As the population of these species are often small and confined to specific areas, they are more vulnerable. Furthermore, island species are less likely to have developed defence mechanism against a broad range of threats like mainland organisms but rather will have developed characteristics based on coevolution and mutualism. Of the 724 recorded animal extinctions that have occurred over the last 400 years around 50% of these were island species.
Key threats to island species include increased pressure from invasive alien species, natural disasters, tourism development, over-exploitation of the land, land-use changes, pollution and climate change. The majority of these threats are human induced. Moreover it is important to recognise that islands are also integral to the social, economic, cultural and political identity of over 600 million islanders.
Islands and their biodiversity provide a wealth of ecosystem services including: Provisioning services such as wood, medicines, plants that can be made into tools or fibres and other important raw materials. Regulating and supporting services such as nutrient cycling, sediment formation, feeding & breeding grounds for juvenile marine species and defence against natural disasters. Cultural services such as spiritual value to indigenous populations, aesthetic value, recreational value - especially to tourists and educational value. Moreover, they support islander livelihoods and economies.
Island biodiversity also represents a treasure trove of genetic information which is an important part of the evolutionary record that spans millions of years. Island species' adapatations are most useful in the practice of biomimicry, which is the design and production of materials or systems that are modelled on biological processes, behaviour and organisms.
From this short introduction to island biodiversity it is clear to see why these ecosystems are worthy of being protected from the threats they face.
By Sarina Chandaria
Year 13
"Of the 724 recorded animal extinctions that have occurred over the last 400 years around 50% of these were island species."