Hepatitis A & E

 Infectious hepatitis- Hepatitis A
·         Hepatitis A virus-  First documented viral disease spread through water
·         By ingesting contaminated food or water-usually in children and young adults
·         Incubation period is 15 to 50 days
·         A typical viral-type illness with variable fever, followed by Jaundice; enlarged liver, vomiting, abdominal pain
·         Virus excreted in faeces and urine during fever phase
·         Virus excretion ceases during jaundice phase - patient is no longer infectious. 
·         After a few days the appetite returns and the jaundice begins to resolve
·         Transmission- Faeco-oral route
Control:
·         Adequate treatment of sewage and water; viruses more resistant to chlorination- inadequate chlorination leads to outbreaks
·         Drinking boiled/safe water and food
Hepatitis E
·         Hepatitis E -infection with hepatitis E virus (HEV)- found worldwide
·         Transmission fecal-oral route
·         Infection is self-limiting and resolves within 2–6 weeks.
·         Occasionally a serious disease, known as fulminant hepatitis (acute liver failure) develops, can cause death.
·         Poor sanitation, ingestion of undercooked meat or meat products derived from infected animals (e.g. pork liver) and rarely, transfusion of infected blood products; vertical transmission from a pregnant woman to her baby.
·         Initial phase of mild fever, reduced appetite (anorexia), nausea and vomiting, lasting for a few days; some may also have abdominal pain, itching (without skin lesions), skin rash, or joint pain.
·         Jaundice, with dark urine and pale stools
·         a slightly enlarged, tender liver (hepatomegaly).
·         Pregnant women with hepatitis E, particularly those in the second or third trimester, are at increased risk of acute liver failure, fetal loss and mortality.
·         Control
·         Safe  public water supplies and proper disposal of human faeces.
·         Maintain hygienic practices;
·         Avoiding consumption of water and ice of unknown purity
·         A recombinant subunit vaccine registered in China- not yet been approved in other countries

Marine Environment - Threats and management strategies.

 Marine Environment

The oceans are home to half the world's biodiversity and is the source of their livelihood (fishing, whaling, or tourism) for many. Ocean water and ice make up almost 98 percent of all the water on Earth. The oceans are home to innumerable species that we are now only beginning to discover. However, the threat to oceans and marine life is often overlooked. Some of them include:

1. Ocean Dumping

Dumping of waste materials from industries, ships and sewage plants into oceans has polluted the marine ecosystem to a great extent. The oceans have been the dumping site of sewage, chemicals, industrial waste, garbage, and other debris from the land. According to reports, only mining companies across the world dump million tonnes hazardous waste directly into our waterbodies every year. Around two-thirds of the marine lives in the world have been under threat from the chemicals we use every day, including household cleaners. The adverse effects of ocean dumping affects humans also as it poses health risks.

 

2. Land Runoff

One of the major sources of ocean pollution is the waste comes from the nonpoint source, which happens as a result of runoff. Surface runoff from both agricultural land and areas carry soil and particles mixed with carbon, phosphorus, nitrogen and minerals, posing threat to the marine life. Water filled with these toxic chemicals land in the ocean, resulting in harmful algal blooms. This kind of water pollution threatens the species of fish, turtles, and shrimp etc. and also humans through the food chain.

3. Dredging

Dredging is an important activity that enhances marine transportation and other related activities. However, dredging has been a major cause of disturbance in the marine ecosystem for many years. As dredging is to remove the deposits submerged underwater, the activity alters the pre-disposed composition of soil, leading to the destruction habitat of creatures and organisms. Similarly, dredging of contaminated materials will result in the regrouping of harmful particles and contaminate large of areas of water bodies. Several cases involving the destruction of underwater lives are extensively reported

4. NOx and SOx

Nitrogen oxides (NOx) and Sulfur oxides (SOx) – the two main pollutants found in shipping emissions- has badly affected both marine environment and ozone layer in a number of ways. Both NOx and SOx are combustion products that are emitted into the environment in the form of smoke. These type of air pollution causes premature deaths of aquatic life

5. Ocean Acidification

The issue of ocean acidification is quickly becoming a threat to both marine lives and humans. Ocean acidification is the continuing decrease of seawater pH caused by the absorption of carbon dioxide (CO₂) from the atmosphere. Ocean acidification has the power to endanger the lives of marine organisms and also humans who depend on fish and fish products for their daily sustenance. Studies have shown that the decreased pH levels affect the behaviour of several marine species, putting them at life-threatening risks.

6. Sea Water Level Rising 

Global warming is alarmingly increasing seawater levels, threatening the marine ecosystem. According to reports, the annual rate of seawater rise during the past two decades has been 0.13 inches a year, which is around twice the average speed of rising over the preceding 80 years. The rise in seawater level means more wetland flooding, destructive erosion and agricultural land contamination and more importantly a serious threat to the habitat of several plants, fishes and birds. It is high time that we understand about the causes and effects of seawater level rising to save the marine environment and biodiversity. 

7. Ozone Depleting Substances

Ozone-depleting substances such as CFC’s and Halon along with other pollutants from ships destroy the ozone layer.  Ozone Depleting Substances omitted by ships across the world include Methyl Chloroform, Methyl Bromide, Bromochlorodifluoromethane and Bromotrifluoromethane etc. These man-made gases are capable of destroying ozone and in effect, these gases causing harm to the marine environment in several ways.

8. Waste Pollution from Ships

Ships are another major source of pollutants such as oil and gas and the waste and garbage generated on board ships poses a significant threat to the marine ecosystem. Both solid and liquid waste in form of food waste, packing material, paper products and cleaning material and rags etc. pollutes the seawater and badly affects marine lives. The vessels used for various purposes- a container or cruise ship- contribute to this pollution in different levels.

9. Noise Pollution from Ships

The noise generated from shipping operations is harmful to marine organisms. Harmful effects of noise pollution on marine organisms include haemorrhages, changed diving pattern, migration to newer places, and damage to internal organs and an overall panic response to foreign sounds. Source of noise pollution from ships include engine noise and the entertainments in cruise ships. The intensity of noise pollution is higher in marine environment since noise travels greater distances easily in water.  Marine life is extremely sensitive to noise due to their heavy reliance on underwater sounds for basic life functions.

10. Oil Spills

The biggest cause of marine pollution – oil spills. The world has witnessed several oil spill disasters that have been one of the major concerns of pollution to the marine environment. Disasters such as the Exxon Valdez Oil Spill and Deepwater Horizon etc. have resulted in the extreme pollution of the marine ecosystem, killing thousands of marine species. The oil spilt destroys the insulating ability of several marine species and also the water repellency of bird’s feathers, exposing these creatures to life-threatening risks.

11. Plastic Pollution

Plastic Pollution is the reason for several environmental problems both at sea and land. Pacific garbage patch (collection of marine debris in the North Pacific Ocean) is a well-known example of the extent of damage plastic is causing to the marine environment. It is estimated that around 8 million tonnes of plastic waste enters our oceans every year, and by 2050, at this rate, it is estimated that there will be more plastic than fish in the water bodies across the world. The plastic pollution has a direct effect on wildlife as it- plastic bags, fishing nets and other debris-chokes tens and thousands of seabirds and sea turtles every year. The ingestion micro plastics by fish and other species also pose risk to their life as well as humans.

Pacific garbage patch

12. Nuclear waste threaten our oceans

When humans step in, the threat to the natural habitat comes not only from their actions but also from the after-effects of it. There is a real threat from nuclear waste leading to radioactivity, and now it has been reported that radioactive lobsters are found in the Irish Sea

13. Threatened Oceans mean threatened Corals

Along with the ocean water, a high percentage of the world's coral reefs are at risk of degradation. High acidity in the ocean water caused by pollution, oil spillages, sedimentation and disturbances to habitats are threatening the wonderful world of the coral reefs. Measures include planning, management, law enforcement, environmental education, and legal protection to restricting development in sensitive coastal areas Australia's Great Barrier Reef, the largest reef in the world, illustrates the potential of careful reef management.

            Management strategies to save ocean include

1)     Research and education to increase public appreciation of biodiversity and the impacts of human activities.

2)     Avoid practices such as overfishing, resource exploitation and

3)     Decision makers must implement appropriate and effective legislations

4)     Marine reserves are reference areas with minimal human impact, and help to reduce changes caused by human actions. Reserves allow scientific education and ecotourism activities impossible in fished areas. Overfishing is eliminated. Reserves can be used to improve public awareness and understanding of natural systems and human impacts on those systems. Thus they address many issues that often are not adequately treated by traditional management approaches. Marine reserves are an essential element in ecosystem management and offer considerable potential for protecting and restoring marine biodiversity.

 

Estuaries & Wetlands - Threat and management

 The position of estuaries at the interface of the terrestrial and marine environment makes them vulnerable to the impacts of human activities, whether land-based or marine, including the impacts of climate change. Estuaries are also a magnet for human activity. Thus, managing estuaries as protected areas can be particularly challenging and management of estuarine protected areas require cooperative governance between a number of community and government. 

Estuarine functioning is primarily driven by the quantity and quality of freshwater and marine mediated by freshwater inflows and tides, fresh and salt waters mix in a nutrient-rich environment that supports a diversity of aquatic species.

 The link between estuaries and their surrounding terrestrial, freshwater and marine systems is vital for many species whose life depend on movement between these systems. This includes many marine species of conservation and commercial value. Thus, estuaries should not be managed as isolated systems

 In addition to the quantity of water entering estuaries, catchment activities and infrastructure such as loads of sediments, nutrients and other pollutants also affect the quality of this water. This can result in smothering of habitats, increased turbidity and eutrophication—all of which can result in significant changes in biotic communities and local extinctions.

The protection of an estuary requires that the quantity and quality of freshwater inflows are maintained as close to natural as possible, in order to maintain ecological functioning and biodiversity in a relatively natural state.

 A wide array of human impacts compromise their ecological integrity of estuaries, because of rapid population growth and uncontrolled development. Long-term environmental problems such as pollution inputs, the loss and alteration of estuarine habitat and other anthropogenic stress require remedial actions to improve the viability and health of these valuable coastal systems.

 

• water quality in estuaries, particularly urbanized systems, is often compromised by the overloading of nutrients and organic matter, the influx of pathogens, and the accumulation of chemical contaminants.

 

• The destruction of fringing wetlands and the loss and alteration of estuarine habitats usually degrade biotic communities.

 

• Estuaries are characterized by high population densities of microbes, plankton, benthic flora and fauna, and nekton; however, these organisms tend to be highly vulnerable to human activities. By 2025 estuaries will be most significantly impacted by habitat loss and alteration associated with an increase of coastal population.

 

• Habitat destruction which modify the structure, function, and controls of estuarine ecosystems lead to the decline of biodiversity.

 

• Excessive nutrient and sewage inputs to estuaries, principally from land-based sources lead to the greater incidence of eutrophication as well as hypoxia and anoxia.

 

• Overfishing is a more pervasive and significant anthropogenic factor, also capable of mediating global-scale change to estuaries.

 

• Chemical contaminants, notably synthetic organic compounds, remain a serious problem, especially in heavily industrialized areas.

 

• Freshwater diversions appear to be an emerging global problem as the expanding coastal population places greater demands on limited freshwater supplies for agricultural, domestic, and industrial needs.

 

• Altered freshwater flows could significantly affect nutrient loads, biotic community structure, and the trophodynamics of estuarine systems.

 

• Ecological impacts are also caused by introduced species, sea level rise, coastal subsidence, and debris/litter.

 Thus, the health of estuary ecosystems is threatened by increased nutrients and algal blooms, loss of habitat and biodiversity, contaminants and pollutants, accelerated rates of sedimentation, disturbance of soils, changes to freshwater and tidal flows, invasive species, climate change.

In order for the protection of estuaries to be successful, all of the following interventions at local to national scales are necessary:

• integrated conservation planning
• ensure quantity and quality of inflows to maintain the protected estuaries in a desired state of health
• provide nursery areas for crustaceans and fish, carbon sequestration and coastal protection
• prioritise conservation of biodiversity

 

Wetlands 

 

Since the advent of industrialization and urbanization the wetlands came under severe threat due to increased anthropogenic-pressures. As per an estimate, India has lost 38 percent of its wetlands between 1991 and 2001 alone.

Threats

• Urbanization and land use changes: During the 90 year period from 1901 to 1991, the number of urban centres doubled while urban population has increased eightfold. This magnitude of growth exerted tremendous pressure on wetlands and flood plain areas for meeting water and food demand of growing population.

• For example, the Kanwar lake in Bihar, Asia’s largest freshwater oxbow lake, has shrunk to one-third of its size due to encroachment, much like Jammu and Kashmir’s Dal lake. And, about 34000 hectares of the water spread area of the Kolleru lake (Andhra Pradesh) have been reclaimed for agriculture in recent years.

• Agricultural residues: As a result of intensification of agricultural activities over the past four decades, fertilizer consumption in India has increased. As per estimates, 10–15 percent of the nutrients added to the soils through fertilizers eventually find their way to the surface water system. High nutrient contents stimulate algal growth, leading to eutrophication of surface water bodies.

• Municipal and Industrial pollution: Domestic wastewater from Indian urban centres is largely discharged in the natural water bodies such as streams and rivers.

For example, River Yamuna, which passes through 6 Indian States, receives untreated waste water from the capital city of Delhi which comes to about about 78 percent of the total pollution load that flows in to the river.

• Similarly, untreated industrial effluents have become a major threat to the survival of wetlands. For instance, the Bellandur Lake in Bengaluru city was ‘on fire’ in May 2015 due to the discharge of effluents (especially nutrient rich foams) by the surrounding industries.

• Climate Change: Global climate change is expected to become an important driver of loss and change in wet-land ecosystem.

•Wetlands located in high altitude as well as coastal areas, like mangroves and coral reefs, are some of the most sensitive classes that will be affected by climate change. For example, climate change caused rise in level of Tsomoriri Lake in Ladakh, a glacial fed high altitude lake, thereby causing submerged important breeding islands in the lake where endangered migratory birds like the Black-necked Crane and Bar-headed Goose would breed.

• Introduced Species: Indian wetlands are threatened by exotic introduced plant species such as water hyacinth and salvinia. They clog waterways and compete with native vegetation.

 Apart from the above major threats, immersion of idols and religious ritual waste, introduction of exotic species, encroachments and unregulated aquaculture, dredging, un planned urbanization and development projects are some of the other dangers threatening the existence of wetlands across the country. 

Wetlands are amongst the most productive ecosystems on the Earth. Historically, they have been at the centre of evolution of human civilization for millennia as they are means of precious ecological goods and services. However, unfortunately, they are also ecologically most sensitive eco-systems and are under threat due to increased anthropogenic-pressures.

 

Management

Ramsar Convention

The Convention came into force in 1975  for preserving the ecological character of wetlands.

The Convention’s mission is “the conservation and wise use of all wetlands through local and national actions and international cooperation, as a contribution towards achieving sustainable development throughout the world”.

India has 37 Ramsar Sites which are the Wetlands of International importance.

Wetlands (Conservation and Management) Rules, 2017:

Nodal authority: As per the Wetlands Rules, the Wetlands Authority within a state is the nodal authority for all wetland-specific authorities in a state/UT for the enforcement of the rules.

 

Prohibited activities:

• Setting up any industry and expansion of existing industries,
• Dumping solid waste or discharge of untreated wastes and effluents from industries and any human settlements, and
• Encroachment or conversion for non-wetlands uses.

Integrated Management Plan: The guidelines recommend that the state/UT administration prepare a plan for the management of each notified wetland by the respective governments.

Penalties: Undertaking any prohibited or regulated activities beyond the thresholds (defined by the state/UT administration) in the wetlands or its zone of influence, will be deemed violations under the Wetlands Rules. Violation of the Rules will attract penalties as per the Environment (Protection) Act, 1986.