In addition, they have an important place in the food web and play a valuable role in carbon cycling by locking away carbon dioxide and nitrogen, which is eventually deposited on the ocean bottom, thereby slowing the impact of global warming. The ecosystem services provided by the marine environment are attributable to its vast size and to a large extent to its complex ecosystems and biodiversity. It is therefore most important to preserve the marine environment and its bioresources. Marine biotechnology can play an important role in reaching these goals. Biosensors are devices composed of a biological sensing component linked to a signalling component which can reveal the presence of an element, molecule or organism of interest. They can detect changes in analytical or biological parameters and may be useful for detecting quickly the presence of invasive species that can disrupt marine ecosystems and the habitats of marine or terrestrial organisms.