Contents:
- News from the Ship: Ocean Watch just left the Galápagos Islands after a week of learning and exploration. Read more about their explorations on the islands.
- Q&A: Every week we answer questions from classes all around the Americas. See if questions from your class are answered this week.
- Shore Crew Action for the Day: Each week we’ll post an activity for you, your family or your class to do. This week learn more about ecosystems and animals.
- Conclusion: Use the “submit comments” window to post questions from your class for the Ocean Watch team, ideas for an activity, questions for other classrooms, or to respond to any of this post!
If you have:
5-10 minutes this week, read News from the Ship, Q&A section, and submit a question of your own!
~45 minutes, add on the activity and build a food web!
Welcome Aboard!
News from the ship:
The Ocean Watch crew just spent a whole week in the Galápagos. The Galápagos is a collection of islands on the Equator about 600 miles west of Ecuador. These island are volcanic, and the Galápagos include 15 big islands and 3 smaller islands. Many of the people who live in the Galápagos live in Puerto Ayora, on Isla Santa Cruz, and this is where the Ocean Watch crew was during their stay.
While in the Galápagos the crew of Ocean Watch met with local scientists to learn more about the islands, and explored on hikes, bikes, and scuba diving. In fact, while exploring the islands writer Herb McCormick met some of the island’s most famous inhabitants, the giant tortoises. The tortoises are such a part of the history of the islands that the Galápagos were even named after them, but “Galápagos” doesn’t mean tortoise. Instead, the word Galapago in the old Spanish language was used to describe the frontal piece of a riding saddle, which has the same shape as the tortoise shell. (The Galápagos Islands have also been called the Enchanted Islands because they often times disappeared into the fog and sailing ships could not find them!)
Herb sent us this letter all about seeing the tortoises. The pictures at the end were all taken by David Thoreson, the photographer on Ocean Watch.
Greetings from the Galápagos Islands!
If you ever come to the Galápagos Islands, a “must-see” is a trip to the Charles Darwin Research Station in Puerto Ayoro on Isla Santa Cruz, where you can take a good, close look at the gargantuan tortoises. So the other morning, on a searing hot day, I rented a bike, peddled up to the station, wandered down a path of crushed lava rocks, slipped through a gate, and looked one old, leathery fella square in the eye.
Even I can tell a saddleback tortoise when I’m placed directly in front of one – they’re the kind with the notched, saddle-shaped shell and the long neck and legs – and this one was a beauty. With his bald pate, piercing peepers and reptilian hide, he looked like a cross between the crazy uncle on The Addams Family and something out of a bad horror movie. He probably had at least fifty years on me, which put his age well over 100 years old. If one looks back at the history of Galápago stortoises, this one is probably lucky to be around.
Author Godfre Merlen wrote a great book we’ve been reading on this trip that tells the history of the island’s tortoises, and I’m going to share parts of it with you. He starts by describing how many years ago the tortoises lived all over the islands:
“They not only succeeded in establishing themselves on dry, low islands, but on high, moist ones as well. Tough as the land they lived upon, their scaly feet withstood the harsh, rocky ground. Strong, curved, knife-like mouths allowed them to feed upon the spiny cactus and acacias when all other vegetation was dry and leafless through the lack of rain. Above all, their slow metabolic rate permitted them to beat the (occasional) droughts… Living at a low ebb in the shade of caves and rocky crevices, they remained like stones through months of blasting heat, when the soil turned to dust. When the rains finally came, the great animals eased out of their slumbers and rocky recesses and lumbered off to feast in a fresh and vitalized world, now leafy and green.
“How many tortoises were there? No one knows, yet there is no doubt that there were many thousands – even hundreds of thousands. Some say a million.”
And then…there weren’t. We’ve learned that the big saddleback and dome-backed turtles were prized by the crews of the whaling ships that used the islands as a base in the Pacific hundreds of years ago. Sailors captured the tortoises alive and stored them in the holds of their ships; the turtles could live a long time without food or water, and weighing up to 500 pounds each they provided the sailors a large and long lasting supply of delicious “sweet meat.” This would ensure the whalers a supply of fresh meat during their long voyages, and crews would stack their holds with literally hundreds of turtles. A cargo of three hundred turtles or more was not unusual. Aboard one ship, the Niger, a misplaced turtle lost in the water casks was discovered two years later, fresh and ready for the table. In 1846 alone, there were 735 ships in the Pacific fleet, and aboard every ship there were dozens of hungry sailors. And they all loved their turtle.
They took them by the tens of thousands. They almost loved them to extinction.
Later, it wasn’t the men on the boats that endangered the turtles, but what they’d brought with them and introduced to the islands: pigs, dogs, donkeys, cattle and goats. Some were predators, raiding nests in search of food; others were competitors for the sparse vegetation. For the tortoises, all of them were extreme hazards to their long-term health and survival.
The population of the tortoises is changing again because of humans, but this time increasing. In 1964, the Charles Darwin Research Station was established and in the years since, thousands of giant tortoises have been bred and/or raised in captivity at the center’s captive breeding center, and returned to their natural habitat. The ancient character I encountered at the station had obviously lived long and prospered, and it was amazing to see these animals up close!
- Herb
P.S. Check out the pictures my friend and crew mate David Thoreson took of the tortoises, and some of the other animals we saw on the islands!
Open the below photos in a full-screen slideshow in Flickr
Questions to the Crew:
Every week we answer questions from classes all around the Americas. See if questions from your class are answered this week!
These two questions are from Ms. Messer’s students in the Falkland Islands, and both are answered by Mark Schrader, Captain of Ocean Watch. These two questions are all about one of the important animals Ocean Watch has encountered on their trip, and how the animals are connected to other animals in the ecosystem.
Q: What do jellyfish eat?
A: Jellyfish eat or ‘graze’ on common phytoplankton and small zooplankton floating around in the water, moved by currents largely controlled by sea temperature. Depending upon the type of jelly, they have complex mouth structures to capture other gelatinous prey, or they have various styles of mucous nets to snare food as it floats by. Many species have long, sticky and/or stinging tentacles used to immobilize and capture food. Because jellies have a low carbon density (they are typically 95% water) their metabolic rate is very low, meaning they can withstand long periods without food. During ‘low food’ periods they will shrink in size, reversing that process when food is abundant.
Q: Why would having a jellyfish over-population affect our seas?
A: Some scientists studying gelatinous animals, or jellies, as jellyfish are called, believe they may be an important ‘indicator species.’ Jellies are highly dependent on temperature and current for food and transportation. When ocean temperatures, currents and atmospheric pressures change, the impact on jellies can be quick and significant. Changes in fish population also seem to have a causal connection to increased or decreased jellyfish populations. Because of these apparent relationships scientists are interested in studying the migratory trends, the habitat and distribution, of jellyfish populations. As a result of the predatory or grazing activities of gelatinous animals, big ecosystem shifts can happen in a matter of days over a very large area and these rapid changes are of interest to scientists.
If you or your class has a question for the crew, put it in the comment field at the end of this post, then check back next week to see if your question is answered!
Shore Crew Action for the Day:
The crew of Ocean Watch spent a lot of time in the Galápagos looking at and learning about animals, and there were a lot of animals to look including flamingos, penguins, sea lions, tortoises and iguanas. In fact, the Galápagos is home to a very unique ecosystem. The word ecosystem comes from “eco” meaning environment or ecology, and “system” which is a collection of parts interacting together. An ecosystem involves the living things, like plants and animals, and the non-living things like soil, rocks, and water in an area.
In this activity you can create a food web and learn more about some of the animals the crew of Ocean Watch have seen in their travels, and how these animals interconnect in their ecosystems.
To get started, download the activity. (Note: the activity write-up suggests you create the food web using stuffed animals. Instead of using stuffed animals you can download and print images of the animals instead! Chose from animals found in the arctic, temperate, or sub-tropic zones. (All three sets of images are a PowerPoint format; you can print them as slides (each image will print as a full page, 8.5 x 11 inches), or you can print as “handouts” (resulting in up to 6 smaller images on a single page).
Do and Share:
See your food web on this website when you email a picture of it to education@aroundtheamericas.org.
Conclusion:
Add a comment to this post by clicking on the comment link below the post title. In this comments field you can ask the Around the Americas team questions, and check back to see if your question was answered in next week’s post. You can also send us ideas for an activity, answers from your science notebook, or questions you have for other classrooms that are part of the Shore Team!
Resources:
This activity is part of the online activities for Around the Americas. Check out our additional activities on topics about acidification, underwater sound, and fishing, and read background information about food webs.
Read more about the history of the Galápagos: http://www.lonelyplanet.com/ecuador/the-galapagos-islands/history
The book Herb mentioned by Godfre Merlen is called Restoring the Tortoise Dynasty: The Decline and Recovery of the Galapagos Giant Tortoise.
The Charles Darwin Foundation is where Herb saw the tortoises, and met with local scientists, including Stuart Banks, who joined our online class. Thank you Stuart!
We’ll see you next week!
