A new perspective on changing Arctic marine ecosystems: panarchy adaptive cycles in pan-Arctic spatial and temporal scales - Ocean Sustainability in the 21st Century - page 178

fishery (Wassmann et al ., 2006 ). No future projection is able to pick up changes in such
small quantities, nor to determine the spatial distribution and aggregation of prey stocks,
which can be more important for predators (including fishermen) than overall biomass.
Reorganizations through each spatio-temporal scale are likely to occur on different,
though overlapping, time-lines. Microbial change (Domain 4) will be far more rapid than
the response of long-lived marine benthic invertebrates, mammals, and seabirds (Domains
2 and 3), and thus species at the smallest scales may go through several adaptive and evol-
utionary iterations before reaching a new steady state. The simplest response is likely to be
adaptation ofanecosystem byspecies already present intheArctic Ocean, assomeareable
to thrive during warmer summers. A farther-reaching response is likely to be the advection
and migration by sub-Arctic species that manage to survive Arctic winters (Bluhm et al .,
2011 ) . Some may just survive while some may colonize after taking advantage of favour-
able growing conditions in the warmer summers. Such a response is generically occurring
along the inflows from sub-Arctic seas, such as the Chukchi and Barents Seas and west-
ern and northern Spitsbergen (Carmack et al ., 2006 ; Ji et al ., 2012 ). Some organisms have
penetrated already along the shelves of the Arctic Ocean and later in this century they will
reachmoreremote interior shelves andbasins.Thisresponsewillbemediated alsobycom-
petition between Arctic and sub-Arctic species, the outcome of which may vary over time
as summers become longer and warmer. As a result, initial trends in biological response
may not indicate the ultimate direction in which physical change drives the system .
Although it is tempting to suppose that the reorganization of the Arctic marine eco-
system will simply be a northward shift in current species distributions and biological pat-
terns, a panarchy perspective strongly suggests otherwise. Although some barriers to ex-
pansion - such as the Bering Sea 'cold pool' (Mueter and Litzow, 2008 ; Stabeno et al .,
2012 ) - may weaken or disappear under future ice deposition, cold temperatures and low
light conditions during winter will remain (Stabeno et al ., 2012 ; Kaartvedt, 2008 ). Spe-
cies that thrive on the continental shelf would be pushed northwards into deep water, but
are constrained by the cost of losing their preferred habitat. Species that move northwards
in summer may still be unable to survive the lethal temperatures during the Arctic winter