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    The Squid Are Back!
    By Danna Staaf | September 24th 2011 12:00 PM | 7 comments | Print | E-mail | Track Comments
    About Danna

    Cephalopods have been rocking my world since I was in grade school. I pursued them through a BA in marine biology at the University of California...

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    To be specific, the Humboldt squid are back in California. Their opening act was a mass stranding on Black's Beach in San Diego last Saturday. A lifeguard had the most poetic commentary on the matter:
    "Of course, as you might imagine, there were some odors associated with that," he said. "The only thing left on the beach right now is the scent of dead squid and seagull footprints."
    As usual, everyone seems to be afflicted with amnesia regarding the regularity of such strandings over the past decade.
    “I was just walking out of the water and it just freaked me out,” said Adam Ehdaid who was looking at the Humbolt squid at Black’s beach. Adam surfs every other day here, and says he’s never seen anything like this.
    Also par for the course, people assume that the stranded squid died after spawning. This guess is based on the fact that many other species of squid do, in fact, die after spawning. However, when I sampled stranded Humboldts in 2009, none of them were sexually mature--blowing a big hole in that theory. So why do they strand? We still don't know!

    The squid quickly followed up the stranding with more vigorous appearances at sea, biting lures throughout Southern California.
    One sports fishing expedition on Wednesday came back with 990 of the large creatures. Dave Schmitt of Davey's Locker Sportsfishing describes the scene as "pure mayhem ... and they're just everywhere."
    This is welcome news for the dozens of teachers waiting patiently to receive squid from Squids4Kids, an outreach program I help to run. We had to put everyone on a waitlist as our supplies dwindled over the last year, but now it looks like there might be an opportunity to restock . . .

    Comments

    rholley
    Reminds me of a rather tacky song that went

    “... what a picture, what a photo-graph! ...”

    This turned up on Wikipedia today:

    Did you know...

    From Wikipedia's newest content:

    Robert H. Olley / Quondam Physics Department / University of Reading / England
    Danna Staaf
    nifty! I would be willing to be that Humboldts grow even faster than bigfins, but I'm sure they're still "one of the fastest."
    Bonny Bonobo alias Brat
    So why do they strand? We still don't know!
    Don't the post-mortems reveal anything at all about why these squid might have stranded? With cetaceans post mortems can occasionally reveal parasites, malnutrition, pollution, poisonings and other factors that may have caused them to strand and sometimes the geography of the beach is a factor causing confused echolocation. Could these factors also be the case with the squid or could they be affected by the oxygen levels, current, tide or wave strength, organic or chemical contents or even the temperature of the seawater maybe? Do they have anything unusual in their stomachs when they die or are they empty? If someone picked them up and threw them back in the sea would they swim away or would they strand themselves again? Could there be predators out at sea that have exhausted them before they stranded? 

    Sorry to ask so many questions but I find it amazing that we have no idea why these squid are stranding!
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Danna Staaf
    Oh my gosh, so many good questions! I'm tempted to wait and do some real research before responding, but then I'd probably get distracted and forget about it.
    In 2009 I collected some stranded samples and sent them to a grad student who works on algal blooms. You can read the results of her workup in chapter four of her thesis. The gist of it was, she found some domoic acid, but not enough to be positive that it was the cause of stranding.


    The squid could be affected by almost all the causes you link--which is one reason it's so difficult to figure out which one, or ones, it is! As far as stuff in their stomachs, John Field, another co-author on the study I did with Fernanda Mazzillo, looked at those, and noted that most of the prey was shallow-water species, suggesting the animals had been foraging close to shore, and might have gotten disoriented if that was an unusual environment for them.

    I know that's probably not a very satisfying answer, but it's the best we've got right now . . . 

    Bonny Bonobo alias Brat
    Thanks for the link to this research thesis Danna. Chapter 4 about the Humboldt squid was very interesting but in many ways also sadly lacking don't you think? It might almost have been better not to have done this study or at least to have not published results from data obtained from only 5 humboldt squid that you sent her, because it goes on to actually deduce that the toxic algae and resultant domoic acid (DA) wasn't responsible for the stranding even with so little evidence to support this finding. 

    For the first time however, this research showed that one humboldt squid had the highly neurotoxic to mammals DA present in its mantle but the research wasn't sure if it was the same squid that also had DA in its stomach? The 5 squid were collected from 2 different locations which was also another rather confusing factor. Maybe the one or possibly two squid with DA came from one location and the other 3 came from the second DA safer location? Maybe that second location was the La Jolla Cove which may possibly have been somehow sheltered from ocean currents carrying the toxic algae, fish that had eaten it and the DA, which was known to have been heavily concentrated in algae several kilometres away?

    It seems to me that there really should be a lot more research into the possible effects of neurotoxic algae blooms and the effects of DA upon edible squid as the author suggests, especially as it might possibly still be causing these Humboldt squid strandings. The paper points out that :-
    Cephalopods have the largest brains of any invertebrate with a complexity analogous to those of vertebrates (Messenger 1996), and it has been suggested that the arrangement of neurons in the vertical lobe of octopus is involved in memory and it has structural similarities to thevertebrate hippocampus (Boycott and Young, 1950; Young, 1965). Moreover, glutamic acid also serves as a neurotransmitter in invertebrates (Messenger, 1996)and all 3 subtypes of glutamate receptors (i.e., kainic acid, NMDA and AMPAreceptors) have been detected in central and peripheral nervous systems of cephalopods (Evans et al. 1992; Messenger, 1996, Garcia 2002; Lima et al. 2003; DiCosmos et al. 2004). The fact that cephalopods have highly developed CNS andsimilar glutamate receptor as mammal potentially indicate that Humboldt squid maybe susceptible to DA neurotoxicity effects.... Cephalopods have the similar glutamate receptors sites as mammals, and as DA binds to these sites it triggers toxicity which indicates that D. gigas can potentially be susceptible to DA neurotoxicity effects.... The presence of sand and algae in the stomachs also supports the hypothesis that these animals were actively foraging in shallow waters. If this is an atypical habitat for them to exploit, they may have become disoriented and accidentally swam on shore.
    Even if only two out of every five squid have possible memory loss or were disorientated by the effects of neurotoxic DA in the algae and fish they were eating in the past couldn't this alone have caused the schools of squid to behave erratically and exhibit this atypical close to shore foraging activity that then possibly resulted in their stranding? What I find amazing is that fisheries may also possibly be catching, freezing and distributing DA neurotoxically affected squid for world human consumption without apparently having ever researched and tested to see if DA is also present in these edible squid's mantles as this is the first paper to have ever proved this can be the case. 
    DA is a neurotoxin produced by several species of the diatom Pseudo-nitzschia (Moestrup and Lundholm 2007) and has caused mass mortality of marine mammals and birds (Work et al. 1993; Scholin et al. 2000). However, determining that DAP is the cause of death in marine animal strandings is difficult. Studies that have come to that conclusion used a combination of observations such as (1) DA detection in hundreds of specimens in question and/or in their prey items; (2) DA detection in thewater along with high concentration (<104 cells L-1) of toxin producing cells; and (3)observations of typical DA neurological symptoms (i.e., seizures, ataxia, headweaving, and stereotypic scratching) and (4) histopathology to show lesion in hippocampus brain region characteristic of DA poisoning (Work et al. 1993; Scholinet al. 2000; Gulland et al. 2002). 
    Are people who have eaten DA poisoned or affected fish and squid also becoming DA affected? Yesterday I visited my friend's relatively young and physically fit father who is suffering from dementia and memory loss, in a nursing home that was full of similarly affected people, all either wandering around in a confused state or sitting looking dejected and staring at the ground. Many of them were physically slim and fit looking, how many of them have eaten DA affected fish and squid I wonder?



    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Danna Staaf
    Quite a sharp analysis, Helen! I'll readily acknowledge that it would have been wonderful to have more and more reliably identified samples, but I would never say that it would be better not to have done the study at all.
    Science proceeds through chance encounters and serendipitous observations just as much as through carefully planned experiments. I was in La Jolla that summer for an entirely different project, and it was sheer luck that I was able to get out to the beaches and collect some samples. If I hadn't been there, it's unlikely anyone else would have sampled the squid, and we would know absolutely nothing about domoic acid or stomach contents in stranded squid.

    I agree that it's frustrating to have inconclusive results, but it's always better to publish the inconclusive results so that readers--like yourself!--can learn what is currently known and move forward. 

    Wouldn't it be nice to be sampling the squid that are washing up right now? Unfortunately, resources are limited. The same people who are very interested in studying this question are also very interested in studying many other questions, and it simply isn't possible to pursue all avenues of research at once. Sigh!

    As for your concerns about humans ingesting squid flesh, I believe that the symptoms of DA poisoning are sufficiently acute that they would be noticed immediately--I'm certainly no medical expert, but I don't think DA is one of those "silent killers" that accumulates over time to produce the sort of early-onset dementia you're talking about.
    Bonny Bonobo alias Brat
    Actially early onset dementia can happen pretty quickly too, now what were we talking about again? Oh yes DA affected squid, yes I agree some research is definitely better than none but more research would be so much better. Yes it would be great to be sampling the squid that are washing up now but not with olive oil and lemon juice.
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine