orcas attacks... which protection for rudder and fins on trawlers?

[La Sirena]

Maybe orca attacks are a real problem in your part of the world, but I can think of a lot of other hazards I would put a much higher priority on.

 

[soin2la]

That might work on land, but not in the Med/Atlantic. There have been a number of attacks in the vicinity of Gibraltar. (You can't get in or out of the Med to the Atlantic coasts without transiting the Strait of Gibraltar).
~A

So how many recreational boaters, or more specifically, sail boaters really need to traverse Gibralter to the Atlantic coasts? The Med is massive, certainly larger than areas most people on here cruise. Why not just avoid the whales until this goes away and it will? Avoid pirates, avoid hurricanes, but insist a few whales have to be “dealt with” in order to carry out an entitlement to sailing. I don’t get it. Or how about hire power boat escorts?

The only method I know that works for certain is “lethal deterrence”. I realize that is not possible in most circumstances and probably illegal in most jurisdictions, but that is the only known method that works for certain.

Jim, perhaps you know Jarred Towers, the DFO west coast whale expert.
https://www.vancouverislandfreedail...-for-first-time-in-more-than-20-years-7204757

Acoustic sounds designed to deter seals from the Broughtons fish farms, chased away a northern resident killer whale family which historically winter fished in Fife Sound.

Pictured, three generations of A5 clan returning to Fife Sound.

 

[PierreR]

So how many recreational boaters, or more specifically, sail boaters really need to traverse Gibralter to the Atlantic coasts? The Med is massive, certainly larger than areas most people on here cruise. Why not just avoid the whales until this goes away and it will? Avoid pirates, avoid hurricanes, but insist a few whales have to be “dealt with” in order to carry out an entitlement to sailing. I don’t get it. Or how about hire power boat escorts?

For the last month and a half I have been watching thousands of pleasure boats pouring out of the med on their way to the Caribbean on Marine Traffic Global Ship Tracking. If you add in the one's with no AIS the numbers will sink the islands for sure.

 

[soin2la]

For the last month and a half I have been watching thousands of pleasure boats pouring out of the med on their way to the Caribbean on Marine Traffic Global Ship Tracking. If you add in the one's with no AIS the numbers will sink the islands for sure.

It is easy enough to believe what you are saying, but my question was how many of them really need to do it?

 

[PierreR]

It is easy enough to believe what you are saying, but my question was how many of them really need to do it?

If they have a boat symbol that is pink, none because none of us need to pleasure boat. Your question is as absurd as my answer.

 

[x2y3z4]

We did the same cruise (starting near Altea up to the engl. Channel) on our 68" trawler in 22/23. No encounters at all. We often saw orcas between Gibraltar up to Muros, that's it.
And yes we met sailor's (driven by textiles ) who got into trouble.

We didn't spend any worries on that.
Have fun & take your time for those legs!




Btw. we enyode Marina Puerto Sherry for some weeks.

 

[balder8]

For the record, I’m a former salmon fisheries biologist, now retired. I have attended Orca symposiums put on by the National Marine Fisheries Service (NMFS). I have also some professional background in using a DC electric field to deter seal predation on salmon caught in gillnets. This study was published in a North American Journal of Fisheries Management, available upon request.

So with that preamble, I would advise against modifying your “fins” and rudder:

1) I don’t think it would deter the whales. If they had a mind to attack your fins and rudder, they will. As alluded above, they are highly intelligent and will figure out a way to destroy them anyways, if so motivated.

2) Those spikes will surely compromise the fins and rudder, with unknown consequences.

The only method I know that works for certain is “lethal deterrence”. I realize that is not possible in most circumstances and probably illegal in most jurisdictions, but that is the only known method that works for certain. A few have suggested “seal bangers”. I can tell you from experience they DO NOT even work on seals. They would likely make the whales more aggressive. In British Columbia there is a herring roe fishery and sea lions dive over the cork line of seine nets to catch and eat the pursed herring. 100 or more sea lions can be inside those nets and the damage to gear and catch is extreme. Seal bangers do not deter this activity and only serve to upset the environmentalists.

I might suggest you travel in a small flotilla at speed if that is at all possible. Perhaps if one vessel is attacked, the others could assist with hazing.

I wish I had better news, but I don’t.

Jim

Thank you very much indeed JDCAVE, this is certainly the most clear and clever reply I have read for a while, including "local" chats here in Europe!I have more or less 1000 nautical miles to do next spring from Andalucia to Portugal,north spanish coasts ( Galicia) and Atlantic coast of France to be back to Royan, a wonderful area to explore again but really exposed to orcas "attacks" or " interactions"...As you explained, "lethal" deterrent are strickly forbidden in Spain and Portugal and Maritime or Police Authorities are not openmind with that. But the thruth is that lot of boaters are buying "firecrackers" and keep them discretly aboard...

 

[Max1]

I've been reading this thread since it started, and look what popped up in my feed today.

 

[Hippocampus]

Thanks for the link. Good argument for stout steel rudders. Would think balanced spade rudders which are most popular on current sail designs are the most vulnerable. Wonder about the specifics of the data. Is that available?

 

[Max1]

Thank you very much indeed JDCAVE, this is certainly the most clear and clever reply I have read for a while, including "local" chats here in Europe!I have more or less 1000 nautical miles to do next spring from Andalucia to Portugal,north spanish coasts ( Galicia) and Atlantic coast of France to be back to Royan, a wonderful area to explore again but really exposed to orcas "attacks" or " interactions"...As you explained, "lethal" deterrent are strickly forbidden in Spain and Portugal and Maritime or Police Authorities are not openmind with that. But the thruth is that lot of boaters are buying "firecrackers" and keep them discretly aboard...

See my post number 38 on this thread regarding the video of orca attacks. What I found most interesting was the suggestion to drop sand when the orcas are nearby, thus confounding their sonar. I'm not sure if this is guaranteed to work but it was kind of interesting nonetheless.

 

[fgarriso]

I had read somewhere that the only attack European boats, I guess they taste better.

 

[ScottC]

Thanks for posting, Max1. Exceptionally informative!

 

[vertigopilot]

Gosh. I wonder if these highly intelligent animals, which communicate amongst themselves, have had this same discussion and decided THEY needed to come up with an efficient and reliable deterrent.

Maybe try playing Miley Cyrus or Madonna on a loudspeaker. That should deter most anything!

 

[balder8]

Thanks for these replies. Hope your coasts will not be soon concerned by this Orcas behaviour...
Here two pictures of the spikes screwed on stabs before painted by antifouling. nothing on main rudder as it is just in front of the large propeller.

 

[soin2la]

Interesting, but I question the legality of it. There, that'll stir up some new debate.

 

[JDCAVE]

Interesting, but I question the legality of it. There, that'll stir up some new debate.

I doubt that it would be illegal. It’s a completely passive system. I’ll ask Paul Cottrell

One of my biologists developed an electrical deterrence system to prevent predation by seals of our salmon catch in gillnet test fisheries in the Fraser River. It was highly successful, but it was passive, the seals could choose to enter the electric field, or not. Mostly they didn’t, it took some extensive studies and approvals to get through the process, but it did work. I would suggest the spikes on stabilizers would be deemed to be less intrusive than the seal deterrent system. Presumably, it isn’t unreasonable to protect your property and stay safe.

Forrest K.W., Cave J.D., Michielsens C.G.J., Haulena M. & Smith D.V. (2009) Evaluation of an electric gradient to deter seal predation on salmon caught in gill-net test fisheries. North American Journal of Fisheries Management, 29, 885-894.

Jim

 

[soin2la]

I doubt that it would be illegal. It’s a completely passive system. I’ll ask Paul Cottrell

One of my biologists developed an electrical deterrence system to prevent predation by seals of our salmon catch in gillnet test fisheries in the Fraser River. It was highly successful, but it was passive, the seals could choose to enter the electric field, or not. Mostly they didn’t, it took some extensive studies and approvals to get through the process, but it did work. I would suggest the spikes on stabilizers would be deemed to be less intrusive than the seal deterrent system. Presumably, it isn’t unreasonable to protect your property and stay safe.

Forrest K.W., Cave J.D., Michielsens C.G.J., Haulena M. & Smith D.V. (2009) Evaluation of an electric gradient to deter seal predation on salmon caught in gill-net test fisheries. North American Journal of Fisheries Management, 29, 885-894.

Jim

Razor wire around you property is passive, but isn't legal in most places.

I'm not thinking of the equivalent of CG or local Fish& Game folks. I'm wondering about International Marine Mammal Protection Acts. I think "intent" would enter any discussions on this, at an official level.

Those seals you mention got a little shock therapy, not serious damage to their mouths, leading to possible starvation.

I don't expect to hear back from Paul, since he is busy with the Little Hunter in Zeballos.

 

[JDCAVE]

Sointula: I’m struggling to understand your background in marine mammal protection, that would make me believe, your opinion is professionally based?

I’ve worked in this field. Have you?

Jim

 

[soin2la]

No need to struggle Jim, I never claimed any professional positions, I'm just questioning the legality of marine mammal periodontics.

 

[Benthic2]

I am all for protecting marine mammals, but at some point it becomes a self defense response. These whales are sinking some of these boats. I would much rather have to defend myself in court for stabbing an orca with my sharpened boat hook, than to end up in the water with several massive carnivorous animals.

 

[soin2la]

Lol, talk about poking a bear with a stick.

 

[Delta Riverat]

Not going to worry about the whales.