GALAPAGOS : LABORATORY OF EVOLUTION

The Galapagos Islands and its Marine Reserve, were declared a World Heritage Site by the members states of UNESCO. This designation recognizes the Galapagos Islands as one of the world's most significant natural areas, and highlights the need to conserve the Galapagos as unique part of mankind's natural heritage.

The Galapagos Islands were officially discovery in 1535 when the then Bishop of Panama, Fray Tomas de Berlanga, and his ship were becalmed and carried out to the islands by the ocean currents. His account of the islands, written to his emperor, Carlos V of Spain, included the first description of the giant tortoises and iguanas. He also commented on the extraordinary tameness of birds.

The Galapagos Archipelago consists of 13 large islands, 6 smaller islands and over 40 islets that have official names. If we were to drain away the ocean from the eastern Pacific around the Galapagos, we would find that the sea floor has a dramatic underwater topography. These mountains, ridges, plateaux and valleys tell us great deal about the origins and development of the archipelago. The first and now easternmost Galapagos Islands formed several (perhaps ten) millions years ago. When the volcanic eruptions began to break through the ocean floor. The mountains continued to grow with successive eruptions and their bases joined to form the Galapagos Platform.

Islands and island life fascinate biologist. The way in which island so clearly depict the results of evolutionary and ecological processes has caused them to be the focus of much research. Ecological relationships and evolutionary history form a framework for understanding the way in which our natural world function.
The nature of the colonization and establishment processes have also played an important role in shaping the Galapagos biota. When the tips of the Galapagos volcanoes first appeared above the sea's surface, some five to ten millions years ago, they were devoid of life. The ancestors of every plant and animal species native to the islands must have arrived there from some other part of the world. We will never know how colonization occurred, as such events do not leave records for us, but the circumstantial evidence allows us to make reasoned guesses about what probably happened.

Oceanic volcanic islands, such as the Galapagos, differ from continental islands in that they have never had contact with the continental land masses. Oceanic islands start off sterile and must gain their biota by long- distance dispersal alone. The islands have a preponderance of reptiles but no amphibians; many birds but few mammals. From the plant kingdom, palms, conifers, and other plants groups that typically have a large flowers or heavy seeds are absent, whiles such groups as fern, grasses, and composites (sunflowers and dandelion family) are more abundant than would be expect.

Sea lions, fur seals, sea turtles, and penguins are all good swimmers, and almost certainly made their way to the islands with the help of favourable currents. Giant tortoises are known to float for some time and could possibly have been carried out by same currents.

The small light spores of many lower plants, such as bacteria and moulds, and of ferns, mosses and lichens are easily dispersed by the wind. Small insects, spiders, and tiny land snails are frequently transported passively by winds. The land birds and bats excepting the migration the migratory species, are generally weak fliers and most likely were blown to the islands by strong winds.

The Galapagos Islands have often been called a "laboratory of evolution".
There are few places in the world where it has been possible to find such a variety of species, both plant and animal, which show so many degrees of evolutionary change, in such a restricted area. Species populations are not static; they are continually changing with each new generation and thus not only have a dimension in present- day space, but one in time too. A species population has a history extending back through time during which changes have occurred. These changes have occurred primarily by the acquisition of genetic modification that passed on from parent to offspring as traits are acquired and become characteristics of population, the character of species at one point in time may become noticeably different from those of its ancestor. At some usually undefinable, point, a news species comes into being. This "descent with modification" is the basis of biological evolution.

The undistinguished appearance of Darwin's finches belies their importance in the history of evolutionary theory, 13 species occur in the Galapagos.

The diversity of beak structure and feeding habits within this group is remarkable. The individual species feed in a variety of ways with each specialized in a particular way. Some eat seed, some eat insects, some remove ticks from tortoises, some eat flowers, some drink blood from the seabirds and there are two species that use twigs or cactus spines to extract insect larvae from holes in the dead branches of trees. Together, they fill the roles of 7 different families of south America mainland birds. The range of beak shapes from that the large ground finch to that of the warbler finch is phenomenal considering their relatively recent evolution from a common ancestor.

Conservation science and the work of CDRS on land

The effects of some of the invaders are relatively obvious: goats strip vegetation and cause erosion, often leaving former forested areas looking like semi-desert; dogs kill land iguanas. Other introduced species have slower, more insidious but more fundamental effects, and are more difficult to deal with. We now have more introduced plant species in Galapagos than native plant species, and many of these are now invading not just the National Park but are also becoming serious weeds on cultivated land. Introduced insect pests and disease organisms are also spreading and causing havoc among susceptible native plants and animals. The 40 worst plant species have invaded large areas and are completely transforming the vegetation, for instance, invasive trees are shading out the native species in the naturally treeless highlands.

Our work at CDRS (Charles Darwin Research Station) is directed at finding solutions to these problems. We work together with the National Park Service, whose job it is to implement the solutions and manage the Park. Our research on land has two main focuses: the endangered native species and communities, and the worst invaders. Our work with the endangered species includes establishing baseline information on their status and distribution, monitoring population changes and trying to understand the reasons for declines and the factors causing the declines. We also work with the National Park Service to plan effective protection action. Our work with invasive species is directed at monitoring their distribution and expansion, trying to determine the factors that we need to understand in order to plan effective control (such as reproductive rate and dispersal ability), and developing effective control techniques. We also undertake restoration: Galapagos is already damaged, and we carry out research on how to promote population growth and community regeneration for threatened species and degraded habitats. Finally, conservation depends on public opinion, and we work with the local communities to promote understanding of conservation issues and with local and national planning bodies in order to promote the incorporation of conservation ideals into legislation. Galapagos has problems, but the future of its unique plants and animals could be assured given the political and public will to do so.

The Marine Reserve of the Galapagos Islands
A case of public involvement in conservation and science in a unique environment

Upwellings of cool water from the Cromwell current are responsible for high marine productivity levels, which support schools of small pelagic species, the invasion of many migratory species, and considerable colonies of sea birds, marine iguanas and sea lions, together with rich life around particularly lava reefs. However, El Nino events every several years, the last event in 1997/98, are responsible for the invasion of very warm water from the west, slowing down currents, and minimizing upwelling, with profound consequences for marine life and unpredictable recruitment patterns for marine species. A very visible sign of those impacts is the bleaching of coral, which in Galapagos is particularly serious because of the limited habitats available for their growth.

The islands, now for nearly two hundred years, also has been the home of human populations, with origin mainly from the ecuadorean mainland. Human migrants came and left, until after world war II, population numbers started to increase consistantly, including the fishing population which now consists in several hundred fishermen using principally coastal rocky bottom resources, such as groupers, spiny lobsters, sea cucumbers (since a few years) and to a much lesser degree pelagic fish which for years also were the target of industrial fishing fleets from several countries.

Initial efforts to create a Marine Protected Area around the Galapagos, not only intended to protect the marine biodiversity, but also the options for local fishermen to diversify their activities and to reduce pressures on coastal habitats, the areas of highest endemism, and include some of the exploited species.

A Marine Resource Reserve in 1986 was the first formally protected marine area in Ecuador. This was, however, largely a top-down effort, with little participation of local stakeholders. Learning from those errors, a new process of participative elaboration of the management plan for the marine area introduced completely new elements of stakeholder participation, contributed to the fact that a special law for the Galapagos Islands involved the whole Galapagos community in its preparation, and that finally an extended marine reserve of 133000 km2 became Law with the support of the Galapagos community. Not only planning, but also science, and decision taking involves sometimes conflicting groups, and even if we are far away from solving all development and marine resource problems and conflicts, mechanisms for conflict resolution and cooperative decision taking are able to maintain dialogue and much lower levels of violence at the local level.

Local conflicts mainly arise around fishing periods and quota for spiny lobsters and sea cucumbers, the last one a non traditional highly profitable fishery, which now however seems to reach strong levels of local overfishing. Also, illegal finning of sharks for exportation of shark fins is in direct competition with the important diving industry and may affect coastal ecosystems.

Serious conflicts still persist with the ecuadorean mainland industrial tuna fleet, who would like to possibilities to keep fishing within the marine reserve, a fishery which has demonstrated to be associated with, for a MPA, unacceptable by catch of dolphins, sharks, turtles, birds and other species, in those cases where illegally fishing vessels could be apprehended. Also, this fishery is in direct competition with rightfully claimed access rights of local fishermen.

The Charles Darwin Foundation has had an essential role in transforming management of the marine area from a top down, ineffective, activity to a surprisingly successful, if not always yet satisfying, issue of bottom up research and decision-making. Surveys of the conditions of exploited species are done together with fishermen, monitoring is done together, reports are discussed and go through hard negotiations on the base of technical arguments . In general, one gets the feeling, that, even if sometimes frustrating experiences are still frequent in terms of co-management and conservation of marine resources, we are much closer, and more local people now accept the need of conservation and wise management practices as the base for a sustainable way of living in the Galapagos. Alternative uses of marine resources, through diving, even sport fishing, are now considered in order to maintain fishing pressures within the fluctuating carrying capacity of marine ecosystems in the Galapagos.

Inclusion of the Marine Reserve within the World Heritage denomitation which Galapagos has held for many years now, is a recognition not only of the unique naturale values, but also of the efforts for improving management and the positive signals of community support for marine conservation, to which CDF has contributed in a very significant way.