I thought this was interesting. They are trying to find ways to join ropes which won’t fail under normal use, but will fail if a whale gets caught up in it.
Very interesting!!!
As is this extended discussion of the issue:
https://mlcalliance.org/2020/02/01/lobstermen-remain-frustrated-over-states-proposed-whale-rules/
This however seems like “old news” to me : at least,
for some place --and I believe it was Maine, which seems
to be the most proactive in this right-whales concern–
I years ago read about the use of knots and also of some
rope-cutting device for the sake of not exceeding certain
forces on a line (“trawl”).
Some ideas newly occur to me.
In New Jersey (Cape May, essentially), I recall some new
regulations --per Obama administration-- requiring the
“sinking” line, and seeing one heap of some 4-strand (IIRC)
such stuff on a boat/dock. The problem seemed to be that
right whales feed by swimming with jaw open and so can
snag an arc’d floating line (it floats up from the sea floor).
Given that change, I wonder why the problem is persisting?!
Beyond this, commercial fishing has a variety of knotting
needs & practices worth considering.
Thanks much,
–dl*
Dan: I reached out to the biologist doing the study and he indicated it should be completed in a couple of months. They are submitting the findings to NOAA as part of the rule making process, so the information will be available to the public at that time.
Great that you made contact with someone involved!
I have not noticed --perhaps from not being attentive!–
what is said or theorized to be the cause for conflict
with the right whales, assuming that it is occurring
with the use of sinking lines?! --how can snagging
occur if the lines lie on the sea floor (with the vertical
lines to floats?)?!
–dl*
More reading … , and I liked this quote:
?Why aren?t we doing things that matter
like changing configurations at the surface
where a whale might actually get caught up??
asked a Zone B lobsterman.
Imagine that, doing things that matter!
An interesting idea arose from some Hackathon
in which students came up with the idea to have
a buoy-inflation device respond to a unique sonic
signal to then inflate a retrieval line/buoy so that
this potential whale-snagged rope is only in place
upon the retrieval boat’s summons & pretty immediate
hauling up!?
BUT THIS IS IN A JANUARY 2019 Smithsonian Mag. article.
AND,
this is a solution seemingly apt for a trawl of many
traps needing only the one device,
not trawls with few traps each, and each trawl in need.
cf. LobsterLift
Oh, and then there is this:
researchers are still working on understanding how whales feed and move through a region. Humpbacks and right whales have been observed coming to the surface with mud on their heads, suggesting that [u]they may actually root around on the sea floor[/u] as they forage. That means that even removing every vertical rope line from the water column may still not be enough.
–dl*
If you ask a fisherman in Maine, he/she will tell you it doesn’t happen—there have been no whale deaths linked to Maine fisherman since early 2000s. The deaths of whales found in Maine waters have been tangled in Canadian lines.
But, to answer your question about how it can happen with just one vertical line, I have been on the water in some productive areas where multiple fisherman are fishing multiple lines quite close together. It can be hard to navigate a boat through all of the buoys in some spots. I believe prior regulations made the fisherman put more of their allotted number of traps on each line (i.e. if you had 10 traps, 5 on 2 lines rather than 2 on 5 lines–those numbers are made up, but you get the point) in an attempt to reduce the number of surface lines. So, it may be they are swimming through more than one line which quickly tangle.
I will post the information about the knots when I receive it.
i don’t think in any other areas of knotting we have something that will ‘fuse/blow out’ at a specific rating because of knot tied in it w/o depending on the tensile, and ruining rope.
.
In the sea etc. where rope is degrading, makes the tensile a moving, unpredictable target.
.
So, to me the most logical solution is as presented.
To make degrading ropes overly strong,
and give a more inert/non-degrading, lesser tensile fuse part; such as the dog bone strategy shown.
.
The planet has always taken better care of us, than we of it; and that is a grave err.
The stability of this planet experiment has always been to the brea(d)th of diversity base.
Earth is only marginally more habitable than it’s uninhabitable siblings; And even at it’s extremes, not so much!