Biotic Factors in Marine Ecosystems

Biotic Factors in Marine Ecosystems

• Competition: Marine organisms compete for limited resources like food, space, and mates.

  • Intraspecific competition occurs between members of the same species.
  • Interspecific competition occurs between different species.
  • Competition significantly impacts population size and distribution, influencing community structure.
  • Examples include corals competing for reef space, or fish competing for prey.

• Predation: Predators hunt and consume prey, affecting prey populations.

  • Predator-prey relationships are crucial for ecological balance.
  • Predator absence/presence significantly alters prey abundance.
  • Predator population changes (e.g., overfishing) disrupt entire food webs.
  • Examples include sharks feeding on fish, and larger fish hunting smaller ones.

• Symbiosis: Close interactions between species.

  • Mutualism: Both species benefit (e.g., cleaner shrimp and fish).
  • Commensalism: One benefits, the other is unaffected (e.g., barnacles on whales).
  • Parasitism: One benefits (parasite), the other is harmed (host).
    • Examples include various worms, bacteria, and fungi.
  • Symbiotic relationships shape marine communities.

• Parasitism: A parasite derives nourishment from a host, often harming it.

  • Parasites impact host health and survival.
  • Parasitism influences host population dynamics and distribution.
  • Examples include marine worms and single-celled organisms affecting fish and invertebrates.

• Herbivory: Herbivores consume plants or algae.

  • Herbivores affect plant abundance and distribution.
  • Herbivory maintains ecosystem balance by preventing excessive plant growth.
  • Examples include sea urchins grazing kelp, and sea turtles consuming seagrass.

• Disease: Pathogens cause illness and death in marine organisms.

  • Pollution, temperature/salinity changes influence disease outbreaks.
  • Disease outbreaks can decimate populations.
  • Examples include bacteria and viruses affecting shellfish and finfish.

• Food Web Complexity: Interconnected trophic levels in a marine ecosystem.

  • Food webs are intricate, including numerous species and trophic levels.
  • Disruptions at one level impact the entire food web.
  • Keystone species abundance changes significantly affect the ecosystem.

• Competition for Space: Marine organisms compete for space on reefs, substrates, or burrows.

  • Limited space influences distribution and abundance of organisms.

• Ecological Interactions: These processes dictate species diversity and community structure in marine environments.

Implications of Understanding Biotic Factors

• Conservation: Understanding biotic factors is crucial for effective conservation strategies.
• Fisheries Management: Understanding trophic interactions is vital for sustainable fisheries.
• Pollution Impacts: Biotic interactions help predict pollution impacts on marine ecosystems.
• Climate Change Effects: Biotic factors determine how marine life reacts to environmental changes.
• Ecosystem Resilience: Identifying keystone species and crucial interactions predicts ecosystem resilience under pressure.