Tag Archives: ecosystem

Human-Beings and Ecosystem Interaction: The Complex Adaptive System

Without ecosystem services provided by the environment, human-beings cannot survive nor exist. Human-environment interaction is common to us. It is the usual scene every time we, humans, wake up in the morning and continue the routine of living.

For a moment, can you describe the details if you will be asked, what are the interactions between an individual and his environment? By posing for a while and observing what is really happening, I have found that the relations between human-beings and environment are complex.

In this article, we will see the reality of complex relations between ecosystem and human-beings within one of the remote communities in the island of Palawan that we have visited.

Human-environment interaction are complex adaptive systems. It is complex because ecosystem and social system have many parts that are interconnected and interdependent with each other. Adaptive since it has feedback structures that promote survival in a continuously changing environment.

Humans are highly dependent on the environment. Ecosystem services such as food, water, clothing, shelter, timber and many other resources are essential for human-beings survival. By using these resources, people affect the environment in a lot of ways. Humans modify the existing ecosystem for their purposes and benefits as well as develop new strategies that seem to be more effective in serving their needs.

The type of society strongly affects the attitude and behavior of people towards nature, and therefore brings impacts on ecosystem. Some of the significant characteristics include population size, social organization, knowledge, culture, belief and many more. Values, knowledge and cultures strongly influence peoples’ “view and principles of life” and subsequently define the way people act. The choice of possible actions is then limited by the available resources and technologies.

The Pala’wans – Environment Interaction

The Pala’wan tribe who have settled in the southern part of Palawan island have simple way of living. They are highly dependent on the availability of natural resources within their areas. The practice of traditional agriculture like slash-and-burn farming is one of their ways to produce staple food such as rice, cassava and other endemic crops. They also know unique strategies in fishing and hunting of several wild animals. For thousands of years, their lives are linked with the environment. Their rich traditional knowledge reflects and embodies a cultural and spiritual relationship with the land, river and wildlife.

The selected photo below shows how Pala’wans are connected with the environment. It was taken in May 2013 when my dad and I, together with my group mates in research study in college, visited Sitio Bayabas, Barangay Bunog, Rizal, Palawan. The site is located within Mt. Mantalingahan, one of the protected areas in the province of Palawan.

The site is considered as one of the sacred places of the Pala’wans. Thus, only limited people are allowed to visit the area. And we are fortunate to have that opportunity! Once more, I’m so blessed to witness these great creations of the Lord.

falls
©2013 Shellemai Roa

The Aesthetic Value of the Site

The aesthetic view of the place is like a paradise. You are free to hear the natural sound of murmuring water from a waterfall that continuously flows and rushes within the blocks of big rocks; it has crystal clear running waters with bluish and greenish color in some parts that seems like a confined pool with fresh and cold water; the fresh gentle breeze that touches your skin with whispering sounds around your ear; the sound of chirping birds and other insects around; as well as the views of mountains, really gives relaxation, peace of mind, thanksgiving and enjoyment to human-being like me. These natural services provided by the ecosystem cannot be compared to any man-made structure.

The Interrelationship of Each System

By looking deeper into the relationship of every factor present in the area, other interactions were recorded. These include the different biogeochemical cycles that sustain the homeostasis of the environment. For instance, sun is the critical source of energy for every living organism, both biotic and abiotic factors. Without it, no one can exist, including human-beings.

The communities benefit from the oxygen produced by vegetation in the area (including us who visited them as well as in a global aspect for it cannot be confined in an area). On the other hand, plants use the carbon dioxide released by humans and animals as well as other organisms that release the same, for the process of photosynthesis to take place.

Direct Benefits Obtained in the site by the Community

Aside from the indirect value of the resources in the area, the water source supplies the needs of the Pala’wans for cooking, cleaning, bathing or swimming and other purposes. Moreover, hunting of wild animals, fishes, shrimps and other crustaceans is one of the major sources of food of the Pala’wan. The provision of these resources support the lives of the tribe. They use arrows in hunting fishes or shrimps. What is so good about them in gathering of resources is they observe proper utilization.

During the trek, Rowel, a Pala’wan, tried to hunt some shrimps for lunch. However, during those times, shrimps are not fully grown yet; thus, he did not collect any.

The Pala’wan also believe that they will suffer in the near future if the available resources are exploited. Furthermore, they believe that every place is guarded by gods and goddesses who take care of the area and they will be punished once they over-use the resources.

fishing using spear
©2013 Shellemai Roa

Intangible institutions like these lead to environmental conservation. Beliefs, cultures and traditional knowledge drive their attitudes and values toward their interaction with natural ecosystem.

Human-environment interaction is observed in every action that we do. Human activities increase or mitigate pressure on the environment. The driving forces which initiate human activities are mainly socio-economic and socio-cultural forces.

Thus, it is very important that we examine the consequences of our actions before we start to act. Consider the impacts that it will bring to ecosystem for we have a very complex system – a system that is interrelated to one another in which an action in one factor is connected to the rest of ecosystem.

©2015 April 18 Shellemai A. Roa

Facts About the Goliath Grouper

Have you ever encountered a Goliath grouper while snorkeling or SCUBA diving? How does it look like? How do these magnificent fishes reproduce? Are they really big as their name “Goliath” suggest? Are they aggressive? This article answers these questions. Read on and learn about the Goliath grouper.

During one of my SCUBA diving spree in Apulit Island, a popular tourist destination north of Palawan Island in the municipality of Taytay, I met the Goliath grouper. I learned about it from a buddy diver who excitedly told me to go diving with him upon a prompt from a classmate in high school who happened to be the mayor of that town. That day actually was our high school reunion day in that isolated, white-beach a few nautical miles from the town proper.

Probably, I am lucky that the Goliath grouper (Epinephelus quinquefasciatus) I encountered several minutes when I plunged into the water was still a juvenile.  But it’s already unusually bigger than the common reef fish I see.

Behavior of Goliath Grouper

I brought with me my automatic Nikon camera encased in a plastic casing to make it water-resistant as taking pictures is a pleasure for me each time I travel. I grabbed the camera hanging by a tough nylon string around my wrist, and took a video of the Goliath grouper following my buddy. Midway the video, a grouper swam by my side then approached me with another one. You can see it below:

How big can Goliath groupers get? The ones above are just juveniles or young ones that could grow to as long as six feet. And they could weigh more than 300 kilograms! The one I saw was about two feet long.

Despite the huge size of the Goliath grouper, they seem to be docile fishes although there are reports that they do attack humans. I saw one video that says so but analyzing the situation, I thought the reason was mainly to feed, not really to attack. Here’s the video of that alleged Goliath grouper attack:

Do you agree with my observation? The moving fins attracted the grouper thinking probably that it was its prey and snapped on it. The prey was the speared fish, not the SCUBA diver who is holding the spear with the fish. It is also possible that the Goliath grouper thought the man as its competitor thus snapped on the competitor’s “tail” and swam away with its booty.

What is the life cycle of the Goliath grouper?

Goliath groupers rely on the protection of the mangrove forests because after their eggs hatch, they settle in the mangrove litter and roots. Thus, the mangroves are crucial in their survival because mangroves serve as microhabitats that prevent predators from eating the very young juveniles. When the juveniles are older, they migrate to the coral reefs and stay there for more than 40 years. When they are old enough to reproduce, the Goliath groupers migrate and spawn into the deeper water column, fertilize the eggs which then are carried by the current, hatch then drift in the currents for 30 to 80 days (Fig. 1).

Goliath grouper
Fig. 1. Life cycle of the Goliath grouper (Illustration by Jane Hawkey, IAN Image Library (ian.umces.edu/imagelibrary/)

The cycle shows that everything is connected to everything else. If something disastrous like oil spill that kills the larvae of fish like the Goliath grouper or makes the mangroves unfit for habitat to fish, then there will be lesser fish available for people to see and enjoy (if they are SCUBA diving or snorkeling tourists) and consume. I wouldn’t have seen the Goliath grouper at all.

The nearshore environment is a fragile one that should be protected or conserved considering the highly complex life that intertwine in mangrove ecosystems. The Goliath grouper is only one of the rich diversity of life that support man.

©2014 November 26 Patrick Regoniel

18 Species of Insects from a Ceiling Lamp

This article demonstrates how deviating from a dull routine can lead one towards discovery. Find out how a little shift in one’s behavior can produce unusual information.

One night, I noticed that the ceiling lamp over our dining table got dimmer than usual. When I looked up, I saw that the central part of the lamp had a dark shade of dirt that blocked the light from going through the glass cover. Ah, the pesky insects once again got trapped on the concave part of the round plate of glass.

I got an aluminum ladder and carefully removed the rounded nut of one of the three bolts that pinned the glass covering metal holder. When I held down the glass, the following mass of winged insects attracted by the light at night greeted me.

insects
A mass of insect remains inside the glass cover of the ceiling lamp.

Instinctively, I walked towards the door to get rid of the “dirt” and clean the glass covering. On second thought, however, I paused and contemplated if I can make out something out of this mass of apparently insignificant stuff.

I went out the other door towards the porch and laid the chaotic array of broken wings. As I did so, distinct shapes and sizes of insects came into focus as I ran my fingers through it.

The picture below shows the 18 species of winged insects that I discovered from the messy collection.

insects
Species of insects sorted out from a mass of insect parts taken from the ceiling lamp.

The pile of material consisted of wasps, moths, winged termites and ants, moth, beetles, flies, plant bugs, among others. All of the identifiable stuff are insects except no. 17 which is a shed lizard skin. This indicates that lizards fed on most of the insects attracted by the light as they get trapped inside the glass cover.

Reflections from the Discovery

As we always try to find meaning to what we observe, I posed a question in my mind on the relevance of the things I’ve found. Are the things I’ve found of any value at all?

While this discovery may not be a ground breaking one, I believe that I have supplied information found nowhere else in print or online. This information may be of special significance to an entomologist.

From what I could make out from this discovery, the collection of insects in the glass covering of the ceiling lamp represents the diversity of living organisms next to our place lying next to forested lots. These insects live and die in the often inundated “bangkal” (Nauclea orientalis) forest once marked by termite mounds. These insects compose the forest ecosystem as intermediaries of nutrient cycling. They are agents that transport nutrients all over the place. Without insects, nutrients remain in the soil and will not be made available in the chain of predator and prey interactions. And these interactions influence human life (see the mango weevil story).

How significant are these insects to me? Well, they took my attention that made me climb a ladder, took pictures, and clean the glass cover of the ceiling lamp when I should have been out somewhere. It has sparked a chain of events that changed my usual routine and made online presence through this musing. And I gained enjoyment from my writing activity.

This is an exercise of being unconventional in one’s thinking. I broke a simple routine of just cleaning the “dirt” from the ceiling lamp. Being unconventional leads to discovery.

© 2014 September 21 P. A. Regoniel

Three Simple Facts About Jellyfishes

How long does it take for the jellyfish to stay alive out of sea water? Do jellyfishes melt in the rain? What ecological role do jellyfishes play in the marine ecosystem? These are three questions answered in this article. Read on to find out.

The trip to Kitu-Kito, a tourist destination north of Puerto Princesa, on board a raft made of large PVC tubings, appeared to be uneventful until tiny blobs of jellyfishes of different sizes gained our group’s attention. While a scourge to swimmers, the jellyfishes became a subject of photographic interest for me.

Various sizes of jellyfishes bob out of the water, from 5-inch diameter ones with venomous tentacles to the cute, half-inch juveniles. Here are two of them:

jelly fishes
Two jellyfishes swim about in the food container filled with water.

How Long Can Jellyfishes Stay Out of the Water?

Taken by curiosity and instinctively, our boatman caught one of the jellyfishes and placed it on the front edge of the raft. The transparent jellyfish helplessly throbbed just like a heart on the wooden surface indicating that it is alive. Its gelatinous bell (its head) looks edible.

The taste of nata de coco flashed in my mind. I had that urge to slice and eat the chewy head.

I wonder if it tastes like nata de coco? Are jellyfishes edible? The boatman said, “Yes, it is.”

The jellyfish, in fact, is a delectable delicacy in Asia. These are dried, preserved and shipped to restaurants in Japan, China, and Thailand. But I never had the chance to taste it and will not venture to do so unless everybody is eating it.

jellyfish with tentacles
The jellyfish looks like nata de coco, a chewy, translucent, jelly like foodstuff produced by the fermentation of coconut water.

“How long can jellyfishes survive out of the water?” asked one of my friends. Being a biologist, and, not knowing exactly how long it will take for these animals to stay out of the water, I retorted, “Let’s use a timer to find out.” And so we did.

Glancing once in a while and observing the jellyfish for its tell-tale throb of life somewhere in the middle of its body, we waited until no discernible movement to indicate life is evident. After a while and looking at my watch’s timer, I blurted out to the group: “48 minutes.”

Now we learned that jellyfishes could survive that long out of sea water. If it does not return within that period to the deeper parts of the sea during the rush of sea water towards low tide levels, then it gets isolated and fried under the sun or get dehydrated. Thus, it somehow distributes nutrients along the coastline as it becomes a part of the beach ecosystem food chain.

Do Jellyfishes Melt in the Rain?

Another question sprang up. “Is it true that jellyfishes melt when out of the water and exposed to the rain?”

Honestly, I could not think of a good reason why jellyfishes will melt in the rain. They’re not ice cream or made of ice. I have heard this wrong notion on many occasions. And so I simply said, “I don’t think so,” explaining a bit about the composition of animal tissue.

As if to confirm my point, by sheer coincidence, it rained that afternoon despite the generally fair weather in the morning. The raft shook with every gust of wind that pass our way and alarmed almost everyone. I have been through this situation many times in the field and I feel confident that the wind will settle in a few moments.

The raindrops fell on the jellyfish, washing it through and through. The jellyfish, of course, did not melt. It’s still there.

3. Ecological Value of Jellyfishes

Jellyfishes form part of the marine food chain. They prey mainly on the zooplankton. In turn, they are favorite diets of sea turtles. Thus, they help stabilize the marine ecosystem.

Transparent plastics thrown into sea water sometimes get mistaken for jellyfishes. This is the reason many sea turtles die as plastics block their gut and keep them full when, in reality, they are without food in their stomachs.

© 2014 September 8 P. A. Regoniel

Unconventional Solution to Water Scarcity in the Small Islands

Water scarcity in the small islands is a paramount problem that recurs yearly. Climate change appears to make this worse as rains no longer provide enough to replenish groundwater sources. Is there a technological solution to this problem? This article explores the issue in the light of personal experience.

One of the pressing issues of today’s modern world is the depletion of natural freshwater sources. This problem is especially true in small islands where people settled and gradually depleted the water reserves as the island’s population increases due to both in-migration and natural reproduction.

Water scarcity occurs when the carrying capacity, that is when water consumption exceeds the island’s capacity to replenish its store of water. Unless people living in the islands are well aware of this possibility, exceeding the island’s capacity to regenerate its freshwater sources is the eminent, expected result of too many people living in the island.

Solution to Water Scarcity in the Small Islands

A few days ago, this issue has come into play as I was one of those requested by a local government institution tasked to ensure sustainable development in the province. Together with stakeholders from island municipalities, we discussed the environmental concerns of people living in the islands. I was part of the sociocultural sector group that deliberated threats to resource sustainability in the islands.

One of the major concerns of the island communities is the lack of water particularly on those days when rains that replenish the groundwater sources are not available. Some of the people have adapted to this condition by designing structures to catch rain water and store these for use during the dry months.

alone in the island
Beneath the small island is a rich diversity of marine life, human artifacts, among others.

This approach seems to go well, but people complaining about water scarcity means that the issue still bogs them. For those who cannot afford to build large structures to keep them sufficiently supplied with freshwater, this is a real problem; except on those cases where an enterprising member of the population undertakes an unconventional solution that trickle down to the public. I describe this simple but working solution below.

Piped Fresh Water from Abundant Water Sources

Several months back, while searching for a place where our research team can take a bath in Bulawit, one of several islands in northern Palawan, I met an ice-manufacturing businessman. He has a considerable stock of freshwater in large tanks in his house despite the difficulty that other communities in the other islands experience.

We inquired a little about this maverick in the midst of freshwater scarcity, and we discovered that he figured out a simple solution to the perennial freshwater problem many people in the community encountered.

woman fills up container
A woman fills up a container with freshwater in Bulawit or New Colaylayan.

With an air of confidence, he explained to us that a few years back, he looked for a good source of freshwater in the adjoining islands and laid down PVC pipes underwater from that place to his house funding everything by himself!

He made a good business out of it. He supplied the freshwater needs of other people in the community for a small fee. He converted a problem into an opportunity. No wonder he’s the richest man in the island.

Is the Businessman’s Solution a Sustainable One?

If the businessman continues to run his water business for some time, chances are, the source of freshwater will get depleted as more people avail of piped water he draws out from the other island assuming natural increase in island population through time. However, if better technology becomes available before the water carrying capacity of the island is exceeded, such as the discovery of a low-cost desalination system or efficient water recycling system, freshwater availability should not be a problem.

Alternatively, natural, long-term remedies such as reforestation or watershed enhancement will help slow down water runoff and help increase the groundwater storage. Without these measures in place, situations such as that in Nangalao Island, will continue to persist.

If all else fails, the only long-term solution is for the people to leave the small islands and live in large islands or continents where freshwater abound.

© 2014 September 6 P. A. Regoniel

Solution to World Hunger: Eat the r Strategists

How can world hunger be resolved? The answer: through eating the r strategists! What are r-strategists and how can these animals help relieve pressure on animal populations that traditionally serve as human food? This article explores the possibility of consuming alternative food sources. 

The increasing demand for food of 7.2 billion people in the world puts pressure on conventional food sources. Thus, there is a need to explore alternative food sources. Scientists recommend the consumption of animals called r-strategists.

What are r strategists?

The so-called r-strategists are animals that reproduce so fast that chances for their populations to get depleted is much lower compared to other animals. These animals can live in unstable environments, meaning, situations and conditions where animal populations are under threat. The adaptive evolution is to have so many of their own kind. Thus saith the r/K theory that became popular in the 1970s.

For better understanding, let me define the r and the K in the r/K theory.

The r/K Theory

The r in the theory refers or comes from the word “rate.” This word reminds us to think about the rate of reproduction by which animals of this group propagate. These animals rapidly reproduce to compensate for their small size which easily become prey to other animals in the higher echelon of the food chain. And each of the offspring get less or no parental care. They can also easily adjust to environments that fluctuate. This adaptation strategy increases their chance to survive as a species.

aphids and ants
Ants and aphids are r-strategists because they rapidly reproduce and are small. These two organisms exhibit mutualism: the aphids provide the sugary honeydew they obtain from the guava to the ants while the ants provide them protection from their predators like the ladybugs (see an interesting ant defense here: http://www.pbase.com/antjes/lady_bug)

Meanwhile, the K in the theory refers to “carrying capacity.” In contrast to the r-strategists, animals that belong to this category undertake controls to their population by remaining close to the carrying capacity of their habitat. They adopt efficiency in resource use to maintain sustenance or adequate resources for each of the individuals in the face of scarce resources.

The carrying capacity of the habitat must not be exceeded to ensure the survival of these species. Thus, the K-strategists reproduce slowly, nurture their young, have larger bodies, and smaller in number compared to the r-strategists. These animals lie belong to the higher rung of the food chain, serving as “pools of nutrients” that can live in a stable habitat for a long time.

binturong
The bearcat Arctictis binturong is a K-strategist because gestation takes about 90 days and the average number of offspring per year is only two.

While recent theories like the Life History Theory supplanted the r/K theory, the terms r– and K-strategists are still used by scientists as this theory appears to be a necessary step in the study of animal adaptation to their environment. If you try to apply this theory by looking at the way animals propagate, it just makes sense. Small animals tend to produce more of their kind while the large animals reproduce slowly.

There are , however, always exceptions to any rule. For example, the bivalve Icelandic quahog (also known as black clam, Islandic cyprine, or black quahog) can live for more than 400 years! Also, the relatively small fish called orange roughy reproduce only upon reaching 20 years of age. And these fishes are estimated to live 149 years! This is the reason these fishes were not able to easily regain their population when their populations were subjected to intense fishing pressure in New Zealand, Australia and Namibia because of their popularity as food.

r-Strategists as Food?

hen and chicks
A free-ranging mother hen provides protection to its chicks.

Generally, the animals that are found acceptable by society to eat today are essentially K-strategists. These include meat coming from cows, swine, goat, chicken, among others. The last one, however, appears to lean on the r-strategists because of their short life span. Besides, these birds are domesticated and their growth is hastened to serve increasing fast food consumption demands.

We do eat fishes that are mostly r-strategists although we tend to consume too much of the wild populations. Thus, controls towards sustaining the population of these marine organisms are instituted in most countries  with intense fishing efforts.

Other r-strategists that are considered pests because of their great numbers may be considered as general food sources. For example, places like Thailand have exotic foods or foods that are generally regarded bizarre by people from other countries. These include fried crickets, earthworms, scorpions, steamed bugs, cockroaches, ant eggs and all sorts of bugs. These are all r-strategists since they reproduce rapidly but many find unpalatable despite their respectable nutritional value.

These pests are abundant in areas where people suffer malnutrition and lack of food. Is it time that these animals become a normal part of the diet? This may be the solution to world hunger. That is, if hungry people have the guts to fill their stomachs with such wiggly, wriggly and critty creatures.

Anyone ready to eat a crunchy and creamy cockroach?

References

Reznick, D.; Bryant, M. J.; and Bashey, F. ,2002. r-and K-selection revisited: the role of population regulation in life-history evolution. Ecology, 83 (6): 1509–1520. doi:10.1890/0012-9658(2002)083[1509:RAKSRT]2.0.CO;2

Schleif, M. 2013. “Arctictis binturong” (On-line), Animal Diversity Web. Accessed September 01, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Arctictis_binturong/

© 2014 September  2 P. A. Regoniel

BioBlitz of a Disturbed Mangrove Ecosystem

Can a three-hour Bioblitz yield useful information? This article highlights the results of a quick trip to a coastal fringe. See what flora and fauna could thrive in a disturbed mangrove ecosystem.

The past two weeks had been quite busy for me as I try to keep up with two graduate and two undergraduate subjects in the university. One of those undergraduate subjects is titled marine methodology.

As an initial step in field exploration, I introduced my students to BioBlitz, a survey method where they have to record all living species within a designated area at a given period of time. The laboratory period for the class is only three hours every Friday so I designated a nearby mangrove area as the site for the activity. I intend to conduct the usual 24-hour duration BioBlitz when we go out in the field in the coming months. At best, it is only a taste of field work.

The Water as Convenient Waste Basket

We walked off at around 7:30 in the morning down to the eastern coastal fringes of the university where a clump of mangroves had grown quite well. I cautioned them to apply OFF lotion to ward off pesky mosquitoes and sandflies common in these forests. They also need to wear old shoes, sneakers or boots to keep their foot safe from shards of glass, nails or similar objects that we might step on. Incidentally, the back portion of some buildings had become dumping grounds for waste materials including bottles, old papers, and assortment of things in the office. I wonder if the administration knows about this undesirable practice.

We negotiated a slippery trail down a steep slope and were greeted by lots of floating waste carried by the waters probably from nearby places. An ordinance prohibits indiscriminate throwing of wastes but then the scene shows something is amiss in people’s attitude. The ordinance seems to work only in visible areas but not in the city’s waters.  I thought I’d spearhead a  coastal clean up and massive information campaign to prevent such build up of waste that lowers the quality of the environment.

floating waste
An assortment of floating waste materials consisting of old slippers, biscuit wrappers, shampoo sachets, instant drink pouches, old toys, sando plastic bags, empty lotion bottles, among others.

With BioBlitz in mind, we proceeded to the shallower regions of the mangrove ecosystem to inventory whatever we could find. It was high tide at 8 o’clock so we have to contend with the limited muddy strip where we could walk without fully submerging our waists. Everyone was mindful that they still have to attend their next class at 10:30 am and had to avoid getting wet all over.

Plant and Animal Species in the Narrow Stretch of Mangrove

Xylocarpus flower
Flower of Xylocarpus granatum.

I lectured on some species of mangroves and their peculiar  characteristics. Notable among these mangroves is Xylocarpus granatum, the monkey puzzle mangrove, easily identified by its pomelo-like fruit and chocolate brown petiole. The other mangrove species we found were the common stilt-rooted Rhizophora spp. , Lumnitzera littoreaAvicennia sp., and Sonneratia sp. We also noted mangrove associates like Nypa fruticans, Heritiera littorea, Excoecaria agallocha, Acrostichum aureum, and Pandanus sp. Just next to these mangroves and their associates are large trees of bangkal (Nauclea orientalis) growing at the slopes.

Below are pictures of macroorganisms found in that narrow stretch of mangrove:

marine macroorganisms
Mangrove macroorganisms (clockwise): beetle, marine cockroach and spider, cricket, mudskipper, sea slater, and sea snail.

I saw a crab but this quickly dipped underwater when I approached it. What was left was an indiscernible picture of the crustacean.

Despite the short duration of our quick survey, we had an actual glimpse of the mangrove ecosystem and its component flora and fauna. The students surely have learned to appreciate the mangrove ecosystem and came up with ideas on how they could unravel more information from what they have personally experienced; that learning and enthusiasm showed up in their field report.

© 2014 July 14 P. A. Regoniel

Palawan Greater Coucal: Three Roles in the Forest Ecosystem

What is the role of a bird such as the greater coucal, a species of cuckoo, in the forest ecosystem? How will removal of its forest habitat compromise the other components of the ecosystem? This article explains how displacement and possible extinction of a bird species can impact on their habitat as well as human society.

Barry Commoner’s first Law of Ecology in his book The Closing Circle states that everything is connected to everything else. What affects one organism affects all.

If applied at ecosystem level, this means that the ecosystem’s integrity and resilience is compromised if one or more of the component parts is lost. Whatever animal or plant you find in an ecosystem will have some special role, function or influence on the other components in that ecosystem. The ecosystem works like a clock, where removal of one apparently insignificant part may prevent it from working properly or diminish the clock’s features or function.

This ecosystem principle made me ponder about the fate of the Palawan greater coucal, a bird associated with many omens in other places, that frequent the remnant forest found at the back of our house.

I took a picture of the bird this morning and feature it below. It looks as if it has just awakened from sleep as it sluggishly clambers on a branch of a tree. It cannot sustain flight just like the other birds.

greater coucal
Palawan greater coucal Centropus sinensis.

Since the land that we now occupy is classified as commercial land, in due time, the forested lot will be gone. These birds will no longer have their special place to roost and food to feed on once the remaining patches of trees that bear fruit and sustain them are cut down to make way for housing.

Do the greater coucals and other birds matter at all? What will probably happen once they are gone?

To find out how removal of the remaining forest will impact on the bird’s population, if indeed they still exist in great numbers, I will enumerate three roles that these wild birds play in the ecosystem.

Three Roles of the Greater Coucal

The greater coucal plays an important role in the ecosystem within which they live and reproduce. They serve many purposes among which are the following specific roles:

1. Seed dispersants

The greater coucals, just like the other birds, disperse the seeds of plants from fruits that they feed on. Their feeding behavior allows the distribution of plant species across a range of habitat. As a result, the plants have a greater chance to propagate their kind.

2. Aid in nutrient cycling

As the greater coucals move or fly with effort from one place to another, the birds are able to transfer nutrients that they bring with them, i. e., in their bodies. These are nutrients derived from their food. After absorbing the necessary food elements for their metabolic needs, the birds dispose of their organic waste somewhere. Their manure serves as fertilizer to plants thus starting off once again the circulation of nutrients.

Once these birds die, dead organic matter is acted upon by the decomposers. Organic matter is broken down into humus, consisting of minerals and other compounds that are available for plant use. Thus, with the aid of birds, poor nutrient areas are enriched.

3. Pest control

The greater coucals also feed on insects and even snails. Such feeding behavior help control their prey which in large numbers become pests. Economic problems can arise due to a lack of natural predator to prevent its propagation in large numbers (see the case of the mango pulp weevil).

This list enumerates at best a limited description of the role of the greater coucal in the ecosystem. A deeper investigation into its biology and behavior may uncover something that we cannot afford to lose.

What if these birds have genes that can cure an incurable illness? We will never know if we drive them out into extinction.

References

Natarajan,V (1993). Food and feeding habits of the Southern Crow-Pheasant Centropus sinensis parroti Stresemann (Aves : Cuculidae) at Pt. Calimere, Tamil Nadu. J. Bombay Nat. Hist. Soc. 90 (1): 11–16.

Payne, RB (2005). The Cuckoos. Oxford University Press. pp. 238–242. ISBN 0-19-850213-3.

© 2014 June 3 P. A. Regoniel

Mango Pulp Weevil: A Pest Control Problem in Palawan Island

This article describes the mango pulp weevil (MPW), Sternochetus frigidus, introduced to Palawan province and discovered in 1987.  The weevil still lingers as a pest control problem that prevents local mango farmers from exporting their agricultural produce in other places. Find out how the MPW looks like and where it grows. A video is included to show how this pest behaves when disturbed and how fast it can move.

Research still has to find a long-term remedy to the problem of mango pulp weevil (Sternochetus frigidus) infestation in the province of Palawan in the Philippines where the world-renowned underground river is found.  Pest control approaches by farmers have so far been unable to eradicate the pest at source which finds the edible fleshy part of the mango as its favorite breeding place. Hence, the name mango pulp weevil or MPW.

The weevil damages a part of the mango pulp thus reduce the quality of the fruit. For more than two decades, mango growers were unable to export their agricultural produce because the mango pulp weevil will threaten the mango industry in other places.

A post-harvest pest control approach done so far to control the mango pulp weevil include irradiation as quarantine treatment (Padilla 2012). This approach appears to be more economical compared to other post-harvest pest control treatments such as the application of heat and fumigation. Local farmers also apply hit-and-miss approaches to control the weevil at source.

Morphology of the Mango Pulp Weevil

How do these pests look like? Below are pictures of the mango pulp weevil.

mango pulp weevil
Mango pulp weevil (Sternochetus frigidus) infesting mangoes in Palawan Island.

These are two of the four MPWs I have found yesterday upon slicing several fruits from our homegrown mango trees. I can feel that they have a hard texture as I turn them around for the right angles to take photos. The insect is quite small (6mm x 4mm) but switching my Panasonic Lumix LX5 to macro mode enabled me to take extreme close up shots at a distance of less than one centimeter.

Overall, MPWs have dominant brown color at the underside and an orange dorsal region mottled with dark, charcoal black bands across the pitted wings. Also, the wings have rough tiny keratinous projections that probably aid them in burrowing through the soft pulp upon maturity. The long snout has two antenna with rounded tips.

Behavior of the Mango Pulp Weevil

The two samples in the pictures shown previously were found in just one mango fruit, occupying about two centimeters of the pulp next to the seed. Initially, I thought there was only one but upon closer look, another weevil with neatly folded legs sprang to life after a minute or two.

Below is a video of how fast these pests could walk about. If given the chance, they will fly within a few minutes and enter into a state of suspended animation or diapause. Weevils do not fly great distances but usually stay close to the parent tree until the next fruiting season (Gove et al. 2007).

Consumers in Palawan can still eat at least half of the mangoes because only one side of the fruit is affected. An alternative way of consuming infested fruits is to flesh out the mango pulp and dry it (dried mangoes). The affected area is normally about 3 cm in diameter.

Preventive Measures to Control the Pest

I have not been so keen before on the presence of the mango pulp weevil in the three mango trees we have in our yard. My friend, a City Agriculturist, remarked that I should do something about the mango fruits that fall when ripe as this will infect other healthy mango trees.

Based on her remark and on the readings I made in writing this article, I recommend that the following measures should be made by consumers or mango owners.

  1. Harvest mango fruits as soon as these are mature.
  2. Remove all fallen fruits and destroy pests in infested fruit. Damaged fruits should be buried at least half a meter below the ground to prevent the weevil from completing its life cycle (Catindig and Heong 2005).
  3. Kill the pest right away when found in mango consumed.
  4. Report to authorities illegal shipments of mango from infested sources.
  5. Undertake indigenous ways to control weevil infestation such as natural fumigation or bagging using newspapers or similar material.

For researchers, studying local farmers’ practices in controlling mango pulp weevil infestation can help minimize costs associated with pest control specifically the use of synthetic pesticides. Comparing the efficacy of such practices will help identify low-cost techniques or approaches that will reduce, if not eradicate the mango pulp weevil problem.

Natural pest control measures such as breeding ants that feed on the mango weevil (Renkang and Christian 2007) may also be explored. Are there ants species in Palawan that can qualify as weevil predators? This ecosystem approach, particularly looking at the food web interactions, may be the more viable pest control option.

Is Banning Mango Export the Answer?

While banning the exportation of mango fruits from Palawan will prevent pest outbreak in other places, this caused a great loss to mango farmers in the province. Other efficient ways to control the pest must be considered or its economic impact be examined further.

Moreover, despite the infestation, it seems that only a small percentage of the mango fruits are affected. Without pesticide use, out of 300 mangoes that we have harvested at home, we found only less than 10 fruits with MPW in it. That’s only three percent.

An economic analysis may be done to look at the actual damage caused by this pest. Banning fruit exportation may not really be the answer. Rather, an effective quarantine measure should be applied.

References

Catindig, J. L. A. and K. L. Heong, 2005. Description of mango pulp weevil. Retrieved on May 27, 2014 from http://www.niaes.affrc.go.jp/techdoc/apasd/Sternochetus%20frigidus%20-B.html

Gove, T.; Joubert; J. P.; and M. S. de Beer; 2007. Literature review on mango seed weevil Sternochetus mangiferae (Fabricius) (Coleoptera: Curculionidae). SA Mango Growers’ Association Research Journal 27, 21-28.

Padilla, L. D. E., 2012. Saving the Phl Super Mango export industry from pulp weevil infestation through irradiation. Retrieved on May 27, 2014 from http://www.bar.gov.ph/digest-home/digest-archives/365-2012-1st-quarter/2055-janmar2012-phl-super-mango-export-industry

RenKang, P. and K.  Christian, 2007. The effect of the weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), on the mango seed weevil, Sternochetus mangiferae (Coleoptera: Curculionidae), in mango orchards in the Northern Territory of Australia. International Journal of Pest Management, 53(1):15-24.

© 2014 May 27 P. A. Regoniel

Four Reasons Why We Should Save Endangered Species

Why do we need to save endangered species? Of what use are wildlife nearing extinction to the human race? This article lists four reasons why we should protect endangered species.

Some people do not understand the importance of keeping a healthy population of animals or plants on the planet. This article, therefore, aims to provide a deeper understanding of the need to preserve endangered species.

Why should we save endangered species? Here are four principal reasons why everyone should do their share in conserving these valuable natural resources:

Four Reasons for Saving Endangered Species

The following are the potential benefits from plants and animals that may be facing extinction:

1. Medicinal value

The drug digitalis, derived from purple foxglove, prevented the death of millions of people. Digitalis is used to treat congestive heart failure (CHF), fluid retention, irregular heartbeat, asthma, epilepsy, tuberculosis, headache, constipation, headache, and spasm. It can also heal wounds and burns. Withering (1785) described the healing properties of the plant as early as the 18th century.

purple foxglove
Digitalis purpurea

This observation means that if one plant species gets extinct, the potential benefits, such as a source of medicine, will be forfeited. However, many plants may be nearing extinction without our knowledge. These plants could contain thousands of important compounds that can lengthen the human lifespan.

Plants are not the only source of medicine. Animals have medicinal properties, too. Here is a list of animals and their medicinal uses:

  • leeches – secretions prevent coagulation and inflammation
  • vipers – elements in their venom control blood pressure
  • scorpion – brain tumor research uses its venom
  • shark – utilized in the study of certain forms of cancer and muscle degeneration
  • bees – honeybee products prevent microbes from thriving
  • lizards – secrete a toxin that may benefit diabetes sufferers
  • frog – produces compounds that prevent infection

2. Agricultural value

Wild species of plants can be a source of vital genes to improve crops that are grown today. Among those genes that scientists splice from the DNAs of plants are pest or disease resistance, salt tolerance, and drought resistance. These properties can help counter the effects of global climate change.

While there are concerns about the products of genetic engineering such as genetically modified organisms (GMOs), these products helped attain food security. People have had a reliable access to a sufficient quantity of affordable and nutritious food. For example, genetic material from a wild corn species stopped a leaf fungus that previously wiped out 15% of US corn crop. Thus, more crop production ensued.

Animals such as gecko and spiders are also important natural pest control agents. Geckos feed on at least five different kinds of pests while spiders are known to prey on cockroaches.

3. Ecological value

Have you heard the popular quote “No man is an island?” No man stands alone.

Animal or plant extinction can drastically change an ecosystem.

Just like humans, an individual plant or animal could not live by itself. It has to interact with the other organisms as well as its environment to survive. Removing one animal or plant species from the ecosystem will compromise the life of other organisms that interact with it.

According to the U.S. Fish and Wildlife Service, one lost plant species can lead to the loss of 30 other insects, plant, and other animal species found in the higher levels of the food chain. These individual species of plant or animal are sometimes called the keystone species. If that species is removed, the whole ecosystem will be changed drastically.

Examples to illustrate this importance of endangered species and how they link with other organisms are the following:

  • northern spotted owl – health indicator of the ancient forest of the Pacific Northwest
  • gray wolf – controls the population of the elk
  • killer whale – affects the diet of bald eagles (see illustration below)
killer whale and bald eagles
Chain of events that show how the killer whale can affect the diet of bald eagles.

Killer whales affect the diet of bald eagles.

The illustration shows the food chain dynamics in Alaska. If killer whales deplete the population of otters, the population of sea urchins will increase. Overfeeding of large algae by sea urchins will leave no place to hide or breeding places for fish that in turn will migrate to other areas. Once the fishes migrate, the bald eagle population switch their diet to marine birds. In this case, it appears that the keystone species are the sea otters.

 4. Bequest value

Leaving out a legacy for the next generation is a desirable value. We would like our children also to enjoy the benefits that could be gained from wildlife species, not only of their mere existence but for the potential benefits that they can provide.

How to Conserve Endangered Species

Endangered animals and plants, therefore, must be conserved by all means possible. Doable initiatives include the following strategies:

  • reforestation,
  • rehabilitation of degraded lands,
  • sustainable harvesting of timber and other natural products,
  • pollution reduction and prevention,
  • waste reduction and management, and
  • development of innovative strategies to conserve endangered species.

Can you think of other ways to conserve endangered species?

References

WebMD, n.d. Digitalis. Retrieved on May 23, 2014 from http://goo.gl/VvlfYD

Withering, W. (1785). An account of the foxglove, and some of its medical uses: with practical remarks on dropsy and other diseases. Classics of Medicine Library.

Zoo Granby, 2014. Why protect endangered species… So what? Retrieved on May 23, 2014 from http://goo.gl/6zFiZn

© 2014 May 23 P. A. Regoniel

Cite this article as: Regoniel, Patrick A. (May 23, 2014). Four Reasons Why We Should Save Endangered Species. In SimplyEducate.Me. Retrieved from http://simplyeducate.me/2014/05/23/4-reasons-why-we-should-save-endangered-species/