ナショナルジオグラフィックさんのインスタグラム写真 - (ナショナルジオグラフィックInstagram)「Photo by Erika Larsen @erikalarsen888 | Writing by Jennifer Kingsley, collaborating in the Bering Sea: Kelp fans out across a beach in the Aleutian Islands, and the volcanic sand it lies on mimics the night sky. These giant algae can survive a few seasons attached to underwater rocks before washing away and growing pale as they lose their chlorophyll—a chemical essential to photosynthesis. Hunters from Russia began coming to these islands in the 1740s in search of sea otter pelts. In the decades that followed, they killed almost every single animal for its fur. This led to an explosion of the sea urchin population—the sea otter’s target prey. Urchins, in turn, feed on kelp, so their overabundance led to what we now call “urchin barrens,” regions with hardly any kelp at all. As sea otters return to these waters, they bring sea urchin numbers down and urchin barrens have a chance to become kelp forests again. This slender algae has small gas chambers—like panes in a window—that keep it afloat. When it dies and reaches the sandy beach, we might step over it without recognizing its beauty or the ecological story that it represents.」7月14日 6時35分