Fourteen years (2006–2019) of capelin diet were examined from the Barents Sea where capelin is a key species both as a prey and predator. The PINRO/IMR mesozooplankton distribution usually shows low plankton biomass in the central Barents Sea, most likely due to predation pressure from capelin and other pelagic fish.
Interactions, drivers and pressures 2020
Feeding, growth, and maturation of cod
Cod is the major predator on capelin; although other fish species, seabirds and marine mammals are also important predators. The cod stock abundance in the Barents Sea peaked around 2013 and have declined since, although it is still above the long-term average. The cod spawning stock and thus the abundance of old, large fish is still high.
Causes of polar cod stock fluctuations
The Barents Sea polar cod stock was above 800 kt in the period 1998-2011 (except from the year 2003 when the stock was probably grossly underestimated) but dropped to below half of that in 2012-15 (Figure 4.4.1). In 2016, the strong 2015-year class brought the stock up to nearly 1 million tonnes but dropped to low levels in 2017-2019.
Spatial overlap between cetaceans (Cetacea) and potential preys
Comparative analyses of cetacean main species and fish distribution in the Barents Sea were conducted based on data from the joint Russian-Norwegian ecosystem surveys (BESS) during August-October 2005-2014.
Causes of capelin stock fluctuations
The Barents Sea capelin has undergone dramatic changes in stock size over the last four decades. Three major stock collapses (when abundance was low for several years and fishing moratoriums imposed) occurred during 1985–1989, 1993–1997, and 2003–2006. During the recent period 2014-2020 the stock estimates have fluctuated considerably.
Cod-capelin-polar cod interaction
The summer overlap between cod and capelin increased from 2008 to 2016, mainly due to an increasing cod stock and increased size of suitable habitat for cod. In later years the cod stock has declined and is now distributed farther south in summer. The effect of this change on overlap with capelin is unclear.