sea otter

Eco Superheroes: How Otters Are Saving The Planet

9 mins

From reducing coastal erosion to saving marshes and kelp forests, otters are natural conservationists but are also facing colossal changes – including climate change, pollution and overfishing – to survive

From the concrete Singaporean jungle to the Ecuadorian Amazon – smart, social and semi-aquatic otters exist in five of the world’s continents, which is no small feat when you consider their beleaguered history. 

Native to the North Pacific Ocean, sea otters once numbered hundreds of thousands before they were hunted to near-extinction during the height of the maritime fur trade in the 19th century. Boasting the densest fur of any species (150,000 hairs per square centimetre!), their water-repellent pelts were their achilles’ heel.

Today, there are an estimated 130,000 sea otters globally though 12 of the world’s 13 otter species – which include the spotted neck and hairy-nosed ­– appear on the IUCN Red List of Threatened Species. If these swimming furballs were to silently sink towards extinction, it would spell disaster for the natural world.

Aquatic Environmentalists

otters among the kelp

As top predators, otters make a significant ecological impact by maintaining the balance and vitality of nearshore ecosystems like marshes and kelp forests. Wave-buffering kelp beds – the fronds of which some sea otters anchor themselves to whilst resting – are among the planet’s most productive ecosystems. 

These apex predators reduce coastal erosion – sea otters have helped stabilise the shoreline of San Francisco’s Elkhorn Slough estuary by consuming root-eating shore crabs that are destabilising its salt marshes 

Sunny California’s sea otters are helping conserve these species-rich underwater forests by preying on kelp-destroying sea urchins. Research published in the Frontiers in Ecology and the Environment journal reveals that the presence of otters’ doubles kelp forests carbon dioxide absorption from the atmosphere.

Another climate-critical ecosystem supported by these adorable aquatic animals are eelgrass beds: underwater meadows that serve as both ocean water purifier and fish nursery. 

These apex predators can also reduce coastal erosion. A study published in January by Nature reports that sea otters have helped stabilise the shoreline of San Francisco’s Elkhorn Slough estuary by consuming root-eating shore crabs that are destabilising its salt marshes. 

Five hundred miles north on Oregon’s Coast, it’s invasive European green crabs that are wreaking havoc on seagrass habitat and undermining the area’s lucrative shellfish industry. The solution could be to reintroduce sea otters, which have successfully controlled the alien species in California’s Monterey Bay. In doing so, they’ve benefited not only the environment, but the local economy too by supporting higher fish catches and contributing to ecotourism.

Changing Water World

mum with sleeping baby otter on her tummy

Whilst otters bolster seagrass, salt marsh and kelp forests’ resilience to climate change, a warming planet is simultaneously whittling down their fish prey, which constitutes around 80 per cent of an otter’s diet. 

Known for their voracious appetite, these agile hunters consume a quarter of their weight every single day. It’s a problem exacerbated by overfishing that’s hit sea otters – who eat, sleep and give birth at sea – particularly hard. They also have to contend with rising sea levels, entanglement in fishing gear and oil spills that can destroy their pelts’ insulating and waterproofing qualities, leading to hypothermia.

Otters have to contend with rising sea levels, entanglement in fishing gear and oil spills that can destroy their pelts’ insulating and waterproofing qualities, leading to hypothermia

Living in wetland habitats like mangroves, lakes, streams and marshes has also made otters vulnerable to pollution, with pesticide run-off from farms being one of the main culprits. A study led by Cardiff University’s Otter Project in 2022 exposed a grisly truth; that traces of forever chemicals – so named for their extreme persistence in the environment – exist in otters across both England and Wales.

City Swimmers

otters singapore

It was contaminated canals, together with land reclamation and the destruction of mangrove habitat that drove smooth-coated and Asian small-clawed otters out of their native Singaporean home in the seventies. 

Fast forward 50 years and these furry apex predators are thriving in the cosmopolitan city-state; the world’s third-most densely populated country. The number of smooth-coated otters – Singapore’s predominant species – has more than doubled since 2019 to 170.

Their remarkable rebound is attributed to a major waterway clean-up, reforestation of land and city-wide conservation efforts, reinforced by some very dedicated local groups like OtterWatch.

Part of the city’s urban matrix, these lovable creatures reside in its canals, reservoirs, parks and gardens, as well as tourist magnets like Gardens by the Bay and Marina Bay Sands’ boardwalk. They’re even known to cross five-lane highways in Singapore’s central business district and short-cut through university campuses as part of their three-mile-a-day wanders.

While there are occasional reports of otters’ raiding residents’ koi fish ponds and taking dips in apartment complex pools, for the most part, they peacefully coexist with Singers’ six-million population.

Wet ‘n Wild 

otters in Argentina

Ten thousand miles away in one of earth’s largest freshwater reserves, an ambitious project is hoping to replicate Singapore’s spectacular otter comeback. Located in north-east Argentina, the Iberá Wetlands holds a staggering 30 per cent of the country’s biodiversity. It could accommodate even more if a native keystone species is returned to its rightful home. 

Once a familiar sight, globally-endangered giant river otters were driven to local extinction in the mid 1900s by coastal development, large-scale dam construction and illegal hunting. ‘They [otters] are really noisy, and have many vocalisations. They’re also very curious, active and confident, which makes them easy to observe, but that was their problem,’ Conservation Director of non-profit Rewilding Argentina Sebastián Di Martino tells The Ethicalist. ‘They were hunted and became extinct in almost all the Panama River Basin apart from the Pantanal Region.

‘We’re trying to form breeding couples to start family groups,’ Di Martino says of the Iberá Project, explaining that so far, they’ve successfully paired five giant river otters individually donated by different European zoos. 

Despite Coco and Alondra giving birth in 2021 to three pups – Yvera, Ipegua and Chiru – their new lives in the wild are still some way off. Currently they’re cared for in three pre-release corrals’ on Iberá’s San Alonso Islandwhich nestles on Paraná Lake’s shore.

Di Martino explains that the plan is to let the first couples roam free in early 2026, with the hope of re-establishing a healthy population of giant otters across both Iberá and 315-acre Impenetrable National Park, located in Chaco province. Three years ago, Di Martino had a chance encounter with a wild otter in Impenetrable whilst kayaking in its Bermejo River; the first confirmed sighting in half a century.

Natural Born Survivors

wild otter ambulance in england

It’s not only large-scale projects that can make a difference, but grassroot organisations too. Rescuing around 30 orphaned otters a year, volunteer-staffed conservation and rescue charity UK Wild Otter Trust (UKWOT)launched the world’s first ambulance for otters in December 2023. 

‘Around a year ago we saw a need for this when we were called to a remote area of Dartmoor [in England’s southwestern region] where an otter had to be euthanized,’ UKWOT’s founder Dave Webb tells The Ethicalist.

In the face of adversity, otters are showing remarkable and reassuring survival skills. Only recently it’s been discovered that they’re one of the few animals able to use tools to hunt, feed and prevent injuries 

Outfitted with life-saving equipment, the all-terrain custom-built vehicle ‘carries rehydration fluid, antibiotics, pain relief and the facility to euthanize on site if required,’ Webb explains. ‘It’s a priority to get the animal out of pain and suffering no matter how that may be needed,’ he continues, adding, ‘the ambulance has reduced response times by half and enables us to get the animal comfortable which increases survival rate.’

Otter Rehabilitation

otter being rehabilitated in england

Some otters will recuperate at UKWOT’s specialist two-acre rehabilitation centre. The largest of its kind in Britain, the centre has capacity for 42 otters. It’s located in North Devon, where the beautiful but brutal children’s book ‘Tarka the Otter’ – which chronicled the life of a young otter in the Devonshire countryside – was set. Hunted to near extinction in southern England, Eurasian otters’ resurgence is largely thanks to a crackdown on toxic overflow from farms into river systems in the early 1990s. 

In the face of adversity, these keystone species are showing remarkable and reassuring survival skills. Only recently it’s been discovered that they’re one of the few animals able to use tools to hunt, feed and prevent injuries. 

In the coastal regions of central California, southern sea otters have been observed using rocks to prize open hard-shelled prey like crabs and clams, reducing damage to their teeth in the process. A new Sciencepublished study puts their survivalist response down to the decline in sea urchins and abalone in the area.

Here’s hoping these lovable furry mammals can continue to battle and persevere against the odds in both our cities and the wildest corners of the planet. 

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