Numlock Sunday: Sarah Gilman on invasive species

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By Walt Hickey

Welcome to the Numlock Sunday edition. Each week, I'll sit down with an author or a writer behind one of the stories covered in a previous weekday edition for a casual conversation about what they wrote.

This interview with Sarah M. Gilman is about her awesome story The Rat Spill in Hakai Magazine.

This is the second of a two-part interview, so if this is your first Sunday edition or you just missed last week, you really should first check out last week’s edition with Sarah, where we talk about how islands are uniquely susceptible to rats.

This week, we talk about what makes a species invasive, what responsibilities humans have to maintain ecosystem stasis, and the strenuous efforts underway to fight back against rats.

You need to check out The Rat Spill by Gilman wrote for Hakai Magazine. Sarah can be found at Hakai and is on Twitter. Her work can be found at her website and as she also did the illustration you can find more of her art here.

Now, I’m picking up just before where we left off last week, when I asked about the invasive species seen in Alaska.

An arctic fox on St. George island in the Pribilofs. U.S Fish and Wildlife Service

Sarah Gilman: Another case in Alaska that's actually really interesting is foxes. So the Russians, when they first got out there, they killed off all the sea otters which were a primary thing for the fur trade along with seals. They started introducing Arctic foxes to all of these Aleutian islands that had no mammalian predators. That devastated seabird populations before anybody was really paying attention.

One of the things the Alaska Maritime National Wildlife Refuge, which is the refuge in my story, has done over the past is have people on staff who are basically employed to eradicate foxes from islands where they had been introduced by the Russians and later by the Americans to harvest for basically fur farming on these islands. I think they cleared something like 40 islands over time and they've seen big recoveries in seabirds in those places afterwards.

Walt Hickey: When I was reading about how rats are omnivorous and voracious and I couldn't help but feel some mild recognition for another mammal that I'm aware of.


You think about this a lot when you're covering what we call invasive species, this idea that a creature can be bad just by living its life and arriving somewhere because of us. That's a morally complicated idea, because we as a species are maybe the ultimate invader. We're versatile and we're almost everywhere on the planet and we've very significantly shaped all of the places we arrived. It's hard when you’re writing about these things, not to recognize a little bit of underlying hypocrisy and how we deal with the other animals that come along with us.

It's hard to deal with that directly in a story, but it's definitely something you're aware of even as you recognize the ecological value of maintaining some places, where possible, with their native flora and fauna. Because biodiversity is really important in the world. The more creatures in the world that there are, the more resilient the world is to change, because all those creatures have different adaptations so whatever happens the chances are better that something's going to get through it. It's important, but at the same time it's a morally problematic idea that a species can be bad just by existing.

Invasive species personally fascinate me. Just recently there was a great story about this aquatic carnivorous plant that is going extinct all over the world except in two places, Virginia and New Jersey, where it is an invasive and hated species. And so what do you do with a species that is only succeeding where it's invading, you know?


Right, exactly. I mean, when you get to that point, when you're trying to control something, and attempting to hold the world in stasis — I might get myself in trouble here a little bit so I should be careful — but it would fail to recognize that the world is this dynamic moving place and that it's going to shift and that we're probably going to play a role in that.

It's like with the Arctic Fox: in Scandinavia and Northern Europe, people are working really hard to save them and they're doing quite badly. And then here you have Alaska where they're an invasive species hammering the seabirds, and they're being actively killed. Whether a species is valued or reviled, it really depends on the context and how it plays in the larger role and also with how it's viewed culturally. A lot of times in Alaska you encounter people, they really don't like Arctic Foxes, but in Northern Europe they're missed.

Obstructions on mooring-lines to stop rats boarding ships. Drawing by A.L. Tarter, 194-


So we're all agreed. We don't tell Sweden about what the Department of Agriculture is doing with the foxes.

You wrote about how prevention is an order of magnitude cheaper than eradication and you went into how the fines for ships and people that dare bring rats onshore are enormous. How have those been effective?

There's two things going on here. One is eradication of a species that has already invaded an island. And the other is just trying to keep them from getting back there. The eradication — that's an enormously expensive task. Imagine an island that has a lot of rock outcrops and maybe some forests. It might not be that big, maybe it's like a thousand acres or something. But imagine all of the places on that island where rats could be hiding. Imagine trying to kill those rats with poison without killing everything else on the island. Also while complying with environmental laws that keep it safe for people and all of these things. And then you have some idea of why it is so hard to plan and execute and eradicate. That's the first starting point. It's enormously expensive.

Rat Island, U.S. Fish and Wildlife Service

I think when they did Rat Island, which is an island in the western ocean off the coast of Alaska, it cost $2.5 million in 2008. Among other islands, the biggest one they've done is down off of Antarctica. That was thousands and thousands of acres a multimillion dollar project.

Getting into prevention: prevention is actually less than fines or deterrence, and more like vigilance and public information. That's sort of boring sounding. It's basically finding ways to keep an eye on the likely points of entry, and then also making sure people coming in and out of a place understand what the signs of an invasive species look like. Like if they had rats, what would they look like so they could avoid introducing them.

That work is not that expensive, it just requires a lot of investment of time and energy. Which is a form of expense, but less so than poison bombing an island essentially, and also obviously much more desirable because it does pretty good job of keeping other things from getting killed. Killing a lot of anything is not a great thing to have to undertake. If you don't have to kill any rats at all and you can avoid killing other species, then it's less expensive in that sense.

On St. Paul and St. George, they have these barrels I talked about, dozens of them spaced around. And they're essentially rodent attractors that have traps in them that they track to see if any rats are making it onto the island. And then they can initiate a very fast response if need be, to address that within a matter of weeks. After that original report, I think they had a strike team on the island to try to chase down this rat. At first they didn't get it, because it's quite difficult to catch rats and especially a lone rat is even harder to get on an island with all of these hiding places and food sources. That prevention, even though it's kind of tedious work that has to last forever by its very nature, is a lot less expensive.

NOAA

So it's doable.

In Alaska actually rats are pretty rare up there still. There's not that many places that have rat infestations. There are definitely places in the Aleutian islands that have rat infestations from ship activity over time. But mainly in Alaska, I think there's a breeding population in Fairbanks of all places, and then there are some in some of the ports down in the southeast, but otherwise they haven't really managed to gain a toehold even in Anchorage. Which is crazy because Anchorage is a big city. It's 300,000 people. The fact that there's not a recognized breeding population of rats there is great.

There may be something about those northern latitudes that is less hospitable to rats. That actually could be kind of another scary thing about climate change in that as those places warm up — Anchorage had these record-setting 90 degree days this summer, July was the warmest month on record in Alaska this year — as that continues, those places may be much more hospitable to rats. It might be much harder for the tribal offices on St. Paul for their biosecurity program to be effective because today they may be also protected by their climate.


How can people follow your work?

I write a lot for Hakai Magazine, where I'm a contributing editor. They should definitely check out how Hakai covers science and society from a coastal perspective. I also worked and still work for a magazine called High Country News that covers the western United States and has a community and environmental lens on those places. I was a staff editor and a contract writer there for about 12 years and now I freelance for them. I have a website that people can look for where I try to post everything I do. Lastly, I'm also an illustrator. I did that painting of the rat full of bones on the rat spill story. So if people are interested in checking it that as well they can find me on Etsy at Hidden Drawer Designs.


If you have anything you’d like to see in this Sunday special, shoot me an email. Comment below! Thanks for reading, and thanks so much for supporting Numlock.

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Send links to me on Twitter at @WaltHickey or email me with numbers, tips, or feedback at walt@numlock.news