In 1993 Dr. Wolfgang Wranik, a biologist from the University of Rostock, participated in a UNESCO mission to Socotra. The following is a report by Dr. Wranik on the island and the urgent need for study and preservation of its biodiversity. [Editor's note]
"Dioscorida is very large but desert andmarshy, having rivers in it and crocodiles and many snakes and greatlizards, of which the flesh is eaten and the fat melted and used instead of olive oil." This is part of the oldest documentedinformation on a mysterious piece of land opposite the great EasternHorn of Africa, called "Dioscorida." This account appears in the"Periplus of the Erythraean Sea", a shipping manual written in thefirst century A.D. by an unknown Greek sailor. Nowadays, about 2000years later, Socotra still belongs to the comparatively unexploredparts of the world. Apart from some 19th century travel accounts,the island has been a relatively well-kept secret, virtually isolatedfrom the rest of the world and effectively closed for foreignvisitors by military considerations and extreme natural conditions. Especially during the time of the south-west monsoon, which blowsfrom April to October, the island is often shut off completely. Evenunder "normal" weather conditions communications from the mainland byair and by boat are severely restricted by lack of harbours, betterairport facilities and adequate aircraft.
The crocodiles and giant lizards mentionedabove have never been found in reality on the island, but thenatural history of Socotra is one of the most fascinating ones in theworld. This unique character is related to its geological history.The separation of Socotra from the African mainland is believed tohave occured in the middle of the Pliocene. The high degree ofendemism in the flora and fauna is the result of this long isolationfrom the mainland of Africa. Although the history of the island is inmany details still imperfectly known, it is possible to suggest thatsome of the endemic species are relics of a very ancient flora andfauna surviving in the Haghir massif, which is considered bygeologists not to have submerged since the Mesozoic. Also the absenceof indigenous mammals is an indication of a very long separation,from a time long before mammals appeared on earth.
These numerous relics and neoendemic forms,which are some of Socotra's most striking features, make the islandof remarkable biogeographic and evolutionary interest.
Socotra is about 120 by 40 km and covers anarea of 3625 km2. It is composed of a basement complex of igneousand metamorphic rocks of Pre-Cambrian age overlain by sedimentaryrocks, mainly limestone and sandstone. Topographically it can bedivided into three main zones. The coastal plains vary considerablyin width, up to about 5 km. A limestone plateau extends across mostof the island, averaging 300-700 m in altitude. This plateau dropsin steep, often almost vertical, escarpments to the coastal plain ordirectly to the sea. It is dissected by a number of deep valleys.The Haghir mountains in the north-west of the island rise up to aheight of 1519 m. They comprise fairly barren-looking granite slopesand pinnacles with montane thicket, woody herbs, and lichens. Theclimate is monsoonal. There are no exact figures available on theannual temperatures and rainfall, but most rain falls in winter. Themountains are frequently shrouded in clouds and heavy dews arecommon. These appear to provide a main water source for vegetationin these altitudes.
The island is sparsely vegetated anddominated by xeromorphic forms, which are well-adapted to the harshclimate, such as the dessicating winds of summer. Only in shelteredvalleys and higher mountain areas is the vegetation more luxuriant. Different main types of vegetation can be recognised. The mostdistinctive is the open deciduous shrub land of coastal plains andlow inland hills dominated by the common shrub, Croton socotranus,and tree succulents such as the bizarre Adenium andDendrosicyos. The higher altitudes are home of frankincense,Socotrine Aloe and wild pomegranate. One of the most famousbotanical curiosities of Socotra is the Dragon's blood tree(Dracaena cinnabari) which is restricted to the zones ofsubmontane thicket and montane grassland.
Altogether some 815 vascular plant specieshave been recorded so far, of which 230-260 are endemic. Lessstudied among the plants are the lichens, bryophytes and fungi. TheSocotri people, especially the bedouins, have a thorough knowledge ofthe flora. Almost all plants have traditional use, such as livestockfodder, fuel, building materials, foods, gums, and resins. Plantextracts are also used as medicines, in cosmetic and hygienicpreparations, in the manufacture of cordage, as insecticides, and intanning and dyeing.
Equally as fascinating is the island fauna,with an exceptional number of endemics, but usually not so strikingand above all comparatively poorly studied. About 12 species ofmammals are known from Socotra, but all of them have been introducedby man or may occasionally come from the mainland. More than 100bird species have been recorded of which 31 are known, or supposed,to breed. Among the landbirds at least 4 species, as well as 14subspecies, are restricted to Socotra. Further taxonomic studiesare needed to clarify the status of a number of forms. The coastalarea with the shores, sea-cliffs, rocky slopes, and small mangrovebelts appear to be suitable breeding habitat for seabirds, butbreeding has not been proven for any species.
Extremely rich and interesting is thereptile fauna comprising 19 out of 22 endemic species. Nesting ofsea turtles, probably Green Turtles but possibly Hawksbills, takesplace on the north coast. There is a major need for research of theinvertebrates, which are mainly represented by a great variety ofmollusks and arthropods. The habitat of the endemic fresh watercrab, Potamon socotrensis, is the numerous, mostly sporadicstreams. Little is known on its biology, and the fresh water biota. It is still uncertain if there are true fresh water fishes onSocotra. Many insects show an adaptation to the island conditionsby reduced wings. Scorpions belong to the few dangerousspecies.
Although Socotra is in broad biogeographicalterms more closely linked with Africa, there are also interestingexamples of relatives to Atlantic islands. Special investigationsfor each endemic species will be necessary to clarify the manner ofspeciation. Several areas on the island, notably the southern andwestern plateaus, the more isolated granite pinnacles as well asgreat parts of the coastal waters, have not been scientificallyexplored so far. There is a definite need for field surveys of anykind.
Besides all the bio-geological pecularities,the cultural history of human inhabitants on the island is equallyinteresting. The special language of the nomadic hill tribes, whichhave no writing, has its roots in the Mahra area on the southernYemeni coast. Arabs, Africans, Greeks and Portuguese came to theisland at different times and contributed their part to its ownmanners, culture, and religious ideas.
Another important special feature of Socotrais that, as a result of the vast isolation during the last decades,it is relatively little affected by human activities. Until now thewhole island, with the exception of some areas in the more exploitedcoastal plains, is still dominated by a traditional balance betweenman and the environment, probably stable for more than 2000 years. For this reason Socotra island may very well be the best preservedsemi-arid tropical island in the world.
Recent political changes have caused theopening of the island and have stimulated plans to improve livingconditions and infrastructure. This marks a crucial turning pointfor this relatively untouched area. Without sufficient ecologicalmonitoring and proper development "safety procedures," the delicatecharacter of ecological balance will be affected, and anyinappropriate development may, in due course lead to severeenvironmental damage, risking the survival of many of the endemicspecies. Of particular environmental concern are the direct impactsof planned development projects, such as an asphalt airport runway,a harbour jetty near Hadibu, and extended road infrastructure. Butit is also important to consider the significant environmentalside-effects of inevitable socio-economic change.
The population of Socotra is estimatedofficially at 80,000, but is probably lower. The transhumantindigenous population of the interior is composed of subsistencefarmers and pastoralists, while coastal dwellers engage mostly infishing and trade. Socotra has lagged seriously behind the mainlandof Yemen in economic development. The most important parts of thelocal economy are the production of livestock and coastal fishery. Anumber of families practice subsistence farming with small-scaleproduction of fruits and vegetables (dates, cow peas, finger millet,sweet potatoes) for local consumption. But the harsh climate onSocotra restricts such cultivation to limited areas.
There are innumerable development problemsfacing the people of Socotra. Malaria, tuberculosis (95%) anddysentaria are well spread. Cholera may occur and infant mortalityis high (about 50%). Only one health clinic exists with basicequipment. For the only doctor, who is Socotri, often evenessential drugs are not available. There are no paved roads on theisland and electricity is only available for a few hours per day inthe larger villages. The overall percentage of illiteracy is 60 to 70%.
Despite these comparatively poor livingconditions, principles of cooperation, self-help, and communitylabour are well established within all communities, and there is awhole range of relevant traditional rules and practices of ecologicalimportance. These rules include regulations which control thecutting of live wood, forbid the use of other than dead wood asfirewood, regulate grazing and the cutting of vegetation as fodder,and preserve the most important fruit bearing trees. Traditionally,the local people practice a rotational grazing. The practice oftransplanting and/or sowing important plant species and protectingthem from livestock while they grow is already in force. Localcouncils meet in the capital Hadibu at least once a year where majorproblems, including livestock management and development projects,are discussed.
How far the changes in the infrastructureand the availability of new sources of cash income will affect thesetraditional forms of land laws and the actual form of living togethercannot be foreseen. There is a preliminary indication of rapidchange in the vicinity of the larger settlements, such as Hadibo andQalansiya, where traditional methods have already been modified. Even if there are no major impacts yet visible, it seems that woodgathering occurs more systematically and there are first signs of awaste problem induced by an increasing influx of goods. Life hasalready become more commercially oriented.
Altogether there are a great number of newproblems that the Socotri people are now faced with. The coastalwaters around Socotra are abundantly stocked with fish. But thisbasic resource of the island is endangered by excessive fishing bylarger boats from other areas. In reality the island and themainland does not execute its territorial sovereignity over the waternear the island. There is a completely uncontrolled collection ofendemic organisms by individuals and foreign institutions, perhapsalso for commercial reasons in the case of pharmaceutical companies. Also unregulated mineral prospecting is occurring. All the effectsof these activities are not yet clear, and even if there seems to belittle prospect for all the proposed development plans to be achievedin the immediate future, the danger for such a fragile islandecosystem is immense, especially by a further increase in private anduncontrolled enterprises.
The net-like character of arrangements canbe also outlined in relation to water. Nowadays the life in thesettlements has been made more comfortable by a permanent watersupply with the help of water cisterns in the mountains and anextended pipe system. By the introduction of pumps, it is alsopossible to truck water into otherwise waterless areas. But thereare also a number of negative concomitants, such as the increase ofmosquitos in freshwater ponds formed by leakage of water pipelines,the danger of disease through lack of control, and an increase inpollution and waste water. Very important from a long-term ecologicalpoint of view is the attraction of water cisterns for keeping largergrazing stocks than in the past. As yet there is no practical way toprovide supplementary fodder, therefore drought and disease continueto provide their traditional control on livestock numbers. There areno exact data available, but the actual livestock numbers seems to bealready clearly at the maximum levels that the water and vegetationcan support. According to 1985 estimates, there were about 70,000goats, about 17,000 sheep, about 500 camels, and about 1800 cattle.
If livestock are enabled by water supply andimportation of supplementary food to survive such droughts andconsequently increase in number, or even if a disruption of thecomplicated patterns of seasonal livestock movement occurs, it can beexpected that the present fragile equilibrium between vegetation, manand livestock will be destroyed very quickly. The vegetation has alsoa key role for holding the soil onto the slopes and reducing thesurface runoff of water. Any removal of vegetation cover, whichcould be also forced by less control of the high demand of wood forvarious purposes, would result in accelerated soil erosion and theloss of surface water through increased runoff rates. This wouldresult in a dangerous, inestimable spiral for the island.
Politically, Socotra is administered as apart of the Aden Governorate of the Republic of Yemen. Theresponsibility for wildlife conservation in the Republic of Yemenlies with the Ministry of Agriculture and with the EnvironmentalProtection Council (EPC). Both have undertaken a variety of taskssetting up a frame for wildlife laws, a site protection system aswell as environmental education activities. One of the most recentsteps was a UNESCO fact-finding mission to Socotra at the end of1993. This mission examined the possibility of a Socotra BiosphereReserve in order to combine development and protection forsustainable development.
At present there is no official conservationpolicy for Socotra. Many details on the most effective strategy arestill unclear. The unique character makes Socotra a potentialcandidate for both designations, a natural World Heritage Site or aMAB Biosphere Reserve. But in practice the mere establishment andmaintenance of large protected areas or nature reserves would not besufficient for sustainable development. Potential sources for theislanders must be developed, such as a small-scale tourism, thecultivation and export of native plants, the collection and storageof seeds, and cutting for propagation within international programs.Further collection of information is needed, survey as well asmonitoring. A stable research station in Hadibo, connected with anursery and an arboretum, would be a very important step.
Socotra is a great chance and challenge formankind, especially as there is fortunately still a welcome to theidea of a conservation strategy among the Socotri people. The islandand the country need financial and scientific support to develop andto realise a research and management plan; but this should be doneunder the basic principle to utilise, as far as possible, localinstitutions already in place and to give the Socotri people the timeand a realistic chance to choose a development path based on theirtraditional way of living.