Table 3. Stressors or inter-tier interactions affecting Tier 3 Essential Ecosystem Characteristics (EEC) identified in the application of the conceptual model to case studies in the Canadian River (1), Colorado River (2), Columbia River (3), and Upper Mississippi and Illinois rivers (4).

	Tier 3 EEC
Stressor or inter-tier interaction	Adult fish recruitment	Juvenile fish recruitment	Larval fish production	Fish egg quality/ production	Invertebrate production	Primary production	Biodiversity
Direct mortality			1
Predation/competition by invasive species			1, 2, 3	3			4
Habitat quantity/quality	4	4	1, 2, 3	1, 2, 3, 4	1, 2, 3
Nutrient flux						1, 2, 3
Trophic level interspecific interactions	1, 2, 3, 4	1, 2, 3, 4	1, 2, 3, 4	1, 2, 3, 4	1, 2, 3, 4	1, 2, 3, 4	4
Predation			3	3
Mortality	1, 3, 4	1, 2, 3, 4	1, 2, 3
Fish condition				1, 3, 4

Tier 3 EECs represent components of the hypothesized biological system upon which the cascading effects of anthropogenic and natural drivers act, and interactions occur.