1. Macroinfaunal Distribution

2. Relationships Among Burrowing Organisms in Mud Flats

3. The Lugworm Abarenicola in Bight at the NE Corner of Kalgin Island

4. High-Energy Site - South Shoal

5. Turbidity and Deposition

6. Geomorphic Complexity Moose Point

7. Geomorphic Complexity Moose Point

8. Geomorphic Complexity Moose Point

9. Geomorphic Complexity Moose Point

10. Geomorphic Complexity Moose Point

11. Crustal Deformations from the Great Alaskan Earthquake of 1964

12. Eroding Intertidal Platform Chickaloon Bay

13. Sea Level Change Tidal Currents Wave Action Turbidity Fluvial Deposition Erosion Ice Gouging Sediment Texture Quiescent Deposition Organic Concentrations Larval Survival Sediment Stability Migratory Predators Recruitment Success Bioturbation Sedentary Predation Success of Adult Macro- Infaunal Populations Primary Factors Secondary Factors Tertiary Factors Primary Biological Effects Secondary Biological Effects Ultimate Consequence

14. Tectonic Changes in Sea Level Tidal Currents Wave Action Turbidity Fluvial Deposition Erosion Ice Gouging Sediment Texture Quiescent Deposition Organic Abundance Larval Survival Sediment Stability Migratory Predators Recruitment Success Bioturbation Resident Predation Success of Adult Macro- Infaunal Populations Primary Factors Secondary Factors Tertiary Factors Primary Biological Effects Secondary Biological Effects Ultimate Consequence

15. Factors Influencing Distribution & Abundance of Long-lived Infaunal Organisms Two primary factors affecting the distribution of intertidal infauna in Cook Inlet appear to be: – Extreme tidal currents caused by the large tidal flux and shape of the basin –Massive loads of silt being dumped from the northern river systems

16. Secondary Factors for Infaunal Organisms Erosion Sediment texture Larval survival Food availability (organic abundance) Predation by adult infauna and migratory predators

17. Site Evaluation

18. Conclusions for Sediment and Habitat Conditions Range and stability of hydrodynamic conditions in middle and upper Cook Inlet is highly variable Wide range of habitats strongly reflects the hydrodynamic and suspended particulate regimes in the inlet

19. CONCLUSIONS Upper inlet is oligotrophic Intertidal sediments generally nutrient- poor Concentrations of TOC and TKN, ranging from moderate to very low, are inversely correlated with particle grain size and with hydrodynamic energy levels Eroding peat may be an important source of nutrition in middle and upper Cook Inlet

20. C:N ratios are inversely correlated with particle grain size and hydrodynamic energy levels Based on Carbon:Nitrogen ratios, it is likely that, in locations such as shoals, the major sources of nutrients for infauna may be bacteria living on sediment or detrital particles (or phytoplankton) Conclusions for Sediment and Habitat Conditions

21. If it weren’t for the currents, Cook Inlet would become a gigantic mud flat inhabited with large populations of Macoma balthica If it weren’t for the mud, Cook Inlet would become current-swept sand and gravel beaches populated with razor or surf clams Instead, it’s both…. Conclusion

22. CONCLUSIONS By any measure, it is clear that the sediments contain only very low concentrations of hydrocarbons Bivalve populations sampled in upper Cook Inlet have not been exposed to detectable concentrations of petroleum hydrocarbon contaminants

23. CONCLUSIONS Tissue and surrounding sediment samples consistently produced completely different PAH and AHC profiles Mainly naphthalenes represented in tissues The limited suite of hydrocarbon analytes in tissue samples indicates that the organisms in upper Cook Inlet accumulate only a subset of all hydrocarbons found in sediments

24. Major Factors Likely to Influence Distribution & Abundance of Long-lived Infaunal Organisms Intensity of currents and wave action Turbidity Suspended and deposited nutrition (bacteria, detrital matter, phytoplankton) Sediment texture and stability Larval settlement and recruitment success Mobile and resident predators