Biological impacts of climate change

The observed changes to Scotland’s ocean climate (see Climate change - Changes in the ocean climate) are also having an impact on the marine ecosystem. In Scotland’s seas, records of changes in the abundance and distributions of important species have been collected throughout the past century, especially for those species which are economically important (commercially exploited fishes), that play key roles in ecosystems (plankton) or those that act as sentinels of ecosystem health and are valued by humans, such as seabirds and marine mammals. The following sections provide further details of why these are important, what is already happening, and what is likely to happen in future due to human-induced climate change.

The marine ecosystem and the links between its component species are complex. Species respond differently to pressure from direct human activities (such as fishing, aquaculture or shipping), as well as to changes due to climate change. The ocean’s role in Earth climate is also intricate, as natural variability on decadal and multi-decadal time scales is held in its memory. These factors result in differences in the current understanding of how human-induced climate change has had an impact and will have future impacts on the marine ecosystem and its components. This is reflected (together with the range of contributing authors) in the level of detail these sections cover.