coast of Newfoundland, Canada, there have been major changes in oceanographic temperature over the last several decades, with both record cold and record warm years being observed. Greenland halibut is an important flatfish species in the area, and is distributed in deep waters over a very wide geographic range. Thus, it might be buffered from temperature change in the overall area by reduced temperature variation at depth, and the diverse temperature conditions over its wide range. We examined intrapopulation variation in temperature and depth distribution, and the biological changes in relation to changes in available temperature. On the Flemish Cap, variatio...

ICES Journal of Marine Science, 2014

Since the late 1980s, a deep-sea fishery for Greenland halibut (Reinhardtius hippoglossoides) has been developing gradually in West Greenland. Deep-sea fish species are generally long-lived and characterized by late age of maturity, low fecundity, and slow growth, features that probably cause low resilience following overexploitation. In order to evaluate whether populations of nine potential bycatch species are negatively affected by the commercial fishery for Greenland halibut, scientific data from bottom-trawl surveys conducted in the same area and period as the commercial fishery were analysed. During the period 1988 -2011, population abundance and size composition changed as catch and effort in the Greenland halibut fishery increased. Two species showed a significant decrease in abundance, and four populations showed a significant reduction in mean weight of individuals (p , 0.05). Correlation analyses show that most of the observed trends in abundance are probably not related to increasing fishing effort for Greenland halibut. The analysis did, however, show that most of the observed decreases in mean weight were significantly correlated with fishing effort during the 24-year period.

ICES Journal of Marine Science

Marine fisheries are often allocated to stocks that reflect pragmatic considerations and may not represent the species’ spatial population structure, increasing the risk of mismanagement and unsustainable harvesting. Here we compile mark–recapture data collected across the North Atlantic to gain insight into the spatial population structure of Greenland halibut (Reinhardtius hippoglossoides), an issue that has been unresolved for decades. The dataset contains 168130 fish tagged from 1952 to 2021, with 5466 (3.3%) recaptured individuals. Our results indicate that fish tagged at <50 cm body length migrate at higher rates, suggesting that mark–recapture studies on adult individuals underestimate population-level migration rates. We find evidence for migrations across management units in the North Atlantic indicating two regional offshore populations: one in the Northeast Atlantic, where the West Nordic and Northeast Arctic stocks, currently managed separately, likely belong to a sin...

ICES Journal of Marine Science, 2001

Distribution and abundance of juvenile Northeast Arctic Greenland halibut (Reinhardtius hippoglossoides) in relation to survey coverage and the physical environment.

ICES Journal of Marine Science, 2002

This paper describes spatial, temporal and biotic patterns in the diet of Greenland halibut (Reinhardtius hippoglossoides, Walbaum) sampled from three different areas of the Barents Sea, namely the Hopen Deep (nursery area), the Bear Island Channel and the continental slope (spawning ground), during April 1996 to January 1998. Percentage of empty stomachs was based on 3294 specimens, and the relative importance of prey groups was assessed using stomach contents from 486 specimens. Multivariate analyses (i.e. Correspondence Analysis and Canonical Correspondence Analysis) were applied to examine which variables could best account for dietary variation. Spatial (horizontal and vertical) and temporal components appeared to be most influential on the variation in diet composition, whereas biotic variables (i.e. predator size, sex and maturity stage) appeared to be of less importance. It is proposed that regional and seasonal differences in diet composition are caused by spatial and temporal variations in abundance and distribution of some of the major prey species, i.e. Atlantic herring (Clupea harengus) and capelin (Mallotus villosus). On the slope there were also clear ontogenetic changes in diet; in smaller Greenland halibut (<50 cm) crustaceans and the cephalopod Gonatus fabricii were the prevailing prey, whereas for larger specimens teleosts and fish offal were the dominating components of the diet. Smaller Greenland halibut appeared to have been foraging at greater depths (>700 m) than the larger ones.

2009

Greenland halibut (Reinhardtius hippoglossoides) have decreased in the eastern Bering Sea and Aleutian Islands since the 1970s. The reasons behind the poor recruitment are unknown, and important knowledge gaps of the ecology of the early life stages have been identified. The objectives of thesis research were (1) to

A trial longline fishery with the Norwegian vessel M/S &quot;Skarheim&quot; was conducted in the northern Davis Strait in August 1993. The purpose of the fishery was to collect biological information on the commer-cial fish species, in particular Greenland halibut (Reinhardtius hippoglossoides) in order to evaluate the potential for a commercial longline fishery. The highest Greenland halibut catch rates of 153-260 kg per 1000 hooks were obtained at depths between 800-1200 m at three fishing localities, 2-4 in NAFO Subarea lA and in water with temperatures above about 0.5 &#39;C. Greenland halibut was caught in all investigated depth strata. The depth distribution of the catch rates in Subarea IA indicates that depths between 800-1000m may be best suited for a commercial fishery on Greenland halibut. Below 1000m, large numbers of Arctic skates were taken in some of the settings. The size distributions of Greenland halibut in the catches were in the size range of 35-100 cm total leng...

Journal of Sea Research, 2013

Spawning and nursery grounds are poorly described for the West Nordic stock of Greenland halibut (Reinhardtius hippoglossoides) and the entire stock is assumed to originate from a common spawning ground southwest of Iceland. Greenland halibut with hydrated eggs in their ovary were caught during a gillnet survey in 1995 in Greenland waters. This suggests that the spawning areas for the West Nordic stock are not limited to the previously described area southwest of Iceland. Further this paper provides information on distribution of immature Greenland halibut in the fjords of East Greenland. The densities in Tasilaq area suggest that this area may be part of a nursery area in the West-Nordic management unit. However, the importance of this area to the stock is currently unknown. The results have potential implications for the management of the West Nordic Greenland halibut as the management seems to comprise of several stocks, or perhaps a meta-population.

Frontiers in Marine Science, 2019