North Ronaldsay has long stretches of clean sandy beaches, at Nouster, Haskie and Linklet Bay. On sunny days the sand is a pale gold but even on wet days it is beautiful, taking on a myriad sheen of all colours of the rainbow. These shores are a favourite haunt of Sanderling, though they can be found on shingle too, feeding on invertebrates amongst other Calidrids. Ringed Plover breed here, occasionally laying their eggs under the edge of stone slabs, where the nests are safe from sheep. Sand and shingle are also a popular habitat for Arctic Tern colonies.

The shore is a treasure trove of sewaeeds and shells. Limpets, whelks and spoot shells (razorshells) are washed up by the tide. The picture on the left shows a clump of whelk eggs. Deep orange shells cast off from Edible Crabs (Cancer pagurus) and toothed shells from Velvet Swimming Crabs (Portunus puber) are also found, often amongst the tangled seaweeds that are so important in feeding the island's sheep population. Two of these seaweeds are the distinctive bladderwrack (Fucus vesiculosus) and tangles (Laminaria digitata).

The fronds of tangles (right) are eaten readily by the sheep. Until recently, the people of the island would collect the stipes (stalks) and sell them to the alginate industry. They used them in medicines and also to make food stabilisers (e.g in pastries, ice cream and the frothy head of beer). However, cheaper alternatives means that this source of revenue is no longer available to the island community. Small, intricate lugworm casts (Arenicolidae), as in the picture below, can be seen along the shore after the tide goes out. Then, at low tide, brittle stars (Ophiuroidea) and starfish (Asteroidea) can be found under rocks. The tide also strands small jellyfish on the shore around August. Pipe-fish (Syngnathidae), strange looking creatures but poor swimmers, are sometimes thrown onto shore by rough weather.