estuarine estuary fresh-water light reflecting reflection salinity salt-water shade shadows shrubbery shrubs sunlight sunshine tidal tide trees vegetation water water-quality bank boat dinghy England fitful foreshore grass Great Britain Hampshire landscape low marine maritime mast mood moody mudflat pole river storm stormy transport weather yacht yachting anchored buoy data-collecting-buoy dissolved-oxygen electronic-data-transfer fish-kill-mitigation floating-device improving-understanding monitoring-buoys moored oxygen-levels scientific-advisory solar-panel solar-powered stationary water-quality-management armor armored armorment armour armoured armourment backstraps bony ridges crocodile crocodylus-porosus danger dangerous dorsal-surface estuarine-crocodile exotic fauna hide hornback huge Indo-Pacific-crocodile large largest-reptile leather leathery lethargic omnivorous opportunistic opportunistic-predator osteoderms patterns powerful predator reptile reptilian ridges rough rugged saltwater-crocodile scales scutes skin tail tail-scutes territorial texture textured textures bird-colonies birds breeding-place colonies color colors colour colours conservation contrast contrasting crowded dark estuarine-wetlands estuary-waters fence fenced foliage food-supply forested-wetland habitat low-lying melaleuca-rhaphiophylla migratory-birds nesting nesting-place nests nursery paperbark-trees paperbarks reserve ripples rippling rookeries rookery roosting roosting-place slow-flowing swamp-paperbark waterbird- habitat wetlands wildlife