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Sand mining and the environment

March 18, 2025 By EarthWise Leave a Comment

Sand mining is the world’s largest mining endeavor.  It is responsible for 85% of all mineral extraction.  It is also the least regulated, possibly the most corrupt, and likely the most environmentally destructive.  Sand is the second-most exploited natural resource in the world after water.  Its global use has tripled in the past two decades.  More than 50 billion tons of sand is extracted from the environment each year.

Sand plays a critical role in much of human development around the world.  It is a key ingredient of concrete, asphalt, glass, and electronics.  It is relatively cheap and relatively easy to extract.  But we use enormous amounts of it.

Sand mining is a major threat to rivers and marine ecosystems.  It is linked to coastal erosion, habitat destruction, the spread of invasive species, and damage to fisheries. 

The harm from sand mining is only beginning to attract widespread attention.  A recent study by an international group of scientists published in the journal One Earth identifies        threats posed by sand mining.  Sand extraction in marine environments remains largely overlooked, despite sand and sediment dredging being the second most widespread human activity in coastal areas after fishing.

Sand is generally seen as an inert, abundant material, but it is an essential resource that shapes coastal and marine ecosystems, protects shorelines, and sustains both ecosystems and coastal communities.  Sand extraction near populated coastlines is particularly problematic as climate change makes coastlines increasingly fragile.

Like all other resources on our planet, even sand cannot be taken for granted.  It must be responsibly managed.

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The rising tide of sand mining: a growing threat to marine life

Photo, posted February 7, 2013, courtesy of Pamela Spaugy / U.S. Army Corps of Engineers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Fighting harmful algal blooms with harmful algal blooms

March 7, 2025 By EarthWise Leave a Comment

Fighting harmful algal blooms using harmful algal blooms

Harmful algal blooms – HABs – occur when colonies of algae grow out of control and produce toxic or harmful effects on people, marine life, and birds.  HABs occur naturally but their frequency and intensity are often associated with increased nutrient loading (mainly phosphorous and nitrogen) in bodies of water that is the result of runoff from sources like lawncare and agriculture.

Researchers at Florida Atlantic University have developed a technique for transforming cyanobacteria – also known as blue-green algae and a prime HAB material – into an effective material for removing phosphorous from water.

Their process converts blue-green algal biomass – essentially hazardous waste – into a custom-made adsorbent material that can pull harmful phosphorous from water.  The algae is first quickly heated up using microwaves and then it is modified by adding lanthanum chloride. 

The study took blue-green algae from Florida’s Lake Okeechobee, synthesized the adsorbent material in minutes, and using only small amounts of it could remove 90% of the phosphorous present in only half an hour.  It worked perfectly well in the presence of natural organic matter.  Using the harmful algae itself to prevent algal growth in bodies of water is an innovative way to reduce its further occurrence.

Phosphorous is a major contributor to the occurrence of harmful algal blooms, which can lead to toxic water conditions, loss of aquatic life, and significant economic losses for the fishing and tourism industries.  This technique could prove to be an essential tool for managing the growing problem of nutrient pollution.

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FAU Engineering Develops New Weapon Against Harmful Algal Blooms

Photo, posted October 27, 2010, courtesy of Jennifer L. Graham / U.S. Geological Survey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tourism and climate action

October 11, 2024 By EarthWise Leave a Comment

Australia’s Great Barrier Reef is one of the foremost natural wonders of the world and is a major tourist attraction.  It is well-known that the changing climate is threatening the survival of the Great Barrier Reef as well as other coral reefs around the world.  A recent study by researchers at the University of Queensland looked at the reactions of tourists to being informed about the impact of the changing climate on the reef.

The Great Barrier Reef faces many challenges.  Unprecedented marine heatwaves have triggered repeated mass coral bleaching events over the past decade. These climate driven disturbances are compounding the cumulative effects of chronic problems such as unsustainable fishing, pollution, and sedimentation as well as acute disturbances such as tropical cyclones and outbreaks of crown-of-thorns starfish.

Operators of five reef tourism boats assisted in the study.  As part of their boat trips, tourists were given climate information via a marine biology presentation and there were also posters around the vessel as well as regular mentions of climate change impacts and actions throughout the trip.

The tourism industry often has the idea that providing information on climate change might be detrimental to people’s enjoyment – basically a buzzkill.  But based on surveys conducted at the end of the trips, the researchers found that informing tourists about climate impact didn’t negatively affect their experience.  In fact, most tourists actually wanted more information, particularly about how they can take meaningful actions of their own.

The researchers believe that their study provides further opportunity to improve climate communication and effectively promote climate change engagement among tourists.

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Reef tourism encourages climate action

Photo, posted October 7, 2008, courtesy of eGuide Travel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Industrial agriculture and the risk of pandemics

August 16, 2024 By EarthWise Leave a Comment

The domestication of pigs, cows, chickens, and other animals as livestock for their meat, milk, and eggs was historically revolutionary.  It boosted food security by giving people a readily-available means of feeding themselves as opposed to more traditional methods such as hunting and fishing.

But the industrialization of agriculture has led to horrendous conditions for animals.  Many are kept in huge quantities and packed together with little regard for their health and welfare.  This approach is designed to maximize production while minimizing costs.

With its chemical inputs and toxic outputs, intensive animal agriculture is also a major threat to the environment.  In fact, it’s a major driver of habitat degradation and biodiversity loss all around the globe.  

According to a new study led by researchers from the University of Exeter in the U.K., intensive livestock farming can also increase the risk of new pandemics.  These findings go against the widely held belief that industrialized farming reduces the risk of disease transmission between animals and humans. 

Zoonotic diseases are those that are spread from animals to humans.  According to the CDC, zoonotic infections account for three in every four new or emerging infectious diseases in humans.  The current bird flu outbreak in the U.S. is an example of this. 

In the paper, which was recently published in the journal Royal Society Open Science, the researchers conclude that the effects of intensifying animal agriculture “are at best uncertain and at worst may contribute to emerging infectious disease risk.”

Industrial animal agriculture is a threat to both human health and the health of our planet.

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Intensive farming could raise risk of new pandemics

Photo, posted January 29, 2016, courtesy of Farm Watch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The most endangered marine mammal

July 9, 2024 By EarthWise Leave a Comment

How to protect the most endangered marine mammal

For the better part of a decade, conservationists have been trying to eliminate the use of gill nets by fishermen in the Gulf of California.  Species such as the corvina fish have been decimated by the use of this fishing gear.  The nets also trap other marine creatures, include the rare and elusive vaquita porpoise.

The vaquita is the world’s smallest porpoise, measuring no more than five feet in length.  It is the most endangered marine mammal. They live only in the Gulf of California, which is the site of intense fishing activity. Some of that activity is directed towards a fish called the totoaba, which is an endangered species itself.  The totoaba’s swim bladder is highly prized for Chinese traditional medicine, so there is a booming illegal market for it.  The gill nets used to catch totoaba are especially lethal to vaquitas.

Every year, for a few weeks, an international team of scientists searches the Gulf for vaquitas.  Recent surveys estimated that there are around 10 individuals in the area where they are most likely to be living.  This year’s survey estimated that six to eight vaquitas are in the area.  The ones spotted appeared to be in good health and one yearling was seen.

Officially, fishing with gill nets is banned throughout much of the upper Gulf of California.  In practice, enforcement has been difficult to do.  However, the Mexican government has been making an effort to improve the situation.  The Mexican Navy dropped 193 concrete blocks with giant hooks designed to entangle gill nets to deter fishers and they plan to drop more.

The survival of the vaquita depends on whether the use of gill nets stops.

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The Most Endangered Marine Mammal Still Exists. Here’s the Latest Count.

Photo, posted July 12, 2011, courtesy of Semarnat via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Iceland power

March 15, 2024 By EarthWise Leave a Comment

Iceland burns very little fossil fuel to power its economy and heat its homes.  About 85% of its energy comes from geothermal power and hydropower.  Its unique geology provides it with the highest percentage of renewable energy in the world.  The fossil fuel that Iceland does burn is primarily used to power cars and trucks as well as boats in its fishing fleet.  And Iceland is rapidly embracing the use of electric vehicles.

Iceland can make far more electricity than its 373,000 people can use.  The majority of its electricity is essentially exported as bars of aluminum.  Iceland is one of the world’s largest refiners of aluminum.  The aluminum ore comes from other countries but gets shipped to Iceland where electricity is cheap.  Refining aluminum is so energy-intensive that some say that aluminum is basically just pure electricity in solid metal form.

Electricity-rich Iceland is finding other ways to make use of its resources.  There is a proposed project called Icelink, which is an electricity interconnector between Iceland and Great Britain.  The high-voltage direct current link would run between 620 and 750 miles and would be the longest sub-sea power interconnector in the world.  It is controversial in Iceland and it may or may not happen.

Another technology that is establishing an early foothold in Iceland is carbon capture.  An Icelandic company called Carbix is doing leading work on taking captured carbon dioxide and sequestering it underground.  Capturing and storing carbon dioxide is energy-intensive and the promise of cheap, clean geothermal power makes Iceland an attractive place to do it.

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Iceland Is Living in our Future

Photo, posted July 2, 2012, courtesy of  Emily Qualey / PopTech via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Disappearing snow crabs

November 21, 2023 By EarthWise Leave a Comment

Snow crabs disappeared

Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas. They are one of ten commercially-fished species in Alaskan waters. The perils of crab fishing in this region have been well documented for many years in the reality TV series Deadliest Catch.

Last year, officials in Alaska canceled the winter snow crab season for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years earlier, approximately 90% of snow crabs mysteriously disappeared ahead of the 2021 season. 

This year, officials in Alaska have once again canceled the snow crab harvest season for the second year in a row, citing the overwhelming numbers of crabs – in the billions – missing from Alaskan waters. 

Scientists have suspected that the warming ocean temperatures triggered this snow crab population collapse.  But did the crabs move someplace else or die off?  According to a new study recently published by scientists at the National Oceanic and Atmospheric Administration, warmer ocean temperatures likely caused the snow crabs to starve to death.  The research team found a significant link between recent marine heat waves in the eastern Bering Sea and the sudden disappearance of the snow crabs that began showing up in surveys in 2021.

According to the study, warmer ocean water dramatically increases snow crabs’ caloric needs. But with the warmer water also disrupting much of the region’s food web, snow crabs had a hard time foraging for food and weren’t able to keep up.

Researchers expect the population may eventually find refuge in colder waters further north.

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Climate Change And Crabs

Billions of crabs went missing around Alaska

Photo, posted August 28, 2013, courtesy of Boris Kasimov via Flickr.

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Trouble For Emperor Penguins | Earth Wise

September 18, 2023 By EarthWise Leave a Comment

Emperor penguins are in trouble

Emperor penguins are the tallest and heaviest of all living penguin species.  The loss of sea ice in Antarctica last year has led to unprecedented breeding failure in some emperor penguin colonies.

In a study published by the British Antarctic Survey, researchers found that no chicks survived from four of the five known emperor penguin colonies in the central and eastern Bellinhausen Sea.   Satellite images showed the loss of sea ice at breeding sites, well before chicks would have developed waterproof feathers.

Emperor penguins are dependent on stable sea ice that is firmly attached to the shore from April through the end of the year.  Arctic sea ice reached an all-time low in December 2022 with the most extreme loss seen in the central and eastern Bellinghausen Sea where there was a 100% loss of sea ice late the year.

This year, the sea ice extent in Antarctica is still far below all previous records for this time of year.  As of August, when oceans normally are freezing up, there were still areas that were ice-free.

Emperor penguin populations have not had to contend with large-scale hunting, habitat loss, overfishing, or other human-caused problems in the modern era, but climate change may be their undoing.  They have previously responded to incidents of sea ice loss by moving to more stable sites in the following year.  But this strategy will not be successful if the sea ice habitat is affected across entire regions of Antarctica.

Scientists are predicting that 90% of emperor penguin colonies will be quasi-extinct by the end of the century, assuming current global warming trends continue.

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Loss of sea ice causes catastrophic breeding failure for emperor penguins

Photo, posted October 7, 2017, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Offshore Wind In The Gulf Of Mexico | Earth Wise

April 4, 2023 By EarthWise Leave a Comment

The U.S. pursuing offshore wind development in the Gulf of Mexico

The US has a goal of deploying 30 GW of offshore wind energy capacity by 2030.  This is an ambitious goal given that the current installed offshore wind capacity in the US is a total of seven turbines capable of generating just 42 megawatts of power.  So, there is a long way to go in a relatively short amount of time.

Since 2021, the Bureau of Ocean Energy Management, a division of the Department of the Interior, has held three offshore wind lease auctions, which grant rights to developers to install offshore wind in specific marine areas.  The first two auctions involve sites in the northeast, including areas in New York.  The third auction, held last December, offered sites off the California Coast – the first US sites in the Pacific.

In February, the Department of the Interior proposed a new offshore wind lease sale in the Gulf of Mexico.  It identified a 102,480-acre area off the coast of Louisiana, and two similar-sized areas offshore from Galveston, Texas.

The proposal is now in a 60-day period of seeking public comments before deciding whether to move ahead with the sale.  As was the case for the other lease auctions, there would stipulations associated with accepted bids including efforts to build up domestic industry for the supply chain and labor force.  There would also be requirements to establish and contribute to a fisheries compensatory mitigation fund to address any potential negative impacts to the fishing industry.

About two-thirds of offshore wind resources in the US are located in deep-water areas that will require floating platforms.  A federal program called Floating Offshore Wind Shot has the goal of developing cost-effective technology for this purpose.

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Gulf of Mexico may be next up for offshore wind leases

Photo, posted May 13, 2011, courtesy of the Department of Energy and Climate Change via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Air Pollution In The Arctic | Earth Wise                     

March 8, 2023 By EarthWise Leave a Comment

Climate change is shrinking the Arctic ice cover, which is making it easier for ships to travel along the northern coast of Russia, known as the Northern Sea Route or the Northeast Passage.  There is also the Northwest Passage, which connects the Atlantic and Pacific Oceans via waterways through the Canadian Arctic Archipelago.

More than 600 fishing vessels sail the waters of the Arctic Ocean, but these fishing vessels are not the worst offenders when it comes to the growing problem of air pollution.  Giant natural gas tankers are becoming a much bigger problem.

In 2021, only 26 natural gas tankers traveled through Arctic waters.  But these ships can be 1000 feet long or more and produce far more CO2 emissions than fishing boats.   In 2019, the tankers accounted for 28% of the emissions and the number of them cruising the Arctic has been growing.

As the ice cover in the Arctic continues to shrink, more and more ships of all varieties, including cruise ships, fishing vessels, as well as tankers, are coming north and spending more time in the Arctic.  Any increases in ship traffic will increase the pollutant load in the Arctic and the Arctic is one of the most vulnerable environments in the world.

Between 2013 and 2019, the aggregated nautical miles that vessels traveled in what is called the Polar Code area increased by 75%. It isn’t just that more ships like tankers are going there.  It is that their operational season is expanding.

Air pollution isn’t the only problem.  Shipping in the Arctic brings with it light pollution, noise, marine litter, and more.  Only zero activity has zero pollution.

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The worst polluters in the Arctic are not what you think

Photo, posted February 26, 2015, courtesy of Chris Parker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Climate Change And Crabs | Earth Wise

November 8, 2022 By EarthWise Leave a Comment

Climate change wreaking havoc on Arctic crab populations

Globally, there are more than 6,000 species of crabs.  In Alaska’s waters alone, there are 18 species, including 10 that are commercially fished.  The perils of crab fishing in this region, including freezing temperatures, turbulent seas, and raising full pots that can weigh well over a ton, have been highlighted for many years in the reality TV series Deadliest Catch.        

One of those commercially-fished species is the Alaska snow crab.  Alaska snow crabs are a cold-water species found off the coast of Alaska in the Bering, Beaufort, and Chukchi Seas. 

In October, officials in Alaska announced that the upcoming winter snow crab season would be canceled for the first time ever due to a sharp population decline. While the number of juvenile snow crabs was at record highs just a few years ago, approximately 90% of snow crabs mysteriously disappeared ahead of last season.  Officials also canceled the Bristol Bay red king crab harvest for similar reasons for the second year in a row.

The closures dealt a severe blow to crab fishers in the region.  According to the Alaska Seafood Marketing Institute, Alaska’s crab fishing industry is worth more than $200 million. 

The canceled seasons also raise questions about the role of climate change in the snow crab population crash. While the causes of the decline are still being researched, scientists suspect that warmer temperatures are responsible.  Temperatures in the Arctic region have warmed four times faster than the rest of the planet. 

As the climate continues to change, the warming waters around Alaska may become increasingly inhospitable to snow crabs and other species.   

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Alaska’s Bering snow crab, king crab seasons canceled

Alaska cancels snow crab season for first time after population collapses

Photo, posted November 16, 2010, courtesy of David Csepp / NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pacific Bluefin Tuna On The Rebound | Earth Wise

September 21, 2022 By EarthWise Leave a Comment

The Pacific Bluefin Tuna is a commercially valuable species that is especially prized in Japan.  The fish is particularly valued for sashimi and sushi and large specimens have been known to fetch enormous prices at seafood auctions.

Aggressive fishing reduced the bluefin biomass through the late 1990s and 2000s to only a few percent of its potential unfished levels.  Beginning in 2011, The Western and Central Pacific Fisheries Commission began management measures that reduced the catch of smaller bluefin as well as limited the catch of larger bluefin.  The goal was to allow more fish to grow to maturity.  The Inter-American Tropical Tuna Commission adopted similar resolutions a year later.  Despite these efforts, increasing concern about declining bluefin levels led to a petition to list the species as endangered.  The National Oceanic and Atmospheric Administration’s Fisheries organization determined that while the population was near historical lows, the remaining 1.6 million fish was a sufficient number to avoid the risk of extinction and that the measures in place were sufficient.

A new assessment of the bluefin population has shown that the species is now increasing and includes many younger fish that will help accelerate its rebound.  The assessment by NOAA showed that the bluefin stock was greater than the first rebuilding target set for 2019. 

According to the NOAA Fisheries biologists that performed the assessment, the species has responded exactly as predicted given the actions that were taken.  The bluefin tuna is an amazingly resilient fish and it is continuing to demonstrate that fact.

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International Actions Pay Off For Pacific Bluefin Tuna as Species Rebounds at Accelerating Rate

Photo, posted June 1, 2022, courtesy of Philippe Yuan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Better Marine Protected Areas | Earth Wise

August 17, 2022 By EarthWise Leave a Comment

Marine protected areas are regions of seas, oceans, estuaries, and in the US, the Great Lakes, that are afforded special protections.  MPAs restrict human activity for conservation purposes, generally in order to protect natural or possibly cultural resources.   MPAs may limit such things as development, fishing practices, fishing seasons, catch limits, moorings, and removal or disruption of marine life.

A new study by the University of Plymouth in the UK looked at the effectiveness of MPAs in increasing the total abundance of reef species.  It looked at the MPAs in Lyme Bay, off the south coast of England, where two of them are co-located but governed by different constraints.

The study found that whole-site management of an MPA can increase the total abundance of reef species within its borders by up to 95%.  This is in contrast to the MPA where only known features are conserved and human activity is otherwise allowed to continue unchecked.  In that place, species abundance increased by only 15%.

The whole-site MPAs were observed to have other benefits as well.   They show higher levels of functional redundancy, meaning that when there are species losses, they are compensated by other species.  Whole-site MPAs also exhibit higher levels of species diversity.

MPAs are increasingly being recognized as a sustainable way to enhance the marine environment even while supporting coastal communities.  The Global Ocean Alliance, a 72-country alliance led by the UK, has set a target of protecting 30% of all marine areas by 2030.  The new study shows that even more important than simply establishing marine protected areas, it is essential that they are effectively implemented.

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Whole-site management of Marine Protected Areas can lead to a 95% increase in reef species

Photo, posted October 28, 2011, courtesy of Benjamin Evans via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shipping And The Endangered Whale Shark | Earth Wise

June 9, 2022 By EarthWise Leave a Comment

Whale shark population continues to decline

Whale sharks are the largest fish in the world.  While they measure up to 60 feet long and weigh up to 15 tons – larger and heavier than a school bus – whale sharks are actually harmless.  They are a graceful, slow-moving, filter-feeding carpet shark.  They are found in marine environments around the world and play an important role in the marine food web and healthy ocean ecosystems.

Whale sharks are an endangered species.  According to the International Union for Conservation of Nature, growing human pressures are putting whale sharks at an increased risk of extinction.  The numbers of these gentle giants have declined by more than 50% over the last 75 years despite many international protections.  Fishing bycatch, poaching, and collisions with ships are the main drivers of the population decline. 

According to new research from marine biologists from the Marine Biological Association and the University of Southampton in the U.K., lethal collisions between whale sharks and large ships are vastly underestimated, and could be the reason why populations are continuing to fall.  Whale sharks spend a large amount of time in surface waters in coastal regions, and the research team theorized that collisions with ships could be causing significant whale shark deaths. 

In the study, researchers tracked the global movements of both ships and whale sharks, and then mapped so-called hotspots where their movements overlapped.  The research team found that more than 90% of whale shark movements fell under the footprint of shipping activity.

While many conservation measures have been taken to protect whale sharks, no international regulations currently exist to protect them from ship collisions.  The researchers say it’s time for that to change. 

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Shipping poses significant threat to the endangered whale shark

Whale sharks (Rhincodon typus)

Global collision-risk hotspots of marine traffic and the world’s largest fish

Photo, posted July 8, 2010, courtesy of Marcel Ekker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Is It Too Late To Save The Vaquita? | Earth Wise

June 6, 2022 By EarthWise Leave a Comment

Can the critically endangered vaquita be saved?

The vaquita porpoise, the world’s smallest marine mammal, is on the brink of extinction.  Scientists estimate that just 10 or fewer vaquitas are left despite international conservation efforts. Found only in Mexico’s Upper Gulf of California, the vaquita is the most endangered marine mammal on the planet. 

According to the International Committee for the Recovery of the Vaquita, the number one threat facing vaquitas is gillnets. The porpoises get trapped in these nets and drown.  Gillnets are often used illegally in the region to catch shrimp and fish, including the critically-endangered totoaba.  The totoaba’s swim bladder is considered a delicacy in Asia and can fetch thousands of dollars.  Despite Mexico banning both totoaba fishing and the use of gillnets in the vaquitas’ habitat, many say the bans are not always enforced.  

But there is a reason to be hopeful.  According to a genetic analysis led by researchers at UCLA, the critically-endangered species actually remains relatively healthy and can potentially survive if illegal fishing practices cease immediately. 

In the study, which was recently published in the journal Science, the research team analyzed the genomes of 20 vaquitas between 1985 and 2017 and ran simulations to predict the species’ extinction risk over the next 50 years.  The researchers concluded that if gillnet fishing ends immediately, the vaquita has a very high chance of recovery.  If the practice continues, however, even moderately, the likelihood of a recovery plummets. 

According to the research team, the surviving vaquitas are actively reproducing and seem healthy.  But poachers’ gillnets will continue to pose an existential threat to the species until more measures are taken to protect the vaquita. 

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Only 10 vaquita porpoises survive, but species may not be doomed, scientists say

Photo, posted October 18, 2008, courtesy of Paul Olson / NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Assessing Human-Caused Wildlife Mortality | Earth Wise

May 31, 2022 By EarthWise Leave a Comment

Assessing the impact humans have on wildlife mortality

Bycatch is the fishing industry term used to describe the deaths of non-target fish and ocean wildlife during the fishing process.  Some bycatch species are thrown away because regulations prohibit them from being kept.  Others are thrown out because they won’t fetch high enough prices.  According to some estimates, global bycatch amounts to about 10% of the world’s total catch. 

Approximately half of global bycatch is a result of trawling.  Trawling is a method of commercial fishing that involves pulling or dragging a fishing net – called a trawl – through the water or across the seabed in hopes of catching fish.  Commercial fishing companies favor towing trawl nets because large quantities of fish can be caught.  But the method is destructive to the seafloor and leads to the indiscriminate catch of all sorts of species, including whales, dolphins, porpoises, sharks, seals, rays, turtles, and seabirds. 

Researchers have developed a new method to assess the sustainable levels of human-caused wildlife mortality.  When this method is applied to a trawl fishery in Australia, it shows that the dolphin capture is not sustainable.  The study, led by scientists at the University of Bristol in the U.K. and United Arab Emirates University, modeled different levels of dolphin capture, including those reported in logbooks and those reported by independent observers.  According to the findings, which were recently published in the journal Conservation Biology, even the lowest recorded dolphin capture rates are not sustainable. 

The new approach is extremely adept at assessing human-caused mortality to wildlife, and can be applied to fisheries bycatch, hunting, lethal control measures, or even wind turbine collisions.

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Wasted Catch

Dolphin bycatch from fishing practices unsustainable, study finds

Photo, posted May 18, 2011, courtesy of Pete Markham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Invasive Species On Ships In Antarctica | Earth Wise

February 23, 2022 By EarthWise Leave a Comment

Invasive species threaten Antarctica

The Southern Ocean around Antarctica is the most isolated marine environment on Earth.  Antarctica’s native species have been isolated for the last 15-30 million years.  As a result, wildlife there has not evolved the ability to tolerate the presence of many groups of species.

New research by the University of Cambridge and the British Antarctic Survey has traced the global movements of all the ships entering Antarctic water and has found that Antarctica is connected to all regions of the globe via ship activity to an extent much greater than previously thought.  Fishing, tourism, research, and supply ships are exposing Antarctica to invasive, non-native species that threaten the existing ecosystems.

In all, the research identified over 1,500 ports with links to Antarctica.  From all these places, non-native species including mussels, barnacles, crabs, and algae attach themselves to ships’ hulls.  The process is known as biofouling. 

The greatest concern is the movement of species from pole to pole.  These species are already cold-adapted.  They may come on tourist or research vessels that spend the northern hemisphere summer in the Arctic before traveling south for the Antarctic summer season.

Mussels have no competitors in Antarctica should they be accidentally introduced.  Shallow water crabs would introduce a new form of predation that Antarctic animals have never encountered before.

Current biosecurity measures to protect Antarctica, such as cleaning ships’ hulls, focus on a small group of so-called gateway ports.  The new findings indicate that these measures need to be expanded to protect Antarctic waters from non-native species.

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Invasive species ‘hitchhiking’ on ships threaten Antarctica’s unique ecosystems

Photo, posted April 12, 2016, courtesy of NOAA’s National Ocean Service via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Right Whales And The Warming Atlantic | Earth Wise

October 25, 2021 By EarthWise Leave a Comment

The warming of the Atlantic Ocean has driven the critically endangered North Atlantic right whale population from its traditional and protected habitat.  This has exposed the whales to more lethal ship collisions, increased entanglements with commercial fishing gear, and greatly reduced calving rates.

Since 2010, the calving rate has declined, and the right whale population has dropped by an estimated 26%.  Ten years ago, there were about 500 North Atlantic right whales; now there are an estimated 356.

These are some of the best studied whales in the oceans; scientists basically recognize each individual whale and when they are the victims of ship collisions or fishing entanglements, it is easy to identify which animal was killed.

Because of the warming climate, the Atlantic Meridian Overturning Circulation – an important system of surface and deep currents – has slowed down, causing the Gulf Stream to move north.  This has injected warmer and saltier water into the Gulf of Maine.  The warming Gulf of Maine has reduced the abundance of copepods, tiny crustations that are the favorite snack of right whales.   This has reduced whale calving rates and forced the whales to move north to the cooler waters of the Gulf of St. Lawrence.

For the past 6 years, more and more right whales have been observed feeding in the Gulf of St. Lawrence, where there were no protections in place to prevent ship strikes and fishing gear entanglement.  In 2017 alone, 17 right whale deaths were confirmed.

According to a recent report from Cornell University and the University of South Carolina, unless its management is improved, right whale populations will decline and potentially become extinct in the coming decades.

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Warming Atlantic forces whales into new habitats, danger

Photo, posted December 8, 2016, courtesy of Sea to Shore Alliance/NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Kenya’s Tana River Basin | Earth Wise

September 6, 2021 By EarthWise Leave a Comment

Climate change threatens biodiversity within the Tana River Basin

The Tana River is the longest river and most important waterway in Kenya.  It flows 620 miles from its headwaters in the Abderdare mountain range and Mount Kenya to the Indian Ocean.  The Tana River produces approximately half of the country’s electricity, and supplies Nairobi, the capital of Kenya, with 80% of its water.   

According to the United Nations Environment Programme, eight million people live along the Tana River, where coffee, tea, corn and other crops are grown for export, and fishing and cattle grazing help produce food for large portions of the country’s population. 

But the long-term ability of the river to provide these and other essential services is increasingly under threat due to many factors, including pollution, soil erosion, deforestation, and poor land use practices.   

Climate change is also complicating matters.  According to new research from the University of East Anglia, many species within the Tana River Basin will be unable to survive if global temperatures continue to rise at the current pace.  However, the study, which was recently published in the journal PLOS ONE, also found that many of these species could be saved if the world could meet the climate goals of the Paris Agreement. 

Globally, climate and land use changes are the two biggest threats to biodiversity.  According to researchers, 36% of the Tana River Basin has already been converted to agriculture. 

The research team says stronger commitments on climate change are needed from global leaders.  The climate and biodiversity crises can only be solved with urgent action to reduce global greenhouse gas emissions. 

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Web Links

The impact of climate change on Kenya’s Tana river basin

Economics of Ecosystem Services of the Tana River Basin

Photo, posted August 19, 2010, courtesy of Luigi Guarino via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting The Ocean Has Multiple Benefits | Earth Wise

June 21, 2021 By EarthWise Leave a Comment

The benefits of protecting the ocean

An international team of authors from 18 institutions has recently published a paper in the journal Nature that offers a solution that addresses several of humanity’s most pressing problems at the same time.  The paper provides a comprehensive assessment of where strict ocean protection can contribute to a more abundant supply of healthy seafood, help address climate change, and protect embattled species and habitats.

The study identified specific areas of the ocean that could provide all of these benefits if they were protected.  Currently, only about 7% of the ocean is under any kind of protection.  According to the study, if the appropriate 30% of the ocean was protected by the actions of the relevant countries by 2030, the cited benefits would be realized.

Safeguarding these regions would protect nearly 80% of marine species while increasing fishing catches by almost 9 million tons a year. It would also prevent the release of more than 1 billion tons of carbon dioxide by protecting the seafloor from bottom trawling, which is a widespread and destructive fishing practice.

Ocean life has been declining worldwide because of overfishing, habitat destruction, and climate change.  The study pioneers a new way to identify the places that – if protected – will boost food production and safeguard marine life, while at the same time reducing carbon emissions.  The study finds that countries with large national waters and large industrial trawl fisheries have the highest potential to contribute to climate change mitigation by protecting the carbon stored on the ocean floor.  The ocean covers 70% of the Earth and its importance in solving the challenges of our time must not be underestimated.

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Web Links

Three Times the Gains

Photo, posted January 10, 2016, courtesy of Hafsteinn Robertsson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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