While Schäfer patiently gave every sea creature that appeared as flotsam the same kind of attention he reserved for stranded whales, he nonetheless led off his seminal treatise on taphonomy with a decaying porpoise.
Often, it will lead to death.We simply don’t know why some apparently healthy whales and dolphins strand themselves.
They spend their lives in schools that are composed of extended families centred around the females – mothers and their daughters are the family focal points.Based on this social structure, the common assumption has long been that healthy animals strand themselves as an altruistic gesture, that they do so to continue caring for distressed family members.Their invasion of the sea was progressive, and therefore we are left to ponder whether in difficult times, individuals might still instinctively react as if land confers an element of safety.Regardless of this, however, if injured or sick, these marine mammals will still be able to rest more easily if they can find a shallow area where they can stop moving. When whales die in the ocean, their bodies eventually sink to the bottom. (For a variety of reasons, there are a lot more bottlenose dolphins than blue whales out along the coast.) Decay sets in soon after the death of a whale, as the insides begin to decompose. Certainly the sight of an entire pod of whales stranded, dozens in a row, begs some kind of explanation, although that is frequently elusive. If not, then what does? Given the chances against any living thing becoming a fossil, it is a wonder that we know anything about life from the geologic past at all.Thinking like a paleontologist makes you something of a connoisseur of dead things. Once word of a whale stranding arrived at the door of a rural doctor or an amateur naturalist in the eighteenth or early nineteenth century, the opportunity would have launched a whirlwind of ad hoc planning for several days of dreary, odorous dissection. Far more intriguing, it is not uncommon for some strandings to involve healthy animals, seemingly unaffected by any of these problems.This is particularly true of pilot whale mass strandings, such as the recent Calais event. Adding to the complexity is how they strand: whales may be dead upon arrival, alive but flailing on the shore, or already decayed to a raft of blubber, cartilage, and bones.Beyond the how, there is still more complexity to the why: what causes a whale stranding? This involves a rapid triage process to know which individuals should be refloated first and the identification of the ‘problem’ individuals – those likely to be at the origin of the stranding.The truth is that individuals will often re-strand and die hours or days after being refloated – doubtless because they were sick or injured in the first place – but some do get away.We have learned a lot since Aristotle first wondered why these creatures strand together sometimes – and will never stop trying to help them. For example, a stranding might consist of one whale, a mother-calf pair, several individuals from a single species, or several individuals from different species. That’s still not clear, although it may be something about the lipids locked in the bones that controls which species can colonize the carcass, along with the stages of whalefall succession.If you’ve ever seen a fossil on display in a museum, you might wonder why it is that animals sometimes preserve nearly intact, while others leave only a single bone. Senescence or disease may provide simple explanations in some cases, whereas the side effects of living near humans can be either plainly obvious (entanglement in fishing nets or ropes) or more difficult to plumb (toxin poisoning from marine algae). How would a whale end up landlocked in our world, a creature so large and strange suddenly so uniquely vulnerable?Whale strandings happen in many different ways, for multiple reasons. Ideally we want the whole picture of the ancient worlds that we study, but we don’t ever truly get that, because of the vicissitudes of how living things fall apart after death.Taphonomy has Old World origins, having been independently developed by Russian and German scientists working in isolation for the first half of the twentieth century. It leads to further injuries, such as cuts and abrasions, as well as internal injuries caused by the unsupported weight of the body on internal organs – their bodies are designed to swim and float, not bear their mass on land.