Mina Invierno
On our way from Punta Arenas to Puerto Natales, we stopped and visited an open-pit coal mine on Isla Riesco. When the mine was going through the permitting process, there was significant local resistance to the mine at the environmental impact portion of the approvals. The population of Isla Riesco is about 100, and they are almost entirely ranchers. They did not want the largest open-pit mine in Chile to open on their island, both because of environmental impact and because they felt it did not fit with their lifestyle. Many of these families have had the exact holding they work today for generations.
When we visited Mina Invierno, it was clear that they were aware that university students from the U.S. might share similar environmental concerns. Our guide was the Chief (Jefe) of Environmental operations, and also ran the greenhouse where they grow the saplings involved in restoration efforts. He started by showing us the mine itself, where they were digging out a seam of low-grade coal (lignite) about 16m wide which was buried under about 40m of overburden. The most striking thing to me at this part of the process was the size of the trucks used to move the overburden out of the hole. They were ENORMOUS. Imagine a small apartment block – perhaps three stores tall – rolling around on wheels, paint it yellow, put a giant shovel blade on top, and that’s basically what they were like. I very much enjoyed that part.
The rest of our tour looked mostly at the way Mina Invierno is trying to mitigate their environmental impact. They plan to fill in the mine as they exhaust it, rather than waiting until the end of their operations to fill it in, and they are working on their technique of environmental restoration now. Gabriel, the Jefe, showed us a hillside that they had replanted. They save the topsoil aside when they begin to dig a new portion of the mine, so they used that topsoil and planted it with grasses commonly found in other open steppe areas of the island. The restoration effort seemed to be working; the area felt very alive, and not at all like the dusty and clearly non-living ambiance of the mine itself. At the end of the visit, Gabriel took us to the nursery, where we got to see lots of baby Nothofagus pumilio and a few Nothofagus betuloides (beech trees). That was my very favorite part of the mine. ❤ And, really, it was not the mine at all.
We had read a paper about the mine before the visit which said that the permitting process had been unjust because it did not meaningfully include the local residents’ concerns. The paper reported that one of the mine’s responses to these concerns was that ranching was bad for the land, too. It was hard for me to see how grazing livestock could have the negative environmental impacts of coal dust, an open pit and unsecured dirt in a very windy environment, and burning low-grade fossil fuels. On the tour, however, our guide again brought this up and explained what they meant. In order to turn this land into ranchland about a century ago, acres and acres of the Northofagus (beech) forests were burned to the ground. They were not even harvested, managed, or used in any way. They were simply set ablaze. The boundary between the steppe ecosystem and the forest ecosystem which we see today is many kilometers from where it originally was because the ranchers burned the forest to extend the steppe. The mine clearly has many negative environmental impacts itself, but after our visit, I understood where their argument of equal harm was coming from, and why they found it difficult to take the ranchers complaints seriously. If the ranchers harmed the land so severely, the miners had a hard time seeing how the ranchers could complain about the mine.
Salmones Magallanes
Part of the research our group will be doing while in Puerto Natales is to study the conditions of the water in the fjord, particularly to see if it is anoxic. Local fishermen have claimed that the salmon farms are “poisoning the water,” and – if this charge is true – it is probably not truly poison, but a lack of oxygen in the water. This could be caused by the decomposition of high amounts of organic matter from the salmon feed and waste. As background for the research we’ll do, and to get both sides of the story, we visited the facilities where the salmon farm Salmones Magallanes raise their fry and smolt (young stages of salmon growth) before transferring them to the sea pens. Salmon are not native south of the equator, so all salmon raised in Chile and sold from is farmed. The largest customer base of Salmones Magallanes is the United States.
Salmones Magallanes also emphasized the efforts they are making to reduce their environmental impact. They filter and reuse 90% of the water in circulation in the tanks at any one time, so that they take less water out of the sea and streams. They also filter the outflow. The quality of the outflow water is tested monthly by the Chilean environmental agency, and once, our guide said, an environmental NGO had come out to do independent testing. “We never heard back from them, so we assumed it was okay,” he said with a smile. I was most impressed to hear that even with all those millions of fish eating and growing like crazy, they only dispose about 100kg of organic waste per year. Given this information, perhaps the salmon farms are not causing anoxia in the fjords after all; it will be interesting to see what our data says.
Another problem with fish farming in South America is the potential for fish to escape. Salmon, which are not native, are known to spawn in local streams, including in the National Parks. This is problematic because salmon are carnivorous, and can put pressure on native fish populations by competing for the same food base or eating them outright. No one is sure, though, if the salmon colonizing the streams were introduced by the fish farms. In the middle of the last century, salmon and trout were intentionally introduced in these waters in an attempt to increase sport fishing in the area. (The salmon today are actually eating most of the trout; one invasive species taking out another.) Salmon farms claim that all the salmon invading the streams come from these events, and none have been contributed by their operations. We won’t be engaging that question directly, but we will be surveying streams to determine their suitability for salmon spawning. We will focus on streams that feed into rivers where salmon are known to spawn. Using our findings, we hope that rangers and scientists will be able to monitor these areas to see if the salmon infestation has advanced into these streams beyond known infested waters.
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