A Surprising Effect of Light Pollution: It Disrupts Aquatic Insects

Many ecologically important insects spend most of their lives in streams, but new research shines a light on how humans put them at risk.

Most people I talk to about light pollution almost instantly relate to my research. They’re relieved to finally run into someone who understands just how aggravating it can be to have a bright white light shining into your bedroom in the middle of the night. However, very few people, in my experience, have thought about how those bright lights might also affect the insects, amphibians and fish living in urban and suburban streams.

You may think of insects as primarily airborne creatures, but insects such as mayflies, caddisflies and stoneflies spend the majority of their lives as larvae in streams, eventually emerging as terrestrial adults who may only live for a few days or weeks. The main way these larval aquatic insects move through their habitat is by “drifting” — detaching themselves from the stream substrate and floating with the current before swimming back down to a new patch of substrate.

Here’s where light comes into play. Drifting puts aquatic insects at risk of being eaten by visually oriented predators like trout, which will consume any objects they can see floating in the water. In order to decrease this risk, insects are more likely to drift at night, even avoiding drifting on nights with a full moon.

The levels of artificial light at night can often exceed that of a full moon, so it is perhaps not surprising that when I experimentally increased light levels near some isolated streams I found significantly lower levels of drift rates. The artificial lighting I used in my first experiments was equivalent to what might shine on a stream from an average suburban neighborhood at night — or the light glaring in your window.

Portland river at night — Portland at night by Allie Caulfield (CC BY 2.0)

Now, it’s true that a small proportion of insects do drift during the day. Sometimes it’s unavoidable — perhaps they’ve encountered a predacious insect and the benefit of escaping certain death outweighs the risk of a trout catching them. However, drifting during the day is certainly not ideal, and most insects will avoid it if they can.

So what’s the significance of all this, and what difference does it really make if the drift rates of aquatic insects changes?

Well, it comes down to the critical role those insects play in stream ecosystems. Larval insects keep algal biomass in check, help break down leaves that fall into streams, and are important components of both the aquatic and terrestrial food webs. Larval aquatic insects are a major source of food for fish and amphibians, and when they emerge from the water as adults they’re a key source of food for animals like bats, birds and lizards. An increase in predation on larval aquatic insects under artificial lights — either through fish being more active and able to see the insects at night or via a shift to daytime drift — could potentially lead to a decreased number of larvae processing algae and leaf litter and fewer adults emerging from streams. In turn that could lead to eventual decreases in populations of bats, birds and other species.

We still have a lot more to learn about all of this. After my previous experiment, I still had a big question: Could these stream-based insects acclimate or even fully adapt to that type of artificial nighttime lighting? After all, if there’s no substantial difference in the predation risk a drifting insect faces at night in a lit stream versus during the daylight, then perhaps there might be less of a difference between the rates of insects drifting at night and day in brightly lit urban and suburban streams relative to their darker and more remote counterparts.

To test this hypothesis, I used a tool called the New World Atlas of Artificial Sky Brightness to locate 11 sampling sites in western Oregon, each of which had a slightly different level of light pollution. I spent the last summer sampling aquatic insect drift rates at each site during the day and at night to see how the light might affect them.

Of course, light itself is usually accompanied by other factors that could affect insect populations. An area has light pollution because humans live or work nearby, so there could also be an increase in other things that change the quality of water, such as sediment runoff or altered flow of rainfall due to impervious surfaces like roads or parking lots. These alterations could lead to different community compositions, which could lead to a change in drift rates just due to alterations in the number of aquatic insects living in the streams, or increased dominance by species that don’t engage in behavioral drift. However, by using the ratio of night to day drift as my response variable, I hoped to eliminate most of these potential confounding variables.

I’m currently about halfway through processing my samples, and so far it’s difficult to say for certain if there’s less of a difference between night and day drift in more brightly lit areas. This is likely due to the interaction of unusually high water temperatures with the presence of light. Two of the darker streams from my experiments also had the highest stream temperatures, and those sites showed less of a difference between day and night drift. This perhaps suggests that the need for aquatic insects to seek out cooler, more favorable habitat overrides any increased risk of predation. I’m hoping these patterns will become more clear once all the samples have been counted.

One of the necessary next steps in the research will be to determine if there’s an increase in predation risk under artificial lights, and then to find if there’s a light level where it’s actually more beneficial to switch to drifting during the day.

Fortunately, the excess of light at night can easily be reversed if there’s enough political and personal will. In France new regulations went into effect this year that stipulate when outdoor lights must be dimmed or turned off, what permissible emission spectra are for outdoor lights, and what are acceptable illuminance levels, among other policies.

Lyon river lights — Lights on the river in Lyon, France. Alan Sandercock (CC BY 2.0)

People can lobby local lawmakers to adopt similar regulations in their own towns or countries, but they can also make changes themselves that can reduce unnecessary light. For example, homeowners can make sure any outdoor lights they have are motion-activated or turned off before they go to bed. They can also only use lights with a correlated color temperature (CCT) of 2700K or less. Outdoor lights should be housed in fixtures that aim light only where it’s needed and reduce glare and light trespass. The International Dark Sky Association website maintains a list of dark-sky friendly fixtures for property owners.

There’s still a lot left to learn about the effects of light pollution on the insects that live in our natural stream and river environments, and the river ecosystems themselves. My research continues, and I hope that more scientists will take up the mantle of better understanding how lights affect these little-seen but important ecological processes.

The opinions expressed above are those of the author and do not necessarily reflect those of The Revelator, the Center for Biological Diversity or their employees.

Previously in The Revelator:

Big Cities, Bright Lights: Ranking the Worst Light Pollution on Earth

Room to Roam: How Animals Benefit From Wildlife Corridors

Ecologist Jodi Hilty explains what conservationists have learned about linking critical habitat areas together.

Animals today live in a shrinking world. Development, resource extraction and roadbuilding have fragmented landscapes and reduced wild spaces making it harder for animals to find food, search for a mate and adapt to a changing climate. To help address these problems, ecologists and conservationists have been working for decades to create wildlife corridors — areas of natural habitat that can reconnect fragmented habitats. These projects have ranged from small-scale efforts to build safe passage over highways to major conservation efforts protecting millions of acres.

For more than 20 years, ecologist Jodi Hilty has been one of the people at the heart of this work. As president and chief scientist of the Canada-U.S. nonprofit Yellowstone to Yukon Conservation Initiative (Y2Y), Hilty has helped lead the organization’s work to connect and protect habitat in the massive region stretching 502,000 square miles across western North America from Wyoming to the Northwest Territories.

She’s also co-author of the book Corridor Ecology: Linking Landscapes for Biodiversity Conservation and Climate Adaptation, due out in April, which explains why corridors are needed now more than ever with a changing climate. We talked to Hilty about what kind of wildlife corridor projects have been most successful and why corridors aren’t just for land-based animals.

What have been some of the impacts of habitat loss and fragmentation on wildlife? What kinds of species have been most affected?

Habitat loss and fragmentation affects wildlife in a number of different ways. Generally, wildlife that have specific needs or large home-range requirements in more intact habitat are more likely to experience a reduction in total numbers or disappear from part of their original range. This is particularly true where smaller and more isolated patches of habitat remain because they often can only sustain smaller populations, and smaller populations are more likely to go extinct.

There are three kinds of animals that have difficulty in places where natural habitat is disappearing or has become fragmented. The first is migratory animals — these are animals that need to move seasonally to obtain resources. For example, some wildebeest and pronghorn populations have been lost in places where they can no longer migrate. Second are animals that are fewer in number and require large home ranges, especially those that have a harder time co-existing with humans, such as grizzly bears and tigers. Many isolated, small populations have gone extinct or are at high risk of extinction. And third are specialist animals that have very specific needs and don’t do well in altered environments — animals like orangutans and tiger salamanders are examples of specialists that face challenges with habitat loss and fragmentation.

Ecologist Jodi Hilty on the Nahanni River. (Photo by Colleen Brennan)

What are some of the most exciting wildlife corridor projects you’re working on now?

Wildlife corridors are one tool that can help reconnect disconnected patches of habitat and so are essential to achieve the Y2Y vision of connecting and protecting habitat in the region for people and nature to thrive. We worked with Vital Ground, a land trust in western Montana this year to purchase lands just west of Missoula to help maintain a corridor between Ninemile and the Bitterroot Ranges for grizzly bears and other wildlife. This is one of the key connections to allow grizzly bears to naturally re-occupy the Salmon-Selway wildland complex in central Idaho.

Road-crossing projects in the Y2Y region are also really exciting. The region already has more than 100 underpasses and overpasses dedicated to getting wildlife safely across roads. A new overpass on the TransCanada highway east of Banff in Alberta is at the design stage, and Y2Y is supporting the Valhalla Wilderness Society to study how to solve the problem of western toads getting killed on Highway 31A in British Columbia. Animals of all sizes can face problems getting across roads safely.

The book you co-authored, Corridor Ecology, is coming out with a second edition in April. What have been some of the most important developments in this field since the first edition was published in 2006?

The science has advanced significantly, and the implementation of corridors has become vastly more widespread, with a proliferation of studies focusing on habitat connectivity originating from all over the world. Over half of these studies are coming from the U.S., followed by Spain, China and Australia.

There have been more than 180 new papers published on connectivity and climate change alone — a field that was in its infancy in 2005 when we submitted the first book for publication.

Likewise, the growth and sophistication of various connectivity modelling approaches also exploded in recent years, as did other related science and implementation efforts.

Which wildlife corridor projects have been most successful?

It is difficult to say — there have been many corridor conservation projects around the world. It is so exciting to see once-denuded creeks in Australia restored so well that a wide corridor of habitat has regrown and wildlife like Lumholtz tree kangaroos (Dendrolagus lumholtzi), which are threatened by large-scale clearing of rainforest habitat, are using the corridors. Closer to my home, Dr. Michael Proctor has been monitoring grizzly bears on the U.S.-Canada border and has been able to verify wildlife using key corridors.

Migrating snow geese — Snow geese stop during their migration from the Arctic at Pongo Lake in the Pocosin Lakes National Wildlife Refuge, North Carolina. (Photo by Jim Liestman, CC BY-NC-ND 2.0)

Most wildlife corridors we hear about are on land, but what about the sky and sea?

The concept of wildlife corridors took off quickly on land but connectivity in the marine environment has recently emerged as a field of research and we are pleased to have University of California, Santa Cruz marine ecology professor Mark Carr and NOAA research ecologist Elliott Hazen contributing a chapter on the topic in our book. There is now research into deep-sea connectivity in oceans, as well as near the shore, like along coral reefs.

In some ways, flyways have been a pioneering part of the world of connectivity. North America has done quite a good job of protecting major flyways, mostly by making sure wetland stop-over sites for birds were maintained or restored. There is increasing discussion about what corridors in the sky might look like, but more work needs to be done to explore this concept.

Previously in The Revelator:

Life in the Crossroads: A New Age for Highway Wildlife Crossings

Trashing the Planet: 15 New Books About Garbage, Climate Change and Endangered Species

March brings new books by E.O. Wilson and Frans de Waal, as well as important reads about wolves and primates.

There’s nothing disposable about the ideas presented in this month’s new environmental books.

The authors on March’s list have pulled out all the stops, with several books about garbage and pollution, the perils of climate change, and the threats facing wildlife and endangered species. We even have a couple of novels that address environmental issues in thought-provoking ways.

Check out the list below, where you’ll find our picks for the 15 best eco-books of March 2019. Links are to publishers’ or authors’ websites, and you can also find any of these titles at your favorite bookseller or library.

Garbage & Pollution:

Throwaway Nation: The Ugly Truth About American Garbage by Jeff Dondero — The world is awash in waste, and we really need to get off the runaway train of disposability. This book digs deep into the garbage pits of human society to reveal the enormity of the problem — and what we can do to fix it.

Landfill: Notes on Gull Watching and Trash Picking in the Anthropocene by Tim Dee — You don’t need to go all the way to Midway Atoll to find birds with stomachs full of trash. The same thing happens in cities around the world. Gulls make the most of the ready smörgåsbords we’ve laid out for them in our landfills, and in some surprising ways they’ve actually thrived as a result. This book looks at the unlikely and unappealing results of this trashy symbiotic relationship.

Clearing the Air: The Beginning and the End of Air Pollution by Tim Smedley — The author, a sustainability journalist, trekked around the globe to some of the world’s most polluted cities to find out how dirty air is killing people and what we can do about it. (Available in ebook format only, for now, with a print edition following in September.)

Garbage: Follow the Path of Your Trash by Donna Latham, illustrated by Tom Casteel — After learning about trash from the previous three books, here’s one to help teach the next generation what they can do about the problem, complete with hands-on science activities for kids ages 9 to 12. (This is an updated version of Latham’s award-winning earlier book, Garbage: Investigate What Happens When You Throw It Out.)

Wildlife and Endangered Species:

Return of the Wolf by Paula Wild — Can wolves and human coexist? As Wild recounts, our two species have lived together for centuries, and in many ways our fates are intertwined. This book — a thematic sequel to the author’s earlier volume on cougars — examines the history of wolves, their ecological roles and their relationships with other carnivores (including humans and dogs) to illustrate how we can keep both people and wolves on the landscape as our territories increasingly overlap.

Genesis: The Deep Origin of Societies by Edward O. Wilson — The famed biologist’s latest book — following up on his classic Half Earth — examines what it means to be human by examining the evolutionary history of other species like naked mole rats and anchovies.

Mama’s Last Hug: Animal Emotions and What They Tell Us About Ourselves by Frans de Waal — Advance warning: You just may get a bit teary reading these stories about the emotional lives of animals, including a dying chimpanzee matriarch whose photo graces the cover.

Primate Research and Conservation in the Anthropocene edited by Alison M. Behie, Julie A. Teichroeb and Nicholas Malone — Speaking of chimpanzees, primates are probably one of the most at-risk groups of species on the planet. This new book provides new research results about the threats primates face (including habitat loss, hunting and climate change) but it’s not all dry academia. The authors of each chapter also discuss what motivates their conservation efforts and what strategies are helping.

Overrun: Dispatches From the Asian Carp Crisis by Andrew Reeves — The author, an environmental journalist, has been covering the story of invasive Asian carp for years. He now delivers a book-length examination of the problem and how humans have been forced to react to these troublesome new residents of North America’s waterways.

Drowned Under by Wendall Thomas — A mystery novel about (among other things) an attempt to steal the world’s last Tasmanian tiger. Agatha Christie never tackled a crime like that!

Climate Change:

There Is No Planet B: A Handbook for the Make or Break Years by Mike Berners-Lee — One of the world’s leading experts on carbon emissions addresses some tough questions in his new book and shows us how we can move forward in a practical, effective way. It’s a book full of hard facts, important analysis, tough choices, positive inspiration and a surprising amount of humor.

Green Buddhism: Practice and Compassionate Action in Uncertain Times by Stephanie Kaza — A collection of essays by the well-known Buddhist ecologist, who offers guidance on compassion and sustainable living to help us in an age of extinction and climate change.

Spaceship in the Desert: Energy, Climate Change and Urban Design in Abu Dhabi by Gökçe Günel — As we look to the future of sustainable cities, we can learn a lot from the first attempt to create a zero-carbon metropolis. Masdar City in Abu Dhabi hasn’t quite become the utopian example that it was intended to be when it was founded in 2006. That’s because, Günel writes, its designers embraced capitalism rather than question how the system caused the very problems they were trying to solve. Examining the recent history of this ongoing project may help us to set a clearer path forward.

The Wall by John Lanchester — A science-fiction novel about an island nation that has to wall itself off from rising seas and other threats caused by “the Change,” including the political divides that tear us apart and cause us to build walls in the first place.

A Fire Story by Brian Fies — A harrowing memoir, in graphic-novel format, about the wildfire that raged through Northern California in 2017 and destroyed 6,200 homes — including that of the author and his family. If you want to learn more about how climate change is affecting people now, this is a good place to start.

Last but not least, check out Guernica magazine’s special “Climate Fiction” issue for a few extra short stories which will roll out through the month of March.

That’s our list for this month, but there’s plenty more to add to your reading lists. For dozens of additional recent eco-books, check out the “Revelator Reads” archive — and come back in just a few weeks for next month’s inspiring list.

What Laws Work Best to Cut Plastic Pollution?

Experts have recommended how the United States can drastically curb the use of throwaway plastics with new federal legislation.

Every minute an estimated 2 million single-use plastic bags are handed out at checkout counters across the world. They contribute to the 300 million tons of plastic waste generated each year, much of which ends up in the environment where it threatens wildlife, endangers public health and costs billions to clean up.

How do you solve a problem this big?

According to legal analysts who advised Congress at a briefing in January, the United States could reduce its contribution to the global plastic pollution crisis by implementing sweeping federal policies that restrict plastic use and hold manufacturers accountable for responsibly handling waste.

The expert group, composed of members from Frank G. Wells Environmental Law Clinic at UCLA and ocean conservation organization Surfrider Foundation, specifically recommended that Congress craft federal legislation banning single-use plastic products such as bags, straws and expanded polystyrene foam food containers. They also called for establishing “extended producer responsibility” schemes, which hold plastic manufacturers responsible for the waste they create.

Their recommendations, along with a new report, drew on research into existing legislation targeting plastic pollution in the United States and across the world. The experts found that the key to reducing plastic pollution is curbing consumption. The report and its presentation resulted from a semester-long project by UCLA students Charoula Melliou and Divya Rao, in collaboration UCLA attorney Julia E. Stein, Surfrider’s legal expert Angela Howe and plastic bag legal expert Jennie Romer.

“We have to stem the tide of plastic entering our waterways and landfills by reducing our consumption in the first instance,” says Stein.

beach pollution — Pollution washes ashore in the Dominican Republic. (Photo by Rey Perezoso, CC BY-SA 2.0)

What Works

There are currently no federal laws restricting single-use plastics, but that doesn’t mean there aren’t good examples that could serve as useful templates.

According to Stein, Congress could shape federal policy by following existing local and state laws that have already been crafted to tackle plastic problems with bans on all types of single-use plastic items, from bags to expanded polystyrene foam food containers to straws. California made headlines in February after lawmakers proposed a phaseout of all plastic products that aren’t completely recyclable.

Such laws are grounded in scientific evidence that plastics are problematic because they don’t break down in the natural environment and pose a danger to wildlife and probably people.

There’s a precedent for using state and local laws to help craft national legislation: microbeads. After several states and municipalities banned the sale and manufacture of health and beauty products containing these ecologically damaging exfoliating plastic beads, the United States passed a federal act doing the same.

Most experts agree banning single-use plastic products is a more useful strategy for reducing plastic use and pollution than recycling, which is much less effective. A ban also tackles the issue at the source, helping to curb greenhouse gases coming from the rapidly expanding petrochemical industry that uses fossil fuels to produce plastic.

Commonly Used Plastics

With plastic so ubiquitous, where to start? Experts say that banning just the most commonly used and littered items could cut pollution significantly.

That puts single-use plastic bags front and center.

Plastic bags are among the top five most commonly found items on shorelines, according to global beach cleanup data. So it comes as little surprise that the most legally targeted plastic item worldwide has become the plastic bag. On the whole, research suggests focused legislation is highly effective at reducing plastic bag use and the presence of bags in the natural environment.

“Single-use plastic bags are particularly problematic as a source of marine debris because of both the quantity generated as well the mobility of bags,” says Anastasia Telesetsky, a professor of law at the University of Idaho who has argued for the need for a global treaty banning most single-use plastics. “Some products are definitely more problematic than others though regrettably most single-use plastic packaging products can be found as part of ‘mismanaged waste’ somewhere in the world.”

Suffolk County on Long Island, New York, adopted a five-cent plastic bag fee at the beginning of 2018. According to county legislator William “Doc” Spencer, in just a few weeks, several grocery stores reported drops in plastic-bag use of as much as 80 percent.

And Suffolk County isn’t an isolated case. Many success stories about plastic bag legislation are documented in the briefing report. Washington, D.C. saw an 85-percent reduction in plastic bag use after a five-cent tax was implemented in 2009. In San Francisco plastic bag pollution dropped 70 percent following a complete ban on plastic bags with a 10-cent fee on compostable and paper bags that went into place in 2007.

While plastic bag legislation may help reduce use and pollution on a local level, the expert group’s briefing report highlights a lack of consistency in U.S. plastic bag legislation. And some states have implemented or attempted to implement rules that prohibit legislation regulating plastic bags and other problematic plastic consumer products, which is why proponents of plastic bans are pushing federal action.

According to the experts, the ideal federal legislation on plastic bags would mirror what’s been found to be the most effective on both local and national levels elsewhere: A ban on all thin plastic bags, and a fee on all other kinds of bags such as those made from paper, thick plastic and compostable materials. And it would be sweeping, so no part of the country could obstruct such a ban.

To further curb use and pollution of throwaway plastics, states and municipalities have also begun to ban plastic straws, plastic foodware like cups and utensils, expanded polystyrene foam food containers, and cigarette smoking on beaches. Several companies have stopped using plastic straws and other single-use plastic items to create less waste.

The briefing’s authors suggest that Congress should, at minimum, create a rule ending automatic distribution of plastic straws at all restaurants and bars and ban expanded polystyrene foam products outright.

“In the United States, where local efforts to enforce source control laws are under threat of preemption in several states, having comprehensive federal legislation that requires source control is a way to protect and augment the work of local governments that are trying to combat plastic pollution,” Stein says.

Broader Focus

Besides banning common problematic single-use plastic products, the expert group also recommends Congress pass legislation that would hold corporations accountable for handling plastic waste at the end of its life.

Extended producer responsibility regulations require manufacturers of plastic products to take their items back for reuse, recycling or disposal to increase recycling rates and prevent plastic waste from entering landfills and the natural environment. Container-deposit legislation is one example of such a program that’s widespread — though not ubiquitous — around the United States.

Telesetsky says these schemes may be useful when designed to manage long-lasting plastic products, but they’re trickier to implement and incentivize when plastic packaging is involved. “The problem with applying extended producer responsibility principles to existing single-use plastic is that there is simply no market for all of the reprocessed cheap packaging plastics that are being generated,” says Telesetsky. “Cheap plastics have a finite usable life before they are inevitably landfilled or burned.”

otter with plastic bottle — A giant otter plays with a plastic bottle. (Photo by Paul Williams, CC BY-NC 2.0)

Telesetsky praises the new briefing because it raises awareness of a critical problem. But unlike the briefing group, she proposes banning single-use plastic products outright, on a global scale, in addition to incentivizing innovation in creating new biodegradable products and packaging, which she argues would stop plastic pollution more closely to its source. And it would address the issue on what she sees as a more radical and international — and thus more impactful — scale.

Yet Stein emphasizes that while her briefing has a national focus specifically tailored to U.S. Congress, the wider view is international.

“We support international efforts to address plastic pollution, but the United States also needs to take responsibility at home for its own contribution to the problem.”

Will Congress take up that challenge?

Stein says she and other members from the UCLA-Surfrider group who traveled to Washington, D.C. in January held several legislative briefings for Congressional members and staff, including those involved with last year’s 2018 Save Our Seas Act.

The act provides some funding for federal marine cleanup and waste-prevention efforts through NOAA’s Marine Debris Program. Already, two of the bill’s cosponsors, Senators Dan Sullivan (R-AK) and Sheldon Whitehouse (D-RI), have begun working on a revamped “2.0 version.”

“Overall, we felt the reception was positive — plastic pollution is a topic that is on the minds of the American public and the congresspersons who represent them,” Stein says. “We’re hopeful that Save Our Seas 2.0 legislation in the Senate may provide a chance to think about comprehensive federal strategies to reduce plastic pollution.”

Wild Cats Have An Unexpected Safe Haven — A South African Industrial Site

A thriving population of servals at petrochemical plant suggests that even heavily industrialized sites can still be good places for conservation.

Ever since the industrial revolution, human activities have resulted in rapid environmental changes including degradation, fragmentation and destruction of habitat, climate change and biodiversity loss. Animals, such as large carnivores, are often among the first to disappear as human disturbance increases.

The fact that human activities have had catastrophic consequences for some species is undisputed. But there are also instances where wildlife has befitted from human interventions, such as raccoons and coyotes that flourish in urban areas. This is because they can exploit resources like food and low levels of competition from other species that are less able to adapt.

We made a startling discovery that provides another example of wildlife thriving in an industrial site. We found that servals, a wild cat, were living in the shadow of a huge petrochemical plant in South Africa.

Using repeated camera trap surveys we found that serval were present — and thriving — at the Secunda Synfuels Operations plant 140 km (87 mi) east of Johannesburg. Constructed to help cope with the fuel embargo imposed on apartheid-era South Africa, the plant processes coal into a petroleum-like product. As part of this production process it emits 20 million tons of carbon dioxide per year. The plant, which covers an area of around 85 km² (32 mi²), supports a serval population density — the number of animals in a given area — far greater than any other site on record across the entire range of the species.

Over several years we also used live traps to capture and release servals at the plant, allowing us to identify their sex and age — something that was not possible using our camera traps. This showed us that the population structure appeared to be stable and normal. This suggests that the high density was not a temporary situation, but a long-term trend.

The cases of modified environments benefiting wildlife should not be taken as evidence that industrialization is generally a good thing for wildlife. As humans modify natural habitats biodiversity tends to suffer, and it is of paramount importance that we curb our impact on the environment. But our findings suggest that even heavily industrialized sites can still have conservation value.

We should not overlook these areas when developing conservation plans as they can still play a role in protecting threatened species.

Why Wildlife Is Thriving at an Industrial Site

We think that there are three main reasons why servals fared so well in this modified environment. The petrochemical plant is surrounded by wetlands, which are home to a large number of rodents, the preferred prey of servals. This provides an ample prey base, which supports a large serval population.

Secondly, there is a fence surrounding the plant, for safety and security reasons. This protects serval living at the plant from persecution from humans. In other areas serval numbers can be controlled by persecution from farmers, who perceive servals to be a threat to their livestock.

Finally, while the fence is intended to restrict the movement of humans, it also stops other large carnivores from entering the area. This keeps competition low, allowing serval numbers to grow.

Silver Linings of Modified Landscapes

Industrial installations often establish exclusion zones around their core infrastructure to improve security and safety. These can also benefit wildlife. Reserves were created around the Jwaneng diamond mine in Botswana and the Venetia diamond mine in South Africa, for example, which now support a broad array of large mammals such as elephants, African wild dogs and cheetahs.

And some of these reserves set up to protect mines, such as the Sperrgebiet exclusion zone in Namibia, have now even been proclaimed national parks.

As well as protecting habitats, modified environments sometimes create entire novel ecosystems, that can increase local richness. Oil rigs, while being unsightly, can act as artificial reefs that offer protection from trawling and support diverse communities of marine life that would not otherwise exist in the area.

There is enough doom and gloom in conservation. Celebrating silver linings such as servals at Secunda will help us shift our focus from problems to solutions, as advocated by the Earth Optimism movement. This is key to moving from a sense of loss to a sense of hope in the dialogue about conservation and sustainability, which is critical for securing the public support, political will and resources to stem the tide of biodiversity loss.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The opinions expressed above are those of the authors and do not necessarily reflect those of The Revelator, the Center for Biological Diversity or their employees.

‘Nero Drilling While Rome Burns’: U.S. Oil and Gas Production Soars in Trump’s Second Year

Experts warn that the rush for new oil and gas drilling in 2018 will have consequences for the climate, but there are ways to slow it down — or even stop it.

Oil and gas development continued to expand dramatically during the second year of the Trump presidency. Experts warn that the administration’s “energy dominance” agenda will have terrible consequences for the climate and the planet, and all that drilling will not get the country any closer to energy independence.

Despite low oil prices, crude oil production in the United States soared from 9.995 million barrels a day in January 2018 to 11.900 million barrels in November, according to the most recent data available from the U.S. Energy Information Administration. Over the same period, natural gas production shot up from 95,426 million cubic feet per day to 107,429 cubic feet per day.

“Given the sequence of scientific climate reports and climate-linked natural disasters, this is definitely Nero drilling while Rome burns,” says environmental activist Bill McKibben. “History will wonder what we were thinking — or if we were.”

This expansion in production occurred during a period of relatively low prices for West Texas Intermediate crude, which kept oil operators from establishing as many new rigs as they did in 2017. In a recent press release, S&P Global Platts Analytics senior analyst Trey Cowan projected that the rig count would soon rebound due to rising prices for crude oil. “If WTI crude stays in the mid-$50/b area, we would expect the rig count to follow suit and show improvement in the weeks ahead,” he said. West Texas Intermediate crude, often used as a benchmark for oil pricing, was $57.01 a barrel as of Feb. 28.

Indeed oil and gas companies are already preparing for future production and filed for a record 6,570 new permits last month, the highest number in five years, according to data from investment banking advisory firm Evercore ISI, which also reported that an additional 1,140 U.S. onshore permits were filed during the first week of February.

More than two-third of January’s permits — 4,200 — were filed in oil-rich Wyoming. “The operators there are getting into a war with each other over who’s going to control the Powder River Basin,” says Kelly Fuller, energy and mining campaign director for Western Watersheds Project. “They don’t necessarily expect to drill all these sites, but they want to get so many permit requests in there so other companies don’t get processed in time. The state oil and gas commission doesn’t have the capacity to deal with what’s going on.” A recent report by Heather Richards of the Casper Star Tribune found the commission is dealing with a backlog of 25,000 permitting requests from contentious companies trying to either secure guaranteed drilling rights or boost their on-paper assets.

All of this drilling and fossil-fuel production poses a major threat to the climate. “At a time when we need to be reducing global carbon emissions at close to 10 percent a year to avert dangerous planetary warming, any increases at all in oil and natural gas production are a threat to those efforts,” says noted climate scientist Michael E. Mann.

The expansion may be even worse than usual for the climate because of the Trump administration’s deregulatory agenda. “Under the current administration there’s been a major rollback in oversight of the oil and gas sector, especially methane emissions, leakage, venting and flaring,” says Julie McNamara, an energy analyst with the Union of Concerned Scientists. Natural gas contains methane, a potent greenhouse gas.

Worryingly, the rush to drill also positions the country for long-term oil and gas use rather than a transition to renewables.

“The infrastructure lock-in that comes from this developments puts us on a course that we won’t soon be able to shake,” says McNamara. “One you build something, it’s very hard to move away from it. The outcome from this will be either a massive amount of stranded assets or it will be something where we’ll just keep burning fossil fuels because the infrastructure is already built. It makes the pivot to clean energy all that much harder.”

Is there any way to slow down or stop this oil and gas development? Fuller suggests there are two ways to approach this.

“First,” she says, “we need all of the policy changes and incentives — the ‘carrots’ that people are talking about — to make sure that we transition the economy to a renewable energy economy.”

Second, people and organizations can stand up to this new wave of drilling. “We need as many people as possible pushing back on these drilling permits and leases,” she says. “This year conservation groups have put in comments on more than 1,000 drilling permit applications and site inspection requests. Even if the Bureau of Land Management doesn’t solicit public comments, they have to consider them if they receive them.”

Even individuals can do that, she points out. “There’s definitely a role for the public to play,” Fuller says. “Everyday people can learn how to write comments and submit them.” A good model for accomplishing that, she adds, is an activist toolbox for commenting on oil and gas projects, which was developed by the organization Rocky Mountain Wild. She points out that two recent lease projects in New Mexico and Montana were deferred after the public mobilized against them.

“Lease sale deferrals are not permanent,” she adds, “but they can last for a while — and while the land is deferred it’s safe from drilling and fracking. During that time, the public has the ability to ask the Department of the Interior for a permanent withdrawal from leasing or to ask members of Congress to permanently protect the land with legislation.”

Ultimately, the experts point out, the most effective way to defer future lease sales and drilling is to decarbonize the economy.

“The only thing that will move us to true energy independence will be the conversion to renewable energy,” Fuller says.

How Do You Protect a Species You Can’t See?

For manatees and other hard-to-spot species, the answer may lie in the minute particles of DNA they leave behind as they move through their environments.

Lucy Keith-Diagne has spent years searching for African manatees in stretches of river the color of chocolate milk. The task is urgent. In the 21 countries where they are found, these manatees — relatives of the species found in Florida — are at risk of poaching, being caught in fishing nets and becoming isolated when dams sever their habitat.

“I’ll be honest, I was a behavioral biologist when I started working in Africa, not a lab person,” says Keith-Diagne, executive director of the Senegal-based African Aquatic Conservation Fund. “But the manatee’s range in Africa is larger than the area of the United States. We need to figure out where they are sooner rather than later if we want to conserve this animal.”

Conservation relies on knowing what species are located where. That means identifying where vulnerable plants and animals are to protect them, and knowing where harmful, invasive plants and animals are to get rid of them. It’s hard to know where things are underwater, so conservation is always more complicated there.

To help study these species that are hard to see or otherwise observe, some scientists have turned to something called environmental DNA (or eDNA) — genetic material that’s been shed into the environment, often from fur, skin flakes, body fluids and feces.

Studying eDNA lets scientists peer into the depths of oceans, lakes and rivers. It also works on land, but that takes more effort. The scientists developing lab techniques for eDNA say it’s time to let it do the important work of finding out where things are — not just manatees in Africa, but a broad range of species with roles in a range of conservation issues.

But getting eDNA into the lab still isn’t easy. Right now scientists put most of their eDNA efforts into studying organisms in aquatic habitats because it’s easier to filter large quantities of water — typically several one-liter bottles at a time — to concentrate a few molecules of genetic material than it is to collect the same amount of genetic material on land. Once they have samples in the lab, scientists then use standard techniques to find and copy small amounts of DNA that match the genetic signatures of the target species.

From Theory to Application

Keith-Diagne thinks it’s time to put this technology to good use. She recently worked with Margaret Hunter, a U.S. Geological Survey research geneticist, and other scientists to create a laboratory test that uses eDNA to identify where manatees can be found. The group, led by Hunter, recently published a paper describing their technique in the journal Endangered Species Research.

“We’ve seen the need for additional conservation tools,” Hunter says. “Even though eDNA has been around for a while, it took us a bit to get to a place where a field biologist could take a sample and get good data from it.”

The need has never been more urgent, and not just in Africa.

The semi-recovery of the West Indian manatee species in Florida and Puerto Rico led to its Endangered Species Act listing being downgraded from “endangered” to “threatened.” But there are actually three species of manatees (one with a subspecies) found in shallow waters around both sides of the Atlantic Ocean basin, and some of them are found in the most remote regions of the world. The conservation status of manatees found outside the United States is, like the water they swim in, murky.

Manatees are on the brink of extinction in Jamaica and Haiti. Brazil considers the Antillean manatee subspecies to be its most endangered marine mammal. The status of manatees throughout their range in the Caribbean, Central and South America, in the Amazon River and in coastal and freshwater habitats in Africa is at best uncertain and, at worst, dire.

Keith-Diagne and other scientists in Africa spend a lot of time searching for manatees from boats to add scientific rigor to local knowledge about manatee habitat. Using eDNA could speed the process, but each sample requires a liter of water, and the water needs to be chilled to preserve the DNA. For their study, manatee researcher Aristide Kamla Takoukam flew from Cameroon to Hunter’s lab in Florida with several liters of water he collected.

From Manatees and Beyond

Hunter isn’t the only research geneticist who believes that we have entered the era where eDNA is an important wildlife research tool. Last fall Mark Stoeckle, a senior research associate in the Program for the Human Environment at The Rockefeller University in New York City, helped organize a conference at the university that brought together genetics researchers and wildlife managers to share breakthroughs and discuss the technique’s future.

The executive summary of the conference report was just four words: “eDNA works. Get going.”

“When we say ‘it’s time,’” Stoeckle says, “it’s because the technology has been proven in medicine and forensic science.” It’s also because getting the same information through other methods — such as hiring a fishing boat — is even more expensive and time consuming, he says.

Stoeckle developed a technique for finding the DNA of a single species in a sample of ocean water that he calls GoFish. The technique takes three days and costs about $15 to look for genetic material from a certain species, or a lab can test for two species for eight dollars more. He says the eDNA test could eventually be used as a more accurate way to protect spawning winter flounder from harbor dredging in the New York City area, where dredging is shut down for a fixed season. But, Stoeckle says, the test is still five years away from being accurate enough to do that.

One place that has eDNA testing down to a, well, science is the Whitney Genetics Lab at the U.S. Fish and Wildlife’s Midwest Fisheries Center in Onalaska, Wisconsin. The lab uses its own technique to process eDNA. It’s even faster than GoFish as it searches for the DNA of two species of invasive Asian carp — bighead carp and silver carp.

These invasive fish slurp down so much plankton and algae that there is little food left for young native species. The carp have already reduced native fish populations in the Mississippi River in the decades since their arrival. The U.S. Army Corps of Engineers, Fish and Wildlife Service and state wildlife agencies are taking expensive precautions to prevent invasive carp species from doing similar damage in the Great Lakes.

The Whitney Lab tests water samples from tributaries of all five Great Lakes and the Mississippi and Ohio River systems. The lab, with as many as nine scientists on staff, can process a group or “case” of 500 samples in two weeks, says Emy Monroe, the lab’s project leader. The lab needs to be that efficient because it analyzes up to 8,500 samples a year.

If the lab detects eDNA from an invasive carp species, and further eDNA tests confirm it, the finding can trigger a fleet of boats to search for and destroy the invasive fish.

But a lab like this does not spring up overnight. The original protocols it uses to analyze invasive carp DNA were developed by the University of Notre Dame in 2011, with funding from the Army Corps. The lab, which now has a $1.25 million annual budget, first started analyzing samples for Asian carp eDNA in 2013. Monroe says it tweaks its program each year to make the procedures more accurate and more efficient — for example, the six Fish and Wildlife field offices that contribute the eDNA put their water samples through a centrifuge before they are even sent to the lab. Nobody’s lugging gallons of water here.

“The take-home is that eDNA is powerful and useful, but it takes a lot of up-front testing and optimization to determine what methods work best for your particular study objectives,” Monroe says.

Keith-Diagne agrees. “Our paper showed that this technique is a little labor intensive, but it works,” she says of their manatee eDNA test.

It’s been a journey getting to this point, she admits. “When I first learned about eDNA, I naively thought that I could just go out to the river and scoop a cup of water and I was going to know how many manatees were there. That’s not where we are yet.”

Still, Keith-Diagne thinks we’ll see the easy-to-use eDNA tester of her dreams in the next 10 years, and that, she feels, could revolutionize a lot of conservation efforts — because she knows she’s not the only scientist who urgently needs to know what lives in the water.

What One Scientist Learned in 50 Years of Studying the Earth’s Climate

Dr. Warren Washington, who helped pioneer climate modeling, has seen science advance, even as policies to meet our climate challenges have lagged.

When Warren Washington completed his doctorate in meteorology from Pennsylvania State University in 1964 he was just the second African American ever to earn a PhD in the atmospheric sciences. In May, Washington, now 82, will return to the school for a ceremony as a building is named in his honor.

It’s just one more thing that Washington, a pioneer in the study of climate change, can add to a long list of accolades. In 2010 President Obama honored him with the National Medal of Science. And this month Washington was named winner of the Tyler Prize, the prestigious award recognizing environmental achievement. He shares this year’s prize with fellow climate scientist Michael Mann.

Washington helped pioneer the field of atmospheric computer modeling, a tool that’s widely used today to help better understand climate change. At the National Center for Atmospheric Research, where he began working in 1963, he helped build one of the first computer models to understand the Earth’s climate. He worked there until retiring last year.

With more than 50 years of research aimed at understanding the Earth’s climate, Washington has had a front-row seat to both scientific discovery and political inaction.

Warren Washington, 1973 — Warren Washington looking at microfilm showing simulation results in 1973. (Photo by UCAR, Ginger Hein, CC BY-NC 4.0, via OpenSky)

“We proved that we could make a model of the atmosphere showing the basic change of seasons, the change of day/night, temperature and winds,” he says, remembering back to his work in the 1960s. “Our first objective was to build a model and get reasonable results, and the second was to use the model to understand future and past climates.”

That groundbreaking work was also incredibly tedious. “Computers at the time were very slow, so it took us one day of computing time to do one day of simulation,” he says.

They continued to refine their models and, in the late 1970s, Washington and his colleagues were enlisted by the Department of Energy to test how increasing carbon dioxide affects the climate system.

“We were one of the first modeler groups to actually carry out an atmospheric model coupled with ocean models and sea ice models — we brought in other aspects of the climate system,” he says. And they confirmed what other scientists were also finding out — that climate change was caused by increasing greenhouse gases, particularly carbon dioxide.

As skeptics posited other theories, like increased solar radiation, Washington and his colleagues used their models to debunk the claims. “Climate models are a tool that allow you to separate one effect versus another and as we did that we got a better understanding of what was happening and became more confident in giving our opinions to the policymakers,” says Washington.

The more advanced modeling today has helped show that hurricanes are getting stronger, and droughts and heat waves more intense. And it’s not just apparent in the models. “We’re the first generation that can actually see the climate changing — in the past you could live a lifetime and never see hardly any climate change,” he says.

Growth of climate modeling graphic — The complexity of global climate models has increased enormously over the last four decades, as shown in this graphic. (Graphic by UCAR, CC BY-NC 4.0, via OpenSky)

Washington admits that the current situation affects him in a deeply personal way. “I have 16 grandchildren and they’re going to see significant climate change in their lifetimes.”

And that, he says, concerns him. As a scientist it also makes him feel a certain sense of responsibility. “We feel an obligation to speak out about what we know, and if we’re honest about it, what we don’t know,” he says. “But the overwhelming consensus from scientists who study climate change is that the culprit is increasing greenhouse gas emissions — so the question is, how do we deal with it?”

The answer, he says, is that we’ll need to invest in technologies like wind and solar, as well as cut back on fossil fuel production, but new technologies to help mitigate climate change will also be important.

“I think the science, engineering and technology fields are coming up with some good ideas that need to be explored,” he says. But that will take more research and pilot studies, which require resources. And that’s one of the reasons he has been unhappy with the Trump administration abandoning the Paris Accord, which he says, may not be enough but is at least moving countries in the right direction. “President Trump has ignored the agreement and he hasn’t given any reason why other than that he doesn’t believe in climate change,” says Washington. “Well, he doesn’t believe in facts in general.”

Fighting the climate crisis is time sensitive and needs to be done as quickly as possible. But Washington says that will take a lot of courage from politicians, something made tougher by the influence of the fossil fuel industry in campaign finance. He is heartened, though, to see that public opinion has shifted considerably and nearly 70 percent of Americans think climate change is now a major environmental issue, according to research from Yale University.

Scientists are also getting better at communicating about their findings, too, says Washington. He thinks that the awarding of this year’s Tyler Prize to himself and Mann, who’s known for his work in science communication, speaks to the efforts of the broader scientific community. “I interpret it as that the whole community has worked hard to do the research and to communicate to the public and policymakers,” he says.

Over the course of his career he has advised six presidential administrations. The current one is not among them, but Washington says if he could, he’d tell the Trump administration to reverse its opinion on climate change and rejoin the Paris Accord.

“We need to get on the right side of starting to do more — we see it happening at the state level and in some cities that are taking take steps to deal with climate change,” he says. “I think there would be a lot of public support for it.”

Endangered Wildlife Are Getting Dosed With Rat Poisons

Products marketed to kill rodents are instead threatening the lives of the wildlife that eat them as poisons travel up the food chain.

People who consider rodents to be pests often turn to an array of products, known as anticoagulant rodenticides, which are marketed to lethally “solve” the issue with poisoned bait. But researchers have been collecting evidence for years showing that it’s not just nuisance rats that can end up dead.

Some of the most recent studies, conducted in California, found that everything from Pacific fishers to bobcats to northern spotted owls often become victims of rodenticides. The list of potentially affected wildlife is long — basically anything that preys on a rodent could be at risk, because the poisons are so toxic they travel up the food chain, and in some cases, can remain in an animal’s body for years. It can even leapfrog in utero from one generation to the next.

“If you have a very poisoned rat, you’re going to have a very poisoned hawk,” says Kelle Kacmarcik, director of wildlife solutions and advocacy at WildCare, a wildlife rehabilitation center in Marin County, California.

And that’s a huge problem.

Spotted owl — The threatened northern spotted owl on the Klamath National Forest in Siskiyou County, Calif. (Photo by Kendra Knight, CC BY 2.0)

“Food web contamination is a red flag indicator for not just for one species but all other species dependent on that prey item,” says Mourad Gabriel, a research associate faculty at the One Health Institute, Wildlife Heath Center at the University of California, Davis and co-director of the nonprofit Integral Ecology Research Center. His research has looked at the risk to fishers and northern spotted owls from rodenticide exposure from cannabis farms, a growing problem in California. But “other species may start to become imperiled because of this emerging threat,” he says.

Rodenticides affect wildlife around the world and have been used since the 1940s, but recent studies in California have helped illuminate the impacts and ignite calls for regulatory or policy changes.

California took an important first step in 2014 by increasing restrictions on some rodenticides and the state is currently evaluating whether it will take more action. But that’s still not enough, say some experts, like those at WildCare, who want to see a state ban on the products and more public education and behavior changes to reduce the use of the poisons. How to target those messages though, depends on the audience.

In urban and suburban areas, the biggest users of rodenticides are regular consumers who buy the products at hardware stores for home use or hire pest-control applicators to treat their properties. In agricultural areas, it’s applied by farmers to keep rodents away from crops. In forested parts of the state, it’s been dumped by the pound at illegal and trespass cannabis operations on public, private and tribal lands.

A bill introduced in the California legislature last year would have prohibited the use of anticoagulant rodenticides except in public health emergencies, but it stalled in committee. A new bill was just introduced in February, providing hope for some legislative action on the issue.

While the state figures out what to do the poisons are traveling up the food chain, endangering more and more wildlife.

A Widespread Problem

Anticoagulant rodenticides are sold under dozens of brand names with a number of different active ingredients. They work by affecting the animal’s processing of vitamin K, which inhibits clotting and coagulation, ultimately leading to uncontrolled internal bleeding. One of the most common first-generation anticoagulant rodenticides uses the blood thinner called warfarin as its active ingredient, but rats appear to have developed a resistance to it.

Manufacturers responded by developing a new line of more toxic products, using active ingredients like brodifacoum or bromadiolone, which have no medicinal uses. These second-generation rodenticides pack a bigger punch in a small amount and are designed to deliver a lethal dose to a rodent with just one feeding. They also have longer half-lives, which means the poison can stay in the animal’s liver for years, compared to just days or months with the first-generation poisons.

Both of these factors contribute to an increased possibility of nontarget wildlife eating poisons intended for rodents. Second-generation rodenticides don’t kill animals right away. It can still take days, and in that time a sick animal often consumes more of the poison and exhibits signs of illness, making it an easier target for predators.

Documentation in California shows that the problem of rodenticides moving up the food chain and affecting nontarget wildlife is widespread.

A 2017 study found that hawks hunting for prairie dogs preferred those that had been treated with rodenticides to those which hadn’t because “the poisoned prairie dogs were easier to capture due to lethargy and decreased awareness,” according to an analysis of the research by California’s Department of Pesticide Regulation.

A study by Gabriel and colleagues tested the livers of two distinct populations of fishers (Pekania pennant) collected between 2007-2014 from the mountains of Northern California and the Southern Sierra Nevada. The researchers found that 85 percent of the fishers had been exposed to one or more anticoagulant rodenticide. That’s bad news for fishers, which are already imperiled by habitat loss and are currently being reviewed for listing under the Endangered Species Act.

More recently, in a 2018 study, Gabriel looked at two owl species in California and found anticoagulant rodenticides in 70 percent of northern spotted owls (Strix occidentalis caurina), which are listed on the Endangered Species Act. And for barred owls (Strix varia), which rely less on rodents in their diet, the researchers found 40 percent had anticoagulant rodenticide exposure.

In both studies, cannabis operations were the likely sources of exposure.

“Rodents love cannabis plants because of the high water and sugar content that these plants have,” says Gabriel. “And so in order to dissuade them from damaging their cannabis plants, cultivators are placing the anticoagulant rodenticides out there.”

Another study by different researchers published in 2015 in Ecotoxicology found that 88 percent of bobcats (Lynx rufus) living in the mountains near Los Angeles had exposure to anticoagulant rodenticides.

The problem isn’t just in rural areas. At WildCare, located 20 miles north of San Francisco in suburban Marin County, tests from 2015-2016 identified 13 species with rodenticide exposure. Raptors tested had a 78 percent poisoning rate. For mammals like bobcats, coyotes, foxes and racoon it was 86 percent.

Many of the animals tested in these studies didn’t die from poisoning, but even these sublethal amounts can still be problematic. California Department of Pesticide Regulation scientist Deborah Daniels reported in a 2013 letter from the department that it can “reduce the fitness of wildlife at a time when wildlife are already meeting numerous challenges.”

For example, in one study, researchers found that rodenticide exposure in bobcats may have led to an increased susceptibility to mange, a parasitic infection that’s increasingly fatal to the species in California.

“No matter how large or small, you’re looking at a toxic poison in the systems of these animals,” says Alison Hermance, director of communications of WildCare. And anticoagulants mean that even a small scrape can cause an animal to bleed out, turning an otherwise minor injury into something fatal.

Researchers have found animals in California with up to five different kinds of rodenticides in their systems at one time. Gabriel says that understanding all the ways sublethal doses of poison affect animals, including the build-up of multiple kinds of poisons, is “a new field of research that needs to be tackled extensively.”

Mixed Results

The fact that wildlife are dying from rodenticides has been documented for years. But what to do about it is still being debated.

Daniels concluded there was enough data to find that “exposure and toxicity to nontarget wildlife from second generation anticoagulant rodenticides is a statewide problem.” And that problem, she wrote, persisted in both urban and rural areas. Testing on 492 animals between 1995 and 2011 found that 73 percent had some traces of at least one second-generation poison.

So California took action to limit the sale of the second-generation products, which it deemed a bigger health threat. In 2014 it banned their sale to ordinary consumers — people could no longer just stop at the corner store to buy some — but they continue to be available to licensed pest-control applicators and those in the agriculture industry.

Unfortunately, the regulation hasn’t been very effective yet. Kacmarcik at WildCare says they haven’t seen the amount of second-generation rodenticides in wildlife decreasing; in fact they found a small uptick during the first two years after the regulation went into effect.

There are a couple of reasons. The first is that some of these long-lived poisons persist in animals for years. The second is that it is still legal to pay someone to apply the poison. And third, people stocked up the products as many stores unloaded their supplies for cheap just before they were banned. So even though the sale of them is no longer legal, they’re still being used.

Mourad Gabriel — Dr. Mourad Garbiel at a cannabis grow site clean up. (Photo by USFS, CC BY 2.0)

For forested rural areas where cannabis operations are often the biggest culprit, Gabriel says, “We are seeing a decrease in second generations, but a major uptick in first generation being applied.” Despite the legalization of cannabis cultivation in California, thousands of operations still flout the regulations and many operate illegally on public lands. Many of these poisons are left behind when operations are abandoned, endangering wildlife and costing the state millions in cleanup costs.

The state, in a November 2018 report, admitted that its “limited data” showed that exposure rates to the second-generation anticoagulant rodenticides had not decreased. The report concluded that these second-generation poisons have “significant adverse impact to non-target wildlife.” But the state doesn’t think the first-generation products pose a significant risk. Gabriel, however, says the risks are still there even though the products are less toxic and there is extensive documentation that the poisons can still transfers to predators. At WildCare, nearly 30 percent of the animals tested had been exposed to a first-generation anticoagulant rodenticide.

Searching for Solutions

The Department of Pesticide Regulation is currently considering whether to reevaluate its regulations for the second-generation products and what specific data it would need if did, says Charlotte Fadipe, the agency’s assistant director. “In general, the department is considering data related to second generation anticoagulant rodenticide exposure rates, as well as any resulting risk of adverse impacts to non-target wildlife.”

Finding solutions to curb the use of anticoagulant rodenticides at cannabis farms will be extra tough. “You’re looking at a new, emerging threat and risk,” says Gabriel. “Current regulations don’t seem to be sufficient enough to keep it in check.” Since those who are running illegal grows aren’t likely to follow stricter pesticide regulations, more resources for enforcement are also needed, he says. Without that many of these cannabis operations will continue to pose a threat to other efforts to conserve wildlife populations in the state.

Hermance says that WildCare would like to see a complete restriction on anticoagulant rodenticides. “It’s such a tragedy that these poisons kill or injure the animals that nature has provided to give us rodent control,” she says. “Hawks, foxes, owls, racoons are out there eating rodents every single day — knock them out and you’re going to have a much bigger problem down the road.”

And in most cases, poisons simply aren’t needed to solve a problem, they’re just easier. “I’m amazed at just how quickly people jump to poison as a solution to a nuisance problem,” she says.

Red-tailed hawk — Raptors like red-tailed hawks have been more effective in Ventura County, Calif. at eliminating pests than poisons. (Photo by Jon D. Anderson, CC BY-NC-ND 2.0)

Until there’s more state action, public education on the risks to wildlife and on alternatives to poisons is needed.

In one recent example, Ventura County in Southern California has turned to raptors to decrease the number of ground squirrels burrowing in its dirt levees and dams. The birds have proven to be better and cheaper than poisons.

That’s the type of lesson that the experts hope will resonate not just in California but around the world. “Stop and think about what’s causing the problem and how you can solve it without poison,” says Kacmarcik. “If we could get more people to do that, you’d see a significant reduction in the poisoning that’s happening.”

Crocking the Genetic Code

New genetic tests may reveal the secret to saving the critically endangered Siamese crocodile from extinction.

Conservationists trying to save the critically endangered Siamese crocodile (Crocodylus siamensis) from extinction face a unique challenge.

Only about 1,000 of these relatively small, heavily poached crocodiles remain in the wild, where their populations are scattered between several Southeast Asian countries. Cambodia, the country with the most Siamese crocodiles, only has about 250 adults, all of which live in small, isolated populations of 50 or fewer individuals. Recent research has shown that very few of these groups are actively reproducing.

Even as the wild population disappears, hundreds of thousands of Siamese crocodiles — perhaps more than a million — can be found on farms in Southeast Asia, where their soft skin is harvested as a valuable commodity. Tapping into this plentiful supply of captive animals could, in theory, help to save the wild crocodiles from completely disappearing.

There’s just one problem, and it’s a doozy. For years now, the captive crocs have been considered useless for conservation purposes because they’re all thought to be hybrids of Siamese, saltwater and even Cuban crocodiles.

According to anecdotal knowledge of the industry, the two non-native species were imported and bred with Siamese crocodiles in order to increase their size and growth rates. That was great for commercial interests, but not much good for the species as a whole. Taking any of those hybrids out of captivity and introducing their genes into wild populations “would alter the fate and identity of the species permanently,” says Frank Rheindt, an evolutionary biologist and assistant professor with National University of Singapore.

Here’s the thing, though: What if that common wisdom about the scope of this hybridization isn’t completely correct?

For several years now, researchers have been investigating whether farmed Siamese crocodiles really are all hybrids. One of the first signs that this might not be the case turned up in 2009, when tests conducted on 69 crocodiles at a wildlife rescue center did not find any evidence of hybridization in 35 of the animals, suggesting that they were possibly pure Siamese crocodiles.

Ten years later, a new paper by Rheindt and his colleagues, published in the journal Molecular Ecology, takes this further. The researchers used novel genomic approach (a much more advanced series of tests than were used a decade back) and examined 60 Siamese crocodiles, including some wild-caught individuals that have been on a farm for many years and another group from breeding centers and other farms. The researchers sequenced thousands of genome-wide markers and found evidence of genetic “introgression” (hybridization) from other species, but not to the degree expected. Only six of the individuals tested contained hybrid genetics from saltwater crocodiles, while another two carried unidentified “ghost” genes that the researchers suspect may have come from Cuban crocs.

The results were so good that 12 of the animals tested in the study were released to the wild. Four more pure Siamese crocodiles were selected for captive-breeding efforts.

This is obviously a small study, but it has broad implications. For one thing, it suggests that there may be more purebred Siamese crocodiles on farms than previously believed — perhaps many more.

“I was highly surprised that we found such a limited volume of genetic introgression,” says Rheindt. “It’s heartening to see that estimates of the surviving pool of pure Siamese crocodiles have risen from the hundreds to the tens of thousands as a result of our study.”

Rheindt says they are now talking with their partners about screening crocodile genetics on a larger series of farms in Cambodia. They’ve also been approached to conduct similar studies on another Siamese crocodile population in Indonesia.

There’s actually a tight deadline to start this work, because the same research contains another startling revelation: The remaining wild Cambodian crocs now have such low genetic diversity that they risk possible extinction in just five generations if their situation doesn’t change.

“Five generations is not a lot,” says study coauthor Balaji Chattopadhyay, a population geneticist and research fellow at the National University of Singapore. “When we see such a drastic drop in genetic diversity, it’s not good for any population.” Species with impaired genetic diversity often have problems breeding, become more susceptible to disease and lose the ability to adapt to changing environmental conditions — all threats the Siamese crocodiles could now face over the next few decades.

For Cambodia’s crocodiles, he says, “It’s like an impending doom situation.”

Finding additional healthy, pure specimens on farms and releasing them into breeding wild populations would start to reverse the genetic loss and “slow the train of extinction,” Chattopadhyay says.

How many more crocodiles would need to swim free in Cambodia for that to happen? “For a slowly reproducing and large species such as the Siamese crocodile, ideally we would want to see a Cambodia-wide population in the high hundreds or more to see this species move out of the immediate danger zone of extinction,” Rheindt says. He believes there’s enough remaining habitat left in the country to sustain those higher numbers.

Of course, other threats still exist, including ongoing poaching. Ensuring that relocated crocs aren’t later recaptured for sale to farms would be critical to the success of any reintroductions. Rheindt admits that the “great value of each crocodile individual and the financial incentives for capture” hampers many of the ongoing conservation efforts for the species.

If the techniques from this study end up revealing more pure Siamese crocodiles, it could be the next step in a long road toward the species’ recovery. Chattopadhyay says the government, farms and conservation groups would need to establish policies on the use of farm animals for reintroductions. After that there would need to be field studies to find the best release sites, and then ongoing monitoring to make sure the relocated animals start breeding in the wild.

“They should be monitored for a few generations at least,” he says. “This is a long-term effort.”

While further decisions about the Siamese crocodile are in the works, the researchers hope the new genomic toolkit they developed for this study will be of use for a wide variety of additional species.

“We wanted to propose a methodology that can be adopted by any conservation effort,” Chattopadhyay says. “We believe this kind of genetic component can help a lot for any conservation management effort where you’re looking into reintroduction from captivity.”

In fact, Rheindt reports, they already have work in the pipeline to study the genetics of heavily trafficked species such as pangolins, frogs and birds.

“Here in Southeast Asia, the scale of the environmental crisis is daunting,” Rheindt says. New tools like this might not stop illegal wildlife trade from happening in the first place, but they could help to heal some of the damage it has caused — starting with the Siamese crocodile.