Appendix Two Overall Natural Character of the Marlborough Sounds - Marine Collective Characteristics The Marlborough Sounds marine environment largely retains its natural character. Bordered by Tasman Bay to the west and Cook Strait to the north-east, exposed to open ocean conditions along its south-eastern flank, yet mostly sheltered by their convoluted form, the Marlborough Sounds are uniquely structured and situated. A number of broad and sometimes interacting environmental gradients traverse the length and breadth of the Marlborough Sounds, notably: wave exposure, tidal influence (currents, tidal height, water exchange), turbidity, sedimentation, temperature, salinity, nutrient availability, and substrate composition. The interplay of these various characteristics creates a unique marine environment notable for its broad scale variability. The marine and terrestrial environments combine visually to form a region of distinctive natural character. Notable features include: an intricate coastline; numerous islands and off-shore rocks and stacks; wild and remote localities; exposed and sheltered waters in close proximity; and strong tidal flows. A. The Physical Environment 1. Form/Geology Cobble/boulder and bedrock shores dominate the inter-tidal and shallow sub- tidal zones of the Marlborough Sounds. Sediments with a mixture of sand, broken shell and silt can occur below the reef zone in shallow wave-worked areas or areas with moderate-high currents. An extensive and comparatively uniform mud/silt bottom typically extends beyond, dominating the off-shore regions of the Sounds. Exceptions to this general pattern include: off-shore reefs, rocks and stacks of the Outer Sounds; off-shore areas of coarse sand and/or pebbles in some exposed locations; mudflats in estuarine areas; pea gravel beaches in eastern Cook Strait; and a very limited array of sandy shores. Notable coastal landforms include: estuaries and tidal flats; cuspate forelands; coastal bluffs; off-shore islands, stacks, emergent rocks, and reefs; numerous headlands and bays as a result of the convoluted and intricate nature of the Sounds as a whole. 2. Dynamic Features and Processes, Including Climate Exposed eastern and northern areas of the Outer Sounds are subjected to high wind velocities funnelling through Cook Strait. The south-eastern coast is also exposed to oceanic swells from the south. Shores in these exposed localities are subjected to moderate-high seas, however, elsewhere the Marlborough Sounds are noted for their relatively sheltered conditions. Strong tidal currents occur around the Outer Sounds, especially off headlands and through constricted channels. Moderate currents also occur off the exposed faces and headlands of the major channels within the inner and middle regions of the Sounds. Tidal range varies from about four metres in the west to 0.5 metres in the east. App Two - 11