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Friday, September 17, 2010

Pity the idiotfish. Someone has to.

There's a fish out there that's not doing too well. I'mma let you get some tissues, because you're going to be using them. Take a good look at this guy, and then commence sobbing.

My life is so hard.
Image: NOAA via Wikimedia Commons

Bummer numero uno: Its name. It's called the longpsine thornyhead (Sebastolobus altivelis), which isn't a great starting point. Even worse: the few people who know about it call it by another, even less-flattering name: idiotfish. This is because, when it is caught, its eyes bug out due to the extreme pressure change that occurs when it is hauled from the deeps to the deck. Yes, this is correct: people mock it for the effects of extreme pressure change on its eyes.

Bummer #2: It lives in a cold, dark place with nothing to eat. For some reason its forebears decided that it was best to live in the oxygen-starved waters of the deep Pacific at depths of 500 to 1,200 meters, where it's cold, dark, and bloody tough to find a decent bite to eat - the marine equivalent of Dartmouth, Nova Scotia, at 8:00 pm on a February weeknight. So, much like the denizens of Dartmouth, this fish makes do by not moving much and by having a really, really slow metabolism. It only eats a few times each year, in fact, and is capable of going months between meals. Most of the time it just sits there, presumably dreaming of onion rings.

And this brings us to the final and most severe bummer: the fishery. Like other slow-growing, long-lived deep-sea fish (such as the infamously overfished orange roughy), longspine thornyhead don't have the life history characteristics to support much of a fishery. This wasn't much of a concern for a long time in Canada, however, because until recently they remained largely free from fishing pressure due to the extreme depths at which they do their thing. This all changed in the mid-90s, though, and you get one guess as to why:

New. Japanese. Market.

Yep. In the mid-1990s, a novel market for longspine thornyhead sprang up in Japan, and B.C. bottom trawl vessels swung (swang? swinged? swanged?) into action. The fishery didn't seem like it made much sense: because idiotfish tend to spread themselves out evenly over the largely featureless deep sea floor, the trawl tows were extremely long (roughly 30 km - see the COSEWIC report link below) and therefore the fishery had to cover huge amounts of territory - and burn lots of fuel - to catch their fish. Hardly the standard blueprint for financial success. However, the Japanese market was demanding, so the fishermen kept supplying.

And supply they did: longspine thornyhead landings shot up from relatively little before 1996 to over 900 tonnes in 1999 (source: COSEWIC report; see below). Overall, during the period of 1996-2005, approximately 6,500 tonnes of longspine thornyhead were caught - representing an estimated 57.6 million individual fish (COSEWIC). Quick - what do you think happens when a fishery suddenly starts targeting a poorly-studied, long-lived, slow-growing deep-sea fish? Yep. Landings soon began dropping, and over 8 years, catch-per-unit-effort (CPUE) had declined by more than 50% (source: DFO Species Profile, see below).

Fast forward to 2009, when the longspine thornyhead was listed as a species of special concern under the Species At Risk Act. However, they can still be caught commercially: in the 2010 groundfish management plan, longspine thornyhead Total Allowable Catch is 425 tonnes, 95% of which goes to the bottom trawl sector. For the past few years, a reduced market and high fuel prices have combined to sharply reduce fishing effort targeting longspine thornyhead. However, these conditions can change and are not a replacement for a sound management plan for the species.

So, if you have room in your heart, spare a small place for the poor longspine thornyhead. It's small, not very attractive, has nothing to eat, and everyone calls it an idiot. Clearly, this is one fish that needs a few friends - and some help from fisheries management.
Longspine thornyhead information:
DFO Species Profile:
COSEWIC Status Report:


  1. This is inspired. But what about the mudfish? It's hard to say who is more pitiable.

  2. Hi Maria,

    Mudfish you say? I still think 'idiotfish' is worse. The former is just a reflection of where the fish lives, the latter is a damning indictment of its intellectual capacity, as estimated by its googly eyes.

    And I just want to point out that I gave Dartmouth, Nova Scotia a shout-out here. This is as close as Dartmouth has been to being famous since Joel Plaskett obliquely acknowledged its existence by referring to walking 'home across the bridge when the Marquee shut down'. Listeners everywhere thought "Hmmm, the one side of the bridge starts in Halifax obviously...there must be some land mass where the bridge ends." And for years, that's been Dartmouth's claim to fame. Until now.