yeah, there are quite strict overfishing policies about and it would make sense for a fishing boat to dump surplus rather than open themselves up for a fine... sense from their point of view anyway. I once seen boxes and boxes of Nephrops being thrown over a harbour wall and suspected that they had either "gone off" of were breaching some regulation on quantity???
I don't think that many (more likely hundreds rather than thousands I suspect) would be by-catch for the same reasons that poisioning doesn't make sense (that many are not likely to be in close proximity). Octo fishing is a commercial fishery in the area so I think the catch was intentional why it go dumped is speculative.
What Is Killing Portugal's Octopuses?
[SIZE=-1]"There's nothing in the scientific literature for this kind of mass mortality among octopus." Twelve hundred pounds is a lot of dead cephalopod, ...[/SIZE]
"There is one other option, however. In December 2007, Portuguese police confiscated 9.4 tons of cocaine in a shipment of frozen octopus from Venezuela. "I suppose it's possible that someone defrosted the animals, took out the cocaine, then threw their bodies overboard," says Weber. Still, like Oliveira, Weber is betting on a biological cause. "We've had swine flu, bird flu," he says, not completely in jest. "Why not octopus flu?""
I saw the cocaine article when I went looking for more news but that was several years ago (as I see you noted) so I discounted the possibility. I still think Colin has the logical direction and I see it was considered but not accepted because of rough seas. A boat in trouble though might dump or lose its cargo.
Wow, I would never have thought of over fishing because I was over-thinking the topic itself. I was thinking they all mated then died, but then remembered that is a squid trait. This forum doesn't screw around.
Octos are not known for mating orgies like some cuttles and squid. Female octopuses incubate their eggs anywhere from 2 weeks to almost a year (depending upon species and water conditions) before dieing and most males can mate more than once and don't die immediately so a mass mating die-off is not a potential here. I wonder why the toxology reports will take so long.
The laboratory results shown that was just too much freshwater content on that part of the coastline. The main reason was that rained a lot during that period and rivers introduced loads of freshwater on the ocean...
«Octopus died from excess freshwater into the sea
The octopus that gave the coast in Vila Nova de Gaia died due to excessive fresh water ran into the ocean during the floods that ravaged the region in previous days, the analysis showed.
According to official sources from the Ministry of Agriculture, the analysis performed by the octopuses National Laboratory for Veterinary Research (LNIV), former IPIMAR revealed that there was an "imbalance in salinity" of the octopus that killed them.»
I understand and respect your skepticism, after all , it´s quite pertinent.
I´m not sure if it were only octopuses that washed up , though the news only mentioned about it, I´m about to contact authorithies just to try to have some more informations.
Also, I´m not aware of how exactly all marine animals react to these sudden changes ( floods, heavy rains,etc..), maybe it´s a nice subject to evaluate and study. :)
I did got an information that some octopuses did had eaten on the last 24 h before die ( after inside examination).
The pollution hypothesis is also out of question, if not some species that were said to be more vulnerable to that would die in big numbers ( like Dicentrarchus labrax or Sparus aurata).
The extension of the coastline that was affected by this happening was 5 kms.
Anyone wants to take a guess?
Illegal fishing boat surprised by an approaching authority, maybe? Not sure.
I hope to get some more info.