effects of bottom trawling

MrTrent

Larval Mass
Registered
#1
I am doing an informative speech on bottom trawling for my communications calss. Can and dr.s of biology or any credible profession give me some information on the effects of bottom trawling on creatures such as the giant squid? i recal hearing that it could be a reason we are running into such once hidden creatures.
 

OB

Colossal Squid
Staff member
Moderator
#2
First and foremost, :welcome: to our forum. As the giant squid Architeuthis dux is (mainly?) a bathypelagic species, it suffers little consequence from bottom trawling, its prey items in turn do not appear to rely on bottom dwelling species, either. Bottom trawling destroys complete ecosystems containing for instance deep water corals that were sometimes centuries in the making and disrupts a balance between species that is entirely fragile. The argument against it is mainly ethical, as is always the case, who would condone wanton destruction of natural beauty for the sake of deep frozen fish fillets. Just because most people will never see it, doesn't mean it isn't there...

Colossal squid, Mesonychoteuthis hamiltoni, which is also believed to be bathypelagic, we run into more and more often because of commercial longliners moving into antarctic waters going after Chilean seabass a.k.a. Patagonian toothfish: apparently we share a prey item, here, with subadult females of the colossal species. As we'll probably fish toothfish to extinction any day soon, this should solve the problem :sad:

The Humboldt, or jumbo flying squid Dosidicus gigas we see in increasing numbers off the West coast of the US and Canada, for likely reasons of commercial fishing draining the ecosystem of many competing predators. The squids' ability to maintain a high metabolic rate even under low oxygen conditions, combined with a very fast growth rate, favours their survival in this case over the more slowly responding pool of vertebrate pelagic apex predators.
 

gjbarord

Sepia elegans
Staff member
Moderator
#3
Having been on pelagic and bottom trawlers recently, I do not believe either pose any real threat to such large animals as giant squid or other large squid. The occurrences are less likely to occur than pulling up marine mammals, which are very scarce. Large, fast moving animals, are able to evade the trawl nets most of the time, at least in my experience.

Sounds like an interesting talk.

Greg
 

OB

Colossal Squid
Staff member
Moderator
#5
I received my Drs. from Leiden University in the Netherlands, if that helps? I currently work at the Netherlands Organisation for Applied Scientific Research (TNO).
 

Members online