Hello everybody. Today, our discussion will focus on the topic Estuary. The Philippine Archipelago is composed of 7,641 (NAMRIA) islands. Originally, there were 7,107 island in the Philippines but in 2016, the National Mappring and Resource Information Authority, reported that there were 534 new islands discovered mostly found in Mindanao. Most islands in the country have cities or towns that are located near an Estuary. It is therefore of utmost importance that people in the community and most specially the LGU or Local Government Unit, must strengthen their approaches to conserve and protect these Estuaries.
Join me, today, as I travel the road less traveled. Why? Because not everybody is willing to talk about it. Estuaries can be a boring topic. So, let’s just think of it as the most beautiful place on earth where our future depends on. It may sound corny but let me begin.
What is an Estuary?
- It is the tidal mouth of a large river, where the tide meets the stream. (www.epa.gov/…/estuaries)
- It is usually found where rivers meet the sea. (National Oceania and Atmospheric Administration (NOAA), U.S. Department of Commerce)
- Freshwater Estuary is similar to brackish water estuary.
- Estuaries are delicate ecosystem. It can be adversely affected by pollution, weather, human activities and encroachment into the habitat of several species of plants and animals.
- It is a semi-enclosed portion of ocean that is somewhat isolated by land and in which freshwater and salt water mix. (core.ecu.edu/geology/woods/estuariesl.htm)
Etymology of the word Estuary. The word estuary originated from Latin words aestus meaning tide and aestuarium meaning tidal part of a shore. In 16th century it became estuary. How do Estuaries differ from other Oceanic environments? (core.ecu.edu/geology/woods/estuariesl.htm – East Carolina University)
- The enormous daily and seasonal variability in salinity and temperature.
- Depth – Estuaries are shallow compared to ocean.
- Salinity – varies with tides and season. In the Philippines, flooding during typhoons and rainy season can influence the salinity of Estuaries because of an increased river run-off from the uplands.
- Temperature is influenced by the: a) depth of the estuaries, for example – shallow estuaries may manifest variable temperature; b) Tidal currents; c) different seasons for example during winter, ice may form in the water. In most of Asia and the Philippines where seasons are mostly wet and dry, rainy season and dry season can influence the temperature of the estuaries that will also affect the inhabitants in it.
Classification of Estuaries According to the Royal Institute of Technology, Stockholm, Sweden Website, the following are the classification of Estuaries.
- Coastal-plain estuaries are basically drowned river valleys where the present sedimentation rate is not in pace with the post-glacial inundation. The bathymetry is still similar to the ancient river valley and sand bars and banks are still developing. The relative age is then quite low.
- Fjords – formed from ice age valley glaciers that broadened and deepened the valley floor. At the mouth large amount of sediments (terminal moraines) were deposited creating a very shallow sill into the fjord when the glaciers retreated. Some sills are not deeper than a couple of meters whereas the depth within the fjords usually ranges up to a couple of hundred meters. Since the sediment flux is usually very low, the bathymetry very deep, the fjords are generally assumed to have a very low relative age. Fjords is described as a long, narrow, deep inlet of the sea between high cliffs, as in Norway and Iceland, typically formed by submergence of a glaciated valley.
- Bar-built estuaries – are strictly speaking also drowned river valleys but in this case the sedimentation rate is in pace with the inundation, creating a more mature estuarine type. Across the mouth of the estuary is a bar where waves break and that is formed by deposited sediments. The estuary is in steady state in the sense that even if occasional storm events break the bar a similar one is quickly created after the event. This type of estuary is associated with tropical climate and rivers with high sediment loads. (google search – the Royal Institute of Technology, Stockholm, Sweden)
- Tectonic Estuary – the tectonic shifting together and rifting apart of the Earth’s crust, creates tectonic estuaries. Example is California’s San Francisco Bay. The San Francisco Bay lies at the junction of the San Andreas fault and the Hayward fault. The complex tectonic activity in the area has created earthquakes for thousands of years. The San Andreas fault is on the coastal side of the bay, where it meets the Pacific Ocean at a strait known as the Golden Gate. The Hayward fault lies on the East Bay, near where the Sacramento and San Joaquin Rivers enter the estuary. The interaction of the San Andreas and Hayward faults contributes to the downwarping, the process of an area of the Earth sinking. (http://education.nationalgeographic.com/education/encyclopedia/estuary/?ar_a=1)
According to Wikipedia, Estuarine water circulation is controlled by the inflow of rivers, the tides, rainfall and evaporation, the wind, and other oceanic events such as an upwelling, and eddy and storms. Water circulation patterns are influenced by vertical mixing and stratification and can affect residence time and exposure time.
Residence Time water is a key variable in determining the health of an estuary, particularly from human-induced stresses. Rapid flushing ensures that there is insufficient time for sediment accumulation or dissolved oxygen depletion in the estuary, thus a well flushed estuary is intrinsically more robust than a poorly flushed estuary.
Exposure Time is the amount of time a water particle spends in the estuary until it never returns. The exposure time can be much larger than the residence time if the water particles are leaving with the ebb tides and returning with the rising tide. (enwikipedia.org/wiki/Estuarine_water_circulation)
At this time, I hope this part of the Lecture has given you more background information about estuaries. The more we know about it, the more we can think of approaches to protect and conserve our estuaries. Different countries have different experiences and challenges on how they can protect and conserve their estuaries. I hope this part of the Lecture will help you and your community. To continue, let us talk about the importance of estuaries.
Importance of Estuaries
- Source of food
- Coastal Protection
- Navigable harbors or waterways for transfer of food, raw materials, manufactured goods, recycled products, movement of people, and tourism.
- Commercial fishing, among others. (NOAA and core.ecu.edu/geology/woods/estuariesl.htm)
- Habitat or natural home of various species of endemic and endangered species of plants, animals and microorganisms.
- Breeding ground of various species.
If in your specific community there emerge another reason why Estuaries are Important, please feel free to add it. If you can write me a note the better. Thank you.
Challenges to Estuaries
According to the United States Environmental Protection Ageny or EPA, these challenges are the following. These challenges are the product of research, study by experts, scientists and employees of the U.S. governmental agencies. (water.epa.gov/type/oceb/nep/challenges.cfm)
- Alteration of natural hydrologic flows . People alter the environment through activities like development (Philippine experience – reclamation projects), construction of dams, flood control structures, and diversions of water, we change the volume and rate that water runs off the landscape, into the ground, and into streams. Increased runoff can result in erosion and sedimentation. Changes in freshwater inflows to estuaries can adversely affect shellfish survival, and fish reproduction and distribution.
- Aquatic Nuisance Species. ANS can disturb the food webs in the estuary and they can also cause the decline in various species of plants and animals.
- Climate Change. Many coastal wetlands and other estuarine habitats are threatened by inundation and erosion as the rate of sea-level rise accelerates. Climate change will also increase stresses to habitat and fish and wildlife populations as temperatures rise. Water quality problems are likely to worsen in estuarine waters if more extreme precipitation events create increased polluted runoff.
- Declines in fish and wildlife populations. The many stresses on estuaries have corresponding impacts on fish and wildlife. As their habitats disappear, the food they depend upon decreases and water quality degrades. Invasive species provide added pressures, replacing many of our native plants and animals.
- Habitat loss and degradation. The health of marine and estuarine systems, and the human economies that depend on them, rely on high-quality habitats that provide essential food, cover, migratory corridors, and breeding/nursery areas for coastal and marine wildlife. For humans, healthy coastal habitats attract the tourism revenues and seafood industries that are vital to many local economies. These habitats also function to make coastal areas more resilient to storms and sea level rise. As coastal population increased, coastal habitats have been converted due to development, highway construction, diking, dredging, filling, bulk heading, and other activities that degrade coastal ecosystems.
- Nutrient Loads. Nutrients such as nitrogen and phosphorus are necessary for growth of plants and animals and support a healthy aquatic ecosystem. In excess, however, nutrients can contribute to fish disease, red or brown tide, algae blooms, and low dissolved oxygen. Sources of nutrients include point and non-point sources such as sewage treatment plant discharges, stormwater runoff, faulty or leaking septic systems, sediment in urban runoff, animal wastes, atmospheric deposition originating from power plants or vehicles, and groundwater discharges.When excess nutrients lead to low dissolved oxygen levels, marine animals with little mobility can die; others must leave the hypoxic zones for more oxygenated waters.
- Pathogens. These are disease-causing microorganisms such as viruses, bacteria, and parasites that can create health risks for people enjoying recreation in and on the water. Pathogens can be introduced into estuaries from inadequately treated sewage, runoff from urban areas and animal operations, medical waste, boat and marina waste, combined sewer overflows, and waste from pets and wildlife. They pose a health threat to swimmers, divers, and seafood consumers.
- Stormwater. Its runoff is generated when precipitation from rain and snowmelt events moves across the landscape without percolating into the ground. As the runoff flows over the land or impervious surfaces (paved streets, parking lots, and building rooftops), ig accumulates debris, chemicals, sediments or other pollutants that could adversely affect water quality if the runoff is discharged untreated.
- Toxics. This include metals, such as mercury, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and pesticides enter waterways through storm drains, industrial discharges, runoff from lawns, streets, and farmlands, discharges from sewage treatment plants, and atmospheric deposition. If consumed by humans, organism that are exposed to these toxics can pose a risk to human health. Wildlife and aquatic plants and animals can also be harmed by consuming contaminated fish and water.
At this time, we were discussing what the EPA had been doing. The ideas that we got from other countries can be replicated in our Local Government Units or LGUs or in our respective communities. For sure, our national laws are in placed but its implementation, as far as, developing countries are concerned may need a little “teeth”. Perhaps, it is nice to know what other countries are doing so we can learn from their Best Practice. How did they do that? This is a question that is relevant when we are referring to new knowledge and technology, and knowing this can be a great help to our local situations. Now, let us continue with the discussion which will focus on approaches to protect and conserve our local estuaries.
The Philippines have several cities and towns that are located in the coastal areas and most probably near the estuaries. The City of Manila has several estuaries that dumps to Manila Bay. These estuaries have been polluted for several decades that fish, plants and other animals can hardly survive the murky and dirty waters of these estuaries. Many years ago, the cleaning up of Pasig River have been on-going and already changed the looks of the river – no more garbage floating on the river. Well, occasionally a few can be seen floating. This is thrown by hard headed riverside dwellers and factories along the river. Example of cities with estuaries are the following:
- Puerto Princesa Underground River Estuaries, Palawan, Philippines – Eco-tourism, National Heritage Site, U.N. Heritage Site, currently one of the world’s 7 Wonders of Nature, Home to 20 Million year-old Serenia (sea cow) fossil (La Venta Esplorazioni Geografiche, Italy)
- Manila and Pasig River, Philippines – shipping, commerce, etc.
- Cebu River Estuaries, fishing, commerce
- Ilog River Estuary, Negros Occidental, Philippines – fishing
- Quinaorian River at Victorias City, Philippines – shipping
- Himamaylan River, Negros Occidental, Philippines – fishing, oyster culture
- New York and Hudson River Estuary – Hudson River estuary stretches 153 meters inland from the Atlantic Ocean. It is home to 200 species of fish, nursery ground of Sturgeon, Striped Bass and American Shad. It supports other wildlife such as birds. (To read more about its various programs and projects, please check the link found in the succeeding paragraph.)
- Caete Estuary, Brazil
- Mondego Estuary of Portugal, located in South Eastern Atlantic Coast of Europe. It serves the shipping, fishing shipyard, small industries, salt production and tourism activities.
- City of Nantes, France, where River Loire begins to meet the Atlantic Ocean. (To read more about its tourism promotion and beautification program, please check the link found in the succeeding paragraph)
- Shanghai, China – is located in the River Yangtze Estuary. (www.google.com/search?q=images+of+cities+located+near+estuaries)
(Citation: Thank you to denr10org – the Department of Environment and Natural Resources, through Mon Paje for sharing this video on youtube. The voting has already been done and PPUR has already been declared as one of the 7 Wonders of Nature. The video was placed here to support the discussion about PPUR as one of the most unique underground Estuaries in the world.)
- Estuaries are assets of a country, city or town where it is located. It is an asset because it could be navigable and therefore used in commerce and trade and to a certain extent, global tourism.
- As habitat of various species of plants and animals, Estuaries provide a source of food while at the same time serve as nursery ground for endemic and endangered species of plants and animals.
- Estuaries can serve the sports, recreation and tourism purposes of a LGU where it is located.
- Estuaries provide job and job opportunities.
- Estuaries can serve as coastal protection.
- Estuaries can do other things, I may not be able to list down here.
Now, therefore, ways and means should be formulated to conserve, protect and beautify these Estuaries not only for sustainability and other purposes previously discussed, but for aesthetic purposes as well.
1. The City of New York and the Hudson River Estuary
2. Nantes City and River Loire, France
On Relevance and Sustainability
As what the Brundtland Report, Our Common Future stated, sustainable development is the “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” (Adams, W. M. Green Development, 3rd Edition, New York, p.5)
Estuaries are relevant to the life and existence of human beings for reasons previously mentioned. For various species of plants and animals Estuaries is an important habitat that needed conservation and protection too.
For programs and projects to be sustainable, there must be an improvement on the level or status of the following indicators formulated by the UN, CSD, this is the United Nations Commission on Sustainable Development. These are:
- Natural hazards
- Oceans, seas and coasts
- Economic development
- Global economic partnership
- Consumption and production patterns
Just to mention a few, Poverty. When poverty level is reduced, Estuaries can be protected from over exploitation and pollution, among others. Another is government. When government provides efficient and effective infrastructure support, implementation of laws, and continuous research and development on how to conserve and protect the Estuaries, the higher is the chances that programs and projects for the conservation and protection of Estuaries can succeed. So, it is in designing sustainable development of Estuaries that the LGU or the community enhance the relevance and put more meaning to the conservation and protection of Estuaries.
Look for this link for more readings:
Suggested Activities for Towns and Cities
- Estuary Conservation and Protection Program needs a boost among Local Government Units in the third world or even in developing countries. Two of the best sources of “tried and tested” programs and projects are the Nantes City in France and New York City in the United States. Their Best Practices can be a source of many ideas that can be replicated in our towns, cities and communities where Estuaries are important source of food, tourism, jobs, livelihood, recreation, and conservation and protection of endemic and endangered species of plants and animals. Check the links I provided here so you can check what activities you can replicate in your LGU or Commnity.
- Conduct a Strategic Planning Workshop on the Conservation and Protection of Estuary in your LGU. Through this StratPlan you will know the real situations in your LGU as far as this Estuary is concerned. You can raise the following questions:
1) Who Are We?
2) Where Are We Now?
3) Where Are We Going?
4) How Are We Going To Get There?
These four (4) questions can provide so much information to enable you to arrive at a list of Programs and Projects and an Action Plan that will be formulated by the stakeholders themselves. People who are directly benefited and affected by this Estuary are the right people to be involved with other members of the community in attendance.
- Conduct a workshop on Solid Waste Management and Disposal with focus on the 4 Rs-reduce, reuse, recycle and rot or composting.
- Conduct a River Clean Up Project
- Conduct a River Life Project
- Encourage your LGU to establish the Landfill Site, Sewage Treatment Facility, Material Recovery Facility and Composting Facility to minimize the landing of polluted water and garbage to the ocean and the waterways like rivers, creeks and canals.
- Organize a volunteer such as Green Army for the conservation and protection of the Environment
- Organize a Blue Army for the conservation and protection of the waterways like rivers, coastal areas, inland waters and estuaries, among others.
- Organize a Brown Army for the implementation of anti-littering and illegal disposal of garbage at any places in your community more specifically the waterways like rivers, creeks, canals, the estuaries, among others.
- Organize a 4-Rs Brigade to encourage people in the community to practice the 4 Rs – reuse, reduce, recycle and rot or composting and by encouraging the people in the community to avail the services of the MRF or Material Recovery Facility rather than “throwing” these recoverable materials to the rivers and other waterways.
- Encourage your LGU to hire an expert on Estuarine Science.
- YOU CAN ADD WHATEVER YOU THINK ARE DOABLE AND HELPFUL IN THE CONSERVATION AND PROTECTION OF OUR ESTUARIES.
Every Local Government Unit and the Local Community, most specially the Stakeholders who shall enjoy and benefit from these doable programs and projects to protect and conserve our Estuaries in the Philippines and elsewhere in the world, have a bigger responsibility to make these programs and projects into reality.
Designing sustainable development programs and projects and implementing them will not only transform and maintain these estuaries into a healthy waterways and habitat of endemic and endangered species of plants and animals but will continue to provide food, jobs, livelihood and tourism among others. That initiative will also create something meaningful not only for the present generation but also for the generations to follow.
- core.ecu.edu/geology/woods.estuariesl.htm – East Carolina University
- denr10org video on Puerto Princesa Underground River Estuaries on youtube.
- National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce
- Puerto Princesa Underground River, Palawan at http://youtu.be/eEHYoa3dH1Y
- Royal Institute of Technology, Stockholm, Sweden, Website
Photos by: Henry Libo-on, Puerto Princesa Underground River Estuary, Palawan, Philippines. The New 7 Wonders of Nature. Photo was taken about 12 hours after the rain. There was rain that midnight, so, the water was not crystal clear or turquoise blue.
Updated February 13, 2017….(HCL)