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 172

Today Future (within domain) Future (across domains)

Highly efficient transfer of metabolic
energy through a few, highly adapted
specialists (e.g. Calanus, Arctic cod
( Boreogadus saida )) (Domain 4)

Decrease in size of primary
producers, resulting in less
efficient energy transfer to
upper trophic levels

Less food available for upper
trophic levels (Domain 3),
shifts in distribution of
species and the use thereof
(Domain 2)

Our domain choices are, we admit, not exclusive, and other groupings may be equally val-
id; nonetheless, our four domains suffice to demonstrate how the concept of panarchy can
be applied in the case of the rapidly changing Arctic marine environment and how pan-
archy is useful for assessing ecosystem structure and reaction to impacts. From this set we
select one focal scale at a time for more detailed discussion. In discussing domains below,
it is important to remember that Arctic marine ecosystems are strongly affected by advect-
ive processes and reflect combined pelagic and sea ice (moving) and benthic (stationary)
elements and processes (cf. Carmack and Wassmann, 2006 ; Grebmeier et al ., 2006 ; Nelson
et al ., 2009 ) . We also take it as given that human activity influences all scales: we live in
the Anthropocene (Crutzen and Stoermer, 2000 ; Zalasiewicz et al ., 2010 ; Zalasiewicz et
al ., 2011 ) .
The largest spatio-temporal scale is that of the Arctic Ocean itself, set within the glob-
al climate system (Domain 1 in Figure 5.3 , Table 5.1 ) . Here the extent of summer sea ice
and the thickness of year-round ice have been decreasing across the Arctic Ocean for dec-
ades, a trend that, assuming today's physical forcing persists, will, within decades, result in
a mostly ice-free summer season. Within this pan-Arctic and decadal scale domain, slow-
variable changes in forcing (e.g. global warming, Arctic amplification, and increasing tem-
peratures in inflowing waters from the sub-Arctic Atlantic and Pacific oceans (Carmack
and Melling, 2011 ) ) are reducing the extent, thickness, and internal strength of sea ice,
shifting the central Arctic from a perennial ice zone (with multi-year ice) to a widening
seasonal ice zone (Kinnard et al ., 2008 ). With the resulting decrease in internal ice strength
and compactness, floes are able to drift more rapidly under wind forcing, with attendant ef-
fects on ocean surface currents (cf. Kwok et al ., 2009 ) and the transport and distribution of