Weltmeere

Unsustainable marine fisheries – In 1992, the total marine catch was at or above the maximum sustainable yield and fisheries were on the verge of collapse. Global catch rates have decreased, though fishing efforts are increasing.

Ocean dead zones – Coastal dead zones which are mainly caused by fertilizer runoff and fossil-fuel use, are killing large swaths of marine life. Dead zones with hypoxic, oxygen-depleted waters, are a significant stressor on marine systems and identified locations have dramatically increased since the 1960s, with more than 600 systems affected by 2010.

VICE News, The Unexpected Threat To Greenland's Melting Glaciers

https://www.youtube.com/watch?v=QubYjSTMGs0