Some light, much mystery on fin whale death

So, the 70-tonne fin whale impaled on the cruise ship that arrived in Vancouver last Saturday? It was necropsied out in Patricia Bay, at the Institute for Ocean Sciences in North Saanich.

They’ve learned a few things already.

1. It was a lady whale–since they conceal their bits in genital slits for streamlining purposes, it’s hard to tell the sex from the outside–and an older one at that.

2. The blubber layer was thinner than usual; that can happen after birthing a calf, which they do every 2 or 3 years. It’s not known whether baleen whales reproduce throughout their lives or go through menopause; so far, it seems only some toothed whales do, like orcas and short-finned pilot whales. So it’s unclear whether her slenderness was related to reproduction.

3. Her stomach was empty.

Okay, so she was a starving West coast middle-aged female. This just prompts a bunch more questions.

Did she die before or after the ship rammed it? Since fin whales can swim at 20 knots and can hear well and cruise ships are noisy, you’d think she was already dead–though whales may not be so attentive when they’re feeding (which she wasn’t) or nursing (which she likely wasn’t) or resting. If she did die first, that’s the second fin whale to die around here this year–one washed up about a month ago near Ucluelet , off the West coast of Vancouver Island.  So, how many naturally wash up each year? And does the baseline number actually represent a healthy or recovering population, or is it cause for concern when the number of fins is a small fraction of what they were before whaling?

If she was still alive, how can we avoid such collisions in the future? Whale avoidance tends to mean slowing down and maybe changing course. Is that the best we can do? Efforts to track whales through underwater listening stations and relay their locations to ships are a ways off still.

Does an empty stomach mean she hadn’t eaten in hours, or days, or months? Since they can eat a couple of tonnes a day, food must a pretty quick residence time in the stomach. Evidence of her starving prompts another question about fisheries managment: fin whales eat schooling fish like herring and sardines. While sardine levels have recovered along the West coast, does that really give us license to fish them again? Or should we just cool it for a while, and maybe let fin whales and other animals have a fighting chance?

The rest of the necropsy results are expected in the next couple of weeks. I’ll see what more I can find about fin whale health before then.