First human impacts and responses of aquatic systems: A review of palaeolimnological records from around the world

Abstract

Lake sediments constitute natural archives of past environmental changes. Historically, research has focused mainly on generating regional climate records, but records of human impacts caused by land use and exploitation of freshwater resources are now attracting scientific and management interests. Long-term environmental records are useful to establish ecosystem reference conditions, enabling comparisons with current environments and potentially allowing future trajectories to be more tightly constrained. Here we review the timing and onset of human disturbance in and around inland water ecosystems as revealed through sedimentary archives from around the world. Palaeolimnology provides access to a wealth of information reflecting early human activities and their corresponding aquatic ecological shifts. First human impacts on aquatic systems and their watersheds are highly variable in time and space. Landscape disturbance often constitutes the first anthropogenic signal in palaeolimnological records. While the effects of humans at the landscape level are relatively easily demonstrated, the earliest signals of humaninduced changes in the structure and functioning of aquatic ecosystems need very careful investigation using multiple proxies. Additional studies will improve our understanding of linkages between human settlements, their exploitation of land and water resources, and the downstream effects on continental waters.

Management pathways for the floodplain wetlands of the southern Murray–Darling Basin: Lessons from history

“…This brief history only sketches the range and intensity of drivers of ecosystem degradation to the river ecosystems of the Murray River. After 60,000 years or more of occupation by the first Australians (Clarkson et al, ), their displacement by Europeans in the south‐east of the continent coincided with abrupt impacts on the aquatic systems (Dubois et al, ). From the 1850s, gold diggings stripped large areas of woodland and actively mobilized soil surfaces leading to the transport of an estimated ~400 M m 3 of sediment into MDB streams from Victoria alone (Davies et al, ).…”

Diatom community responses to long‐term multiple stressors at Lake Gusinoye, Siberia

“…Lakes also provide freshwater and protein for human populations, and therefore the history of a lake is often intertwined with the regional history of human activity (Dodds et al, 2013;Jackson et al, 2016a). Understanding which threats are most important for individual lakes is crucial to managing freshwater ecosystems, but because different threats have different causes, pinpointing when they first started to have a major impact on an ecosystem needs a long-term perspective (e.g., see Dubois et al, 2018 for a review). Understanding which threats are most important for individual lakes is crucial to managing freshwater ecosystems, but because different threats have different causes, pinpointing when they first started to have a major impact on an ecosystem needs a long-term perspective (e.g., see Dubois et al, 2018 for a review).…”

“…Understanding which threats are most important for individual lakes is crucial to managing freshwater ecosystems, but because different threats have different causes, pinpointing when they first started to have a major impact on an ecosystem needs a long-term perspective (e.g., see Dubois et al, 2018 for a review). Paleolimnological records can also provide useful insights into natural variability and baseline conditions before human-environment interactions (Dubois et al, 2018). For example, although there are several long-term monitoring networks (e.g., The International Long-term Ecological Research [ILTR] network (Vanderbilt & Gaiser, 2017) and the Global Lake Ecological Observatory Network [GLEON] (Rose et al, 2016)), none of these are found in Russia.…”

“…However, even though the provision of freshwater ecosystem services is fundamental to human well-being, ecosystem functions are often compromised by human activity, threatening the health of the lake itself. Understanding which threats are most important for individual lakes is crucial to managing freshwater ecosystems, but because different threats have different causes, pinpointing when they first started to have a major impact on an ecosystem needs a long-term perspective (e.g., see Dubois et al, 2018 for a review). While long-term monitoring can provide some of these answers, such records are rather rare and not available for most lacustrine ecosystems.…”

“…However, through careful exploitation of lake sedimentary archives, including preserved microfossils and chemical constituents, it is possible to reconstruct environmental impacts on lake ecosystems through time, whether they be caused by atmospheric pollutants, disturbance from agriculture and aquaculture, or impacts of global warming, leading to alterations in local ecology and biodiversity. Paleolimnological records can also provide useful insights into natural variability and baseline conditions before human-environment interactions (Dubois et al, 2018).…”