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Coastal upwelling is the best known type of upwelling, and the most closely related to human activities as it supports some of the most productive fisheries in the world. Coastal upwelling will occur if the wind direction is parallel to the coastline and generates wind-driven currents.
Integrated coastal zone management minimizes the negative human impacts on coasts, enhances coastal defense, mitigates the risk associated with the sea level rise and other natural hazards. The beach erosion is a type of bioerosion which alters the coastal geography through beach morphodynamics .
A marine coastal ecosystem is a marine ecosystem which occurs where the land meets the ocean. Worldwide there is about 620,000 kilometres (390,000 mi) of coastline. Coastal habitats extend to the margins of the continental shelves, occupying about 7 percent of the ocean surface area.
Significant habitat loss is occurring particularly in seagrass meadows, mangrove forests and coral reefs, all of which are in global decline due to human disturbances. Coral reefs are among the more productive and diverse ecosystems on the planet, but one-fifth of them have been lost in recent years due to anthropogenic disturbances.
Human activities affect marine life and marine habitats through overfishing, habitat loss, the introduction of invasive species, ocean pollution, ocean acidification and ocean warming. These impact marine ecosystems and food webs and may result in consequences as yet unrecognised for the biodiversity and continuation of marine life forms.
Dead zones occur in the ocean when phosphorus and nitrogen from fertilizers in land runoff cause excessive growth of microorganisms, which depletes oxygen and kills fauna. Worldwide, large dead zones are found in coastal areas with high human population density.
The map indicates coastal sites where oxygen levels have declined to less than 2 mg/L (red dots), as well as expanding ocean oxygen minimum zones at 300 metres (blue shaded regions). [1] Ocean deoxygenation is the reduction of the oxygen content in different parts of the ocean due to human activities. [2] [3] There are two areas where this occurs.
Collapsed Ordovician limestone bank showing coastal erosion.NW Osmussaar, Estonia.. Coastal geography is the study of the constantly changing region between the ocean and the land, incorporating both the physical geography (i.e. coastal geomorphology, climatology and oceanography) and the human geography (sociology and history) of the coast.