Sunday, July 4, 2010

oh that stugeon's lucky it's endangered

So yes, after ranting about my cultural identity back to sturgeon... I will hopefully be seeing quite a bit of them over the next three years (me getting my PhD sorta depends on it). Google Atlantic Sturgeon, and you will find that they are big and ugly (and look a bit like they've escaped a Jurassic Park movie) and quite endangered - it seems people got greedy exploiting them for they're meat on the one hand (which apparently tastes quite good, I wouldn't know, I believe that fish are friends not food), and taviar on the other - really? Fish eggs? Whose brilliant idea was that?
Unfortunately for them, they're not a cute as seals or as charismatic as dolphins and whales (dooooooo youuuuuuuuuu speaaaaaaaaaakt whaaaaaaaaaaaales?! I picked some up conversing with the ones migrating down the East African Coast) so they haven't exactly gotten around to replacing Pandas as Greenpeace' new poster child. On the up side, New York and a couple of other States up here are currently working on management plans to help restore populations (this is also quite fortunate for me and my thesis...).
Part of the problem is that Atlantic Sturgeon need about 20 years to mature and reproduce, so we can't just stop fishing (which you're already not allowed to do, but they still get caught by accident) them for a few years and all will be well. Sturgeon's life cycle is similar to that of salmon, in that the females migrate up their natal river (i.e. the river they were born in) to lay their eggs... the young then migrate back towards the coast, usually live in estuaries for a few years and the spend their "juvenile/subadult" stage(s) in coastal aggregations- several studies have shown that protecting them at that stage will have the strongest effect re-establishing populations.
In order to protect them, it's kinda helpful to figure out where they can (still) be found, and what their fine scale migration patterns are. One of the guys I'm working closely with figures that out doing accustic tagging: We pull the sturgeon out of the water, make certain measurements and then surgically implant an acoustic tag (I'll get to this in a bit, that's the funny part of the story so if you don't want to know all the science-y stuff skip there....it starts with "okay, here's he funny story") and toss it back into the water.
So while he's figuring out where they're going, I'll figure out where their coming from. This is actually a kinda cool method - basically while the sturgeon are being measure and tagged, I'll snip off part of their fin, extract the DNA and sequence a little piece of their DNA. I'll be able to use this sequence as a sort of license plate: If you look at the combination of the first few letters on a German license plate you know what city/county the car is from. If you look at this sequence the combination of basepairs will tell you what river they're from. Kinda cool, huh?
Okay, so when we pull a sturgeon (hopefully more than one) out of the water trawling we weigh it (I think the heaviest one I laid eyes on til this point was about almost 30kg so over 60lbs), then we lift it on a measuring board and make some measurements (the longest one we got was 1,4m which is over 4 feet long - and remember, these aren't fully grown yet). Then we scan for a "pit tag" and inject one if it hasn't been tagged yet (that way, however else pulls it out during trawling surveys knows where else it's been), put in another tag We'd do this with three people, our "sturgeon hunter" (that's how he's labeled his gloves) would make the measurements and all that stuff, we had one person taking down all the data on the clipboard and I had the important job of watering the fish (you want to keep the stress levels as low as possible, we're trying to save these fish, not kill them) and holding the fish down the fish when it gets clipped for an ageing sample. These are powerful fish, basically all muscle, fast swimmers (remember, they can migrate UPstream!) and if you remember how tall/short I am and how much I weigh (yes, I know officially you don't know that since I'm a lady...) you'll understand why I view sturgeon wrestling as a completely acceptable alternative to rugby.
Keeping in mind, mine vs. the fish' measurements I was kinda surprised when I was told "Okay, Shannon just transfer the sturgeon to the trough while I get the accustic tags". Maybe because I play rugby with his girlfriend :-) Anyway, a common way of lifting them is grabbing the tail with one hand and supporting the head with the other, something about flipping them on their back/upside down makes them very docile. Unfortunately, I lack the arm span to that with the ones that are a bit larger, so I've developed my own method of cradling them to lift them into this V-shaped wooden trough we use to do "surgery" - getting them in there is als a bit difficult because it on top of a table and so the top rim is about at my should heigth.
Anyway, so we disinfect/locally anesthetize a bit the make an incision about 2 finger-breadths wide, pop in the tag and suture it shut. Yes, I'm writing this like it's the most normal thing to do, but I'll admit - I was surprised the first time I saw one of the accustic tags! They're a bit longer than my middle finger and thicker. It's less popping, more wedging and a little bit of swearing to get the d... f... &*!$## thing in.
(okay, here's the funny story).
On about the third fish we were tagging (this was before I had optimized all my lifting out, transporting etc. techniques), which was also one the larger ones, one of the other girls on the cruise was trying to lift the sturgeon out of the trough. Being my usualy helpful friendly self, upon seeing her struggles I asked if she needed a hand, then stoopd on my tip toes in order to get my hands under the sturgeon (which she was holding by the tail and had so far only managed to flip on it's side)... yes, of course the sturgeon chose that moment to snap up.
You should have seen the "oh crap"-faces on the two girls watching , as they're eyes widened when I took/staggered to steps back from the force of the sturgeon-head butt/sucker punch which caught me just above the chin.
Oh, that sturgeon is luck it's endangered - and my firm belief that fish are friends, not food :-)

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