Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4550112 | Journal of Sea Research | 2010 | 10 Pages |
Abstract
The Northwest Atlantic marine community underwent dramatic changes during the last 30Â years, including the collapse of many groundfish stocks and an increase in shrimp populations. Greenland halibut Reinhardtius hippoglossoides is an important commercial species and one of the top fish predators in this system. It is a large, wide-ranging flatfish that is found at depths up to 2200Â m and it has an opportunistic diet which makes it a potential candidate for an ecosystem indicator. Analysis of stomach contents of Greenland halibut between 1978 and 2003 indicates that diet composition reflects the major changes in community structure. Over the entire period there was a clear increase in the importance of invertebrates, particularly after 1992. This change was associated with a higher importance of Pandalus shrimp and Gonatus squid and a protracted reliance on zooplankton by predators under 25Â cm length. Capelin Mallotus villosus was the dominant prey between 1978 and 1992 for predators in the 12-63Â cm range, but its importance dropped off drastically in the mid 1990s. Levels of main prey in the diet of Greenland halibut correlated well with fishery-independent surveys. Greenland halibut sample capelin well, compared to bottom trawl surveys and acoustic surveys. Greenland halibut consumed small shrimp which are not routinely caught by surveys and may be important in deriving information on year classes and growth of shrimp. Our results suggest that Greenland halibut's diet is a useful tracker of ecosystem change.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Oceanography
Authors
K.S. Dwyer, A. Buren, M. Koen-Alonso,