E1-6
Factor 2: Environmental Changes (E)
The following key questions related to factors causing or contributing to the decline
of Steller sea lions are structured as follows: [Specific
type of effect] [Reason for the decline]
[Mechanism].
E1: Have environmental changes reduced
ecosystem-wide production (primary and
secondary) and prey abundance or availability resulting
in decreased survival or births of sea
lions through nutritional stress?
E2: Have environmental
changes reduced local production (primary and
secondary) and prey abundance or availability resulting
in decreased survival or births of sea
lions through nutritional stress? (This
question also addresses changes in the timing of
local production during the year and effects on
sea lion prey availability.)
E3: Have environmental
changes altered the distribution of prey
patches, reducing their availability
resulting in decreased survival or births
of sea lions through nutritional stress?
E4: Have environmental
changes altered the composition of the fish
community, reducing the abundance, availability,
or quality of prey resulting in decreased
survival or births of sea lions through nutritional
stress?
E5: Have environmental
changes altered the composition of biological
communities causing increased predation (i.e.,
trophic cascade) on sea lions resulting in decreased
survival through direct mortality?
E6: Have environmental
changes altered the composition of biological
communities causing increased competition for
prey with sea lions resulting in decreased
survival or births through nutritional
stress?
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