Science Spin May 2009

Galápagos Romance

It is rousing, and romantic to believe that old fashioned marine science, conducted in old wooden sailboats still exists. It is exciting that there are still places in the world, untouched by Gore Tex boots, where the elemental scientific processes of sampling, surveying and investigative ecology still hold much relevance.
The dream lives, I can tell you, and romantic science is being practiced with much bustle and ado in the Galápagos Islands off Ecuador.

The sterile safety of the white laboratories of my scientific background in the west of Ireland seemed a long way away when I participated recently in a research cruise in this archipelago I now live in. A cruise involving a pirate ship, volcanoes, marine iguanas, Martian landscapes, whales, sharks and a lot of seaweed.

Motivation

Our motivation for the voyage may have been one or a collection of many things. Perhaps the notion of a young Charles Darwin provided the motivation for one of our young scientists aboard. Restless in Europe and with a passing interest in barnacles and geology, and little did he know at the time, evolution, Darwin set sail on a similarly appointed ship to the same archipelago which is now synonymous with his name.

Perhaps it was the image of both my grandfathers, unwittingly investigating the biochemical composition of seaweed, used to fertilize our land that drove me to the ends of the earth to equally inhospitable shores to find the truth about seaweed. More than once it occurred to me that perhaps I was subconsciously emulating John Steinbeck's 1940s novel The Log from the Sea of Cortez. If you haven't read this book you should. If you haven't read this book and you are an aspiring marine biologist, then you must.

The scientific motivation was the realization of several field experiments. We were studying 'top down' and 'bottom up' effects on intertidal algal ecosystems. That is to say, a seaweed´s growth may be controlled from the bottom up by changes in oceanographic properties such as nutrients due to an El Niño event (a temperature change that happens every few years in the waters of the Pacific Ocean) or from the top down by grazing pressures.

There is no better place to address such grand ecological questions as these as Galápagos. Situated on the equator, but with water as cool as Clew Bay in the cold season and penguins sharing living space with marine iguanas, they are a hotspot of diversity driven by a confluence of currents bringing productivity and importantly, left undisturbed by humans and other large mammals for a relatively long time.

This confluence of ocean currents directed our research interests and the bow of our boat ´´LV Pirata´´ as we steamed to Genovesa Island in the far north east of the archipelago. Here, the Panama current, warm and nutrient poor from the north, is stroking the islands, stealing further south in the warm season.

Due to these nutrient poor waters, intertidal algae are not as lush in Genovesa. This has a considerable physical consequence for the endemic marine iguana, the iconic symbol of Galápagos. Here the iguanas are one twelfth the size of the iguanas on Fernandina Island in the far west of the archipelago, our next mooring, where the Counter Equatorial and Cold Humboldt Current direct from Antarctica converge causing upwelling, productivity, and lush intertidals.

Vessel

Our vessel was a reconditioned mail ship which plied the coast of Ecuador in the 1920s and ominously flies the pirate flag alluding to a hidden past. Under thrust and sail, she made a passage of 80 miles or so to Genovesa in 10 hours.

Every item of clothing we wore and tool we carried had been in quarantine for three days prior to the voyage. The islands we would visit are as pristine as landscapes come, a troublesome seed or insect from the port town of Puerto Ayora would be most unwelcome to the local ecosystem.

Efforts like these seem futile at times; most of the islands have seen introductions at some point of pests ranging from fire ants to feral goats. Coming from a world of litigation and safe scientific practices it was delightful to realize our landings would not be much safer than those of Darwin 170 years ago. The panga (wooden dinghy) was masterfully manoeuvred to the safest looking point of lava rock in between sets of waves where we hurriedly disembarked.

Our experiments lay at the lowest of the intertidal. Cages were designed to exclude various grazers from algal plots including marine iguanas, the bright red sally lightfoot crabs which light up the intertidal as they descend to forage at low tide, sea turtles and a host of reef fish who graze the intertidal at high tide. The addition of nutrients and cultivation of algae on plates of differing colours and thus temperature, was also investigated.

Fish censuses were performed at high tide, speedily so when sharks were sighted. What emerged from our experiments, some of which lay in situ for three years, is a massive data set, with the power to tell us many things about biological and climatic forces and the effects they have in relation to each other.

Dream

The Galápagos Islands are an ecologists dream to study processes such as this. The islands contain some of the least impacted ecosystems in the world. Humans only arrived here in the 18th century; interestingly the first settler was an Irishman named Patrick Watkins who enterprised for a few months in the 1700s selling vegetables to passing whaling ships.

The population stands today in the region of 30,000. 97 per cent of the archipelago is national park and while the conservation dream lives strong, the islands face a world of trouble. The burgeoning population is creating new visible threats to its ecosystems; unbelievably, extinction of some species is occurring here. This is driven by a desire to take advantage of the tourist dollar and facilitated by corruption, a South American theme that is well represented in the authorities governing Galápagos.

The currents that drive our research slowed our pirate ship on our 18 hour passage to Fernandina Island. Galápagos is noted for the unpredictability of its currents, making the diving which is some of the best in the world cold and dangerous at times. The rewards can be overwhelming; this is one of the few locations where upwards of 100 hammerhead sharks may be not only enjoyed but expected in one dive.

Where the distance the sharks keep when conducting scientific diving is appreciated, the curiosity and desire of the Galápagos sea lions to play with transect lines and generally interact with a diver is most welcome.

Fernandina lies in the far west of the archipelago and contains the newest and most active volcano in Galápagos. As the islands are still growing and moving slowly eastward with the underlying plate movement, the newest, tallest and more volcanically active islands are found to the west, with the older, more rounded islands to the east.

Fernandina is a giant cone, with a terrain entirely impenetrable to all but the hardiest of organisms. Shards of lava rock, several times higher than a human, lay jagged and haphazard awaiting erosion and a smoother future. Our experimental plots differ here; hordes of gastropods attracted to the structural complexity of an algal ecosystem growing under conditions of high productivity is one interesting highlight.

Fin whales accompanied our departure from Fernandina and the start of our return passage home. The Bolivar Channel which separates Fernandina from the largest island, Isabella is a safe bet if you desire sightings of these magnificent animals who take advantage of the incredibly nutrient rich waters here. The same southwest swells which supported our choice of direction leaving Santa Cruz a week earlier came directly on our starboard and lended to the dramatic character of the Martian environment as we rounded Cerro Azul, a volcano on the island of Isabella.

Dusty red earth is surreally punctuated by craters and mini volcanic cones in this remarkable corner of the island. This volcano awoke in June 2008 prompting Galápagos National Park personnel to airlift giant tortoises out of the path of the lava flow. These tortoises, which achieved gigantism in the absence of other large herbivores, have a now almost zero success rate breeding in the wild due to predation of their eggs by introduced rats among other things. Careful captive breeding programs are proving successful in maintaining some populations.

Station

On arrival home, many laboratory hours were spent in The Charles Darwin Research Station sifting through and processing algal samples. While sea lions and marine iguanas disregarded one another on the dock outside the doors of the laboratory, meso-grazers such as amphipods, crabs and gastropods were taxonomically sorted and seaweed dried and weighed for biomass estimation as the science was brought to fruition inside. The research station is located in Santa Cruz Island where a team of Ecuadorian and international scientists work to provide information to the Galapagos National Park Service to guide their management strategies.

The station represents hope for the islands, an institution of objective research supported by international interests. Tourists (some 145,000 in 2006) are encouraged to visit the station to gain an informed perspective of the natural spectacles that delight them in their time in the islands.

Two innocuous, yet loaded photos sum up and bluntly reinforce a theme of change which drives our current research here. While the voyage I have documented is part of a project headed by Luis Vinueza of Oregon State University and a Galápagos resident, investigating the direction of control of the varying processes which affect intertidal ecosystems, I am investigating temporal changes in these ecosystems, brought about by the anthropogenic and climatic changes realized in Galápagos in the past 30 years.

One of the photos is from 1975 and displays a rocky intertidal thickly carpeted in a brown seaweed, limp and heavy on the rocks waiting for a tide to float its fronds and regain its grace. The other photo, from 1985 displays the same piece of rocky shore, this time displaying the baldness and hostility of the rock; the seaweed, Bifurcaria galapagensis, disappeared in the early 1980s and the truth is, it hasn't been seen since.

This is not an intertidal suffering under the strain of an industrialized hinterland. This is Galápagos and this is modern day extinction in the last place you would expect to find it. Galápagos is becoming more and more represented in the IUCN (International Union for the Conservation of Nature) 'Red List' of threatened species; our work will hopefully better enable us to understand the processes which are nominating species as candidates for this list.

While the demise of the seaweed B. galapagensis is attributed to a failure to recover from the 1982-1983 El Niño event, local fishing practices to feed an increasing population are indirectly believed to be affecting others. An oversimplified picture tells that the removal of lobsters that eat among other things, sea urchins, leads to an increase in their populations, which leads to ´´urchin barrens´´, vast sub tidal areas cleared of large seaweeds by the over represented urchins. The picture needs more resolution, however, and more science. At present, Margarita Brandt of Brown University, Maryland is investigating such interactions.

This is one of the remotest, most biodiverse and forgotten about archipelagos in the world. As The Sea Shepherd Conservation Society proclaims from its offices in Puerto Ayora, the largest town in the islands and my home, Galápagos is the ´´line in the sand´´. If we can't protect nor conserve Galápagos, where can we?