Human activities have a range of impacts on the environment, both positive and negative. Many activities have profound negative impacts on the environment that create direct and indirect stressors on ecosystems. These stressors have an additive, synergistic or antagonistic effect on one another, creating cumulative effects to the environment that are different from and more significant than the individual, direct impacts of activities. Although many development activities have individually minor impacts, collectively over time their impact on the environment can be substantial. Over time, indirect impacts of activities may have more severe impacts on ecosystems than direct ones, and can have impacts on larger temporal and spatial scales than that of individual activities. In some instances, multiple activities may cause a single, common stressor; for example, a factory and a nearby landfill may both release polluting run-off into a river. Other times, multiple activities overlap in time and space and produce multiple different environmental impacts that interact with each other, creating more complex environmental impacts. For example, increasing ocean acidification amplifies the sound of shipping and other marine activities, which then increases the exposure of marine organisms to noise. Below are some factors contributing to cumulative environmental change:  Marine ecosystems are particularly vulnerable to cumulative environmental impacts due to the spatial connectivity of aquatic species and the ecosystems themselves. Marine ecosystems experience environmental impacts from a range of marine-related activities, such as shipping, fishing, offshore oil and gas industries, and deep-sea mining. Some environmental impacts of marine activities are:   Marine ecosystems are also affected by the environmental impacts of terrestrial activities through pollution, waste disposal and run-off. As a result of the multitude of impacts and activities interacting in marine ecosystems, cumulative effects are particularly difficult to quantify and manage. The production and consumption of various energy sources have far reaching direct and indirect impacts on the environment. The construction of dams for hydroelectric energy, for example, represent one of the most major human interventions in the hydrological cycle. Dams directly impact the flow of rivers and their chemical characteristics, effecting river health many kilometres downstream. Additionally, the inundation of surrounding ecosystems by water results in a loss in terrestrial habitat and wildlife in the area. The energy production sector can result in many negative impacts on the environment, such as air pollution, acid rain, deforestation, emission of radioactive substances, and ozone depletion, all of which contribute to climate change. Energy production is associated with large amounts of infrastructure, such as power plants, pipelines, wind and solar farms, and dams, which contribute to the environmental effects of land use change.