Question: Which two threats to marine ecosystems are the most serious?

What are 2 threats to the ocean?

The Five Biggest Threats to Our Oceans

  1. Overfishing. We have methodically depleted the fish in our oceans. …
  2. Coastal pollution. …
  3. Habitat destruction. …
  4. Warming. …
  5. Acidification.

What are the biggest threats to marine life?

Global warming is causing sea levels to rise, threatening coastal population centers. Many pesticides and nutrients used in agriculture end up in the coastal waters, resulting in oxygen depletion that kills marine plants and shellfish. Factories and industrial plants discharge sewage and other runoff into the oceans.

What are the threats to aquatic ecosystem?

Major threats to freshwater fishes and other freshwater biodiversity, include: habitat modification, fragmentation, and destruction; invasive species; overfishing; environmental pollution; forestry practise; and climate change.

Which of the following is a threat to coral reefs?

Coral reefs face many threats from local sources, including: Physical damage or destruction from coastal development, dredging, quarrying, destructive fishing practices and gear, boat anchors and groundings, and recreational misuse (touching or removing corals).

What are the threats of Australian marine ecosystem?

Australia’s marine ecosystem faces myriad threats. These threats include global warming, overfishing, industrial coastal developments and pollution.

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What are the two top threats to our freshwater?

The creation of dams and water-diversion systems blocks migration routes for fish and disrupts habitats. Water withdrawal for human use shrinks and degrades habitats. Runoff from agricultural and urban areas hurts water quality.

What are the major threats to aquatic biodiversity and ecosystem services?

Six threats affect aquatic biodiversity; climate change, overexploitation, water pollution, habitat degradation, flow modification and exotic species invasion.

Which coral reefs are most threatened and why?

Key Findings. Coral reefs of Southeast Asia, the most species-rich on earth, are the most threatened of any region. More than 80 percent are at risk, primarily from coastal development and fishing- related pressures.

What are the major natural threats to coral reefs?

Coral reefs are sometimes disturbed by natural forces, such as extreme rain events that dilute seawater, waves associated with hurricane-force winds, volcanism, earthquakes, and thermal stress from unusually warm water (such as El Niño events).

Which of the following destroys coral reef?

Pollution, overfishing, destructive fishing practices using dynamite or cyanide, collecting live corals for the aquarium market, mining coral for building materials, and a warming climate are some of the many ways that people damage reefs all around the world every day.