Humans affect the polar sea primarily through harvesting resources and, indirectly, through activities that contribute to climate change.
While the provided reference only mentions "harvesting from the sea," it's crucial to recognize that the dominant impact today stems from human-caused climate change.
Direct Effects: Harvesting from the Sea
- Whaling: Historically and, in some regions, presently, whaling significantly impacts whale populations. Although some whale species are recovering, many still exist in lower numbers than pre-whaling. The reference notes that some nations continue whaling in polar waters.
- Fishing: Overfishing depletes fish stocks, impacting the entire food web. Although not mentioned explicitly in the reference, this is a major human impact on polar seas.
- Sealing: Historically, sealing had a significant impact. Today, most Antarctic seal populations are increasing. However, unsustainable practices could reverse these gains. The reference notes an increase in most Antarctic seal species.
Indirect Effects: Climate Change
While the reference doesn't explicitly state this, Climate change is arguably the most significant way humans affect the polar sea. It manifests in numerous ways:
- Sea Ice Reduction: Increased global temperatures lead to melting sea ice, reducing habitat for ice-dependent species like polar bears and seals.
- Ocean Acidification: Increased atmospheric carbon dioxide dissolves in the ocean, making it more acidic. This threatens marine life, particularly shellfish and plankton, which are essential to the food web.
- Changing Ocean Currents: Climate change can alter ocean currents, affecting nutrient distribution and impacting marine ecosystems.
- Increased Freshwater Input: Melting glaciers and ice sheets increase freshwater input into the ocean, which can disrupt salinity levels and affect marine life.
Species-Specific Impacts
- Bowhead Whales: According to the reference, the bowhead whale is the only truly endangered Arctic mammal, demonstrating the impact of human activities.
- Seals: Populations of most Antarctic seal species have increased, indicating potential recovery from past exploitation, though this also highlights the potential vulnerability of specific species to changing environmental conditions.
- Whales (General): Most whale species still number fewer than they once did due to whaling practices.
Conclusion
Humans affect the polar sea through direct resource extraction and indirectly through climate change, impacting various species and altering the delicate balance of these fragile ecosystems. While certain species show signs of recovery, continued sustainable practices and global efforts to mitigate climate change are essential to protect the polar sea.
