Gathering a sample from the deep seafloor is a difficult and arduous task. Regular sampling is often impossible due to the high costs associated with research expeditions to deep-sea environments. Large ships with a specialised crew are needed to deploy the sampling equipment and retrieve the sample.
In the early days, researchers relied on small trawls and dredges to scoop samples from the seafloor. But dredges and trawls have to be towed on long wires to reach the seafloor and may not always give a true picture of what lives there. Imagine trying to build a picture of the inhabitants of London by flying across in a balloon and using a bucket lowered on a rope to catch the people beneath. Purely by chance you might catch a policeman and a traffic warden – and assume that the population of London was just policeman and traffic wardens!
Without samples we cannot understand life in the deep ocean but gathering truly representative samples is a difficult task.