# Explain how the establishment of marine protected areas (MPAs) contributes to the conservation of biodiversity in ocean ecosystems.

> IB DP Biology Higher Level (2023 syllabus) — A4.2 Conservation of biodiversity · Explain · 4 marks

## Mark scheme (4 marks)

1. MPAs restrict or prohibit extractive activities such as fishing or mining, reducing direct anthropogenic pressure on species and habitats
2. Protecting critical habitats such as coral reefs, seagrass beds or mangroves allows species populations to recover and maintain structural complexity that supports high species richness
3. MPAs act as 'spillover' reservoirs, allowing populations of fish and invertebrates to grow inside the protected area and replenish adjacent exploited areas through larval dispersal or adult migration
4. By maintaining larger, less disturbed populations within MPAs, genetic diversity is preserved, improving the long-term adaptive potential of species to environmental change such as ocean warming or acidification

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