Altered species composition

Definition

Altered species composition refers to changes in the variety and abundance of species in a given ecosystem, often driven by environmental factors such as climate change, pollution, or habitat destruction. In marine ecosystems, altered species composition can significantly impact food webs, biodiversity, and ecosystem services, particularly in the context of stressors like ocean acidification.

5 Must Know Facts For Your Next Test

1. Ocean acidification, caused by increased CO2 levels, can disrupt the calcification processes of marine organisms, leading to shifts in species composition.
2. Species that are more sensitive to pH changes may decline in abundance, while more resilient species may thrive, resulting in altered community structures.
3. Changes in species composition can affect food availability for higher trophic levels, impacting fish populations and marine mammals that rely on specific prey.
4. Habitat loss from coastal development can exacerbate altered species composition by removing critical habitats for various marine species.
5. The introduction of invasive species can also lead to altered species composition, as these newcomers often outcompete native species for resources.

Review Questions

• How does ocean acidification contribute to altered species composition in marine ecosystems?
  • Ocean acidification lowers the pH of seawater, making it more acidic. This change can hinder the growth and development of calcifying organisms like corals and shellfish. As these foundational species decline, it leads to a ripple effect throughout the ecosystem, altering community structures and reducing biodiversity. Species that rely on these calcifiers for habitat or food may also decline, further changing the overall composition.
• Discuss the implications of altered species composition on ecosystem services provided by marine environments.
  • Altered species composition can significantly impact ecosystem services such as fisheries production and coastal protection. As certain species decline and others proliferate due to changing conditions like ocean acidification, the balance necessary for healthy fisheries is disrupted. This shift not only affects food supply for human populations but also compromises the natural barriers provided by ecosystems like coral reefs against storms and erosion.
• Evaluate the potential long-term effects of altered species composition on marine biodiversity and ecological resilience.
  • Long-term alterations in species composition can lead to diminished biodiversity and reduced ecological resilience in marine ecosystems. A loss of biodiversity weakens the ability of these systems to adapt to environmental changes or recover from disturbances. This decreased resilience can result in a less stable ecosystem that is more susceptible to future stressors such as climate change or pollution, ultimately leading to further declines in both species diversity and ecosystem health.

Related terms

Biodiversity: The variety of life in a particular habitat or ecosystem, encompassing the different species and their interactions.

Ecosystem Services: The benefits that humans derive from ecosystems, including food production, water purification, and climate regulation.

Trophic Levels: The hierarchical levels in an ecosystem, comprising producers, consumers, and decomposers, which determine the flow of energy and nutrients.