Zooplankton Discoveries in the Galapagos

The Galapagos Islands, isolated by geography, have incubated species found nowhere else. Diego Figueroa first visited Galapagos at age 12, on a graduation trip from his elementary school in Ecuador. Now a graduate student at the College of Oceanic & Atmospheric Sciences at Oregon State University, Figueroa returned to Galapagos to research the distribution and community structure of zooplankton in the waters of the archipelago.

Although there has long been intense study of land animals on the Galapagos, marine creatures have been studied only in the last 20–30 years; much of that research was on larger animals: marine mammals, sea turtles, marine iguanas and penguins. More recently, there has been significant study of fish. However, there has been little basic oceanographic study of the base of the food chain—phytoplankton and zooplankton.

Figueroa’s research focuses on the effect of the Equatorial undercurrent on zooplankton: whether the Equatorial undercurrent is directly correlated with upwelling in Galapagos, how the current meanders around the western side of the islands and center of the archipelago, and how the undercurrent affects the distribution of zooplankton.

In his sampling of the waters of Galapagos, he has also discovered a number of species that seem to be previously unreported. His initial findings have generated much research interest; he is currently preparing this work for publication.

Social problems nearly derailed the research before it started. Figueroa flew to Ecuador with research assistant Kellie Hoefel, stopping first in Quito to buy sampling bottles and other supplies. Before he could leave for Galapagos, however, fishermen had launched a protest. They took over facilities at the Darwin Research Station and the Galapagos National Park Service on the island of Santa Cruz, closed the main road, and blocked the airport. No one could get into or out of the islands for a month.

The government complied with demands for the easing of fishing regulations and for the resignation of the Director of Marine Research—Figueroa’s contact for all the work he had come to do. Figueroa needed to convince a new director of the importance of his work; this delayed the start of work another two months.

The protest and armed takeovers had been sparked by restrictions on fishing, made by the Galapagos National Park Service in order to let stocks recover from overfishing. Fishing in Galapagos has proven a powerful economic magnet.

Harvesting sea cucumbers, for example, is big business. Sea cucumbers are harvested by hand—by diving down to the seafloor from boats and using a knife—then dried and exported to Asian markets. The work is dangerous; most fishermen don’t even use scuba gear, diving instead with only a hose attachment. However, the returns are high—about $5 per sea cucumber. A fisherman might bring up 20, 30, or even 40 sea cucumbers in a single dive. In Ecuador, on the continent, the average salary is $200–300 per month, but a sea-cucumber fisherman can make that much in one day.

Figueroa was finally able to start work three months after he had arrived in Ecuador. He and Hoefel went out with a Galapagos National Park Service patrol boat that was looking around the archipelago for illegal fishing. They took over 400 samples by sending a zooplankton net down to near the seafloor. All sampling was done on top of the Galapagos shelf, on average about 200 meters deep.

While sampling, they were involved in several chases of illegal fishermen. Generally, the illegal fishing is done by having a larger vessel stay outside the marine reserve and sending several smaller boats, or pangas, in on quick trips. The pangas do not show up on the radar of patrol boats, and must be caught in the act of fishing in the reserve. Another illegal fishing method is to tie a long line—up to miles long—with many baited hooks onto a raft. The raft is left floating and picked up at a later date to retrieve everything that has been hooked.

When the patrol boat encountered illegal fishermen, Figueroa and Hoefel were ordered to stay below deck, until it was safe. It is not unusual for there to be gunshots in these encounters, especially when the illegal vessels are from foreign countries. The illegal catch confiscated was primarily sea cucumbers and shark fins.

Figueroa’s preserved samples of zooplankton were taken back to the laboratory to be sorted, counted and identified under dissecting microscopes. The location of the Galapagos islands makes them subject to the influence of three main ocean currents—all of which have the potential of bringing zooplankton species from remote regions. Since there had been no previous studies of zooplankton in the area, Figueroa needed to compare samples to every known zooplankton species, a daunting task.

In addition to his planned ocean sampling, Figueroa also made serendipitous discoveries among zooplankton communities in the grietas of Galapagos. Grietas are inland pools, formed when fault lines in the volcanic islands split open, and connected by underground lava tubes to the ocean. Several of these seawater pools are close to towns and are popular spots for swimming and snorkling. The water may be 30 meters deep, and crystal clear—filled with parrot fish, eels, and other colorful creatures.

One afternoon, while Figueroa and Hoefel were swimming in such a pool, he wondered what smaller animals lived there. Next time, they took a zooplankton net, swimming with it and dragging it along.

Figueroa and Hoefel sampled at several grietas, varying the method of sampling to fit conditions.

• In Grietas Delfin (near Hotel Delfin), they would place the net on a floater. One person would swim with the float into the center and release the net, while the other would haul in the net from shore.

• At the less accessible Deep Grietas, there was only a small crevice reaching to the water; samples were made by setting up a pulley system and lowering the net through the crevice.

• The Cactus Forest Hole grieta was a depression in the middle of a Giant Cactus forest that had a small underground tunnel connects it to the sea. When the tide came up, the depression flooded. Sampling was done by tying a net to a floating board and swimming it around.

• The Tunel del Estero is a lava tunnel on Isabela Island that runs into the sea, forming a marine cave. This site was sampled by swimming about 40 m into the tunnel, where you can hear waves crashing above, on top of the tunnel.

When Figueroa took the samples from the grietas back to the lab, he found that many of the zooplankton there look nothing like the zooplankton that live in the ocean. A number of his speciments seemed to be undescribed in the scientific literature.

Figueroa is continuing to categorize zooplankton species from his samples and has begun writing up some of his work for publication. Figueroa was recently awarded the prestigious Nancy Foster Marine Science Fellowship, with up to four years of tuition and stipend for expenses.

Figueroa foresees becoming a professor and returning to Galapagos to further develop his research. He believes that more scientific knowledge is needed to fairly balance the interests of those who want to fish, those who want to protect the islands, and those in the tourism industry.

Flyover of Galapagos Islands (above and under water) from NASA Earth Observatory. 8.4 MPEG file

Diego Figueroa, PhD candidate in biological oceanography, returned to the Galapagos Islands in his native Ecuador and discovered new species of zooplankton.

Galapagos is an archipelagao of volcanic islands 600 miles west of Ecuador. Equatorial currents from the west bathe this World Heritage site, bringing up colder, nutrient-rich water from the depths.

Galapagos tortoise. The isolation of Galapagos has given rise to species found only here. Eco-tourists come to the island to see unique animals and volcanic langscapes.

Figueroa and Hoefel shop at a local fish market in Puerto Ayora on the island of Santa Cruz. Fishing is a key industry on Galapagos. Several times in 2004, fishermen went on strike to protest government quotas on sea cucumbers and other fish.

Figueroa did his sampling aboard a Galapagos National Park Service boat that patroled the archipelageo looking for illegal fishing.

Cactus Forest Hole grieta. Grietas dot the islands. These cracks in the volcanic rock can be open or grotto-like. The connect with the ocean through lava tubes and are filled with seawater. With their clear water and colorful fish life, grietas are popular with tourists and locals for swimming and snorkling.

Deep Grietas. One day after a recreational swim, Figueroa wondered what the zooplankton in the grietas were like. He returned to sample. A number of species he discovered there seem to be previously unreported.