17 of the Most Endangered Animals

Scientists estimated that there are about 2 million identified animal species globally, but around 80% of all animals are still not discovered and described yet. Out of the species we know, 83 669 are listed in the IUCN Red List.

Over 3 714 species from the Animalia kingdom were classified as critically endangered on that list, along with 5 907 species considered endangered6 858 considered vulnerable, and 37 considered extinct in the wild (living only in captivity).

However, there is still not enough information about 15 311 species, and some of them could also be on the verge of extinction. 

17 Most Endangered Animals in the World

Out of the thousands of critically endangered species, there are a few better-known species that are on the decline or under threat more than others. 

1. African forest elephant

Most Endangered Animals in the World

The African forest elephant is native to the humid forests of West Africa and the Congo Basin. It is one of two elephant species living in Africa.

Scientific name: Loxodonta cyclotis

Population: less than 30 000

Size: 5.9 – 9.8 ft tall, 4 400 – 8 800 lbs

Status: Critically Endangered since 2021

The biggest threats to African forest elephants can be collected in three groups: habitat loss, poaching, and fragmentation of herds.

African forest elephants live mainly in forests, savannas, and shrublands in developing countries of West and Central Africa. The residential and agricultural developments, new roads, and mining diminish their habitat and separate herds from each other, making it challenging to breed and mix the gene pool. 

However, the main problem African forest elephants face is poaching for ivory and bushmeat, which steadily grew since the 1970s, peaking in 2011. Although actions have been taken, unsustainable poaching is still a persistent threat driving the number of animals down each year.

Conservation: 

  • The Central African Republic, Democratic Republic of Congo, Gabon, Senegal, and Côte d’Ivoire banned elephant hunting.
  • There has been a ban on the international trade of African forest elephants and their parts since 1989. 
  • Scientists use thermal imaging and translocation to monitor the herds of African forest elephants.
  • There are checkpoints on major roads and railroads for illegal bushmeat transportation.

2. Amur leopard

Most Endangered Animals in the World

Amur leopard is considered the rarest big cat in the world. It still resides in southeastern Russia and northeastern China.

Scientific name: Panthera pardus orientalis

Population: less than 100

Size: 25 – 31 inches tall, 42 – 54 inches long with 32 – 35 inches long tail, 55 – 106 lbs

Status: Critically Endangered since 2007

Amur leopards used to roam through eastern Siberia, northeastern China, and the Korean Peninsula. Due to extensive hunting during Japanese rule, Amur leopards are considered locally extinct in the South and North Korea.

Although hunting for Amur leopard is banned, poaching is one of the main threats. There is also much illegal hunting in Russia by villagers with no gun or hunting permits who kill Amur leopards preying on their stock animals.

Deforestation and habitat loss are amongst the biggest threats to the Amur leopards. Their habitat in Russia was reduced to 20% of its former glory just in the 1970s.

Human-induced fires are amongst the biggest reasons for lost habitat. These fires often take down conifer forests, which are preferred Amur leopard habitat. The area turns into an open landscape with tall grass and shrubs, which leopards often avoid. 

The diminishing population caused another problem to arise: inbreeding. Due to the small gene pool, more Amur leopards breed with their relatives causing increased numbers of cubs born with abnormalities, which causes lower cub survival.

Conservation: 

  • Amur leopard body parts were banned from trade.
  • There are 16 protected areas and six nature reserves in Shanxi Province and a nature reserve in Jilin Province in China.
  • An ALTA initiative was started between Russian and western conservationists to save the Amur leopard and tiger from extinction, and antipoaching teams patrol the leopards’ range.

3. Eastern black rhino

Most Endangered Animals in the World

Eastern black rhinoceros can be found in highland forests and savannas of Kenya and northern Tanzania. It is a cousin of the Western black rhino, considered extinct since 2011.

Scientific name: Diceros bicornis ssp. michaeli

Population: 583

Size: 4.5 – 6 tall, 10 – 12.5 ft long, 1 750 – 3 000 lbs

Status: Critically Endangered since the late 20th century

Once living in Somalia, Tanzania, Kenya, and Ethiopia, Eastern now black rhino can only be found in Kenya and Tanzania. In the last three generations population declined by 90%. The threat started with habitat loss which divided the rhino population. Stranded crashes of rhinos were high-density and bred very slowly.

Nowadays, the biggest threat to Easter black rhinos is poaching. According to research data, poaching has an ongoing rate of 3.1 rhino/day, although this number, in reality, is about 20% higher due to a large area that researchers cannot check.

Eastern black rhino horns on the illegal international market constitute around 95% of all rhino horns sourced in Africa. 

Although black rhino numbers are slowly increasing, the war with poachers is far from over. Since 2007 poaching has increased, posing a risk to staff and investments. 

Conservation:

  •  WWF launched a program to relocate eastern black rhinos to other, more secure, less populated areas.
  • Many law enforcement agencies in Kenya started to use high-tech solutions, train and equip rangers to stop poaching.
  • There are 86 conservancies – community-run areas with defined borders collectively covering 65 000 square miles, where said communities manage Eastern black rhinos amongst other endangered animals.

4. Bornean orangutan

Most Endangered Animals in the World

Bornean Orangutan lives only in Borneo Island. Along with two other orangutans, it is the only genus native to Asia.

Scientific name: Pongo pygmaeus

Population: ca. 104 700

Size: 3’3″ – 5’6″ tall, 66 – 220 lbs 

Status: Critically Endangered since 2008

A few significant threats on Borneo Island contribute to Bornean orangutan numbers decline. The biggest one is habitat loss to deforestation and fires. 

Deforestation proceeds at a pace of 1250 square miles per year. It means that 12 360 square miles of the forest will be lost by 2050. About 45% of the Bornean orangutan population lives in forests designated for agriculture and other uses.

It doesn’t help that whatever forest is left stands on peatland that burns due to artificial drainage almost every year. All the habitat loss leads to fragmentation. Although Bornean orangutans prefer a solitary life, they meet on occasions to mate. However, habitat fragmentation prevents meetings and therefore breeding.

Another threat to Bornean orangutans is hunting. Although banned in Borneo, hunting is an illegal activity fueled by human-animal conflict. Due to lack of space in the wild, orangutans come to farms and plantations in search of food and destroy crops. Bornean people hunt them to prevent damage to farms, but also as meat. 

Conservation:

  • A few collaborations work in order to manage selective logging. The objective is to leave enough fruit trees intact for Bornean orangutans.
  • Plantations are asked to put better security on their crops to prevent human-orangutan interactions and reduce orangutan killing.
  • The wildlife trade monitoring network helps enforce laws prohibiting the capture and trade of Bornean orangutans.
  • Many orangutan rehabilitation centers rescue, treat and prepare orangutans to be released in protected areas in Borneo.

5. Cross River gorilla

Most Endangered Animals in the World

Cross River gorillas are a subspecies of the western gorilla. The whole population is limited to the tropical and subtropical broadleaf forests along the Cross River on the border between Cameroon and Nigeria.

Scientific name: Gorilla gorilla ssp. diehli

Population: 100 – 250

Size: 4’7″ – 5’9″ tall, 220 – 440 lbs

Status: Critically Endangered since 1996

The biggest threat to Cross River gorillas is habitat loss. The population is fragmented and surrounded by Africa’s most densely populated human settlements. Because Cross River gorillas won’t nest in the close vicinity to humans, even in the protected areas of national parks and sanctuaries, they don’t have a lot of space to occupy.

Unfortunately, due to the low numbers of Cross River gorillas, there is a high risk of inbreeding. There is very little genetic diversity, leading to several abnormalities, i.e., immune system disorders. It may, in turn, lead to an increased possibility of transmitting Ebola from the closest human population.

Poaching is not the greatest threat to Cross River gorillas per se, but they often get caught in traps set to capture other animals. This leads to injury and occasional death. Moreover, a few opportunistic hunters manage to illegally kill 1- 3 gorillas per year for the bushmeat and body parts trade.

Conservation:

  • The Cross River National Park in Nigeria and Takamanda National Park in Cameroon form a transboundary area protecting around 115 Cross River gorillas.
  • The Kagwene Gorilla Sanctuary in Cameroon was opened in 2008 as a part of the IUCN action plan.
  • Locals in Cameroon living in the villages bordering with Cross River gorilla habitat strongly discourage gorilla hunting due to their ancient beliefs and totemic traditions.

6. Grauer’s gorilla

Most Endangered Animals in the World

The largest of four gorilla subspecies, Grauer’s gorilla lives in mountains forests in the eastern Democratic Republic of the Congo.

Scientific name: Gorilla beringei ssp. graueri

Population: less than 3 800

Size: 5’2″ – 6’5″ tall, 168 – 461 lbs

Status: Critically Endangered since 2016

Grauer’s gorillas face many threats, and their population is decreasing fast. The biggest of the dangers is poaching. Although hunting for great apes is illegal, bushmeat is still prevalent across Grauer’s gorillas’ range. Mineworkers and armed groups are the lead bushmeat consumers due to the lack of domestic protein in rural areas.

Forest habitat fragmentation is the second biggest problem. Due to artisanal mining and farming prompt logging, diminishing Grauer’s gorillas’ habitat and dividing their population. 

Civil unrest poses another threat to Grauer’s gorilla survival. In the 1990s and early 2000s, armed groups and civilians took residence in the forests, greatly restricting Grauer’s gorillas’ habitats and making it difficult to monitor their population and implement hunting regulations. At least 69 armed groups reside in the Grauer’s gorilla range.

Conservation:

Conservation of Grauer’s gorillas is a dangerous and challenging task, considering that armed groups and militia control most of the Democratic Republic of the Congo.

Militia takes offense to any park rangers’ attempt at stopping illegal logging, Grauer’s gorilla hunting, and body parts transportation. There were a few retaliatory killings of gorillas and park rangers alike over the years.

The Democratic Republic of the Congo doesn’t have the resources to train and equip the country’s small group of park rangers.

7. Hawksbill turtle

Most Endangered Animals in the World

With worldwide distribution, the Hawksbill sea turtle is the only living species of the Eretmochelys.

Scientific name: Eretmochelys imbricata

Population: 15 000 – 25 000

Size: 3 ft long, 180 lbs 

Status: Critically Endangered since 1996

Tortoiseshell trade is the greatest threat to the Hawksbill turtle. Around 400 000 nesting females were killed for the Japanese market of bekko (tortoiseshell) between 1950 and 1992. Due to Hawksbill turtles’ longevity, that period approximates only a single Hawksbill turtle generation.

The egg collection and slaughter for meat contribute to the second-largest threat to Hawksbill sea turtles. In some parts of the world, turtle meat is used as a shark, lobster, and reef fish bait. 

Hawksbill turtles and their sea turtle cousins continually get entangled in fishing gear and other marine debris left by humans. They are also more fragile than other sea turtle species and often get poisoned by oil pollution. 

Tourism development is also considered a threat to Hawksbill sea turtles. They are particularly fond of nesting under dune vegetation. Therefore beachfront development and human activity on the coast cause turtles to relocate.

Conservation:

  • There is a ban on international trade and transport of Hawksbill turtle meat and body parts.
  • Many nesting sites have been under monitoring and protection.
  • There is an international collaboration to research the species and develop better conservation measures.

8. Javan rhino

Most Endangered Animals in the World

Javan rhino is possibly the rarest large mammal in the world. It is now endemic only to the western tip of Java island.

Scientific name: Rhinoceros sondaicus

Population: 18

Size: 25 – 31 inches tall, 42 – 54 inches long with 32 – 35 inches long tail, 55 – 106 lbs. 

Status: Critically Endangered since 2007

Like its African cousin, the Javan rhino’s biggest threat is poaching for rhino horns. The impoverished people of Java sharing habitat with Javan rhinos believe that rhino skin is an antidote for snake venom. It isn’t easy to convince them that they should not kill endangered species.

Another big threat to Javan rhino is habitat loss. One of the reasons is the human presence and development, and the other are palm trees Argena obtusifolia. These palm trees grow uncontrollably, taking over rhino forests and halting the growth of rhino food plants.

On top of the diminished number of edible plants, Javan rhinos have to compete for food with banteng, a species of cattle, which forages the same plants as rhinos when the grass is scarce.

Conservation:

  • In December 2011 an area of 147 square miles was dedicated as a rhino breeding sanctuary.
  • The Asian Rhino Project started a program in 2012 to eradicate arenga palm in the Javan rhino habitat to help grow rhino food plants. 

9. Pygmy three-toed sloth

Most Endangered Animals in the World

The smallest of the four members of its genus, the Pygmy three-toed sloth, lives only on a small Isla Escudo de Veraguas, on the Caribbean Sea.

Scientific name: Bradypus pygmaeus

Population: ca. 79

Size: 19 – 21 inches long, 5.5 – 7.7 lbs

Status: Critically Endangered since 2006

The island Pygmy sloths inhabit has no permanent human residents, although the seasonal visitors often cut timber to maintain their wooden shelters and houses. The practice greatly affects the small habitat of the island, and therefore the lives of Pygmy sloths. 

Researchers believe that the numbers of Pygmy three-toed sloths were low for a long time due to their isolation and restricted space on the island. Additionally, as many people discover Pygmy sloths, there is growing interest in collecting them for captivity.

There is also a small conflict between countries that want to claim jurisdiction of the island. Governments can’t decide to whom the island belongs, and therefore there is no protection plan for the fauna and flora of the island.

Moreover, there are plans to build a tourist destination, therefore limiting the already limited space pygmy sloths have.

Conservation:

Conservation of pygmy sloths is difficult because the island’s custody is not entirely clear. Panamian government, regional politicians, and local Ngäbe-Buglé Comarca (an administrative region with Amerindian population) continuously disagree with each other complicating any long-term protection.

10. Saola

Most Endangered Animals in the World

Saola also called an Asian unicorn, is one of the rarest bovines in the world. It is a very elusive animal living in the Annamite Range in Vietnam and Laos.

Scientific name: Pseudoryx nghetinhensis

Population: 25 – 300

Size: 33 – 37.7 inches tall, 4’9″ long, 176 – 220 lbs

Status: Critically Endangered since 2006

The main threat to Saola is hunting. Although Saola itself is not purposely targeted, it falls prey to the traps and snares left for other, more desirable species sharing Saola’s habitat.

The number of snares is astounding in Vietnam, where every opportunistic hunter-gatherer goes into the jungle looking for easy income. Poachers hunting for bears, tigers, and Sambar with guns and dogs often kill Saolas accidentally. 

Human encroachment into Saola’s territory fragmented the population, making it difficult for Saolas to breed. Saola’s generation time is only about 5-10 years. Considering a relatively short lifespan and the hunting pressure, there was a steep decline in their numbers during the last few decades.

Saolas are extremely shy in the wild and difficult to keep in captivity, making it challenging for researchers and biologists to study and help with reproduction.

Conservation:

  • There are two newly established Saola reserves in the Thua-Thien Hue and Quang Nam provinces in Vietnam. 
  • WWF helped set new management in the Vu Quang Nature Reserve, where Saola was first discovered.

11. Sumatran elephant 

Most Endangered Animals in the World

Sumatran elephant is one of three subspecies of the Asian elephant, and it lives only on the Indonesian island of Sumatra.

Scientific name: Elephas maximus ssp. sumatranus

Population: 2 400 – 2 800

Size: 6’6″ – 10’5″ tall, 4 400 – 8 800 lbs

Status: Critically Endangered since 2011

The biggest threat to Sumatran elephants is people’s encroachment into elephants’ territory. New human settlements and agriculture cause major habitat loss for Sumatran elephants. Not having enough space, elephants often break into farms and plantations and destroy crops in search of food. 

It causes a lot of human-elephant conflicts, as angry farmers kill elephants with poison, electricity, and traps. There are plenty of illegal plantations also within National Parks in Sumatra, dividing elephant populations even further.

On top of losing their habitat, Sumatran elephants face another, more common problem for the species. Poaching for ivory follows wherever there are elephants. This caused a 50% decline in numbers between 1985 and 2007. 

Conservation:

  • Sumatran elephants are under Indonesian law protection.
  • Tesso Nilo National Park, established in 2004 in Riau Province, is the largest area in Sumatra protecting Sumatran elephants.
  • There are Crop Protection Units to drive elephants away from farms to reduce human-elephant conflict and SMART patron units protecting elephants from poachers in National Parks.

12. Sumatran orangutan

Most Endangered Animals in the World

Rarer even than Bornean orangutan, the Sumatran orangutan lives only in the northern tip of Sumatra. 

Scientific name: Pongo abelii

Population: 13 846

Size: 4′ – 5′ tall, 66 – 198 lbs

Status: Critically Endangered since 2000

One threat that greatly outweighs any other threats for Sumatran orangutans’ survival is humans and their constant development.

Once widespread orangutan population in Sumatra is now confined only to the northernmost part of the Aceh Province. The numbers are decreasing every year due to converting their habitat into oil palm plantations and other agricultural lands.

Road-building and logging contribute to the fragmentation of the Sumatran orangutan population. The Aceh Province government has no protection plan in place.

Moreover, although orangutans are under legal protection in the country, the Province of Aceh, where over 82% of the Sumatran orangutan population lives in forests, constructed a spatial plan with disregard for orangutan habitat. The national government deemed the project illegal, but there has been no change so far.

A small portion of the orangutan population in Sumatra are also deliberately hunted, and any infant offspring that is found in the forest is promptly sold in the illegal pet trade. 

Conservation:

  • Sumatran orangutans inhabit five areas within the Gunung Leuser National Park.
  • Bukit Tiga Puluh National Park launched a successful breeding program for Sumatran orangutans in two Sumatran provinces.
  • There is a rescue and rehabilitation program in place for captive or displaced orangutans. Its goal is to re-introduce Sumatran orangutans back into the wild.

13. Sumatran rhino

Most Endangered Animals in the World

The hairy rhinoceros, known more commonly as Sumatran rhino, exists only in Sumatra and Borneo in five small populations.

Scientific name: Dicerorhinus sumatrensis

Population: 30

Size: 3’3″ – 5′ tall, 6’5″ – 13′ long, 1 320 – 2 090 lbs

Status: Critically Endangered since 1996

Although poaching was the greatest threat to Sumatran rhino in the past, nowadays, illegal hunting is limited due to small numbers and the difficulty of finding each specimen in the wild.

The recent biggest threat to Sumatran rhino is humans. The disturbance humans cause in the forest negatively affects rhinos, causing them to relocate. Sumatran rhino living in Aceh Province in Sumatra must deal with habitat loss due to deforestation for agriculture and new roads.

In other locations, Sumatran rhinos are disturbed mainly by people poaching for and illegally collecting exotic birds, pangolins, fish, and non-timber forest products. As solitary and shy animals, Sumatran rhinos are easily disturbed. 

Due to very low numbers, and fragmented population, Sumatran rhinos suffer from the Allee effect. It means that their physical fitness is dependant on the number of specimens remaining within the population. Inbreeding is another one of the threats connected with low numbers. It manifests itself in more recessive traits in offspring, reducing their chances of survival.

Conservation:

  • The breeding program of Sumatran rhinos in captivity brought seven new Sumatran rhinos.
  • There is a Rhino Sanctuary in Way Kambas National Park, established in 1995 for managed breeding.
  • WWF launched intensive management over the areas where Sumatran rhinos still reside.

14. Sumatran tiger

Most Endangered Animals in the World

Once one of three Sunda tigers, along with Bali and Javan tigers, now extinct, the Sumatran tiger is the only surviving population in the Sunda Islands.

Scientific name: Panthera tigris ssp. sumatrae

Population: ca. 400

Size:  inches tall, 87 – 100 inches long with tail, 165 – 308 lbs 

Status: Critically Endangered since 1996

Sumatran tigers suffer due to tremendous habitat loss. Oil palms and acacia trees plantations now take more than 80% of the former Sumatran tiger habitat.

The high-intensity logging and road-building lead to further depletion of tiger habitats. Though protected by Kerinci Seblat National Park, Sumatran tigers still suffer due to low numbers of prey animals and anthropogenic climate change.

People’s encroachment into tiger territory also leads to human-tiger conflict, as tigers attack livestock and humans alike, and people try to retaliate. 

The most common for many endangered species threat, poaching, also threatens Sumatran tigers. The high demand for tiger parts in local and international markets drives illegal killings. Farmers, afraid for their livestock, contribute to illegal hunting and often sell tiger carcasses to souvenir shops and pharmacies.

Conservation:

  • Indonesian Forestry Ministry, Safari Park, and Australia Zoo started cooperation conserving Sumatran tigers in the wild. 
  • In 2009 Indonesian president announced reduced deforestation in tiger habitats.
  • $210 million have been invested between 2005 and 2015 to law-enforcement activities supporting forest rangers.
  • The Batu Nanggar Sanctuary opened in 2016 to support the conservation of Sumatran tigers.

15. Vaquita

Most Endangered Animals in the World

The smallest of all living whales, Vaquita, lives in only one place in the world – Baja California, the northern end of the Gulf of California.

Scientific name: Phocoena sinus

Population: 18

Size: up to 5′ long, up to 120 lbs

Status: Critically Endangered since 1996

Vaquita was pushed to extinction by being a bycatch of fisheries using illegal gillnets to catch Totoaba and Mexican shrimp.

Despite regulations including a partial gillnets ban in the Gulf of California, illegal fishing for another endangered species thrives. The demands of the Chinese black market for Totoaba’s swim bladder drive prices up, making it more viable for Mexican fishers to illegally fish for another endangered species – Totoaba. 

Totoaba and Vaquita inhabit the same waters of the northernmost part of the Gulf, making it difficult for Vaquitas to avoid being entangled in the gillnets. 

A smaller but also viable threat to remaining Vaquitas is pollution and habitat alteration. Since they inhabit shallow coastal waters of the Gulf, a lot of pollution from runoff and beach development affects Vaquita’s feeding and therefore breeding. 

Conservation:

Conservation of the rarest porpoise on earth is proven difficult. Illegal fishing with gillnets continues, and it’s proving challenging to stop.

An effort of keeping a herd of Vaquitas in captivity until their habitat is safe failed, resulting in traumatizing and ultimately killing one female Vaquita. Like many other porpoises, Vaquitas are more sensitive than dolphins and don’t bear captivity well. 

16. Western lowland gorilla

Most Endangered Animals in the World

Western lowland gorilla is the smallest of the four gorilla subspecies and inhabits forests and swamplands of central Africa.

Scientific name: Gorilla gorilla ssp. gorilla

Population: less than 100 000

Size: 4 – 5’6″tall, up to 440 lbs

Status: Critically Endangered since 2007

Illegal hunting for bushmeat is the biggest threat for Western lowland gorillas. Due to logging and road development, gorilla habitats became more accessible for poachers and eased the transport of bushmeat out of forests.

The buildup of the road network also fragments Western lowland gorilla habitat, putting more pressure and stress on animals.

Gorillas can contract the Ebola virus from people, and increased human population in close proximity to gorilla habitats results in more infected specimens. Although National Parks try to keep poachers, logging, and roads from gorillas, the Ebola virus is highly infectious and cannot be easily stopped from spreading. 

The ever-increasing number of oil palm plantations is another threat to Western lowland gorillas. Illegally hunted and fighting with the Ebola virus, gorillas have less and less habitat to take refuge. Gorilla habitat has a perfect climate for a very prospective palm oil business.

With corrupt governments and conservation foregone in favor of economic development, gorilla habitat could be cleared within a few decades.

Conservation:

  • WCS has been working with the Congo Basin community to appoint management programs for gorilla habitat protection.
  • New hunting restrictions in Congo have been proposed to stop hunting gorillas for bushmeat.

17. Yangtze finless porpoise

Most Endangered Animals in the World

Endemic to the Yangtze River in China, the finless porpoise is the only freshwater whale, and after the extinction of Baiji, in the country.

Scientific name: Neophocaena asiaeorientalis ssp. asiaeorientalis

Population: 500 – 1 800

Size: 6’2″ long, up to 160 lbs

Status: Critically Endangered since 2013

Like Vaquita, Yangtze finless porpoise is facing a threat from gillnets. Although not purposely targeted, finless porpoises get entangled in the illegally set nets, get hooked on rolling hooks, or get electrocuted by accident.

The Yangtze River is an increasingly traveled body of water, and a lot of vessel traffic collides with porpoises, and the noise of motor engines compromises foraging. Sand mining in the river greatly affects finless porpoises and their prey’s reproduction, limiting the food supply for porpoises.

The human population in the Yangtze River basin and thousands of factories produce tons of effluent and sewage, discharging it into the river. Pollution affects the health and fertility of porpoises and their source of food.

Along with developed banks, dams across the river block porpoise movements between the river and lakes and affect migration and breeding of porpoises’ food sources.

Conservation:

  • New laws prohibit the use of rolling hooks, gillnets, electro-fishing, and other harmful fishing gear.
  • A few parts of the Yangtze River have been closed for fishing altogether to conserve finless porpoises’ food sources and habitat.
  • There are proposed regulations for the heavy vessel traffic on the Yangtze River, i.e., reducing speed while passing through porpoise reserves.