Gam of porpoises Sometimes known as the common porpoise or puffing pig on account of its sneeze-like blow when it surfaces to breathe, the illustrated harbour porpoise is not as easily seen as some of its relations. It does not readily "bow-ride" in front of sea-going craft and shows little of itself at the surface. Observers who therefore get prolonged views of it are particularly fortunate and a fleeting glimpse is more usual. Porpoises have four collective nouns associated with them (which they share with whales). Those better known include school and pod, whilst the term herd is in keeping with other semantic bovine connections such as cow, bull and calf for the female, male and young respectively. The word gam, as well as being another collective noun for porpoises and whales, has a definition as a social gathering of whalers at sea. Generally speaking, the term pod is used for smaller, perhaps family, groups whilst school or herd refers to the larger groups. The collective noun pod is also applied to hippopotamus, seals, and whiting; school to fish and herd to many creatures, but those specifically listed as herds include wrens, curlew, antelopes, asses, chamois, elephants, giraffe, goats, hares, seals and sperm whales.

Porpoises, like most cetaceans, have suffered in recent times from human interference. This has been both directly in terms of hunting and also indirectly from habitat pollution and degradation, as well as accidental capture in fishing nets. Nevertheless, the harbour porpoise is still the commonest and most widely-distributed cetacean in British waters.