The Possible Effects Of The Rapid Decrease Of Mangrove Forests On Food Chains.pdf

Mangroves are vital ecosystems found in coastal areas around the world, providing a range of ecological services and playing a pivotal role in the sustenance of various food chains.. The

HOCHIMINH UNIVERSITY OF TECHNOLOGY HUTECH INSTITUE OF INTERNATIONAL EDUCATION

ASSIGNMENT REPORT

MPU3243 ENVIRONMENTAL STUDIES

SEPTEMBER 2023 SEMESTER HUTECH, VIETNAM

INSTRUCTOR’S CODE: ALH0200282

Table of contents

I Introduct ion 3

II The Roles of Mangroves in Food Chains 6 III The Possible Effects of the Rapid Decrease of Mangrove Forests on Food Chains 11

IV Conclusion 15 References 16

I Introduction

Figure 1.1 Mangroves forest in Loxahatchee, Florida

Source:

https://www.sarasotamagazine.com/travel-and-outdoors/2022/11/mangr

oves Mangroves (or salt-tolerant plants) are plants with special abilities to survive in brackish water, where salinity is high, low amount of oxygen, scarce fresh water Each mangrove tree has an ultrafiltration system to protect plants from the ingress of sea salt, along with a dedicated root that helps plants breathe in mud or at high tide To avoid water in the evaporated trunk, some plants also have the ability to limit the opening

of breathing holes in the leaves, or change the direction of the leaf's tilt

to avoid intense sunlight at noon

Mangroves are a group of trees and shrubs that live in the coastal intertidal zone They are often referred to as the "nurseries of the sea" due to their critical role in supporting marine life and coastal food chains.There some types of mangroves that belong primarily to the families such as Rhizophoraceae, Acanthaceae, Lythraceae, Combretaceae, and Arecaceae (The Editors of Encyclopedia Britannica, 2023)

These coastal ecosystems, found in tropical and subtropical regions, are characterized by the presence of salt-tolerant trees and shrubs that thrive

in the challenging interface between land and sea Mangroves are unique

in their ability to adapt to the harsh conditions of high salinity, periodic inundation, and anaerobic soils Their specialized adaptations enable them to contribute significantly to coastal food webs Mangroves are vital ecosystems found in coastal areas around the world, providing a range of ecological services and playing a pivotal role in the sustenance

of various food chains (Hermansen, 2011)

Mangrove trees come in around 80 distinct varieties All of these trees thrive on low-oxygen soils with slow-moving streams that enable fine particles to build Mangrove forests can only thrive near the equator in tropical and subtropical latitudes because they cannot resist cold temperatures (NOAA, 2023)

To maintain the nibs, saline tolerant plants produce seeds called germplants The sprouts are highly adaptable and regenerated The sprouts grow right on the mangrove tree, only falling when it has grown and growing to a certain extent Some pillars are likely to float, so when they fall, they will drift away from the water before finding the right place to grow A number of other seedlings do not float, when falling will plug into the mud below The sprouts are capable of producing their

own nutrients through photosynthesis and can last up to weeks, monthly

or even a year until the right environment is found

Mangroves only grow in tropical, subtropical and subtropical regions near the equator because they cannot tolerate cold temperatures

Mangroves cover about 137,000 km2 of the earth's surface, an area larger than Bangladesh Can be found in 123 countries around the world, however, the majority (75%) of mangrove forests in the world are concentrated in 15 countries Indonesia alone occupies ¼ the world's mangrove area Australia, Braxin and Mexico are also high-density mangrove countries (Vì Biển Xanh, n.d.)

However, according to a report in 2014 by the World Wild Fund (WWF), the alarming statistic that more than 35% of the world's mangrove trees have disappeared, with rates exceeding 50% in countries like India, the Philippines, and Vietnam, raises concerns about the consequences of this habitat loss In the Americas, mangroves are being cleared at a rate faster than tropical rainforests This essay will explore the roles of mangroves in food chains and the potential effects of their rapid decline on the components within these intricate ecosystems

II The Roles of Mangroves in Food Chains

Figure 2.1 The ecosystem in mangrove forests

Source: https://vibienxanh.vn/1.2.3-rung-ngap-man.html Many mangrove forests are distinguished by their dense tangle of support roots that gives the trees the appearance of standing on stilts above the water Because of this tangle of roots, the trees can withstand the regular rise and fall of tides, which means that most mangroves are inundated at least twice a day The roots also cause sediments to settle out of the water and pile up on the muddy bottom by slowing the passage of tidal waves (NOAA, 2023)

Mangrove trees help to maintain the shoreline and reduce erosion caused

by storm surges, currents, waves, and tides Mangrove forests are

especially appealing to fish and other species looking for food and protection from predators due to their extensive root structure

Mangroves provide habitat and food for many species Mangrove forests are home to many wildlife species such as crocodiles, birds, tigers, deer, monkeys and bees Many migratory birds depend on mangroves such as cranes, pelicans, spoon spoons Beneath the complex network of mangrove roots is also a unique ecosystem, a quiet environment, safety for juveniles of living organisms in early life Shrimp and lobster mud use mud bottoms as a home Mangrove crabs eat mangrove leaves Falling leaves also add nutrients to the mud, becoming a food source for many other benthic organisms (Vì Biển Xanh, n.d.)

Mangrove ecosystems are veritable powerhouses when it comes to their roles in coastal food chains They are the cornerstones upon which the intricate web of life in coastal areas relies, providing primary production, detritus production, acting as critical nursery grounds, facilitating trophic transfer, and hosting various coastal predators Moreover, mangroves are not isolated systems; they maintain a dynamic connection with the open oceans, fostering the exchange of nutrients, organisms, and energy Let's delve deeper into each of these aspects

a) Primary Producers:

Mangrove trees, alongside associated algae and seagrasses, play the pivotal role of primary producers in coastal food chains Through the process of photosynthesis, they harness the energy of sunlight to convert carbon dioxide and water into organic matter This organic matter forms the foundation of the coastal food web, serving as the energy source for all the organisms within it Mangroves' unique adaptations, such as their

ability to thrive in high salinity conditions and their specialized root systems, allow them to flourish in challenging coastal environments

b) Detritus Production:

One of the most remarkable features of mangroves is their continuous production of detritus They shed leaves and branches, providing a substantial source of organic matter in the form of leaf litter and woody debris This detritus serves as a rich nutrient base for detritivores, which are organisms that feed on decomposing organic matter Crabs, mollusks, polychaete worms, and other small invertebrates play a crucial role in breaking down this organic material They effectively recycle nutrients and return them to the ecosystem, contributing to the nutrient cycling and the overall health of the coastal environment

c) Nursery Grounds:

Mangrove ecosystems are renowned as essential nursery grounds for a wide variety of marine species, with a particular emphasis on fish and invertebrates The complexity of the mangrove root systems and the shelter they provide create safe havens for the early life stages of these species Juvenile fish, crabs, shrimp, and other invertebrates find protection and access to an abundance of food resources within these habitats Many commercially valuable and ecologically important fish species, including snappers and groupers, rely on mangroves during their early life stages to provide optimal conditions for growth and development Consequently, mangroves are crucial to ensuring the recruitment of populations and the sustainability of these species

d) Trophic Transfer:

Trophic transfer is the process by which energy and nutrients are transferred from lower trophic levels to higher trophic levels in the food chain Mangroves play a vital role in this process Detritivores and herbivores that feed on the organic matter produced by mangroves become prey for a range of predators, including birds, crustaceans, and larger fish This trophic transfer supports the growth and maintenance of populations throughout the ecosystem, creating a dynamic and interconnected web of life It is this flow of energy through various trophic levels that sustains the biodiversity and ecological balance in the coastal environment

e) Coastal Predators:

Mangrove ecosystems provide habitat for various coastal predators that are integral to the food web Some of the most iconic predators found in these habitats include reptiles like crocodiles and snakes These reptiles are top-level predators within the coastal food chain and prey on a variety of species, such as fish and birds Their presence and role as apex predators contribute to the regulation of prey populations and help maintain the overall balance of the ecosystem

f) Export of Biomass:

The impact of mangrove ecosystems goes beyond their boundaries The biomass produced in mangroves, including leaves, detritus, and invertebrates, often gets exported to adjacent coastal habitats, such as seagrass beds and coral reefs This exported biomass serves as an important source of nutrition for various species in these neighboring environments The presence of this additional energy source enriches the biodiversity and productivity of these habitats, highlighting the interconnectedness of coastal ecosystems

g) Connection to Open Oceans:

Mangroves are not isolated ecosystems but are intricately connected to the open oceans Tidal and oceanic currents enable the exchange of nutrients, plankton, and fish larvae between mangroves and the open sea This connection is vital for maintaining the health and diversity of coastal ecosystems Fish larvae that originate in mangrove areas can be transported by ocean currents to other regions, thereby influencing the composition of species in different parts of the coastal environment This connectivity contributes to the resilience and adaptability of these ecosystems in the face of environmental changes

In conclusion, mangroves are indeed the lifeblood of coastal food chains They are primary producers, detritus producers, critical nursery grounds, facilitators of trophic transfer, and home to coastal predators Their connection to the open oceans ensures a dynamic exchange of energy, nutrients, and organisms that supports the overall balance and health of coastal ecosystems The loss or degradation of mangrove habitats can have profound consequences for the intricate web of life in these regions, highlighting the need for their conservation and protection

III The Possible Effects of the Rapid Decrease of Mangrove Forests

on Food Chains

Figure 3.1 Mangrove trees lost by erosion in the Sundarbans Source:

https://india.mongabay.com/2020/05/erosion-an-important-cause-of-mangrove-loss-in-the-sundarbans/

In the past, the importance of mangroves to the environment and people was little known As a result, many mangrove forests around the world were devastated

However, today, even though the importance of mangroves is better understood, mangrove forests around the world are still disappearing at breakneck speeds In just over a decade, at least 35% of the world's mangroves were destroyed This speed is even faster than the disappearance of tropical forests!

In some places, the area of mangrove forests has increased thanks to reforestation efforts However, these efforts are still very small, not enough to compensate for the mangrove forests that have been devastated

The greatest threat to mangrove forests is human activity Many people destroy mangroves by cutting down trees for firewood and wood, or taking land to raise shrimp, planting trees or other construction and development purposes Exploiting forest fisheries such as digging for soil ginseng, crab crab or scissors and pushing nets near seedlings will hurt or turn on their roots

Mangroves can also be damaged or destroyed by chemicals and pollutants such as sewage from factories, pesticides and fertilizers These substances follow water flowing from the field, or wastewater from aquaculture areas and cities, Follow the rivers and canals and then gather in the mangrove forest

Climate change causes sea level rise to also affect mangroves Some areas of mangrove trees will be flooded with too much (or too salty) that make them uninhabitable

If mangrove trees cannot move to higher ground, due to dikes or other obstructions, the tree will soon be flooded (Vì Biển Xanh, n.d.)

The rapid decrease of mangrove forests, often due to human activities such as deforestation, land conversion, and pollution, has significant and

far-reaching consequences for food chains in coastal ecosystems These effects extend from the primary producers to the top predators and can disrupt the balance and functionality of the entire food web Below are the possible effects of the rapid decrease of mangrove forests on food chains:

a) Primary Production Decline:

The loss of mangroves as primary producers leads to reduced organic matter production through photosynthesis This decline in primary production has cascading effects throughout the food chain, impacting all organisms that rely on this energy source

b) Detritus Reduction:

The disappearance of mangrove forests results in a decrease in detritus production Without the constant supply of mangrove leaf litter and woody debris, detritivores have less food available This can lead to declines in populations of crabs, mollusks, and other small invertebrates that play a vital role in nutrient recycling

c) Nursery Grounds Disruption:

The loss of mangrove habitats removes essential nursery grounds for numerous fish and invertebrate species This affects the recruitment and survival of juvenile individuals, potentially leading to reduced populations of commercially important fish species

d) Trophic Disruption:

Mangroves act as key links in the trophic transfer of energy and nutrients With their decline, the transfer of energy to higher trophic levels becomes compromised Predators may face reduced prey availability, leading to population declines or shifts in their diets