Robotic Urchin Harvester Project - Otter Force One

[wnissen]

Just wanted to share my thoughts, which largely echo Eric, who is vastly more experienced than me. Most of the kelp is pretty shallow, it needs to be close-ish to sunlight. Still, the visibility is pretty bad at times. A few meters at most. I don't know how well computer vision Deep Convolutional Neural Networks or whatever you're using deal with darkness, swell, and backscatter but that may be a big challenge even for identification.

Though it doesn't look like it on our time scale, urchins are pretty mobile and smart. Have a look at any time lapse when crushed urchin or a predator like a sea star is around. On a scale of minutes, they move away pretty quickly. On a scale of minutes they scoot quickly away from a predator, as Monterey photographer Kate Vylet shows. I wonder how well the urchins would detect the sound of the box.

 

[Eric Sedletzky]

It seems sort of pointless unless this is a stepping stone to an autonomous vehicle. I wonder if the ROV operator needs a California fishing license?

I would assume they would need a license, unless they get some sort of exemption through DFW.
If the machine is used by an operator then it seems a little complicated and a convoluted solution when stuffing a bag by hand is fairly quick and easy to do. It’s also pretty economical when considering the basic gear needed to collect by hand.
By far the biggest obsticle I have found is what to do with them once they are out of the water. Composting them is a convenient way of getting rid of them since there is nothing much to eat inside. But finding a location to dump that many is another issue. I wonder about environmental concerns with that much concentrated biological matter plus the salt content, there is still sea water inside them.
They mention in the article a person averages 100 urchins per hour picking by hand. I will prove this number absolutely wrong by anyone who would be willing to witness me collecting urchins with a timer. In an hours time I will have collected hundreds. My game bag is a lot larger than the one they show and there is time involved in emptying out the bag once they are full. They also are not taking into account that the urchins need to be shook down to the bottom of the bag periodically because they get hung up on each other.
Like I said, I can collect 40 gallons of urchins on one 85 cf tank. Total time in the water is about an hour maybe a little more, but that’s three bags full = three dives. I estimate between 800 to 1200 urchins so they are way off.

 

[Eric Sedletzky]

Just wanted to share my thoughts, which largely echo Eric, who is vastly more experienced than me. Most of the kelp is pretty shallow, it needs to be close-ish to sunlight. Still, the visibility is pretty bad at times. A few meters at most. I don't know how well computer vision Deep Convolutional Neural Networks or whatever you're using deal with darkness, swell, and backscatter but that may be a big challenge even for identification.

Though it doesn't look like it on our time scale, urchins are pretty mobile and smart. Have a look at any time lapse when crushed urchin or a predator like a sea star is around. On a scale of minutes, they move away pretty quickly. On a scale of minutes they scoot quickly away from a predator, as Monterey photographer Kate Vylet shows. I wonder how well the urchins would detect the sound of the box.

It would be interesting to know if they just sit there and not know what’s going on with the machine, or if they percieve it as a threat and either lock down or run. With voracious sea stars, there’s millions of years of evolution and adaptation to know that they are predators and they run like hell! How they know they are predators I don’t know, but they do. I’ve even had them lock down on rocks before with a grip that they can achieve by gripping the substrate with their spines after I start messing with them to get them loose off the rocks. So apparently they must know that I’m some sort of predator after them too. A good swat with an ab iron solves that problem.
I’m working on designing a mini rake for harvesting just for this problem.
I’ve had my share of spines in the ends of my fingers and knuckles thank you.

 

[Jcp2]

I’m working on designing a mini rake for harvesting just for this problem.
I’ve had my share of spines in the ends of my fingers and knuckles thank you.

Bob Evans would like to sell you a Whackerspoon.

 

[Eric Sedletzky]

Bob Evans would like to sell you a Whackerspoon.

A what?

 

[Jcp2]

A what?

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I have one. It’s cast aluminum, nice heft to it, good for whacking stuff.

 

[Bigbella]

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I have one. It’s cast aluminum, nice heft to it, good for whacking stuff.

These have never failed . . .

 

[Akimbo]

The second would be to suspend the general wanton waste clause specific to purple urchins and have that in writing, and the third would be to suggest enacting a cash bounty for purple urchins based on poundage.

Good suggestion but would be hard to get through the bureaucracy. Maybe dive shops can offer competitions with the prize of 10 air fills and posting a picture of the winner? Small cost, good PR, and bragging rights for the winner.

They mention in the article a person averages 100 urchins per hour picking by hand. I will prove this number absolutely wrong by anyone who would be willing to witness me collecting urchins with a timer.

Better have continuous video to convince California Fish and Game.

IMO, they should eliminate all restrictions on purple urchin removal until further notice, including requiring a $54 fishing license. A lot of divers who are interested in ocean ecology are not fisherman. It is also a good skill exercise for OW classes.

I spoke with some divers from Sonoma State working on the kelp restoration project in Mendocino Bay. One was a grad student and he said he can't see any reason not to just smash urchins instead of collecting them. I can't ever remember smashing an urchin and the innards surviving more than 30 seconds before fish eat them.

 

[Bob DBF]

Be careful when smashing urchins.

Urchin Matters | Pacific Sun

Smashing urchins is also controversial because the process can allegedly release eggs and sperm into the water, where the gametes might meet and produce larvae, and eventually more urchins. Russo says so few urchins in the overpopulated areas currently contain viable gonads that the concern is not legitimate.

Rogers-Bennett doesn’t feel that citizen groups without scientific permits should be tackling the restoration effort, partly because of the risk of promoting reproduction.

“Most urchins in a barren are sterile, but you do find some that are reproductive,” she says. “We want to be sure nobody is smashing urchins during the reproductive cycle.” Purple urchins usually spawn naturally in winter months.

 

[Akimbo]

Be careful when smashing urchins.

Urchin Matters | Pacific Sun

Smashing urchins is also controversial because the process can allegedly release eggs and sperm into the water, where the gametes might meet and produce larvae, and eventually more urchins. Russo says so few urchins in the overpopulated areas currently contain viable gonads that the concern is not legitimate.

Rogers-Bennett doesn’t feel that citizen groups without scientific permits should be tackling the restoration effort, partly because of the risk of promoting reproduction.

“Most urchins in a barren are sterile, but you do find some that are reproductive,” she says. “We want to be sure nobody is smashing urchins during the reproductive cycle.” Purple urchins usually spawn naturally in winter months.

I have seen this hypnosis many times but no evidence. Neither has that grad student on the kelp restoration project. I doubt much escapes all those fish that sucks up all soft tissue.