Overview of human interactions with marine ecosystems：练习题

Which of the following human activities involves dredging to remove resources from the seabed for use in construction and building?

Many marine ecosystems act as nursery areas for commercially important species. What is the primary benefit of these nursery areas to human populations?

Why is 'blast fishing' (using explosives) considered an unsustainable human activity compared to traditional line fishing?

Which of the following represents a direct economic benefit that humans derive from marine ecosystems?

Eutrophication, often caused by human activities such as agricultural runoff, leads to an algal bloom in marine ecosystems. What is the subsequent impact on dissolved oxygen levels that negatively affects other marine organisms?

State one way in which marine ecosystems provide a direct source of building materials for human use.

Describe the impact of oil spills on the physical characteristics of marine mammals and birds that inhabit affected areas.

Explain how the dredging of seabed resources for the construction of infrastructure can lead to the decline of local fisheries.

Human activities profoundly influence marine ecosystems, both positively and negatively.

Marine ecosystems are of significant importance to human populations, yet they are increasingly threatened by various human activities.

(a) State three ways in which marine ecosystems provide direct benefits or resources to humans. (3 marks)

(b) Describe how the removal of resources, specifically through the dredging of sand and mud, can negatively impact the biodiversity of a coastal ecosystem. (2 marks)

(c) Define the term sustainable resource and explain how implementing a closed season helps ensure that a fishery remains sustainable. (3 marks)