underwater explosives/ seal & sea lion deterrents

[Sideburns]

When salmon fishing and/ or squid jigging, seals will chase off everything and even take your catch right off of your line. When jigging at night, the lights used to attract squid also bring in the seals. If the seals show up, its game over.

 

The federal gov allows most non lethal methods of deterring these animals. Allowed methods can be found here https://www.fisheries.noaa.gov/webdam/download/99268041 or for the NOAA main pineped deterent info page - https://www.fisheries.noaa.gov/west-coast/marine-mammal-protection/deterring-nuisance-pinnipeds I have used unreliable chinese firecrackers many times in the past to scare away the seals, and this does not seem to bother the squid at all.... maybe even enticing them to bite.

 

I have also made and used small 5-10 g, weighted bp "salutes?"(small section of sand at the bottom of a top fused black powder filled cardboard tube) a few times to scare these pests away. Although none of these bp or flash filled devices make much noise above water, the black powder versions seem to be much less effective.

 

I am not trying to build "pype bomms" (intentional), although I realize that's pretty close to what Ive been imagining as successful deterrents. Heavy containment.... Is there a safe way to do this? Less containment because the water pressure already accomplishes sufficient containment?

 

Do any of you pyro guys know much about how underwater pressure waves travel underwater? Or about wildlife deterrents in general? What would work better, something slower like a propellant charge, or something fast like a flash salute? Is there any way to make a brighter flash underwater? I'm not real keen on making flash powder, but I am fairly experienced with black powder making and own a ball mill.

 

Thanks guys

-Sideburns

 

Btw, the fishing area is in the Puget Sound, in 50-200 foot deep saltwater. The seals are anywhere from the surface to the bottom, but always very visible with the fish finder when present.

 

 

 

 

[saminaz]

Wouldn't these need to be commercially manufactured devices so as not to run afoul of the transportation restrictions on self produced pyro?

Perhaps something like commercial pistol or shotgun launched " bird bombs" could be used?

[memo]

seal bombs , bird bangers , bear bangers. check out the fishermen for seal bombs and a big ammo store for the others. i have not lived in the usa for over 20 years. you could get all these before i left , now who knows.

 

memo

[Sideburns]

Wouldn't these need to be commercially manufactured devices so as not to run afoul of the transportation restrictions on self produced pyro?

Perhaps something like commercial pistol or shotgun launched " bird bombs" could be used?

Good question. I'll do what I can to research the transportation issue.

 

seal bombs , bird bangers , bear bangers. check out the fishermen for seal bombs and a big ammo store for the others. i have not lived in the usa for over 20 years. you could get all these before i left , now who knows.

 

memo

I know seal bombs still exist, but I think they require some kind of commercial license to purchase. Ive asked around locally at sporting goods stores to no avail. Also the expense of those items would likely be a problem for me. The seals come back pretty quickly if you dont continually deter them, the quantity of seal deterrents needed per fishing trip is approx 10-20.

[Sideburns]

FYI (for those who dont already know)

 

These seals are invasive. They are not native to the area. There are now so many in puget sound that they are rapidly decimating the native salmon runs and other native fish in the area. Even the orca whales are suffering because of the seal problem. Fisherman and land owners illegally kill many seals each year.

[Piccaso]

The do make seal crackers for sale commecially but they do require a federal explosives permit to purchase use and poses. The problem is they have very little effect and the animals return quickly. The other problem is making them is the same a producing a m80 which is illegal every where in the U.S. and even if it where not you would still need the permit to transport them. The shotgun launched ones are known as shell crackers but again you need the license to purchase them. The only way to do it above boards is to get your explosive license. I wish I had better news for you , I researched this very thing as I wanted the shell cracker to get rid of the birds in my blueberry orchard.

Edited December 5, 2019 by Piccaso

[pyrokid]

Fish for seals instead!

[BetICouldMake1]

I would think that you'd be able to make something effective with a fairly small charge if it was well confined and weighted to go off underwater. Others on here could explain the physics better than me, but I'm just thinking of discussions I've seen about the pressure wave produced when firing a gun underwater due to water being denser and less compressible than air.

 

You might also consider trying to rig (or purchase) an acoustic deterrent, something like a submerged subwoofer seems like it would be effective.

 

Or, ya know, do it the old fashioned way: spear gun.

[biffo24]

Hi this sounds like a real problem for you and the seals,I dought weather they would be so determined to stay around with crackers going off if they weren't hungry,it sounds like but I cannot be sure that food in their native area's has been decimated by overfishing so they've upped sticks and moved in to your fishing spot.Sorry to hear about this in yet another region,the acoustic approach sounds worth checking out. Good luck B

[FrankRizzo]

Just make them on-site to avoid the transportation issues; think Tannerite. Cardboard tubes could be pre-prepped with one plugged end and a glued-in waterproof fuse. Two small peanut butter jars or similar could be used to contain the perchlorate and aluminum powder separately. A small electronic scale for measuring, some plugs for the other end, and whatever glue you decide to use. Mix, load, stow, and use.

[Sideburns]

I would think that you'd be able to make something effective with a fairly small charge if it was well confined and weighted to go off underwater. Others on here could explain the physics better than me, but I'm just thinking of discussions I've seen about the pressure wave produced when firing a gun underwater due to water being denser and less compressible than air.

 

You might also consider trying to rig (or purchase) an acoustic deterrent, something like a submerged subwoofer seems like it would be effective.

 

Or, ya know, do it the old fashioned way: spear gun.

 

One of the new idea's in seal deterrents is actually an underwater speaker contraption that plays killer whale hunting noises! Its an expensive device, but makes me wonder if any old waterproof speaker could play underwater.

 

I hear seal tastes like venison, seal fishing sounds like a hoot, I'm in! lol

 

Just make them on-site to avoid the transportation issues; think Tannerite. Cardboard tubes could be pre-prepped with one plugged end and a glued-in waterproof fuse. Two small peanut butter jars or similar could be used to contain the perchlorate and aluminum powder separately. A small electronic scale for measuring, some plugs for the other end, and whatever glue you decide to use. Mix, load, stow, and use.

 

Washington law specifies separate ingredients that are easily combined the same as an explosive device, but looks like the transportation issue only applies to larger quantities? Reading all the the rcw's is pretty painstaking....

[Arthur]

Sink a speaker in a weather balloon play some noises see what happens

[Sideburns]

I gotta say, I kinda felt like a troll..... asking the questions I did. Although I have little experience with this site, I halfway expected to get thoughtless responses like "Danger Danger" "you'll shoot your eye out" Etc.. Etc...

 

Instead, all I got was thoughtful advice and valid concerns. Two thumbs up fellow pyro's!

 

I certainly haven't given up on the pyrotechnic deterrents, but I think I will spend some time looking for info on underwater acoustic devices, maybe even throw an old marine speaker and some speaker wire in the boat. Good advice. Thanks guys!

[Sideburns]

Back to the funner pyrotechnic methods though....

 

I was surprised to see such a bright flash underwater from black powder. (well milled, granulated, fast burning bp) Quite visible even through the overhead and submerged led light that was already deployed from my boat. I kinda doubt many methods like stars would stay ignited very far from the initial detonation, but are there any methods of brightening the burst charge itself that have a good chance of working underwater? I guess I'm not sure how much of the oxygen needed in the longer duration (coarser particle metals) bright effects actually come from the atmosphere/air..? Then again, I might be overthinking this......... Lol

 

I should mention also, a lot of my outside the box, change it up thinking here comes from the fact these seals are likely getting used to these simple pyrotechnic noise makers from commercial and recreational fisherman. The same simple pyrotechnic deterrent devices that worked so well over the last few years are just not working so well anymore.

[Arthur]

What feeds on seals? What does their hunting pack sound like? Can you replicate it and replay it under water. It may be a much wider band of sound than humans can hear.

 

Have you a source of the marine zoological data in your town/state/country?

[Sideburns]

What feeds on seals? What does their hunting pack sound like? Can you replicate it and replay it under water. It may be a much wider band of sound than humans can hear.

 

Have you a source of the marine zoological data in your town/state/country?

 

Orcas (killer whales) love to feed on seals. They are very afraid of orcas. Humans are the next leading cause of unnatural death. One google patent Ive found, shows a speaker device in a tube that plays a proprietary orca hunting soundtrack.

 

I am fairly knowledgeable on this local ecosystem and the food chain in this area. What did you have in mind?

[Arthur]

All you have to do then is get your own recording of Orcas so that the seals are chased away by audio orcas.

[Arthur]

If you browse youtube on submarine videos there are sometimes sonar clips of whales -may be borrowable! Go on a whale watching trip and see what you can record! Whale noise includes low frequencies.

 

Just look at the real cost of research and production of a whale sound effect versus the cost of the permits and the "explosive but approved and transportable" seal frighteners.

 

IIRC the Puget Sound is a submarine training and testing area so they are listening to what you do.

[memo]

side burns

are you in washington state

[Arthur]

https://www.youtube.com/results?search_query=orca+sounds+underwater

 

one of the choices lasts ten hours, is that long enough for you to fish?

[Sideburns]

side burns

are you in washington state

Yup. 30 min south of Seattle.

[Sideburns]

https://www.youtube.com/results?search_query=orca+sounds+underwater

 

one of the choices lasts ten hours, is that long enough for you to fish?

Yeah, that should be long enough.... Funny I just did the same youtube search this morning! Thanks.

 

I am out in the shop now getting some stuff ready for Saturday night, going back out for some more squid! I'm working on some led boat bottom lights at the moment..... I can see it now.. "hey man, the lights look great, but why are there speakers cut into the bottom of your hull?"

[Arthur]

Somebody know about long term submersible speakers, whether they will talk to you... They are called sonar arrays the navy has a few! And I'll bet they have a system being decommissioned at the moment somewhere.

[Sideburns]

Somebody know about long term submersible speakers, whether they will talk to you... They are called sonar arrays the navy has a few! And I'll bet they have a system being decommissioned at the moment somewhere.

I had no idea speakers were ever used in sonar sonar.... Modern recreational/fishing sonar transducers are little piezoelectric devices of some kind.

 

 

Quick! Somebody talk me out of painting and decorating a few slowly sinking underwater explosives to look like a tasty squid with a fuse hanging out of its butt. I crack me up.

[memo]

Yup. 30 min south of Seattle.

there are plenty of tribal fishermen in your area , you should talk to them. there is a banger that is about 4 inches long by about a 1/4 inch that shoots from a gun that would work perfect. years ago i got them from the skok. tribe in union on hoods canal, the fishermanthat were netting fish