Its always bothered me that we as a species feel the need to spend millions of dollars on research to answer a question that can be pieced together with common sense. Its true that a definitive answer can further the health and well being of Orcas, but what about when even with all the research we still just don't know the answer for sure. The reason for the collapse of the Orcas dorsal fin is one of those questions, researched, studied, and hypothesized, and the only real answer 'The Experts' can give is 'its not caused by being unhealthy', and then give a few most likely reasons.... in other words guesses. I wonder how much those 'educated' guesses cost. Since the experts can't answer this question without beakers and test tubes, lets see if common sense can succeed where science has failed.
I should point out that the dorsal fin is not bone or cartridge, its a hard collagen not unlike whats in your lips, just much harder or perhaps packed in tighter. Imagine 2 stuffed teddy bears, both stuffed with cotton balls. One bear you stuff til its just full enough to take form, the other bear you pack and pack and pack full of cotton balls til you can't easily add any more. Both bears look roughly the same, yet on closer examination, the 1st teddy bear is loose and floppy, and the 2nd teddy bear is stiff and rigid. Now replace teddy bears with an Orca dorsal fin and cotton balls with collagen.
Now lets look at the dorsal fin of an Orca in captivity. AS seen in the photo below, the dorsal fin is completely collapsed.
1) Have you ever seen a surf board, you know that 'fin' on the bottom. What is that for? Well I don't surf and a surfer could answer the question as to what it does better than I can, but the basic use of that fin is directional stability. On an Orca, the dorsal fin serves the same purpose, it stabilizes the Orca from rolling over in the powerful currents and allows sharp turns in those currents. An Orca can swim at a top speed of approx 30 mph, an incredible feat when you consider that they are fighting strong ocean currents.
There's an old saying, 'use it or loose it'. Perhaps this is what happens with the Orcas dorsal fin. When an Orca is in captivity, it is in perpetually calm shallow water. It no longer has the ability to swim against raging ocean currents, diving for food, jumping and swimming at top speed for miles at a time. Instead it is place in a 'fishbowl' and the dorsal fin is never really used. When astronauts are in space, they are required to exercise because in a weightless environment they don't use much of they're muscles and would suffer from sever muscle atrophy if they didn't. Though dorsal fins are not muscles, perhaps this is the same situation. With lack of use, the Orcas body tells itself that the dorsal fin no longer needs its normal nutrients, causing the collagen to weaken til eventually the dorsal fin completely collapses.
2) Has anyone ever considered that the diet of an Orca has something to do with it. In captivity an Orca eats about 240 lbs of fish each day. I have to ask myself, are these frozen fish? Does a fishing trawler go out every morning and bring back a varied heaping pile of live fish for there captive Orca? Of course not. Now maybe, just MAYBE, they will feed their captive Orca fresh fish... but LIVE fresh fish daily. I doubt it. So you're asking yourself, so what if its live, fresh or frozen, does it matter? That is a big YES on 2 counts. First, Orca are not HUMAN... there nutritional intake is far more complex than just 'fish'. When an Orca goes hunting for food, perhaps they have a particular fish in mind. But that doesn't mean they always get it, Orca have been known to eat sharks, dolphins, seals, shrimps, tuna, crabs... the list goes on. Their diet is vastly varied, which means the daily nutrients they receive are vastly varied. Now replace that daily 'buffet' with a daily can of 'pork and beans', do you think that can of 'pork and beans' is going to be sufficient?
Or maybe its as simple as them eating a particular fish type that is high in some nutrient that helps the production of or maintenance of collagen? Something that their trainers aren't feeding them? I'm not saying they are being starved, only that MAYBE they aren't eating what they would eat if they were in the wild.
So this is my final thought on the whole thing: I want to be clear, I'm not an activist, when I was young I loved the Shamu show at Sea World. But we didn't know much about Orca then, we didn't know that by bringing them into captivity we'd be changing them, even unintentionally and unknowingly hurting them. I don't believe we should harp on the past and reopen old wounds. But rather learn from the past and prevent from causing new wounds. Perhaps we shouldn't have Orcas in captivity. Perhaps we should just leave these animals alone to do what they do, live, have families and keep the oceans food chain in balance.
