---
title: "Dead Zones — AP Environmental Science Definition & Exam Guide"
description: "Dead zones are oxygen-starved areas of water where aquatic life can't survive, caused by eutrophication. Learn how they connect nutrient pollution to runoff for the AP Enviro exam."
canonical: "https://fiveable.me/ap-enviro/key-terms/dead-zones"
type: "key-term"
subject: "AP Environmental Science"
---

# Dead Zones — AP Environmental Science Definition & Exam Guide

## Definition

Dead zones are areas in bodies of water where oxygen levels are extremely low or completely depleted, leading to a lack of aquatic life. These zones often result from excessive nutrient pollution, causing algal blooms that deplete oxygen when they decompose.

## Related Study Guides

- [8.5 Eutrophication](/ap-enviro/unit-8/eutrophication/study-guide/pht3gvVqyWzrKeAwXm4F)

## Review

### Related Terms

- [Eutrophication](/ap-enviro/key-terms/eutrophication): Eutrophication is the process by which bodies of water become enriched with nutrients (such as nitrogen and phosphorus), leading to excessive plant growth (algae) and subsequent dead zones.
- [Hypoxia](/ap-enviro/key-terms/hypoxia): Hypoxia refers to low oxygen levels in water, which can occur in dead zones. It is harmful to aquatic organisms that require oxygen for survival.
- Nutrient Pollution: Nutrient pollution happens when excessive amounts of nutrients, often from human activities like agriculture and wastewater discharge, enter water bodies and contribute to the formation of dead zones.