Preventing Ecosystem Collapse: Alaska’s Kelp Forests

Over the past few years the media, such as the NY Times, have hyped a coming apocalypse and an existential crisis as ecosystems collapse. Inside Climate News, one of the more egregious fear mongers suggests “Global Warming Could Collapse Whole Ecosystems, Maybe Within 10 Years”. In contrast, most scientists agree ecosystems are very complex and still not well understood. By understanding each ecosystem’s unique pressures from humans, other organisms and natural climate change, perhaps we can make ecosystems more resilient and prevent the alleged "crises".

The International Union for the Conservation of Nature (IUCN), the foremost scientific organization evaluating threats to species and ecosystems, has created the “Red List of Ecosystems” that provides assessments that characterize threats to individual ecosystems.  To date, only one ecosystem has collapsed, central Asia’s Aral Sea. It’s the world’s fourth largest inland water body. Landlocked, its fate is determined by the balance between inflowing water and evaporation. But 2000 years of irrigation has disrupted that balance. Between 1950 and 2007, irrigation nearly quadrupled causing the Aral Sea to largely dry up, eliminating most of its species. The Aral Sea has been sacrificed in order to feed a growing population. However most other ecosystems have a more optimistic future.

 

The first IUCN Endangered ecosystem I’ll examine in a series of articles is Alaska’s giant kelp forests. The fate of kelp forests is largely determined by the interactions between urchins, otters, humans and killer whales.  Hungry kelp-eating urchins can quickly convert a kelp forest into an urchin barren stripped of kelp. However, urchins are regulated by their primary predator, sea otters. Before Alaska’s fur trade began in the mid 1700s, otter populations and kelp forests flourished. One hundred and fifty years later overhunting exterminated or reduced all otter populations, urchins proliferated and kelp forests declined. Alarmed, a 1911 international treaty forbade hunting otters. To further their recovery, otters were re-introduced to islands where they had been eliminated. With improved human stewardship, otters rebounded to their pre-hunting abundance by 1980. With fewer urchins, kelp forests flourished again. But then killer whales began overhunting otters.

FIg 1.  Extent of Alaska's kelp forests: From the Aleutian Islands in the west to southeastern Alaska.

Each killer whale population has a specialized feeding strategy. Some strictly eat fish while others feed on marine mammals. Some congregate around Alaska’s eastern Aleutian Islands near Unimak pass to prey upon migrating gray whale calves. In the 1980s some killer whales began reducing Steller sea lion and harbor seal populations along Alaska’s Aleutian Islands. An autopsy of one killer whale revealed 14 research tags originally attached to endangered Steller sea lions. As seal and sea lion populations declined, killer whales increased their intake of otters, which allowed urchins to again multiply.  

 

Mostly due to killer whale predation, otter populations declined by 50% to 80% and kelp forests declined by 50% between 1980 and 2000  Those declines prompted the designation of kelp forests as Endangered and possibly Critically Endangered. However more recent surveys evoke hope. Along the coast of Alaska from the peninsula south, otter populations have been steadily increasing at a rate of 12-14% a year and there kelp forests dominate. However depleted otter populations throughout Alaska’s Aleutian Islands still remain at 50% of their 1980 abundance. There, with fewer otters sea urchin barrens became more common.

 

 

 

Although these biological interactions control ecosystem shifts between kelp forests and urchin barrens, climate factors play a role, and in a most positive way. Otters are limited by ice. In places like Glacier Bay where ice has retreated, otter habitat is expanding. Likewise, kelp benefit from less sun-blocking ice while greater concentrations of carbon dioxide enhance photosynthesis and promote more growth. Life is good.

 

published in Battle Born Media What's Natural column

Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus, authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism, and member of the CO₂ Coalition

Contact: naturalclimatechange@earthlink.net

Children and the Insect Apocalypse

The American Psychological Association reports young people are suffering from  “a chronic fear of environmental doom”. A recent national survey reported “eco-anxiety” is causing 43 percent of our youth to feel hopeless. Psychologists warn such hopelessness leads to suicide, drug addiction and anti-social behavior. Why such eco-anxiety?  Their hopelessness is driven solely by media narratives. Young people lack the scientific knowledge, lack years of observation, and have yet to acquire the critical thinking skills needed to detect any ecosystem collapse. Its headlines like the Guardian’s, “Plummeting insect numbers 'threaten collapse of nature”, that induce paranoia that “insects are hurtling down the path to extinction, and threatening a “catastrophic collapse of nature’s ecosystems”.

 

In contrast, most scientists studying insects readily admit science lacks the data to make such apocalyptic claims. Science has only identified about one million of an estimated 6 to 10 million insect species worldwide, and only a small percentage of those named species have enough data to evaluate their biology, behavior, or changes in abundance. Nonetheless “the last 3 years have seen a global outbreak of media headlines predicting a global insect apocalypse” and scientists are concerned that such “confusing and inaccurate science” will negatively affect support for insect conservation”. Many have published critiques exposing “the insect apocalypse myth.” 

 

Worse, apocalyptic myths are damaging our children’s mental health. Competing for readership with supermarket tabloids, the New York Times announced, “The Insect Apocalypse Is Here”. The Guardian fearmongered, “Insect apocalypse’ poses risk to all life on Earth”. And despite her lack of the requisite scientific knowledge, the United Nations invited 16-year old Greta Thunberg to lecture the world that “entire ecosystems are collapsing. We are in the beginning of a mass extinction”. 

 

How do we protect our children from succumbing to bogus  “chicken little science”? We must teach them to be good critical thinkers. My parents always warned, “believe half of what you see and none of what you hear.” The world’s oldest scientific motto advises, “Take no one’s word.” To maintain objectivity, us scientists were advised to entertain “multiple working hypotheses”. Likewise, adults must teach children to question all fearful claims. But due to the politicization of science, many adults refuse to read anything outside their beliefs. Many indiscriminately share catastrophic headlines without any critical analysis. For the sake of our kids’ mental health, many “psychologists warn parents and guardians against being climate change alarmists."

 

The apocalyptic NY Times headlines were prompted by a severely flawed German study claiming 75% of flying insects declined in 27 years. That study surveyed insects at 69 different locations, but 37 locations were surveyed only once, and 20 locations were surveyed just twice. Such snapshots of abundance at one location in just one or two years can never determine a meaningful  trend. Never! That’s bad science. Yet the media eagerly elevated a flawed study from just one small region of Germany to suggest a global insect Armageddon.

 

The media simultaneously highlighted another single study by Dr Lister in a Puerto Rican forest to implicate a “global climate crisis”. Researchers claimed higher local temperatures devastated insect abundance and collapsed frog and bird populations that feed on insects. However the media ignored longer term research in the same forest that refuted the temperature claim. It reported that after a destructive hurricane new and more edible vegetation began regenerating and enabled an abnormally higher abundance of opportunistic forest insects, frogs and birds. Unfortunately, Lister’s first survey happened in the 1970s when insect populations had spiked. His second survey happened in 2015 after the forest had matured and insect abundance dropped to normal pre-hurricane numbers. Lister had misinterpreted half of a natural population fluctuation as a catastrophic decline driven by climate change.

 

Giving less attention to optimistic studies is not unusual. Where were media headlines that moths more than doubled in Great Britain over the past 50 years? Why no media fanfare for the 2020 peer-reviewed study that found no change in US insect abundance since 1980?  That study evaluated a network of Long-Term Ecological Research sites established by the National Science Foundation. They found at some sites insect abundance and diversity increased or was unchanged, while at other locations there was a slight decrease. The result? No net change.

 

Although transforming natural habitat into agricultural land greatly benefitted people, it did reduce insect populations. However due to better conservation efforts and efficient farming practices, agricultural lands that once covered 63% of America in 1949 were reduced to 51% by 2007. (Unfortunately, due to biofuel subsidies, agricultural land increased in the Corn Belt.) Additionally, genetically modified plants continue to reduce the indiscriminate spraying of insecticides once practiced in the days of aerial crop dusting.

 

To trust the science, we must examine all the science. We can then honestly tell our children why there’s great hope for our future.