L. Henderson \ Oceans First, Issue 2, 2015, pgs. 1-9.
Climate change associated with increasing ocean temperatures is impacting the narwhal population of the Arctic Ocean, an area highly susceptible to rising temperatures. Among other things, these unique cetaceans are being affected by ice-entrapments and top-down controls from killer whale predation. Examining these factors can help predict the dangers to narwhal populations for future conservation efforts. Increasingly delayed ice formation due to global warming is causing high mortality of narwhals as they become entrapped in the rapidly freezing ice of the harsh winter. Warming ocean temperatures are opening up Arctic waters for killer whales to hunt narwhals as well, killing many more than they need for food in the process. The small population of narwhals is especially vulnerable to climate change. The narwhals are an important part of the Arctic food chain, being one of many secondary consumers, and increase its biodiversity with their distinctive protruding tusk, unique to the narwhal only. This review synthesizes the events causing increased mortality rates of narwhals to provide a scope for future conservation efforts.