Accessing all the necessary organs can require moving the whale. Sometimes, if a stranding location is accessible enough, heavy equipment like an excavator can help lift part of the body to assist in splitting it open.
When that’s not the case, experts can use what’s called the window method, Bloodgood says. That basically just means cutting strategically placed holes along the body to access the desired organs. Near the pectoral fin is generally a good target for a sample of the lung, for example. One problem with this method is that it doesn’t always work if the body has decomposed and been tossed around in the waves before washing onshore. In that case, things get all jumbled up, and the lungs could end up by the tail, for instance.
After the deconstructing is done, Bloodgood goes back to the lab, taking samples of each of the tissues to conduct further analysis. One area of interest for her is ear bones. If a whale were in fact affected by the sound waves used by boats surveying wind farm locations (something that’s unlikely, given the type of sound waves used), their ear bones might show evidence of trauma associated with noise. That damage could be visible under a microscope or in a CT scan.
Bloodgood has been investigating this theory, with a particular focus on dolphins—their heads, unlike whales’, are small enough to fit in the scanner. There’s been no sign of such damage in any of the samples she’s examined.
Despite all the things that experts like Bloodgood can observe and test for, the system can never be perfect. Not all dead whales end up on beaches, and not all that do are in good enough shape for a thorough investigation. What’s more, it turns out to be quite difficult to entirely disprove that any single cause contributed to a whale’s death. Even if a stranded animal had an infection, or was hit by a boat, it’s theoretically possible there was another factor as well.
Still, in many cases, the necropsy turns up enough for scientists to feel confident assigning a cause of death. And after an investigation is complete, they publish a report, which is then analyzed by the National Oceanic and Atmospheric Administration. Enough such reports can point to trends.