5000 x 3333 px | 42,3 x 28,2 cm | 16,7 x 11,1 inches | 300dpi
Date de la prise de vue:
2 juillet 2019
Lieu:
Bischof Islands, Juan Perez Sound, Gwaii Haanas National Park Reserve, Haida Gwaii
Informations supplémentaires:
Sea lettuce, kelp, sea stars, urchin can be seen at low tide, Bischof Islands, Haida Gwaii, BC., part of an unbalanced ecosystem. Sea otters are a keystone species in this Pacific Northwest ecosystem. When they were hunted to near extinction in the 1800s it started to alter the ecosystem in a trophic cascade. Removal of the sea otters (predator) allowed urchins (herbivore) to expand and eat all the kelp (plant) and create urchin barrens, Species dependant on the kelp forests (fish fry, etc.) lost their habit. Kelp forests appear to be still flourishing in the Aleutian Islands where healthy populations of sea otters remain. Adding to the problem is appearance of the sea star wasting disease in 2013 that caused a massive die-off of sea stars, another urchin predator. The result is the creation of massive urchin barrens where little else lives. Another factor is the crash of the abalone population, which eat kelp. Abalone are now an endangered species, culturally and nutritionally important to the Haida people. Sea otters and sea stars are both predators on abalone and the reintroduction of sea otters to restore balance to the ecosystem is opposed by those who depend on the abalone for income. A further complication is the urchin fishery. Urchins can survive years of starvation when they've eaten their food source (kelp), but their edible roe shrinks, destroying their food value. So this an ecosystem in danger of going out of whack, further stressed by climate change as the coastal waters warm.
