Threat Factors and Protection Measures of Finless Porpoises in the

Yangtze River, China

Christy Pan Sze Yui

Nansha College Preparatory Academy, Guangzhou, 511458 China

Keywords: Yangtze Finless Porpoise, Water Pollution, Species Conservation, Habitat Protection.

Abstract: As a critically endangered cetacean, finless porpoise does have a wide-spread distribution over the Indian and

Pacific Oceans, as well as the freshwater basin of the Yangtze River in China. In recent decades, the finless

porpoise’s population has experienced a great decline globally, primarily due to water pollution caused by a

variety of sources, including industrial pollution, agricultural runoff, and daily waste. Containments in the

water could have negative impacts on the porpoise’s physiology status and their reproductive system.

Therefore, a complete and comprehensive understanding of the causes and solutions is essential. The Yangtze

finless porpoise's habits, survival, and reproduction are the main topics of this essay. The present state of

existence of the Yangtze finless porpoise is investigated and assessed using an analysis of scientific research

and cases. Additionally, the implications of these findings for species conservation and management are

discussed. Conservative Policies such as the Yangtze River Fisheries Administration and the Yangtze River

Protection Law of the People's Republic of China were evaluated. This study highlights the urgent need for a

combined effort of government, institutions and all the individuals to address water pollution and protect

habitat in the Yangtze River Basin.

1 INTRODUCTION

The finless porpoise, scientifically known as

Neophocaena phocaenoides, are a type of the

cetacean that mainly inhabit in Asian Oceans and

some freshwater basins. Their population has

declined dramatically in recent years as a result of

habitat destruction, bycatch from fishing, and the

possible consequences of excessive vessel traffic.

However, water pollution has a wider impact on the

porpoise habitat, as well as their health condition,

resulting in the need in more urgent attention.

For instance, the Japanese finless porpoise that

inhabits in inland water bodies is suffering from

massive chemical pollution. High levels of toxic

chemicals were known to accumulate in finless

porpoises of the Inland Sea.e.g. their blubber may

contain up to 132 ppm of total DDT, 320 ppm of total

PCB, and 10 ppm of total butyltin in their liver. These

pollutants might be the fundamental causes

underlying the decline in the porpoise population, due

to their potential harmful effects on survival and

reproduction. Moreover, even though the Japanese

government effectively controlled the runoffs of

organic matter, the amount of phosphorus and

nitrogen still remain at a high level since 1978, which

might be an underlying factor in the population

reduction of porpoises, but the effect of

eutrophication on their survival remains to be

investigated (Kasuya, Yamamoto and Iwatsuki,

2002).

The Yangtze finless porpoise is the only

freshwater cetacean in the world, is also affected by

water pollution. They have been listed as "Critically

Endangered" on the International Union for

Conservation of Nature's (IUCN) Red List since 2013

(Wang et al., 2024). As Yangtze River Delta

developed rapidly in the past 20 years, there has been

severe disruption and impact on the Yangtze finless

porpoise's living environment. While the pollution

from excessive traffic contributes to the pollution

hugely, agriculture, chemical toxins, and daily debris

also result in serious consequences on the water life,

food supply, and wetland regulations of Poyang Lake

(Yuan et al., 2024), which may indicate the cause of

the notable drops in YFPs from over 2,500 in 1991 to

Yui, C. P. S.

Threat Factors and Protection Measures of Finless Porpoises in the Yangtze River, China.

DOI: 10.5220/0013852700004914

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 2nd International Conference on Renewable Energy and Ecosystem (ICREE 2024), pages 163-167

ISBN: 978-989-758-776-4

163

1,040 in 2012 (Nabi et al., 2018). However, the

Yangtze River contains the most stable and abundant

population of the Yangtze finless porpoise.

Additionally, large quantities of research have been

conducted and estimated on these porpoises.

Therefore, this paper takes the Yangtze finless

porpoise as the focus, analyzes and evaluates the

existing conservative approaches and the policies that

the Chinese government proposed.

2 INFLUENCE FACTORS ON

YANGTZE FINLESS PORPOISE

2.1 Hydraulic Engineering

The basin of Yangtze River, together with lakes and

subchannels that connect it, is home to the majority

of the Yangtze finless porpoises (Chen et al., 2020).

Initially, the Yangtze River and its substream were

tightly connected, and the Yangtze finless porpoises

were able to migrate along the mainstream of the

middle and down waterways. However, the Yangtze

River was severely disunited shortly after the dam

and dike building in the middle of the 20th century,

which greatly divided the Yangtze finless porpoise

population. Currently, only the Dongting and Poyang

Lake remain connecting with the major steam of

Yangtze River (Li et al., 2022), and thus, the

porpoise’s habitat was largely reduced. It means that

the shortage of available resources and habitat had

been a serious factor that threatened their continued

existence.

What’s more, large quantities of disruptive

activities still operate near the benthic zone of

Yangtze River, where approximately 80% of the

Yangtze finless porpoises are concentrated (Chen et

al., 2020). Even though intensive sand degradation in

the Yangtze River had been banned since 1998, it was

restarted in 2001 in Poyang Lake, a reserve with the

highest Yangtze finless porpoise density (Nabi et al.,

2018). Furthermore, the construction of the Three

Gorges Reservoir also contributed hugely to the

degradation of the Yangtze finless porpoise’ habitats.

Due to the increase in the sediment concentration, the

river exhibited a high level of turbidity. In this case,

Yangtze finless porpoise sonar system is seriously

disrupted, which makes it difficult for them to

navigate, detect prey and flee from danger, and

migrate between the Yangtze River and Poyang Lake

(Nabi et al., 2018).

2.2 Chemical Pollution

In recent years, areas near the Yangtze River are

experiencing significant developments. The Yangtze

River is a busy "golden waterway," full of docks,

man-made barriers along the riverbanks, and recently

extended agricultural land—even in areas reserved

for porpoises (Chen et al., 2020). Hence, Yangtze

water is severely contaminated by both organic and

inorganic substances from recent, extensive

industrial, agricultural, and residential developments

(such as metals, fertilizers, and Pops) (Yang et al.,

2012). These human activities cause the shrinking of

porpoise’s habitat, degrading available areas that the

porpoise could inhabit, which explicitly challenges

efforts to keep the Yangtze finless porpoise in

conservation.

Since 1992, aquatic organisms in the reservation

zone of the Yangtze River have been constantly

exposed to high levels of pesticides and agricultural

runoff from nearby farmland. Six Yangtze finless

porpoises died at Dongting Lake between April and

June 2004 as a result of improper use of chemical

pesticides (Wang, 2009). This is because the

pesticides have adversely effetcs on the liver’s

function and other physiological processes in

Yangtze finless porpoise (Nabi et al., 2020).

The Yangtze River Delta region received

6,642,000 tons of agricultural fertilizer, 197,010 tons

of pesticides, 297,840 tons of plastic film, and

8.856% and 22.672% of the nation's total agricultural

COD and agricultural ammonia nitrogen in

wastewater discharges, respectively, according to

data from the 2020 China Environmental Statistics

Yearbook (Yuan, Xu and Kong, 2023). As a result,

these runoffs likely leak in the waterways since the

cultivated lands are located close to the Yangtze

River main stem, meaning that the porpoise’s habitat

is significantly altered due to the excessive amount of

nutrients.

Despite the impacts that agricultural land use

bringing about, in the framework of fast urbanization

and industrialization, the growth of construction land

and dams are also the greatest threats to habitat

patches (Yuan, Xu and Kong, 2023). In the Three

Gorges reservoirs, the concentration of heavy metals

such as coopers, leads, and cadmium frequently rises

by more than 25% with increasing water depth (Yang

et al., 2012). On the top of that, the Yangtze River

also exacerbated water pollution by trapping

sediments from hydropower impoundment reservoirs

that constructed in the upper region (Yang et al.,

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2012). Toxic chemicals can directly contaminate the

waterbody and result in biochemical harm to the

Yangtze finless porpoise. The sedimentation could

also lead to the decrease of albedo, causing the river’s

temperature to rise, and eventually contribute to the

formation of dead zones, which might then become a

major threat to the finless porpoise’s survival.

Additionally, the overall increase in the amount of

shipping also contribute to the worsening of the

Yangtze river’s water quality. As a rapid developing

region, areas near the Yangtze River in developing in

a boosting pace. In consequence, the demand of river

transportation had grown significantly. In 2000,

400millions tons of cargo were transported on the

Yangtze River, and recent research suggested that the

number had increased up to 5 times in 2006 (Nabi et

al., 2018). As a result, the possibility of oil spilling

had mainly increased, which is a threat for the

porpoise habitat, porpoise’s motor agility and their

insulative ability.

2.3 Population Expansion

The swings that occur in carbon emissions within the

ecological urban agglomeration surrounding Poyang

Lake are significantly impacted by population growth

(Yuan et al., 2023). This is significant since,

according to research, the Poyang Lake and the

Yangtze River that it borders have the largest density

of finless porpoises (Wang, 2009). Increasing carbon

emissions may cause the water's concentration of

dissolved oxygen to drop, which may worsen the

conditions that support Yangtze finless porpoises.

For organisms like Yangtze finless porpoise,

water acidification can negatively impact their

reproductive rhythms, slow down their growth, and

decrease their resistance to infectious diseases (Nabi

et al., 2020). In spite of the lake's ability to replenish

its own dissolved oxygen, the free carbon dioxide

combines with the water to create carbonic acid,

which then decomposes into bicarbonate and a

hydrogen ion. Consequently, the PH value of the

waterbody drops and the acidification harms aquatics

organisms, which are sensitive to acidity, disrupting

the food chain. To be more specific, the calcifies that

the Yangtze finless porpoises fed on rely on were

unable to form their shells due to the lack of carbonate

ions, so the numbers of the calcifies drop, leading to

a decrease in the accessibility of food resources.

3 POLICIES

As a major threat to the Yangtze Finless Porpoise,

excessive vessel traffic has always been a problem

that has not been fully mitigated yet. Despite

physically harming the porpoise, cargo ships and

other vessels (including fishing boats, passenger

ships, etc.) could also release water pollutants into the

Yangtze River; hence, oil spills might occur, which

contaminate the water and directly poison the aquatic

animal’s respiration system and ability to perform

insulation. In addition, runoff from nearby cultivated

lands or agriculture sites is also a major source that

contributes to the worsening of the water quality in

the Yangtze River. In order to address this problem,

the Chinese government established laws and

constraints that restrict the shipping industry in the

Yangtze River region. In 2014, enforcement of

fishery laws such as the Yangtze River Fisheries

Administration was established, supervising the

fishing activities in the Yangtze River, which helps

lower the number of vessels traveling through the

Yangtze River every day. Furthermore, the Yangtze

River Protection Law of the People's Republic of

China was established by the Chinese central

government, which also imposed limitations on the

use of fertilizer and pesticides in agricultural areas

close to the Yangtze River. These conservation

strategies are effective for the overall protection of

the porpoise species. By limiting the usage of man-

made pesticides and fertilizer, banning the majority

of fisheries, and setting up stricter enforcement, fewer

harmful chemicals are polluted into the river, which

ensures the safety of the porpoise. However, there are

still some limitations hidden behind these policies.

First of all, setting up restrictions is only a short-

term solution. As long as a large number of

transportation needs still exist in the Yangtze River,

water pollution remains a significant problem in the

protection of the porpoise population. As a rapidly

developing region, the Yangtze River is the central

channel that vessels rely on, meaning it is hard for the

porpoise to really stay out of zones that have the

possibility of being contaminated. As a result, the

government might need to consider transforming the

main transportation method from shipping to land

transportation, which is helpful in reducing the

number of pollutants released by ships traveling in the

Yangtze River. Still, transporting on land might be

more expensive compared to the shipping fee,

meaning that the government needs to consider the

financial effects that this policy brings about. More

Threat Factors and Protection Measures of Finless Porpoises in the Yangtze River, China

165

importantly, the government needs to estimate and

compare the environmental consequences of land

travel with shipping, such as the amount of air

pollutants released during transportation and the level

of energy consumption between land vessels and

ships.

Secondly, even though the policies restrict the

public from dumping trash or releasing toxic

chemicals into the river, man-made trash and daily

waste (including plastic bags, glass water bottles, and

food waste) are still the majority of the pollutants that

lead to the decline in water quality in the Yangtze

River. Submerged contaminated soil and growing

human activity continue to be major contributors to

toxic pollution, which drastically lowers the quality

of the water. Under this circumstance, not just the

habitat of the porpoise is contaminated and polluted;

the porpoise directly suffers from the trash, increasing

the risk of the porpoise being tangled in trash like

plastic bags. In conclusion, the government might

need to set up reinforcements that aid with the laws,

such as setting up digital cameras to monitor regions

where trash dumping occurs the most, and the people

who violate the restrictions should be charged a fine.

Additionally, the government can provide funding to

local organizations that support the preservation of

Yangtze finless porpoises. For instance, the

institutions can organize weekly events that promote

the urgency of stabilizing the porpoise’s population

while raising public awareness of this problem.

Lastly, the Yangtze River Protection Law of the

People's Republic of China suggested that local

people's governments at or above the county level in

the Yangtze River basin should instruct a well-

documented overview of future development projects

with precise arrangement and procedures. This

regulation makes it very evident how the government

will regulate construction applications; it prohibits

the development of chemical parks and projects

within one kilometer of the bank of the Yangtze River

and its subchannels With the establishment of this

policy, there would be less industrial waste being

released into the Yangtze River, meaning that it

would be less likely for the porpoise’s habitat to be

damaged by chemicals, which enables the porpoise to

inhabit a relatively secure environment.

A recent research paper suggested that the

growing numbers of YFPs in the Yangtze region is

most likely the result of individual and governmental

efforts working together (Huang et al., 2020).

4 DISCUSSION

Despite efforts, the issue of habitat fragmentation

persists, leading to an increase in trapped and injured

finless porpoises alongside the growth of their natural

population. Consequently, enhancing protection and

rescue capabilities has become imperative. On March

9, 2024, the Zhenjiang section of the Yangtze River

inaugurated a "porpoise hospital" to provide timely

assistance to stranded and injured porpoises. To

bolster emergency relief efforts, the government

plans to leverage an intelligent monitoring system

within the protected area and the Yangtze River

Porpoise Rescue Base, establishing a comprehensive

mechanism for monitoring, rescue, and protection.

This initiative integrates manual patrols, AI-powered

cameras, and 5G inspection drones to create a robust

three-dimensional network for porpoise rescue. Such

measures ensure swift detection of distressed

porpoises, enabling prompt activation of emergency

response protocols.

The government's regulations were effective in

protecting the Yangtze finless porpoise overall, as

demonstrated by the data and research results listed

above. Nevertheless, issues and gaps still need to be

resolved to guarantee the species' long-term survival.

It is crucial for the government and the public to

address non-environmental-friendly problems caused

by shipping, water-related projects, and various

human activities that have long-lasting effects on the

habitat of the Yangtze River porpoise, compounded

by extreme weather and other natural factors. On top

of that, questions remain about the genetic diversity

and long-term viability of the Yangtze finless

porpoise populations. It is important to monitor and

manage genetic diversity within the population and to

ensure the sustainability of different methods that aid

in lessening the negative effects of fragmentation in

the Yangtze finless porpoise population.

5 CONCLUSION

The Yangtze finless porpoise, a symbol of the

Yangtze River Basin's ecological health, faces a

severe threat to its survival. Their critically

endangered situation was caused by the enhancement

of water pollution in the shorelines of the Yangtze

River. Based on all the pre-existing studies and data

analysis, this paper briefly summarizes the current

research status of the Yangtze finless porpoise. By

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166

focusing on the causes of the decline in the porpoise

population, this paper discusses multiple major

sources that lead to water pollution in the Yangtze

River: man-made pesticides, agricultural runoffs,

industrial wastes, construction of Hydropower

impoundment reservoirs, and decrease in dissolved

oxygen level caused by excessive carbon dioxide

emission. The reproductive health, survival, and

behavior of the endangered Yangtze finless porpoise

species are severely impacted by these risks.

Consequently, comprehensive conservative

measures have been applied to address current issues.

The Yangtze finless porpoise and its habitat are

protected by laws and regulations that are effective,

such as the People's Republic of China's Yangtze

River Protection Law and the Yangtze River Fisheries

Administration. Stricter enforcement of vessel traffic,

industrial runoff, pollution from agriculture, and the

development of chemical parks are some of these

restrictions. In this paper, the controversial parts of

these policies were discussed, highlighting an urgent

need of well-refined and more advanced conservative

strategies.

However, the effectiveness regarding to the

preservation of the finless porpoise of Yangtze

requires a combined effort from all relative parties,

including government, private institutions, as well as

the individuals. More significantly, public awareness

needs to be increased in order to observe the

population of Yangtze finless porpoises over the long

term. This could ensure the Yangtze finless porpoise's

survival for upcoming generations, making it a

symbol of a more healthy and sustainable ecology

along the Yangtze River.

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