Harbor Seal Rodeo

A story by Jim Harvey, PhD.

Harbor seals in the waves

Director of the Moss Landing Marine Labs, Jim has done it all, or so it seems. But his latest work has turned him into a marine cowboy. Catching harbor seals in the name of science is only for the hardy. Timing, steadfastness and knowing what to do (and not to do) when a seal has latched onto your hand are only some of the qualifications needed for the job. Jim takes us out in his little boat and from there into the mud, wrestling with seals.

JIM HARVEY is the Director of Moss Landing Marine Labs (MLML), which administers the Master of Science in marine science program for the California State Universities in northern and central California. Jim joined the faculty in 1989 where he taught for 23 years. He then became Chair of the Department for 4 years, responsible for the academic program, before being appointed as Director in 2013.

Jim was born in San Diego and lived there for just one year, before his father, who was getting his masters at San Diego State, moved to Berkeley to do his PhD in botany. Jim was raised in the Santa Clara Valley, now known as Silicon Valley, where he went to San Jose State for his undergraduate work.

Jim always had an interest in marine biology, but the path to his current career wasn’t foreordained. His father taught at San Jose State University (SJSU) as a botanist, with a strong geology background and extensive knowledge of birds. According to Jim, his dad seemed to know everything, and he knew he could never compete with his dad. While out surfing one day Jim had an epiphany: ‘marine science’! His dad didn’t know anything about marine science.

After getting his Bachelor’s Degree at SJSU, Jim attended MLML where he completed a Masters Degree studying the feeding, reproduction and aging of blue sharks. He got his PhD from Oregon State University completing his Doctoral Thesis on harbor seals. Jim continued his studies spending two years at the NOAA facility in Seattle as a Post Doc student.

During those two years, he was considered a jack-of-all-trades, as he already had tagging experience, aerial survey experience, and had handled animals before. NOAA always sent Jim when something needed to be done in Alaska. When gray whales got caught in ice and they wanted to tag them, they sent Jim as he had previous experience tagging gray whales. When the Exxon Valdez spill occurred in Prince Williams Sound, they sent Jim to do aerial surveys for oil and its impact on wildlife. He recollects that they sent him to every natural and man-made disaster in Alaska for those two years.

Just when Jim finished his PostDoc, a position opened up at MLML. What incredible luck! As a student at MLML, Jim had decided the kind of job he’d really like was an MLML job. It was a small marine lab with lots of good graduate students, a very dynamic place. So he geared his work experience towards the skills he’d need, purposely taking jobs and training that would enable him to get the kind of position he wanted. Little did he know that even his ‘natural disaster’ experiences would come in handy.

Jim became a professor at San Jose State in 1989, stationed at MLML.  He arrived 2 months before the 1989 6.9 Loma Prieta earthquake destroyed the lab.  Jim was in the lab at the time, as the foundation moved 3’ towards the ocean. The whole lab didn’t fall down, but ended up severely tilted. He recalls it was pretty exciting.  A geological oceanographer was helping teach the class, and the two of them had just finished and walked out the classroom door as the quake started. Jim yelled back into the room to get the students out, and they were already running as he yelled ‘Earth…….!’.

Jim and his colleague ran into the atrium as students tried to run out the main door. A 2-story seawater tank outside was swaying from side to side with about five feet of water sloshing out the top. Students were going to run right beneath it, and Jim yelled, “NO, NO, come back!” So they all stood there trying to keep their feet under them.  Cracks were forming in the ground at least a foot wide and three feet deep. According to Jim, you were just kind of dancing around trying to stay upright. The shaking only lasted 14 seconds, but it seemed like 2 minutes. Built on sand, the whole area liquefied causing great damage to the structures. The building was red-tagged and knocked down with everything in it, including Masters theses.

Jim and others convinced the county to put in structural supports, and for 2 days, staff and students passed stuff out the door through a human chain. Everything was stored in Salinas. And for the next ten years classes were held in trailers in Salinas, nearly 60 miles from Monterey Bay.

 You can watch Jim’s story on Youtube here: https://youtu.be/W-KJiXsQNHI

HARBOR SEAL RODEO 

I’m gonna tell a little about a capture event for harbor seals here in Elkhorn Slough. Harbor seals are very difficult animals to capture, because they are very wary of humans, first of all. They are sitting right next to the water when they’re on land and resting, so they’re capable of getting in the water and fleeing very rapidly. And because they are in an estuarine system, they’re really used to getting in the water whenever there’s a disturbance.

It’s taken a long time for us to develop methods to be able to capture these harbor seals, for that very reason. You start coming close to them and they immediately get into the water, and it’s difficult once they get into the water to be able to catch them.

So we devised a method of capturing harbor seals that uses a net on the back of a boat that’s set at a very fast pace. Basically, you’re doing a big beach seine, with a net around the harbor seals. And if you do it properly and the seals behave properly, we’ve been able to catch, up to the largest number of animals we’ve caught in one net was eighty-five, which was way too many seals. But in this case, and mostly with harbor seals in Elkhorn Slough, you don’t catch that many. You often times catch zero, or you catch what is probably the optimum number of about ten or fifteen.

The way this is done, the seals are on the haul-out site, resting up near the water on the mudflat, and two boats come up to the seals, like I said, at a pretty fast pace. The first boat is the one that has the net in it, and as you get close to the seals, the seals most likely will start going into the water. Hopefully some portion of them won’t – those, which are sort of unsure what they should be doing. So they may be standing there looking around like, “Oh, look at these boats coming. What am I gonna do?” If there’s a slight hesitation on their part, then what happens is the first boat comes up. They drop a buoy that has one end of the net off the back of the boat, and then the boat proceeds to go around, kind of making a curved arch around where the seals had been or maybe still are, and in that whole time the net’s playing out off the back of the boat.

That net’s about 150’. Well, no, it’s about 300’ long, and about 14’ deep. It’s a pretty good size net. It’s set, like I said, very rapidly. The second boat comes, picks up the buoy and pulls that first part of the net to shore. Now you presumably have a net that goes from one end of shore around and then back to shore again. And any seals that were on the shore hopefully are gonna get caught, and any seals that got into the water and never swam too far away may potentially get caught.

This happens all in the course of about maybe three minutes. So you’re doing it really quickly. The two boats have people in them, and as soon as you get to shore both boats’ occupants jump out of the boat. The first thing that you train yourself to do is put an anchor on the shore, because we’ve done this before where you didn’t put the anchor out, and all of a sudden you look around and the boat’s floating off.

So you learn very quickly that somebody throws the anchor on the shore. Now you have both boats on shore. People jump out of their boat and grab the net, and now you start pulling it to shore. And what’s supposed to happen is the seals are in the water now swimming around trying to find their way out, and you need to get them back to shore pretty rapidly. Because, if you don’t, the seals finally, sometimes, but not all the time, start to figure out that there’s no escape. They can go up on shore, but they can’t get past this net that’s in the water. So the smart seals will start thinking about it and just jump over the net, the surface part of the net.

So that’s why you want to get to shore really quickly, so you don’t give them a lot of time to think it through. And if you do it properly, the net gets pulled to shore, and now you’ve got a series of seals, maybe, like I said, optimum would be ten to fifteen seals in this net. They’re in the bag of the net. You’re pulling both the top of the net that has the floats on it, and the led line that’s the heavy part of the net, and you’re pulling these two in together, and there’s this big bag of the net that has the seals in it.

So as you pull this to shore, you now have this bag of seals, basically, that you’re pulling to shore. That’s why you can’t do this like with one or two people. You have to do it with a large group. And we typically have about twelve to fourteen people that are helping with us to pull this bag of seals to shore.

Now the hard part comes. That part’s relatively easy, but once you’ve got this seal in the bag in front of you, especially if it’s in mud, it’s very difficult to walk in that space, let alone do any kind of work. So the way we have to do this, is you have to open up the top part of the net. Somebody has to go into the net where the seals are all going like this and biting at you, and barking at you – well screaming at you. And then you have to grab their rear flippers, and you pull them partially out of the net. And somebody throws another individual net that we have – we call them hoop nets – that are about eight feet long. They’re a cone shaped net with a rubber around the outside of the ring, so you can have this opening that you flip up in front of the seal. Pull the net over the seal, or often times we just let go of the flippers and the seal will want to go forward back to the water, and in so doing it gets into this net. Then we twist the net, put the seal in its own bag, and you pull the next seal out of the big bag net and back up onto shore. Then we grab the next one, and we keep doing that over and over again, until we get all of the seals out of the bag net into their own individual bags.

The hard part, as you might imagine, is going in if there’s a whole bunch of seals that are free inside the bag, and you have to be able to grab the net, or grab the flippers and not get bit. And, often times, some of these animals are, the big males are up to two hundred and fifty pounds, two hundred and sixty pounds, so you’re sort of fighting a linebacker in the bag, is what it feels like.  You often times can’t move something when it’s stuck, so you now have a seal that’s turned and is coming towards you, and you can’t move because your feet are in the mud.

And so you just fall backwards. You sometimes will throw a bag in front of the charging seal, one of our capture nets in front of it, or somehow try to keep the seal from biting different people, who most of the time work pretty good at not getting bit. But every once in awhile somebody gets bit by a seal. It’s not a pleasant thing, cause seals, the way they catch their food, especially large fish, is they grab their fish and then they go like this, shake their head to tear it. And they do the same thing with your hand or your arm or anything else. They’ll grab you like this and start shaking, and so before we go capturing seals, those people who are handling the seals, I just tell them it’s sort of not intuitive, if you get bit r e l a x. Because if you hold your arm stiff and they grab it and start shaking, they’re just gonna rip your skin. But if you relax, you’ll go with em and it’ll be less painful and a lot less damage. Which is hard to do. To think about it: “Oh relax! My arm is in the seal’s mouth, relax, everything will be fine.” It’s a hard thing to do.

But I’ve trained myself, and so a lot of the other people who’ve done it have also gotten pretty good at when they do get bit, they just relax. At some point the seal will let go of your arm or your hand.

So now you have them in their individual bags. Then we will often times transport them to some place that’s a little more stable ground and use that to go about tagging them. And it involves weighing them, putting a little tag in their flippers that identifies them individually. We oftentimes will put a radio tag on them, and the way we do that is basically glue it to their hair.

My good colleague and friend, Robin Brown at Oregon Department of Fish and Wildlife, and I are the ones that pioneered that technique in the world, of gluing tags to seals and sea lions which is now done everywhere. But we were the first ones to do that with seals in Oregon. And it works out really well, because you can glue the tag to the hair. If you do it well and the seal’s in good shape, it’ll carry that tag for about 8 to 9 months, maybe a little longer, and then it molts and the hair falls off, and the tag falls off. So basically it gets rid of the tag after about a year, and most of our radio tags last about a year. So, it works out really well. The seals don’t have to carry this thing around after the tag stops working.

But now a days, the traditional way of doing this now, the standard way of tagging elephant seals, sea lions, or whatever, is to glue things onto their hair. We did that early on, learned how to do it, then told the rest of the world how to do it, and everybody else has been doing it since then.

So, yeah, the harbor seal captures are always like, I’ve always explained it to other people, like a rodeo. There’s just lots of things going on. There’s lots of yelling, because it’s so dynamic, seals are going after different people, or different things have to be done, and it’s rarely a calm event where you’re able to sort of just slowly do. It’s sort of like, “Oh, get that, grab that line, put your net down!” So, it is fun, in the sense that it’s a rodeo. But at the end of the day, hopefully, if it’s been successful you have a bunch of harbor seals that are now tagged and running around. They get over the event probably, in my estimation based on watching them, probably in about an hour they’ve gone back to totally forgetting that it just happened to them.

We’ve been tagging seals in one location, where we had the seals in one spot and continued to process or tag them there, and the animals we just disturbed are hauled out about 200 yards down the beach from us. So it’s very common and I think, pretty obvious that the seals don’t quite understand that the disturbance we just created is gonna hit them again. They sort of independently think that, “Oh, it happened, some of those guys, those crazy people just, you know, disturbed us, and now I’m just gonna go about my ways and continue to be a harbor seal”, right next door to where we were working. I think the seals get over it really rapidly after we’ve disturbed them.

Yeah, I think that’s pretty much the story. Now there’s lots of little caveats about that. So each time we do this, something else bizarre happens. Or we have to improvise how we go about capturing seals. It all depends on the location and what’s going on with the seals. We’ve had one place in Elkhorn Slough here where the seals went up this little tributary. So now we had a couple seals way up this little, narrow tributary – it might have been six feet wide, so we came up with a brilliant idea. Let’s just put the net right across the little tributary and then we’ll go walk up along the mudflat and scare them down into the net. And that worked.

But the process ends up being a little bit scary because the seals, once you’re moving them down into the net, swim very rapidly so all you see is this wake, where the seal’s under water swimming and you can see this wake of this seal coming. And the net’s sitting there, and we’re all standing there holding the side of the net going, “OK, what’s gonna happen?” and then all of a sudden, it hits the net, and you grab the net and hold on, and you’ve got to do the same thing I mentioned before, where you’ve got to pull the seal out of the net and make sure you’re not getting hurt, and the seal doesn’t get hurt at the same time.

This method is something we’ve developed over a long period of time, and we’ve been very successful at catching seals that way. And now we’ve tried out a variety of other ways of catching seals some of which are tangle nets, where it’s like having a gill net for salmon, but it’s for seals, so it’s got a bigger mesh and you put it in the water. It has really thin lines so the seals don’t quite see the net in the water, and they’ll swim into the net, get caught, and then you’ve gotta pull them up into the boat, take them out of the net and put them into these little hoop nets, as I’ve mentioned before. We then go ahead and process them, weigh them, and put tags on them, that sort of thing.

But it all depends. It depends on the seals and what location it is, and how the seals are behaving.

Jim Harvey, PhD

Post Script

This is not a Monterey Bay story, but one that’s related to that story that was a scary one, was we were tagging seals in Northern California in a river system that I’d never worked in before. And because the seals were really close to the mouth of the river, I had to observe them from a distance with a spotting scope. So we were trying to figure out how we were going to catch these seals at this one location, but I had to figure out how we were going to do it from a long distance.

So we get in our boats. We start down the river, the estuary, towards the mouth of this estuary that goes out into the ocean. And I’m in the front boat, driving the boat with the net, and we throw the buoy over like we normally do, and the next boat comes up and the guy jumps out, grabs the buoy, and as I’m driving the boat, I look back to see how he’s doing. I had miscalculated how much water was flowing out of this bay. So now all of a sudden, we’re basically in a rip.  I have a net now in the water that’s being pulled, and one of my colleagues who jumped out of the boat is holding onto the buoys and is being dragged along the beach with this buoy in his hand as the net is pulling him. And he’s trying to put an anchor in the water, er on the land, to try to stop this net from going forward.

Finally, I looked ahead and I could see the ocean coming up, so I realized if we didn’t do something really rapidly, we were gonna be swept out into the ocean with this net and this boat and then it was going to get really hairy. So I just finally told him, “Let go, let go!” He let go of the buoy, I got the boat to shore, and the net just kinda went like this and came round to the stream side of it. We didn’t catch a single seal. I suspect most of the seals were just sitting there watching us, laughing. It was pretty hilarious. Our weak attempt to try to get seals in that spot.

So, like I said, every place is different. Every place, every seal capture has got its different little parts that are either funny or scary.