Why do ocean currents influence the climate of coastal regions differently in eastern and western continental margins?
A Depth only
B Warm currents raise temperature, cold currents cool
C Salinity only
D Tides only
Warm currents transfer heat toward higher latitudes, warming coasts, while cold currents lower coastal temperatures, creating distinct climatic conditions along eastern and western margins.
Which factor explains the lower biodiversity in deep-sea ecosystems compared to coastal waters?
A High light availability
B Extreme pressure, darkness, and low food supply
C Warm water
D Shallow water only
Deep-sea organisms must adapt to high pressure, minimal light, and scarce nutrients, limiting species diversity compared to productive coastal ecosystems.
Why is nutrient upwelling along the western coasts of continents essential for marine productivity?
A Brings warm water
B Nutrient-rich deep water supports phytoplankton growth
C Increases salinity
D Reduces wave height
Upwelling supplies essential nutrients to surface waters, enhancing phytoplankton biomass, which sustains higher trophic levels, including commercially important fish.
Which ecological interaction is described by the consumption of one species by another in marine ecosystems?
A Photosynthesis
B Predation
C Decomposition
D Evaporation
Predation transfers energy from prey to predator, structuring food webs and maintaining population balances in marine ecosystems.
Why are coral reefs considered highly vulnerable to climate change?
A Resistant to heat
B Sensitive to temperature rise and ocean acidification
C Shallow only
D Increase salinity
Coral-algae symbiosis is disrupted by warming and acidification, causing bleaching, reduced calcification, and potential collapse of reef ecosystems.
Which factor is primarily responsible for the seasonal variation of phytoplankton populations in oceans?
A Salinity
B Light and nutrient availability
C Tides
D Wind only
Seasonal sunlight and nutrient influx regulate phytoplankton growth, affecting primary productivity and the overall marine food web.
Why are mangroves critical for mitigating coastal erosion?
A Increase waves
B Roots stabilize sediment and reduce shoreline loss
C Reduce rainfall
D Change temperature
Dense mangrove roots bind soil, absorb wave energy, and prevent erosion, protecting coastlines and habitats for numerous species.
Which oceanic region is most affected by thermohaline circulation, impacting global climate patterns?
A Coastal shelves
B Deep ocean basins
C Coral reefs
D Estuaries
Thermohaline circulation moves water masses globally, redistributing heat, regulating climate, and influencing marine nutrient transport and ecosystems.
Why do estuarine areas serve as critical breeding grounds for many marine species?
A Shallow waters only
B Nutrient-rich mixing of freshwater and seawater
C High salinity only
D Deep water
Nutrient-rich waters support phytoplankton and invertebrates, providing abundant food and shelter, ensuring reproductive success for marine species.
Which factor explains why phytoplankton form the foundation of oceanic food webs?
A Predators consume them
B Convert sunlight to chemical energy
C Absorb salinity
D Provide oxygen only
Phytoplankton are primary producers performing photosynthesis, producing biomass and energy for herbivores and higher trophic levels.
Why is the study of ocean tides essential for human settlements along coasts?
A Aesthetic value
B Prevent flooding and plan navigation
C Reduce rainfall
D Increase waves
Knowledge of tidal patterns allows safe harbor construction, flood management, and efficient navigation, mitigating risks from high or low tides.
Which factor makes coral reefs hotspots for marine biodiversity?
A High pressure
B Shallow, warm, and clear waters for photosynthesis
C Ice cover
D Low salinity
Optimal light and temperature conditions support symbiotic algae and diverse species, creating complex, productive, and resilient reef ecosystems.
Why are mangroves considered essential for fisheries in tropical regions?
A Increase rainfall
B Provide shelter, nursery grounds, and food for juvenile fish
C Reduce waves only
D Alter tides
Mangrove ecosystems support early life stages of fish and crustaceans, increasing survival rates and sustaining coastal fisheries.
Which human activity directly accelerates coral reef degradation?
A Boating only
B Pollution and overfishing
C Swimming lightly
D Tourism management
Excessive nutrient input, fishing practices, and habitat destruction reduce reef resilience, biodiversity, and ecological services.
Why do upwelling regions influence regional climate and agriculture?
A Shallow waters
B Cool surface waters and nutrient-rich fisheries
C Low salinity only
D Increase waves
Upwelling lowers coastal temperatures and enhances fish productivity, affecting local climate, food supply, and agricultural practices dependent on marine resources.
Which ecological process ensures nutrient cycling in marine ecosystems?
A Photosynthesis only
B Decomposition of organic matter
C Tidal action
D Evaporation
Decomposers recycle nutrients from dead organisms back into water, sustaining primary productivity and supporting food webs in marine environments.
Why do polar oceans support fewer species but abundant plankton?
A High temperature
B Cold, nutrient-rich waters favor plankton growth
C Warm water only
D Shallow reefs
Low temperatures limit species diversity, but high nutrient availability supports dense phytoplankton populations, forming a base for marine food chains.
Which human-induced factor contributes most to ocean acidification affecting coral reefs?
A Fishing
B CO₂ emissions
C Boating
D Swimming
Increased CO₂ dissolves in oceans, lowering pH, reducing coral calcification, and threatening reef structure and marine biodiversity.
Why is it important to study mangrove root structures for coastal protection?
A Aesthetic purposes
B Roots stabilize soil and dissipate wave energy
C Increase rainfall
D Reduce tides
Complex root networks prevent erosion, reduce wave impact, and protect human settlements and ecosystems along tropical coasts.
Which factor primarily affects the formation of thermohaline circulation in the global oceans?
A Wind only
B Temperature and salinity differences
C Tides only
D Wave height
Variations in water density due to temperature and salinity drive deep ocean currents, distributing heat globally and maintaining climate stability.
Why do estuaries support migratory bird populations?
A Low salinity only
B Nutrient-rich waters provide food and resting sites
C Reduce waves
D Shallow water only
Abundant invertebrates and fish in estuaries supply energy for migratory birds, making them crucial stopover and breeding habitats.
Which factor is responsible for seasonal variability in marine phytoplankton?
A Wave height only
B Nutrient availability and sunlight
C Salinity only
D Ocean depth only
Seasonal changes in nutrient supply and sunlight intensity regulate phytoplankton growth, influencing marine productivity and food web dynamics.
Why are coral reefs more abundant in tropical regions than in temperate regions?
A Low sunlight
B Warm, shallow waters with stable temperatures
C Ice cover only
D Low oxygen
Coral-algae symbiosis requires sufficient light and temperature stability, restricting reef development to tropical and subtropical regions.
Which oceanic feature supports high productivity through nutrient upwelling and dense plankton populations?
A Deep trenches
B Continental shelves and coastal upwelling zones
C Abyssal plains
D Open ocean only
Nutrients rising from deep waters in upwelling zones boost phytoplankton growth, forming the basis for productive fisheries.
Why are wetlands critical for flood mitigation and water purification?
A Increase rainfall
B Absorb excess water and filter pollutants
C Increase salinity
D Alter tides
Wetlands act as natural sponges and filtration systems, reducing flood risks and improving water quality before it reaches rivers or oceans.
Which factor contributes to the vulnerability of coral reefs to bleaching events?
A Deep water
B Sea temperature rise and UV radiation
C Ice cover
D Low salinity
Elevated temperatures and excessive sunlight stress corals, disrupting symbiotic algae and causing widespread bleaching and mortality.
Why are mangroves important for carbon sequestration?
A Increase rainfall
B Store carbon in biomass and sediments
C Reduce waves
D Increase tides
Mangroves trap carbon in their roots, stems, and soils, acting as significant carbon sinks and mitigating climate change effects.
Which ocean current moderates the climate of northwestern Europe?
A Labrador Current
B North Atlantic Drift
C California Current
D Benguela Current
Warm waters of the North Atlantic Drift flow northeast, increasing winter temperatures and enabling temperate climate conditions in Europe.
Why is it important to monitor plankton populations in marine ecosystems?
A Aesthetic value
B Indicator of nutrient availability and ecosystem health
C Reduce tides
D Increase waves
Plankton abundance and composition reflect productivity and environmental changes, serving as early indicators of ecosystem health.
Which human activity is most responsible for wetland loss globally?
A Birdwatching
B Drainage for agriculture and urban expansion
C Light fishing
D Sailing
Wetlands are reclaimed for farmland and urban areas, destroying habitat, reducing biodiversity, and increasing flood and pollution risks.
Why do polar oceans experience dense phytoplankton blooms during summer months?
A Warm water only
B Increased sunlight and nutrient availability
C Shallow reefs
D Low salinity
Summer provides extended daylight and nutrient-rich waters from melting ice, promoting rapid phytoplankton growth and supporting polar food webs.
Which factor determines the global pattern of coral reef distribution?
A Ocean depth, temperature, and sunlight
B Salinity only
C Wave height only
D Ice cover only
Corals require shallow, warm, sunlit waters for photosynthetic algae, restricting reefs to tropical and subtropical regions.
Why do estuaries act as nutrient traps for coastal ecosystems?
A Reduce tides
B Mixing of river and seawater concentrates nutrients
C Increase salinity
D Low temperature only
Estuarine mixing delivers nutrients from rivers to coastal waters, enhancing productivity and supporting fisheries and bird populations.
Which human activity directly threatens coral reef survival?
A Boating lightly
B Overfishing and pollution
C Swimming
D Ecotourism management
Removal of key species and water contamination degrade reef structure and biodiversity, reducing ecosystem resilience.
Why are upwelling zones among the most productive marine ecosystems?
A Warm water
B Deep nutrient-rich water rises to surface
C Shallow only
D Low salinity only
Nutrient influx from deep waters supports phytoplankton growth, which sustains high fish abundance and fisheries productivity.
Which factor influences the vertical stratification of temperature in oceans?
A Depth and light penetration
B Salinity only
C Tides only
D Wave height
Sunlight warms upper layers, while deeper waters remain cold, creating distinct thermal zones that influence marine habitats.
Why is monitoring mangrove health critical for climate mitigation strategies?
A Increase rainfall
B Carbon storage and coastal protection
C Reduce tides
D Increase salinity
Mangroves sequester carbon and buffer coastlines against erosion and storms, contributing to both climate mitigation and ecosystem resilience.
Which ocean current cools the west coast of South America?
A Gulf Stream
B Peru (Humboldt) Current
C Kuroshio Current
D North Atlantic Drift
Cold waters flow northward along South America, reducing coastal temperatures, enhancing upwelling, and supporting productive fisheries.
Why are wetlands referred to as “biological supermarkets”?
A Produce food only
B Provide diverse species and abundant resources
C Increase tides
D Reduce waves
Wetlands support numerous plants, fish, and bird species, offering rich resources and habitats vital for ecological balance and human sustenance.
Which factor primarily drives thermohaline circulation in the global oceans?
A Tides
B Differences in temperature and salinity
C Wave action
D Wind only
Density differences from varying temperature and salinity cause deep ocean currents, distributing heat globally and influencing climate and marine ecosystems.
Why do mangroves reduce the impact of tsunamis on coastal areas?
A Increase rainfall
B Roots dissipate wave energy
C Lower salinity
D Alter tides
Dense root systems absorb and slow down tsunami waves, reducing inland damage and protecting coastal communities and ecosystems.
Which human activity contributes most to ocean acidification affecting marine life?
A Boating
B CO₂ emissions from fossil fuels
C Tourism
D Fishing lightly
Dissolution of excess atmospheric CO₂ lowers ocean pH, affecting calcifying organisms like corals and shellfish, threatening marine ecosystems.
Why is the study of estuarine systems critical for fisheries management?
A Aesthetic purposes
B Estuaries serve as breeding and nursery grounds
C Reduce waves
D Increase tides
Estuaries provide safe habitats with abundant food for juvenile fish, ensuring sustainable fish populations and supporting coastal fisheries.
Which factor limits coral reef formation to tropical and subtropical regions?
A Deep waters
B Warm temperatures and sufficient sunlight
C Ice cover
D High salinity
Coral-algae symbiosis requires stable warm temperatures and light for photosynthesis, restricting reefs to tropical and subtropical latitudes.
Why do polar oceans support high plankton productivity during summer despite low biodiversity?
A Warm water
B Extended daylight and nutrient availability
C Ice cover
D Shallow reefs
Summer sunlight and nutrient influx from melting ice trigger plankton blooms, sustaining higher trophic levels despite low species diversity.
Which factor is responsible for nutrient enrichment in coastal upwelling zones?
A Warm surface currents
B Rising deep, nutrient-rich waters
C Ice cover
D Low salinity
Upwelling brings nutrients from deep layers to the surface, enhancing primary productivity and supporting dense fish populations.
Why are wetlands important for migratory bird conservation?
A Increase salinity
B Provide abundant food and resting habitats
C Reduce waves
D Alter tides
Nutrient-rich wetlands supply food and shelter for migratory birds during travel, contributing to biodiversity and ecosystem health.
Which human activity most threatens mangrove ecosystems?
A Birdwatching
B Coastal development and aquaculture
C Light fishing
D Sailing
Land reclamation and aquaculture lead to mangrove loss, reducing biodiversity, carbon storage, and natural coastal defenses.
Why do thermohaline currents play a crucial role in global climate regulation?
A Only affect tides
B Redistribute heat and nutrients across oceans
C Only surface currents
D Only coastal areas
Deep ocean currents transport warm and cold waters globally, influencing climate patterns, nutrient distribution, and marine ecosystem productivity.
Which ecological function is performed by decomposers in marine and coastal ecosystems?
A Photosynthesis
B Nutrient recycling
C Carbon release only
D Oxygen depletion
Decomposers break down dead matter, releasing nutrients back into water or soil, sustaining primary productivity and ecosystem health.