Every morsel of food, every sip of water, the air we breathe is the result of work done by other species. Nature gives us everything we need to survive. Without them, there is no us. Enric Sala, Marine Biologist
In late June, a deadly heat dome settled over the Pacific Northwest, humans and other species suffered horribly from extreme temperatures that the area had not ever experienced before. As a result of the corresponding near-shore marine heatwave, billions of intertidal species such as rockweed, snails, mussels, barnacles, sea stars boiled to death in extreme temperatures in the intertidal zones of the region. Some of those marine temperatures at the coast were 125 degrees.
These species are generally protected from normal temperature swings and salt salinity. As a result, they serve as environmental indicators of nearshore life forms.
The NPS describes the three tidal zones thusly:
Bounded by high and low tides, the intertidal zone is rich in algae and invertebrates, but the particular mix of species varies with proximity to shore. The high intertidal zone, which is inundated only during high tides, has species including rockweed, acorn barnacles, turban snails, and lined shore crabs. The middle intertidal zone, which is exposed to the air at least once a day, is home to creatures such as sea lettuce, aggregating anemones, chitons, gooseneck barnacles, mussels, and ochre stars. The low intertidal zone, which is exposed only during very low tides, is inhabited by coralline algae, giant green anemones, purple sea urchins, and bat stars.
In the narrow band between land and sea, plants and animals must endure being pounded by icy waves at some times while being parched by hot, dry air at others. Despite these extreme conditions, wave-swept rocky shores are full of life because they also have plenty of light, nutrients, and oxygen.
Bounded by high and low tides, the intertidal zone is rich in algae and invertebrates, but the particular mix of species varies with proximity to shore. The high intertidal zone, which is inundated only during high tides, has species including rockweed, acorn barnacles, turban snails, and lined shore crabs. The middle intertidal zone, which is exposed to the air at least once a day, is home to creatures such as sea lettuce, aggregating anemones, chitons, gooseneck barnacles, mussels, and ochre stars. The low intertidal zone, which is exposed only during very low tides, is inhabited by coralline algae, giant green anemones, purple sea urchins, and bat stars.
Salmon spawn in the gravel of tidal rivers. This clip shows the devastating effects to them from the recent heat dome over PNW.
Stephen Leahy is an environmental reporter who contributes to The Guardian and National Geographic. He has a must-read post in The Atlantic in which he describes an obliteration of intertidal sea life in the PNW from the heat dome.
Harley, who is investigating the extent of the June die-off, has learned from marine scientists at various institutions that an estimated 100 million barnacles died on a 1,000-yard stretch of shore near White Rock, British Columbia. While not all sites are as bad as White Rock, large numbers of dead marine animals have been found along much of the Salish Sea shoreline, from Olympia, Washington, to Campbell River, British Columbia. The situation is so alarming that Harley said it could lead to the collapse of the region’s maritime ecosystem.
This kind of destruction is so notable because rockweed, mussels, and other intertidal species are incredibly tough and used to wide swings in temperature. They spend 12 hours under the cold waters of the northern Pacific Ocean and then, at low tide, 12 hours exposed to the air and hot sun. Only an extreme, extreme event could kill them. This massive die-off may result in a radically different shoreline ecology, one without the thick carpet of mussels and rockweed that has lined much of the Salish Sea shore since the last Ice Age.
Many land-based species have also died from the heat. I’ve read numerous reports of flightless nestlings, including hawks and terns, throwing themselves out of nests and off rooftops, risking death and injury to avoid being cooked alive. The California Department of Fish and Wildlife has warned that nearly all endangered young salmon in the Sacramento River could die. Officials in Washington State also say that salmon in the Columbia and Snake Rivers are at risk. Overheated bears have been seen wading into backyard pools and ignoring swimmers at Lake Tahoe in order to get some cool relief.
Leahy describes a goldilocks zone that every living creature (including us) needs to survive. The zone is neither too hot nor too cold, he says in his piece. For tropical coral colonies like the Great Barrier Reef, it is 90 degrees. If the temperature goes above that, coral bleaching occurs and kills portions of the stressed reef. Other species like salmon require cold water no warmer than 68 degrees for survival. Leahy points out that Arctic species like sea birds the temperatures are 70 degrees. He notes the Siberian temperatures as another red code alert as temperatures reach over 100 degrees in Siberia, 32 degrees warmer than normal.
He continues:
Climate scientists are sounding the alarm loudly, urging the world to take action now in order to, as one scientist put it, “prevent the worst outcomes of global warming.” If billions of some of the toughest species on the planet dying is not the worst outcome, I’m sure we don’t want to see what is.
Climate, nature, and humanity’s well-being and survival are deeply interconnected. As the marine biologist and National Geographic explorer in residence Enric Sala told me, “Every morsel of food, every sip of water, the air we breathe is the result of work done by other species. Nature gives us everything we need to survive. Without them, there is no us.”
Water is life.
