Floating Plastic Islands!

by Abitha Begam

Have you ever imagined an island made of plastics with a beach, lined with a plastic coastline? Yes! Kudos guys, we have made it. Have you ever thought about where all our plastic wastes are? Where does it go? Where does it gets settled?

It’s yes! Obviously, the answer would be to the ocean. Not all plastics enter the ocean but the majority do. Many of the plastic waste gets escaped from the environment reaches the nearby water bodies or gets dumped nearby and ends in the ocean. Whereas some plastics like microbeads present in the cleansers and toothpaste, intentionally makes a way in ease. All these plastics in combination with the microplastics form garbage patches.

So, now you can ask me a question, how do these large bottles, bigger plastic bags get shredded? Yes, I will explain you. Collectively, the plastic material discharged in the ocean will be left as such, during the season of monsoon, the ocean currents (gyres) formed drift all the garbage present on the surface of the ocean. Among them, some of the garbage when gets stuck into the aggressive ocean currents becomes microplastics and forms a garbage patch area.

Source: National Oceanic and Atmospheric Administration

Around 8.3 billion tonnes of garbage had been discharged into the oceans all these years. All this garbage mainly plastics forms patches over the oceans, some gets sunk while some float. There are five major offshore plastic accumulation zone namely North Pacific, South Pacific, North Atlantic, South Atlantic and the Indian ocean garbage patches among which The Great Pacific Garbage Patch (GPGP) is considered as the largest.

“Do you know how big is the Great Pacific Garbage Patch (GPGP)? It is three times bigger than France in size”

Source: https://www.iberdrola.com/wcorp/gc/prod/en_US/comunicacion/docs/Infographic_five_plastic_islands.pdf
S.NoName of the garbage patchDiscovered inArea of the patch (Estimated)
 1.North Pacific19971.6 million Sq Km
2.South Pacific20112.6 million Sq Km
3.North Atlantic2009Estimated to be spread over 100 km
4.South Atlantic2017About to be estimated
5.Indian ocean20105 million Sq Km

According to a study made in 2010, it is found that India disposes nearly of 0.6 million tonnes of plastic wastes annually while China topped with 8.82 million wastes per year. These wastes collectively form garbage patches in the ocean.

According to a study led by Mirjam van der Mheen, as there is no direct technique for measuring the plastics present in the ocean, the team has made to retrieve data from 22,000 satellites since 1979, has made a simulation on how the monsoon currents drift the garbage in the ocean.  to their surprise, they have found how the Indian Ocean garbage patch has been missing.

Source: Simulation results of Mirijam van der Mheen study.

Due to the unique physical features of the Asian continent, the Indian ocean does not form a gyre, which obviously never let the garbage patches be present. The fact of the missing garbage patch is due to the monsoons that get created in the ocean. Hence due to the Asian monsoon system, the stronger trade winds push the waste towards the west of the southern Indian ocean making a way towards the south Atlantic Ocean.

These microplastics and the litter ends up in marine pollution and pose a serious threat to marine biodiversity. Some recent reports of South Africa highlighted the baby sea turtle dies due to the consumption of plastics.

So what’s in our hands, as it is a man-made crisis, it is completely possible to solve the problem, which requires some initiative and awareness from our side. Primarily reduction in the production of plastics could be made in control. Secondarily reduction in the usage of plastics can make it possible.

 Even a small change from our end can make bigger differences. Carrying a bag for groceries and purchase, switch over to steel lunch boxes and bottles, avoiding cosmetics consisting of microbeads, taking part in ocean clean-ups and by being minimalistic.,

Even your smaller change matters!

Faunas of the Indian Ocean

by Abitha Begam

India is not only a country of diverse cultures, languages but also has a very rich biodiversity, one such type is the Indian ocean. The Indian Ocean is the third largest ocean counting after the Pacific and the Atlantic Ocean, which stretches from Africa to Australia. It has been the home of 115 species of aquatic animals to date. Due to its fewer plankton levels, the ocean has minimal species when compared to other oceans. Though there are lesser species, some of them are very rare among them.

The Indian Ocean wildlife is majorly found in the coral reefs of Africa and Australia. The most interesting fact about the Indian ocean is, it is the warmest ocean on the earth and 40% of the world’s offshore oil production has been carried out in this ocean. The major primary islands of the Indian ocean are Madagascar, Maldives, Mauritius, Seychelles, and Sri Lanka which serves as a home for various species of fauna. The wildlife of the aquatic animals has always been parallel to the wildlife of the terrestrial animals. Due to the fragile environment, aquatic animals are facing some serious issues.

The Indian Ocean has been the treasure trove for various aquatic animals, though it has lesser marine life, it has consisted of a rich and very rare array of species at specific islands and coastal areas. In which some are endangered and could not be existed at all in the other parts of the world. Among them, some of the species are briefed below.

Okay, let me test your knowledge about aquatic animals.

Which is the only aquatic habitat with no sense of smell and earflaps and also with a small hump on the back? Yes! You are right, they are the Humpback whales.

Source : BLACK TOMATO (https://www.blacktomato.com/destinations/iceland/swim-with-whales/)

Habitat: Found near the shores of the ocean and all around the world

Favorite food: Krills

Diet: omnivores in nature

Endangered level: low, once it was about to be endangered

Interesting fact: they follow a newer type of migration like they could be found in the polar climate regions during summer and tropical to sub-tropical climate region in the winter for mating. They can also travel around 16,000 miles a year.

Humpback Whales are majorly found in the islands of Madagascar. The interesting fact about them is, the male humpback whales have the ability to produce a beautiful song in their throat. It has got a small hump in the back and so it was named after it. Their senses are made specifically to adapt to their underwater habitat. They weigh about 40-100 tons and have a lifespan of nearly 45-50 years. They were on the verge of extinction, but now it has been completely recovered.

Have you heard about vegetarian marine mammals? Yeah! you are reading right, Dugongs are one among them!

Habitat: Warmer tropical waters and seagrass forests present in the Pacific and Indian ocean

Favorite food: Seagrass

Diet: Herbivores in nature

Endangered level: Medium, close to getting threatened

Interesting fact: they can live up to 70 years

Dugongs are a type of mammal which are similar to manatee which is commonly known as sea cows. They are of brown-grey color, which weighs up to 150- 400 kg. It is the state animal of the Andaman territory and is found as an isolated breed in the National Park of Gulf of Kutch. They are herbivorous and grow at a length of 2.7m-3m. Because of their friendly nature, it allows the visitors to see in close. They have some specific dietary habits and hence it cannot be caged. They also have a strong history, whereas a 5000-year-old cave has depicted the images of Dugongs, symbolizing their origins from Malaysia.

Do you know: Tortoise and Turtles are not the same! They look alike but still have many different features. The life span of tortoises exceeds more than turtles.

Habitat: Shallow marine waters

Favorite food: jellyfish and tunicates

Diet: Carnivores in nature

Endangered level:  Medium, only the breeds living on the pacific coast are endangered.

Interesting fact: they can live up to 50-60 years

Olive Ridley Sea Turtles are the turtles that have been named after their olive-green color present in their shell that is found predominantly in the Indian ocean, which grows to 62-70 cm in length and weighs about 35- 35 kg. They have predominant nesting sites in India and they are majorly in parts of Odisha, Chennai, and Ratnagiri. They are now found in Versova beach of Mumbai. The female turtle’s nests in mass nestlings are named arribadas. They lay a batch of 110 eggs in a single clutch which requires an incubation period of 52-58 days, two times each season.

Habitat: Tropical coastal waters present in the coastlines of South America, China, Africa, and India.

Favorite food: Squid

Diet: carnivores in nature

Endangered level: Medium, under threatening

Interesting fact: they have stripes in the back which gets faded later and hence it is named the tiger shark

Tiger Sharks are considered one of the biggest sharks in the world. They are carnivorous and they weigh about 385- 635 kg with a life span of 30-40 years. They are also known as leopard sharks, as they have ferocious teeth resembling leopards through which they can even bite the shell of a turtle. They move slowly in general, but in case of attacking their prey, they can move at a speed of 20 mph. This fish in other terms it could be called garbage fish as it just swallows any trash other than its prey. Plastics, empty cans, and plates are majorly found in their stomachs. They also migrate with respect to the temperature of the water.

Habitat: Tropical coral reefs present on the coast of Australia and Southeast Asia

Favorite food: Algae

Diet: omnivores in nature

Endangered level: low, concerned less

Interesting fact: Male fish does major works like waiting for the eggs to hatch and fanning of the eggs. Clownfish is a famous fish, which got popularized by the film “Finding Nemo”. It is bright orange-colored with stripes of white in between. They are also known as false clownfish, anemonefish, and false percula. They are majorly found in shallow waters of the Red Sea, Indian ocean, and the western pacific. These fishes weigh about 250 gm and grow at a length of 10cm- 18cm. These fishes are born with both male and female sex organs at the time of birth and adapt themselves according to the stage where they are in their lifecycle. They are not considered as endangered but in case of coral reef destruction, their life may go in vain.

Skincare Chemicals and Corals – A Cause of Concern?

Our obsession of skincare and its products is inevitably eternal, but so are its impacts. The environmentally-derogatory effect that virtually unlimited skincare products such as sunscreens have, cannot be compensated for by nature’s limited lifespan.

When we go to the beach or on vacation, for example, practically everyone applies sunscreen to their body. It’s possible that the sunscreen you use won’t stay on your skin. Sunscreen can wash off and into our waterways when we swim or shower. Corals and the fragile marine environment are harmed by sunscreens and other cosmetics. Physical (mineral) and chemical sunscreens are the two most common forms. Mineral sunscreens work by creating a physical barrier on top of your skin that reflects the sun’s rays away from your body. On the other hand, chemical sunscreens contain synthetic substances that absorb UV rays before it reaches your skin. While applying sunscreen before going to the beach can shield us from the hazards of the sun, it can have the opposite effect when it comes to life under water.

A research paper from Hawaii and the US Virgin Islands revealed the devastating impact that sunscreens have on coral life. The team examined the effect of Benzophenone and Oxybenzone (ingredients in sunscreens) on coral forms as well. It was proved that these chemicals, use in over 3,500 sun-care products affects the DNA of coral life, and results in an increase in the number of coral deformities and abnormalities.

It was further reported by the U.S National Oceanic and Atmospheric Administration that the chemicals in sunscreens can induce defects in young mussels, and decrease the fertility of fish.

The next time you decide to go to the beach or visit a national park, make sure to keep the following points in mind:

  1. Avoid aerosols.
  2. Try not to visit beaches, etc. between 10 AM and 2 PM.
  3. Oxybenzone, Benzophenone-1, Benzophenone-8, OD-PABA, 4-Methylbenzylidene camphor, 3-Benzylidene camphor, Octinoxate, and Octocrylene are all dangerous substances to avoid.
  4. Look for Protect Land + Sea Certification on items.

The misery of seahorses

On a planet where humans kill millions of their own kind, Damocles’ sword always lies hanging over the heads of animals. That’s a given when animals face the deadliest threat everyday – us.

Things sadly become worse for one of the most fascinating creatures on this planet – the seahorse. One instant it tries hard to live through another day of a plastic-filled nightmare, and the next instant, swoosh! It gets mired in the mesh of a fishing net and that’s the end of its story.

Seahorses in the side-lines

Catching or trading of seahorses is prohibited under the Wildlife Protection Act of 1972. While this has reduced their direct fishing, the number of seahorses being caught as by-catch has increased alarmingly. Between 2015 and 2017 alone, around 13 million seahorses were caught as by-catch in India’s coasts, with Tamil Nadu catching the most.

Areas of southern India where seahorses are found (Image Source)

Why are seahorses being caught as by-catch?

Contemporary fishing techniques involve the use of highly sophisticated gears which not only catch the required kinds of fish, but also those not needed. Usage of nets with mesh sizes smaller than 10mm, trawling near the shore, usage of destructive fishing equipment, etc. – unlawful activities like these are responsible for the dropping seahorse numbers.

Image Source

What happens to the seahorses caught as by-catch?

On the one hand, banning the fishing of seahorses has been advantageous in India to a certain extent. On the other hand however, this has induced several fishermen to sell them in markets for handsome profits. Many a times, these creatures are taken back home and stored in aquariums, where they are deprived of their natural habitats and eventually succumb to starvation or disease. Unregulated trade of these marine horses has also emerged as a concern-causing threat in recent times.

Image Source

Do we need to protect seahorses?

Seahorses ostensibly seem insignificant members of the environment, but in truth, hold a very pivotal place. These unique creatures are vital components of the ecosystems where they are found. Not only do they predate on creatures found in the lower oceanic levels, they also serve as food for several other animals. Thus, reducing their numbers would be equivalent to amputating a significant part of the environment adversely.

Increasing by-catch of seahorses is a wakeup call for taking further steps towards marine conservation. The case of the horses of oceans shows that legal protection has been helpful on paper, but more needs to be done to implement their protection in practice.

Dwindling numbers of sharks a cause for concern

Sharks are one among the many apex predators of oceans. Yet, not even that fact can save them from the inevitable consequences of human actions. Since the 1970s, their numbers have dropped by over 70%, and this figure is bound to increase given the pace at which human advancement in the context of environmental disregard is taking place.

Are sharks important components of the marine ecosystem?

Indubitably, sharks are as important as any other organism in the world. Imagine a world where they don’t exist at all. Organisms present at lower trophic levels in a food chain multiply beyond the capacity of the environment. The reason? One of their significant natural predators no longer exists. And the result? Disaster. Lower trophic levels start competing among themselves for food, and greater competition will eventually force them too to disappear. We’ll have successfully killed two birds with one stone.

Whilst sharks help in regulating the abundance of their prey, they also exert a certain amount of control over them with respect to aspects like distribution and behavior. For instance, their presence intimidates animals like turtles. This prevents from overgrazing from a single area of seagrass, thereby also protecting other organisms that live in that habitat.

Ultimately, oceans are empty without sharks.

The case of the Arabian Sea

India is the second-largest shark-fishing nation in the world. However, while sharks are being overfished and pushed towards the brink of extinction throughout the world, the Arabian Sea region has been shining the red signal for a long period of time. Over 50% of the shark species found here are threatened with extinction due to several reasons. While several governmental measures to protect sharks have been enforced (such as prohibition of fishing certain protected shark types or the banning of import or export of shark fin), Indian overfishing has been one of the leading reasons behind the decline of shark populations in the Arabian Sea. Gill nets, long lines, trawls, etc. are dragged through oceans in order to catch large numbers of fish, and sadly, sharks fall prey to this.

Pollution, coastal development, global warming, etc. – all these do impact sharks adversely. However, topping this list of reasons behind shrinking shark populations are fisheries. Be it for making products such as boots and bags, or to consume their meat, overfishing is a serious concern for shark populations as they grow slowly and produce few young,   making them particularly vulnerable to extinction.

Image Source

The notion that sharks are monstrous bloodthirsty animals is an encumbrance that needs to be tackled, because the harsh truth is that it is we who are “monsters” that have begun an unfair and endless war against them, as well as the environment as a whole.

“Sharks are beautiful animals, and if you’re lucky enough to see lots of them, that means that you’re in a healthy ocean. You should be afraid if you are in the ocean and don’t see sharks.” – Sylvia Earle

Suffocating marine life to death

While terrestrial organisms like humans enjoy breathing 21% of oxygen present in the air, marine organisms have to depend on a mere 1% of oxygen concentration in water. However, the unquenchable avarice and ridiculous megalomania of humans has started depleting even this small quantity of oxygen.  With the thin line on which the marine world breathes on being vanished rapidly, only adverse repercussions await.

Falling oxygen levels and rising dangers to marine organisms

The diffusion of oxygen from the air into the sea plays a major role in fulfilling the oxygen requirements of marine organisms. Oxygen produced by photosynthesizing marine plants is also used by these organisms to meet their needs.

What happens when the necessary supply of this gaseous elixir is disturbed? Danger steps in. Since the 1950s, oxygen content in oceans has dropped by 2%, and the fact that this figure is only expected to rise in the upcoming years highlights the seriousness of the issue.

Presently, there exist certain pockets of the ocean with little or no oxygen. While such places called “oxygen minimum zones” exist naturally, human activities are expanding these zones and the threats that come with them. But what’s more is that apart from these zones, the levels of oxygen, a gas as essential to marine life as it is to us, are dropping at numerous other places of oceans too.

Image Source

What are the reasons behind declining oxygen levels?

Global warming fuelled by human actions is primarily responsible for plummeting oxygen levels. The warmer the oceans become, the lesser the oxygen that can dissolve in them and the greater is the threat to members of the marine world. Ocean de-oxygenation leads to the production of gases such as carbon dioxide and methane which contribute further to global warming.

The discharge of sewage, chemicals and other pollutants into oceans directly also contributes to de-oxygenation. In addition to that, draining pollutants into oceans increases the content of nutrients and favors the growth of organisms such as jellyfish and algae which create an endangering mismatch in the marine environment.

Pockets of low oxygen levels force numerous marine species to search for areas with sufficient oxygen, compelling them to alter their natural behaviors. This may also lead to massive changes in their distributions, posing a threat not only on them, but our economic activities, such as fishing, too.

Human activities that turn blind eye towards the environment are forcing thousands of marine organisms to breathe their last. While we continue pushing for accelerated development, the rich life in our oceans is choking to death. Reforms need to be made, especially on an individual basis, before we lose this environmentally diverse planet from our hands.

Agatti Island of Lakshadweep Atolls: Coral Reef Bleaching

by Rohan Nath

Introduction 

Coral reefs support approximately 0.5 million species worldwide and are considered to be the  most diverse marine habitat. The annual growth of corals is based on environmental  conditions and are severely slow with a growth of only a few mm to 5 cm per year. Natural  and anthropogenic disturbances can influence the changes in the ambient environment and  affect the growth rate of coral reefs. Scleractinian corals get bleached and subsequently die  when there is a loss of endosymbiotic dinoflagellates due to elevated sea surface temperatures  (SSTs). This loss of algal endosymbionts under stress conditions is known as coral bleaching.  Coral bleaching can also be caused due to increased light intensity and salinity increased  copper concentration, as well as exposure to cyanide. There have been 29 widespread  bleaching cases in India since 1989. SST fluctuations have led to large scale bleaching and  mortality of corals in the Lakshadweep Islands, the Andaman and Nicobar, the Gulf of  Kachchh and the Gulf of Munnar. The Agatti Island (Fig. 1) have suffered from local coral  bleaching during 2010 as well as bleaching of coral-associated organisms like giant clams  and sea anemones. 

Fig. 1. An overview of the Agatti Island. Image Source: Google Earth.

Coral Bleaching 

The mortality of coral and associated organisms is prevalent throughout the island (Table 1). Table 1.  

Location Organism Mortality Rate
Northside of Agatti IslandCorals 64%-69%
Sea anemones 81%-83%
Giant clams  70%-85%
Southside of Agatti IslandCorals 75%-85%
Giant clams  83%-91%
Sea anemones  91%-93%

The mortality rate of corals, giant clams and sea anemones is higher on the south side of the  island compared to the north side of the island (Fig. 2). Variation in the depth during low tide  and high tide periods forms a possible reason for the mortality difference between the north  side and south side of the Island. The exposure of the coral reefs of the south side of the  Island to the sunlight during low tide is partial or full while the other sides are not. Low tide  exposure is a more valid reason for the difference in mortality than the elevated sea surface  temperature. The mortality of coral increases in May and June due to bleaching when the  temperature increases resulting in an extended exposure time during low tide and direct  contact with sunlight (Fig. 3).

Fig. 2. Percentage of bleaching in both North and South side of the Island.  Image Source: Vinoth, R., Gopi, M., Kumar, T. T. A., Thangaradjou, T., &  Balasubramanian, T. (2012). Coral reef bleaching at Agatti Island of Lakshadweep  atolls, India. Journal of Ocean University of China, 11(1), 105-110.
Fig. 3. (A, B) – bleached coral; C – bleached giant clam; D – bleached sea anemone. Image Source: Vinoth, R., Gopi, M., Kumar, T. T. A., Thangaradjou, T., &  Balasubramanian, T. (2012). Coral reef bleaching at Agatti Island of Lakshadweep  atolls, India. Journal of Ocean University of China, 11(1), 105-110.

There have been several bleaching events in the past due to elevated sea surface temperature  (Table 2). 

Table 2. 

Location and Year Bleaching  (%)Sea surface temperature of the  corresponding period (°C)Reference
Andaman, 2010 36-39 31-33 Krishnan et al.,  2011
Gulf of Munnar, 2008 10.5 31-33.5 Edward et al.,  2008
Gulf of Munnar, 2007 12.9
Gulf of Munnar, 2006 15.6
Gulf of Munnar, 2005 14.6
Palk Bay, 2002 50-60 32 Kumaraguru et  al., 2003
Gulf of Kachchh, 1998 11
Gulf of Munnar, 1998 82 3 above the seasonal average Arthur, 2000
Lakshadweep, 1998 89

The sea surface temperature of the Lakshadweep reef areas elevated at a rate of 0.21 °C per  decade from 28.50 °C in 1985 to 28.92 °C in 2005. The annual average maximum of sea  surface temperature remained the same, but the annual average minimum sea surface  temperature increased at a rate of 0.30 °C per decade from 27.2 °C to 27.8 °C. The El Nino  increased the sea surface temperature from 1997-1998 to 31 °C. 

Sedimentation and turbidity are also two important factors contributing to corals mortality.  However, the corals of Agatti Island currently do not face such a threat. The bottom  sediments are stabilized by the dense seagrass beds in the lagoon areas. 

Conclusion 

There is an average of 73% bleached corals, with bleaching-related mortality of sea  anemones (87%) and giant clams (83%) in the Agatti reefs. The bleached corals need time to  slowly recover in time and replaced by new coral colonies over the old ones. Past researches  proved that corals can recover after the removal of adverse conditions. Coral reefs are  important as a habitat and ecosystem for migratory fishes and need urgent attention. 

Reference 

1. Vinoth, R., Gopi, M., Kumar, T. T. A., Thangaradjou, T., & Balasubramanian, T.  (2012). Coral reef bleaching at Agatti Island of Lakshadweep atolls, India. Journal of  Ocean University of China, 11(1), 105-110.

The Pondicherry Shark

A shark species that was thought to be wiped from the surface of the earth was not given much attention since the 1970s. But the Pondicherry Shark, a small-sized long-snouted shark belonging to the rare requiem shark family.

We used to be able to find Pondicherry sharks all over the Indo-Pacific region, from the Gulf of Oman to New Guinea. Today, the International Union for Conservation of Nature has classified it as critically endangered today (IUCN).

There are extremely few species of Pondicherry sharks available for study, and we know really little about this species. The Pondicherry shark population was widely distributed in the Indo-Pacific area, but was most commonly found along India’s coast. The bulk of Pondicherry shark specimens come from India, and according to various old stories, the Pondicherry shark occasionally entered freshwater and was observed in the rivers Hooghli and Saigon. If the reports are correct, the Pondicherry sharks’ limited salinity tolerance could be the cause.

[Source]

The shark species is truly enigmatic, and not much is known about its natural history. The black tips of the dorsal, pectoral, and Tai fins distinguish it. At the base, the front teeth are serrated, and at the tip, they are smooth.

Throughout its range, it is most likely threatened by increasing fishing pressure. Even though the capture of Pondicherry sharks and their fin-export has been banned entirely throughout the country, shark fishing and trade still persists because sharks, with their keen teeth, look similar and are frequently misdiagnosed by fisherman. Shark fins are in high demand in Southeast Asian countries, while shark meat is consumed domestically. Shark pieces are used in the preparation of Sorrah Puttu and other seafood dishes.

Pondicherry penetrates freshwater rivers within its area every year due to its peculiar lifecycle. This indicates that there is a bottleneck near the river mouths, where all the sharks congregate. Unfortunately, this makes them an easy target for unlicensed gillnetters, which has resulted in the extinction of an already elusive shark species.

Sharks play a crucial role in maintaining an intricate balance in nature. As an apex predator, they help to gauge the ocean’s health. Sharks eat larger predatory fish like groupers, therefore their numbers are likely to increase if they aren’t present. A coral reef system’s herbivore fish life is diminished as the population of larger predatory fish such as groupers grows.

This is clearly indicative of what our actions have led to – they have forcibly pushed an entire species of shark to the brink of extinction. Will this rare shark family simply be the next to be forgotten, and erased off the list of scarce creatures that share the same planet as our? There may not be a single answer, but it is certainly not hard to surmise the answer – it is imperative that we change our ways to protect the Pondicherry sharks.

Reference:
Source 1
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Source 5

Olive Ridley Turtles: Conservation of Nesting Sites along the Coast of Odisha

By Rohan Nath

Introduction

The well-being of a seabeach decides the population of sea turtles residing on them. Sea turtles are highly dependent on land for the reproduction phase of their life. Even though predation of both hatchlings and adults by whales, sharks, large fishes and saltwater crocodiles, play a role in their mortality, the prime reason of turtle mortality is due to certain marine fishing practices. On the beach, predators like birds, beach mammals, insects and crabs’ prey upon both eggs and hatchlings. Hence, threats to beaches which are used as a nesting habitat to the sea turtles hampers the reproduction of sea turtles. Anthropological activities like sand mining, cluttered beaches, developmental activities along the coast and coastal armouring harms the habitat of these sea turtles.

According to WII-DGH Turtle Project Interim Report of 2011, there is a high affinity between sea turtles and their breeding grounds and hence, the whole population can suffer a serious damage due to reduction or loss of even a single rookery. The National Research Council reported in 1990 that urbanization and developmental activities on the coast have destroyed the nesting beaches of the Indian sea turtles.

Several researchers are currently involved in the conservation of the habitat of olive ridley sea turtles (Fig. 1) along the coast of Odisha and how developmental activities affect the sea turtles and their nesting habitats.

Fig. 1. Olive Ridley turtle hatchlings at Gahirmatha nesting ground in Odisha.
Image Source: India Times

Location

The state of Odisha has seven districts with coasts: Puri, Ganjam, Jagatsingpur, Khurda, Bhadrakh, Kendrapara and Balasore with a coastline of about 480km (Table 1) (Fig 2). Along the coast, there are around 250 coastal fishing villages.

Table 1. The coastal districts of Odisha and their characteristics.

Fig. 2. The coastal districts of Odisha.
Image Source: https://www.researchgate.net/figure/Coastal-districts-of-Orissa_fig2_226504527

Developmental activities along the coast of Odisha

The developmental activities along the coast of Odisha are summarised below (Table 2).

Table 2. Developmental activities

The destruction of nesting habitats of sea turtles due to developmental activities

The construction of ports requires the dumping of sand or silt to increase the level of the site of port construction. The biodiversity is affected by the supplementary construction in locations surrounding the port site resulting in an increase in pollution, land use changes, and the destruction of natural habitat. Olive ridley turtles generally breed in the offshore waters of Odisha. The entire food chain of the sea turtles is affected due to the vast amount of dredging of shipping channels which have an effect on the light penetration and turbidity of the water on the benthic habitats. This can result in an increase of biochemical oxygen demand and primary productivity of the water. Intense amount of noise may discourage the adult olive ridley sea turtles from foraging sites and nesting grounds.

Ports, specifically Indian ports in depraved conditions are responsible for water pollutions from cargo discharges, accidental fuel oil leaks and bilge cleaning. Large mega-ports have an adverse effect on the biodiversity of the coast. The breeding sites of the turtles have been degraded by elevated noise levels and pollution. Light pollution hampers the survival of the hatchlings and the nesting behaviour.

The vast number of fish landing centres and fishing harbours and jetties pose a serious threat to the population of the sea turtles. The construction of new fishing harbours and jetties by the Government of Odisha may further aggravate the issue. New fishing harbours might lead to more intense fishing activities and mechanized fishing fleets increasing the accidental catch of turtles.

Casuarina plantations lead to a reduction of nesting space and harms the nesting behaviour of the turtles. It changes the topography of the beach by deposition of litter and its root growth limiting the space available for the turtle to nest. Predators like jackals and hyenas which predates on sea turtle eggs takes cover in these plantations.

Numerous defence facilities and establishments affect the nesting sites of the sea turtles. The training centre INS-Chilika and Golabandha, the missile test programme at Chandipur-on-sea and Wheeler Islands are positioned close to the nesting sites and the target ranges are in the offshore open waters where the turtles aggregate for breeding. Critical behaviours of the sea turtles like, nocturnal sea-finding behaviour and nest site choice of both hatchlings and nesting females are disrupted due to artificial illumination of these establishments.

Reference

  1. Behera, S., & Tripathy, B. (2014). Review of current developmental activities and their possible impact on olive ridley sea turtles along the Odisha Coast of India. Testudo, 8(1), 38-55.

Algae – sore reminders of how we pollute water bodies

The night of August 18, 2019 had residents of Chennai enthralled. A night stroll on the Elliot’s Beach turned out to be unforgettable as visitors saw a blue light glimmering the waves that crashed on the shore.

Photo by: B. Velankanni Raj (Image Source)

It was later reported that the Noctiluca algae (commonly known as sea tinkle) were responsible for the magical blue glow on the waves.

While the algae-produced light was fascinating, the reasons behind the sudden emergence of these microscopic organisms is a cause for concern. The sea tinkles in Chennai in 2019 were more than just a treat to the eye. They were reminders of what our activities have wrought.

A rapid increase or accumulation of algae is called an algal bloom. Sewage drainage into water bodies, deforestation, runoff of fertilizers and pesticides, etc. – all these increase the quantity of nutrients present in water bodies. The result? Rapid growth of algae. Rising temperatures of water bodies due to global warming also contributes to surges in the algae populations.

Do algae blooms harm oceans and other water bodies? The sad answer is yes, they do. Massive algae population explosions not only highlight rising pollution and global warming levels, they also impact the environment adversely. By releasing toxins in the water, making water unfit for utilization, and depriving aquatic life from oxygen and sunlight, algal blooms are a dangerous threat to aquatic ecosystems.

Algal blooms have occurred time and again since the early 2000s. In the Northern Arabian Sea, these blooms have been reported annually. The smallest state of India, Goa, and the city of Mumbai too have witnessed such sightings.

Algal bloom blankets a section of the Achenkoil River in Kerala (Image Source)

The negative consequences of human activities on the environment are aplenty – algal blooms are just one of them. Their repeated occurrences point out to the bleak future we are determinedly pursuing.