The waves of a tsunami can wash creatures quite far inland where they will likely perish as the water recedes. Turtles, dolphins, and sharks, for examples, have often been found washed up more than 500 metres inland following past tsunamis. Beaches are often left covered with dead sea creatures who suddenly found themselves on dry land and were unable to escape back to the water. Turbidity clouds are also a concern (often caused by sediment and debris that are swept back out to sea causing a thick 'cloud'in the water) because they can block sunlight from reaching past the surface of the sea - algae requires sunlight to photosynthesise and coral reefs depend on algae which means there can be a severe knock-on effect.