Two weeks, three field stations, and billions of bugbites later, the Bio FSP has emerged from the jungle and has internet access once again at La Selva Biological Station on the Caribbean slope.
There’s so much to write about, but I’ll take it one location at a time, starting with Cuerici.
The Cuerici field station is in one of the most beautiful places I have ever seen. We left Monteverde right after breakfast and drove to San Jose, where we left Ryan Calsbeek and picked up Matt Ayers, our professor for the middle third of the course. Then we drove another 2 hours or so (uphill all the way) until we were driving on the continental divide. Eventually our bus pulled over and we met Carlos and Alberto, our hosts at Cuerici. They drove our bags down to the Cuerici field station, and we followed them on foot with our backpacks. The hike in was about 4 km, mostly downhill, on a dirt road. We got to the field station right after dark.
The next day Carlos (who owns the property and runs the field station) led us on a hike up a trail he cut himself. The trail is a loop that starts at the field station and goes up through a section of secondary forest dominated by Alder trees and a species of bamboo. After about 15 minutes of walking we crossed into the primary forest, which has never been cut. Here we found 1000-year old oak trees growing side by side with orchids, bromeliads, and bamboo. Near the top of the trail is a lookout facing the pacific coast, from which you can see Chirripó, the tallest mountain in Costa Rica, as well as the Osa Peninsula, which is where Corcovado is located. Carlos’ family has lived on this land since at least his grandfather’s generation, so he knows it and its history inside and out. The mountains here remind me of home in a way, but they’re also so much higher and clearly newer – the view from the field station in the morning is almost always a vista of mountaintops floating above the clouds. The weather here is also different; it’s sunny in the morning, but clouds and fog roll in like clockwork around lunchtime. After lunch we’ve seen days that clear up again, but we’ve also had rainy afternoons. It’s colder here too – at night it can be below freezing, and windy.
After a break for lunch we gathered again so Carlos could show us the trout farm that he runs.
Apparently 70 years ago the Costa Rican government thought it would be a brilliant idea to introduce rainbow trout from Canada and the western US into high-elevation streams, but quickly found that they were detrimental to the endemic ecosystems.
They’ve since removed all the trout from the rivers here, but some still live in lakes where people can fish for them recreationally and the government still raises them in hatcheries as food.
Besides the government’s facilities, Carlos has the
only other rainbow trout fishery in Costa Rica.
While the government imports eggs from Washington state in the US, Carlos breeds his own fish and raises them, keeping some as reproductive fish, selling some to restaurants, some to the lakes that are stocked with trout, and keeping others to eat.
They’re kept in pools that are built into a hillside so that water can flow downhill from one canal to the next without using any electricity.
The water that flows through the system comes from a spring above the station, and once it’s gone all the way through the different trout pools it rejoins a stream that runs through a hydroelectric generator that Carlos built himself down the hill from the station.
The whole operation is so well planned and thought out, and all without most of the technologies used in the United States for the same purposes.
He’s been breeding fish for 22 years, without the help of books about fish husbandry or information from the Internet.
He also keeps cows, ducks, chickens, a horse, and a few dogs.
Apparently his family used to log the land, but they’ve stopped cutting trees from deep in the forest and instead use the Alder trees along the forest’s edge that regenerate quickly.
He’s clearly brilliant and probably taught himself most of what he knows, so it’s been quite the experience to talk to him about all his endeavors and experiences.
He also only speaks Spanish, so that’s been a lot of fun too.
We were so impressed by the fishery and so touched by how much Carlos clearly cares for the fish and his impact on the land that we decided to do our project on the trout.
We started out by asking him questions about the fishery and asking him what questions he has about raising the trout; about what he feeds them (commercial feed and sometimes worms from the compost), how many he has, whether he’s ever experimented with different densities in each pool, etc.
Turns out one of his biggest questions was just how the water temperature, dissolved oxygen, and pH has been changing.
Imagine running a fishery and not having the equipment to quantify DO, let alone water temperature!
Groups in past years have taken these measurements as their project, so we also measured these things aside from our project so Carlos can begin to have a year-by-year record of temperature, DO, and pH in the ponds.
Our real project, however, was built around the relationship between the relative growth rate of the fish and their densities.
We compared the trout’s body condition to the density of trout in their pond, and we (meaning mostly Maddy, the math major) also set up an economic model to show whether it’s more profitable to grow fish at higher or lower densities depending on their growth rate and the food they’re given.
The growth rates we used were based on a study of wild brown trout, so the model obviously isn’t perfect, but it was really interesting to see how density affected yearly profit—turns out in almost every scenario we imagined it was more profitable to grow the fish at lower densities.
In any case, we ended up spending two full days with Carlos, catching fish from each pool with a net, measuring their length and weight, marking them by clipping their anal fins, and releasing them back into their pool.
The next day we caught them again and used the number of marked fish we caught to estimate the total number of fish in each pond (something Carlos doesn’t know exactly).
Working with the fish was incredible – they’re absolutely beautiful, especially in the sunlight.
We put the fish we netted into a smaller tub, and each took turns hand-catching them from the tub and measuring them before returning them to the water, which was pretty amusing since some of them put up quite a fight.
On our last day Carlos caught 10 of the trout and cooked them up for lunch—only one of them was marked, which almost perfectly matched our population estimations for that pond!
Now that we have internet again I’ll try to catch up with posts about Corcovado and Las Cruces whenever I get a minute to write. Stay tuned!
-Madi
Santa Rosa was VACATION!! No projects here at the beach. Absolutely the most gorgeous beach ever; maybe 4 or 5 miles end to end with mountains wrapping around the ends to make a little bay. It was like we were in a movie. It was so remote; we hiked 11km in to the beach and ran straight into the ocean. Salt water never tasted so good. That afternoon the whole group walked all the way down to one end of the beach laughing about how we finally had some time to relax and we couldn't sit still.
We camped in 4 person tents in a campground right behind the beach. It was right in the middle of turtle breeding season and there was no moon, so every night there were turtles coming up to build nests and lay eggs, and every afternoon turtle nets were hatching. We saw both within 12 hours. The first night we walked down to the other end of the beach with a guide who studies the turtles and tags/tracks them. It was a late night but totally worth it...we saw an Olive Ridley laying eggs. She lays arond 70 eggs and then spends at least 40 minutes covering up and patting down the nest in this circular dance--she was so careful! You couldn't even tell where the nest was when she was done patting it down. Watching her return to the ocean under only the starlight was one of the most beautiful things I've ever seen. The next day we saw Olive Ridley and Green turtule babies hatching.
After we left Santa Rosa we arrived at Monteverde, which is a montane cloud forest. Everything here is so lush; someone noted "it's like a greenhouse!" There are orchids, ferns, bromeliads, and super colorful flowers everywhere. It was mildly terrifying to get here in our monster (stick shift) bus on the super steep, narrow, windy roads/bridges, but it's been incredibly worth it. We've seen hummingbirds, waterfalls, plants growing wild in the forest that many people pay lots of money for at a flower shop...but strangely, not too many clouds. It should be really foggy with nearly constant precipitaition, but it's been sunny every day we've been here. Apparently it was sunny all of last year's stay also. It really shows you signs of climate change--it's scary to think this incredibly unique habitat might be gone soon.
In the afternoon we went for a hike around some of the trails in the park and saw our first troop of monkeys! They were white-faced Capuchin, in a troop of 15 or so, with a few babies. Further along we also saw a coatimundi, an agouti, and a million kinds of birds and bugs...and we heard howler monkeys, but didn't see them. Right in front of the field station there's a huge wetland (the floodplain of the Tempisque River) that's protected as part of the national park. At the end of our hike Ryan showed us a boardwalk that goes out into the wetland and a tower that we can climb to look out over it, both of which gave us some amazing views of the birds that live there. Finally, near sunset we hiked a trail that leads up to a ridge a little ways from the field station to a place called "La Roca" (yup, it means "the rock"). The trail basically ends at a huge rock outcropping high above the wetland with the most incredible views. I can think of few other places I've been where you can look as far as you can in every direction and not see a single sign of civilization - it's incredible. It felt almost like we were in a movie, watching the wind move over the wetland grasses with egrets flying in pairs over the river. It was such an incredible spot that a few of us decided to come this morning to see the sunrise. This involved waking up at 5:20 am, searching for our clothes and hiking boots with our headlamps while hoping not to run into any scorpions, and hiking/running back up the trail in the early morning light. It was more than worth it...the pictures don't come close to doing it justice. While the rest of the group walked back towards the field station for breakfast (which starts at 6:30!!) I went for a short run down the road that leads into the field station, obviously hoping to come across a jungle cat, but instead saw another group of capuchin monkeys and some pretty cool birds. I made it back just in time for breakfast, which included rice and beans (obviously) and SO MUCH delicious fruit.