By Dilini De Silva
The first time I went diving was off the coast of southern Sri Lanka. As I descended into the blue, the initial strangeness of breathing underwater quickly gave way to awe. A school of vibrant fish swirled past, weaving through coral formations that pulsed with life. I was hooked. That moment sparked my love for diving, and before long, I earned my PADI certification. Beneath the surface, every slow, measured breath felt like meditation—an immersion not just in water, but in a vast, living world that few ever get to see. It was also impossible to ignore the damage: bleached corals, plastic debris, and marine creatures struggling to survive. As divers, we are privileged to witness the ocean’s breathtaking beauty—but that privilege comes with a responsibility to protect it.
The Ocean Under Threat
Oceans are in crisis. Climate change is warming the waters and acidifying the seas. Pollution, overfishing, and habitat destruction are devastating marine life. Coral reefs—the rainforests of the ocean—are bleaching at alarming rates. Marine species are disappearing. Plastic waste is suffocating ecosystems. But divers are not just passive observers; they are on the frontlines of ocean conservation. By participating in coral restoration, ocean clean-ups, citizen science, and responsible diving, they play a crucial role in protecting and rehabilitating marine environments.
Restoring Coral Reefs: Giving Life Back to the Ocean
Coral reefs support 25% of all marine species, but they are under severe threat from rising ocean temperatures, pollution, and destructive fishing practices. When corals die, entire ecosystems collapse. Fortunately, divers are helping to restore these vital underwater habitats. Organizations like the Coral Restoration Foundation train divers to transplant coral fragments onto damaged reefs, helping new corals grow and providing stable environments for marine life. Through careful placement and monitoring, these efforts increase reef resilience, ensuring that fish and other marine species have a thriving habitat.
Removing Ocean Waste: Combatting the Plastic Crisis
Every year, millions of tons of plastic enter our oceans, entangling marine life, polluting water, and destroying ecosystems. Abandoned fishing gear—known as ‘ghost nets’—continues to trap and kill marine creatures long after being discarded. Divers are uniquely positioned to help combat this crisis. Clean-up dives, such as those organized by Project AWARE’s Dive Against Debris, empower divers to remove plastic waste from the ocean floor. Not only do these efforts directly improve underwater environments, but they also provide valuable data on marine pollution, helping to inform conservation policies and raise global awareness.
Citizen Science: Divers as Ocean Advocates
Scientific research is crucial for ocean conservation, and divers can play an active role in gathering essential data. Citizen science programs like REEF’s Volunteer Fish Survey Project enlist divers to monitor species populations, track coral bleaching, and identify invasive species. This grassroots approach supplies researchers with vital information about marine health, guiding conservation efforts and influencing policy decisions. Every dive becomes an opportunity to contribute to scientific knowledge and support ocean preservation.
Responsible Diving: Protecting What We Love
Beyond active conservation efforts, every diver has a responsibility to minimize their impact on the marine environment. Simple actions—such as maintaining proper buoyancy, avoiding contact with coral, and using reef-safe sunscreen—help protect fragile ecosystems. Supporting eco-conscious dive operators and promoting sustainable tourism ensures that marine environments are preserved for future generations.
The Power of Divers to Make a Difference
Divers have a unique and powerful opportunity to be stewards of the ocean. Whether through coral restoration, clean-up dives, citizen science, or responsible diving practices, they are playing a vital role in marine conservation. With every dive, they not only explore the ocean’s wonders but also contribute to its protection. By taking action, divers can help ensure that the underwater world remains vibrant and resilient for generations to come.
Are you ready to take the plunge into marine conservation? Whether you’re a seasoned diver or just starting your journey, there are countless ways to get involved. Join a coral restoration project, participate in a clean-up dive, or simply share your passion for ocean conservation. Together, we can make a difference—one dive at a time.
By Thisutha Bulathgama
Underneath the placid waters of Sri Lanka, a hidden crisis is unfolding—a threat to the livelihoods of coastal communities, marine ecosystem and the country’s national security. Illegal, Unreported and Unregulated Fishing, also known as IUU fishing, is fishing in places with no regulations, without authorization, and, or without reporting catches. IUU fishing causes significant harm to local fishermen, marine lives and the country’s economy.
IUU fishing is far more dangerous than many realize. Its consequences ripple across the environment, economy and society, threatening the very fabric of Sri Lanka’s coastline. Environmentally, it decimates Sri Lanka’s fishing population, and harms coral reefs and sea beds. IUU fishing also causes the unintentional capture of protected species such as sea turtles and dolphins, pushing these vulnerable species closer to extinction.
Economic impacts too are equally alarming. Small-scale fishermen, the backbone of the island’s coastal economy are hit the hardest. As IUU fishers rake in the fish stocks, the local fishermen suffer, pushing their families further into poverty. On a larger scale, the country’s seafood exports are impacted due to the international restrictions imposed on countries failing to restrict IUU fishing. But the repercussions go beyond economics. IUU fishing threatens food security, leaving coastal communities struggling to feed themselves. Even more disturbingly, this issue is often linked to organized crime, including human trafficking, drug smuggling, and forced labor. It’s a web of exploitation that extends far beyond the ocean.
Sri Lanka’s Fight Against IUU Fishing
As a developing nation, Sri Lanka has recognized the dire necessity of addressing IUU fishing.
The country has demonstrated its commitment to international cooperation by ratifying key international agreements such as the Agreement of Port State Measures to Prevent, Deter and Eliminate IUU Fishing, and the United Nations Convention on the Law of the Sea. In partnership with the International Organization for Migration (IOM), and private stakeholders such as Zindhu Maritime Solutions (Pvt.) Ltd., the Sri Lankan government has implemented Vessel Monitoring Systems. These systems use cutting-edge technology to monitor the high-seas fishing operations. Despite these efforts, challenges persist. Weak enforcement, inadequate monitoring and corruptions are among the top contenders hampering progress on this front.
To fight against IUU fishing, Sri Lanka must take bold & decisive steps. Strengthening laws and policies, expanding regional cooperation, and imposing stricter regulations are critical. But the fight does not end with the government. Consumers too have a significant role to play. Supporting ethical fishing methods and choosing sustainably sourced seafood can drive progress towards responsible fishing. Educating local fishermen and responsible authorities about the long-term impacts of IUU fishing can foster a collaborative effort to protect Sri Lanka’s rich marine resources for future generations. Most importantly, collective action is key—the government, civil society and international organizations must work together to enhance the long-term sustainability. Only united action can safeguard Sri Lanka’s marine biodiversity, sustain livelihoods, and prevent further environmental and economic damage.
The stakes are high, and the clock is ticking. IUU fishing is not just an environmental issue—it’s a threat to Sri Lanka’s economy, food security, and social stability. By taking decisive action today, we can protect our oceans, support coastal communities, and ensure a sustainable future for generations to come. Let’s join hands to turn the tide against IUU fishing!
By Sanduni Nakandala
What are PFAS?
PFAS, or Per -and-Polyfluoroalkyl substances, are the world’s most persistent pollutants. Invisible yet everywhere, these synthetic chemicals are prized for their ability to resist water, oil, heat, and stains, making them essential in fabrics, nonstick cookware, firefighting foams, and countless industrial applications. Their resilience comes from the multiple carbon-fluorine (C-F) bonds they contain—some of the strongest in chemistry. This makes PFAS nearly indestructible in nature, leading to their infamous nickname: “Forever Chemicals.”
Why are PFAS so dangerous?
What makes PFAS so effective also makes them a global threat. These chemicals do not break down in the environment, meaning they accumulate over time in water, soil, and even living organisms. They bioaccumulate in marine life and biomagnify up the food chain, reaching dangerous levels in top predators—and ultimately, humans. Scientists have linked PFAS exposure to serious health risks, including cancer, hormone disruption, and developmental issues in children (Time Magazine, 2023). Alarmingly, manufacturers knew about these risks as far back as the 1960s but continued production anyway (Time Magazine, 2023). It wasn’t until the early 2000s that meaningful regulations were even considered.
How does PFAS reach the ocean?
The ocean is our planet’s final sink, where everything eventually flows. PFAS enter marine ecosystems through multiple pathways:
- Industrial discharge and wastewater runoff
- Landfills and sewage sludge (often used as fertilizer, which leaches PFAS into rivers)
- Atmospheric deposition—A 2019 study found that sea spray aerosols are a significant source of certain PFAS in the atmosphere, illustrating how these chemicals can travel vast distances (Xiao et al., 2019).
- Contaminated rivers that transport these chemicals from inland sources to the coast
Even wastewater treatment plants, designed to clean our water, are not equipped to effectively remove PFAS. Once released into the ocean, these chemicals hitch a ride on sea currents, spreading from industrial hotspots in East Asia and Europe to the most remote and pristine corners of the Arctic. Migratory marine species further transport these chemicals, contaminating fragile ecosystems miles away from their original source.
A Growing, Invisible Threat
The ocean is our greatest life-support system, regulating climate, producing oxygen, and sustaining marine life. But PFAS pollution is silently disrupting this delicate balance. With each passing day, these chemicals spread further, infiltrating ecosystems that have never been exposed to industrial activity.
How will this contamination alter marine biodiversity? What cascading effects will it have on human health, fisheries, and food security?
As we uncover the full scope of PFAS pollution, one thing is clear: the time to act is now.
Stay tuned for Part II, where we explore what can be done to tackle PFAS pollution—and how you can help protect our oceans.
Cont’d
By Thisuri Rojie Ekanayaka
As the winter weather rolls into the Northern Hemisphere while Sri Lanka’s skies begin to clear, the tourist industry prepares for “The Season” to begin. Indeed, post-war Sri Lanka has seen a boom in tourism, creating jobs for local communities and bringing in much needed foreign currency. The Western and Southern coasts have especially thrived, and together these areas account for over 60% of the hotel room capacity in the country. But this has also led to fears of Sri Lanka becoming “Bali 2.0” and it raises questions about whether we are doing enough to protect our fragile marine eco-systems.
The coasts of Sri Lanka cater to a wide variety of interests. You can simply relax on a beach, try a water sport or even check out the local wildlife. But in excess, these activities can exact a heavy environmental toll. Some of the major concerns are waste from hotels and restaurants; coastal erosion from unregulated construction; leaking of pollutants and disturbances to habitats from water sports and transport; as well as improper interactions with wildlife causing stress and injuries to animals.
Some key pieces of legislation that protect the environment from tourism include the Wildlife, Fauna and Flora Protection Act; the National Environmental Act; the Coastal Conservation Act; and the Tourism Act. Their implementation falls upon a range of government institutions. For instance, the Sri Lanka Tourism Development Authority issues guidelines on water sports and wildlife tours during its registration processes while the Coast Conservation Department and Urban Development Authority regulate construction. The Sri Lanka Coast Guard meanwhile is mandated with monitoring environmental violations and engaging in conservation efforts.
Despite the existence of these laws and institutions, serious issues persist. According to industry insiders and experts, this is caused by a lack of awareness, poor enforcement of laws, corrupt practices in government agencies and insufficient penalties for violations. Tackling these problems is crucial but not sufficient. It’s also necessary to proactively support the conservation and regeneration of the environment. Lessons can be learnt from neighbours such as Thailand which have closed off certain tourist-heavy coastal regions temporarily to allow the environment to recover.
Striking a balance between supporting local economies and conservation is essential for success and this should not be seen as two entirely separate concerns. Adequately protecting Sri Lanka’s coasts will not only benefit the environment, but it will also ensure the sustainability of the tourism industry itself.
This article is also published in The Morning. Read it here: The Morning
By Madhushini Gananathan
What is the unseen wave of death silently endangering the ocean’s most magnificent creatures? Ship strikes have been a drastic threat to the marine life of our country. Sri Lanka is an important hub for global shipping, strategically located in the Indian Ocean. The key shipping routes passing our country include the Asian Europe route, the Middle East to South East route, and Africa to East Asia route. These routes incorporate the ports of Colombo and Hambantota.
The impact on marine species is quite devastating, particularly harming blue whales found off the southern coast, which are the primary species affected along with other species such as Bryde’s whales, dolphins, sea turtles, and other sea creatures. It is noteworthy that ship strikes-collisions between vessels and marine animals- cause severe injuries, fatalities, and disruptions to our marine ecosystems in several ways. The blunt force trauma results in fractures, internal bleeding, and organ damage, often leading to marine species death. Also, fast-moving boats with propellers can cause deep cuts and amputations, leaving oceanic fauna severely injured, which can cause prolonged suffering. Further, fast ships generate intense noise, disorienting marine creatures.
This growing concern of ship strikes brutally exacerbates the disruption of marine ecosystems, causing the loss of keystone species, especially blue whales which play a vital role in nutrient cycling. Also, it tends to cause altered behavior and declines in populations with repeated ship strikes and frequent vessel traffic, leading to changes in migration routes and feeding grounds. The growing tourism industry in Sri Lanka also plays an important role. Declines in blue whale populations due to ship strikes could diminish whale sightings, potentially reducing tourist numbers in whale watching tourism. This drastically affects the local communities that rely on tourism revenue. The overlap of major shipping lanes near Sri Lanka, especially south of the island, increases the risk of ship strikes, as slow-moving whales often surface to breathe in these high-traffic zones as massive cargo ships, oil tankers, and fishing vessels navigate these busy routes. High-speed vessels increase collision risks with marine animals like whales, as they have less ability to stop quickly if a whale is in their path, leading to greater impact force. A recent global study published in 2024 estimated that thousands of whales are injured and killed each year after being struck by ships.
To address this growing concern, several solutions can be implemented such as re-routing shipping lanes away from critical marine habitats and enforcing slower vessel speeds in areas of high marine life activity. Additionally, improving defections and monitoring systems in real-time with advanced technology such as Radar systems, acoustic detection, and underwater drones can help to avoid these ship strikes. Protecting Sri Lanka’s marine biodiversity is crucial not only for preserving its unique ecological heritage but also for sustaining the livelihoods of coastal communities and maintaining global environmental balance. Collaborative action encouraging partnerships between government agencies, local communities, and international organizations leads to innovative conservation. As Michael J. Moore reminds us, true progress lies in harmonizing economic pursuits with the delegate rhythms of our oceans- ensuring that every gain is measured by the health of our marine future.
By Muthu Tharanga Rajapakse
වසර මිලියන සියයකට අධික කාලයක සිට පරිණාමය වෙමින් පැවත එන මුහුදු කැස්බෑවන් ලොව පුරා ප්රධාන වශයෙන් විශේෂ හතක් හඳුනාගත හැකිය. ඉන් කැස්බෑ විශේෂ පහක්ම ශ්රී ලංකා මුහුදු සීමාව තුළ හඳුනා ගත හැක. ඉතා දීර්ඝ ආයු කාලයක් හිමි මුහුදු කැස්බෑවන් ස්වභාවික සම්පත් සංරක්ෂණය පිළිබඳ ජාත්යන්තර සංගමයේ(IUCN) රතු දත්ත වාර්තාවට අනුව ශ්රී ලංකා මුහුදු සීමාව තුළ ජීවත් වන කැස්බෑ විශේෂ සියල්ලන්මද ඇතුළුව දේශීය මෙන්ම ගෝලීය වශයෙන්ද තර්ජිත සත්ත්වයින් ලෙස හඳුනාගෙන ඇත.
අවුරුදු තිහක් පමණ වන විට බිත්තර දැමීම සඳහා ශරීරය හැඩගැසෙන ගැහැණු කැස්බෑවන්, පෘථිවි චුම්බක ක්ෂේත්රය පදනම් කරගනිමින් ඔවුන් බිහි වූ වෙරළ තීරයටම බිත්තර දැමීම සඳහා පැමිණෙන බව අනාවරණය වී ඇත. නමුත් වර්තමානය වන විට එම ස්ථාන වල සිදු වී ඇති නව ඉදිකිරීම්, වෙරළ දූෂණය වැනි දෑ ඔවුනට තර්ජනයක් වී ඇත. කැස්බෑ පැටවකු බිත්තරයකින් නිදහස් වීමට දින හතලිස් පහකට ආසන්න කාලයක් ගතවන අතර මෙම කාලය අතරතුර සිදුවන වෙරළ ඛාදනය වැනි වෙරළබඩ වෙනස් වීම් තුළින් ද බිත්තර විනාශ වීමේ අවධානමක් පවතී.
අතීතයේදී කැස්බෑ මාංශ සහ බිත්තර වෙළඳාම සාමන්ය පරිදි සිදු විය. වර්තමානය වන විට එය සම්පූර්ණයෙන්ම තහනම් කර තිබූ නමුත් මේ වන විටත් පෞද්ගලික වාසිය තකා ඇතැමුන් වෙරළ ප්රදේශ වල ගැවසෙමින් කැස්බෑ බිත්තර සොරකම් කර විකිණීමට පෙළඹී තිබේ. ඒ සඳහා නිසි නීතිමය ක්රියාමාර්ග නිසියාකාරව ක්රියාත්මක නොවීමත් මෙවැනි තත්තව මගහරවා ගැනීමට නොහැකි විමට තවත් එක් හේතුවකි.
කැස්බෑවකු ආසන්න වශයෙන් වරකට බිත්තර 80-150 අතර ප්රමාණයක් මුදාහරින නමුත් විශාල කැස්බෑවකු ලෙස වර්ධනය වී ඉතිරිවන්නෙ 1/1000 ක් වැනි ඉතාමත් සීමිත සංඛ්යාවකි. ඒ සඳහා ඉහත සඳහන් වූ හේතූන්ට අමතරව වෙරළ තීරයේ කෘතීම ආලෝකකරණය, දේශගුණික විපර්යාසවල බලපෑම්, සාගරයට මුදාහරින අපද්රව්ය, නාවික තෙල් කාන්දු වීම්, සාගර පත්ලේ කැණීම්, මත්ස්ය කර්මාන්තයේදී භාවිතා කරන මසුන් ඇල්ලීමේ දැල් වැනී දෑ හේතුවෙන් කුඩා කැස්බෑ පැටවුන්ටද විශාල කැස්බෑවුන්ටද නිරන්තරයෙන් හානි සිදුවනවා මෙන්ම ඔවුන්ගේ අහාර රටා, වාසස්ථාන සහ උෂ්ණත්වය මත සිදුවන කැස්බෑවන්ගේ ලිංගිකත්වයේ වෙනස් වීම් සඳහාද බලපෑම් එල්ල කරනු ඇත.
අලුත උපන් කුඩා කැස්බෑවන් රාත්රී කාලයේදී චුම්බක ක්ෂේත්රය පදනම් කරගනිමින් පැය 48ක් පුරාවට එක දිගට පිහිනීම’Swimming Frenzy’ සිදු කරන බවට පරීක්ෂණාත්මකව තොරතුරු ඉදිරිපත් වෙමින් පවතින අතර ඒ අනුව බිත්තර වලින් එලියට පැමිණෙන කැස්බෑ පැටවුන් මුහුදට නිදහස් කිරීම ප්රමාද වුවහොත් ‘Swimming Frenzy’ අහිමි වීමත් සමග ඔවුන්ගේ පිහිනීමේ ජවය දුර්වල වීමට ඉතා ඉහළ ප්රවණතාවයක් පවතී. එමෙන්ම දහවල් කාලයේදී ඔවුන් මුහුද වෙත මුදා හැරීමේදී විලෝපිකයින්ගේ ගොදුරු බවට පත්විම සහ නොයෙකුත් අනතුරු සඳහා මුහුණ දීමටද සිදු වනු ඇත.
කෙසේ වුවත් මුහුදු කැස්බෑවන් ඉතාමත් වැදගත් හා වටිනාකමක් උසුලන සත්ත්ව කොට්ඨාශයකි. සදාචාර සම්පන්න සහ සිතීමේ බුද්ධිය නොමද වශයෙන් ඇති මිනිසුන් වශයෙන් වඳවී යාමේ තර්ජනයට ලක් වී සිටින මුහුදු කැස්බෑවන් ආරක්ෂා කිරීම උදෙසා කටයුතු කිරීමට අප සියල්ලන්ම වගබලාගත යුතු නොවේ ද?
By Janya Edirisinghe
Mariculture, commonly known as marine farming, is a specialised subset of aquaculture, that is practiced in seawater habitats and lagoons as opposed to in freshwater aquaculture. Fish like sea bream, cod, halibut, and sea bass are examples of products cultivated through mariculture. It accounts for about 40% of the world’s aquaculture production. Countries such as China, Japan and Indonesia are some of the top mariculture-producing countries.
What are the types of Mariculture?
Mollusk Culture
Clams, oysters, scallops, and mussels are popular sea animals that can be farmed in regions with temperate climates. The process of mariculture involves initially collecting larvae from natural habitats or artificially fertilized larvae grown in hatcheries. Usually, parents are captured and taken to spawn their children in captivity.
Then, the larvae are taken to a different location to grow where hanging culture is practised, where they can grow suspended on strings, trays, stacks or mesh bags that hang from long lines floating in the water.
A few other methods of growing molluscs include vertical/rack culture, where they grow directly on sticks staked into the ground or on racks upheld by posts and bottom culture in which clams, for example, grow on shells, rocks or cement slabs on the sea floor. Also, molluscs such as abalone are grown in tanks.
Crustacean culture
Shrimp are mostly grown in tropical regions. Initially, the babies are grown in hatcheries, and they are then taken to grow in ponds, concrete raceways, and tanks. The shrimp ponds used to be located in rice fields and mangrove forests all around the world, but the subsequent destruction of mangrove areas has encouraged farmers to grow shrimp in inland ponds filled with transported seawater instead.
Marine Plant Culture
Most marine aquatic plants such as seaweed are grown in temperate regions. The plants used for breeding are originally sourced from their natural environment. Most farmed plants tend to be grown in hatcheries and once they reach a certain life stage, the plants are transferred to grow sites where the young plants are grown attached to suspended lines or floating rafts, in bottom cultures anchored to the sea floor and in inland tanks, similar to the way that molluscs are grown.
Finfish culture
Finfish are farmed in both temperate and tropical regions. Their defining feature is that they have fins and an example of a finfish includes salmon, which is also an example of a diadromous fish and these are the types of fish that migrate between the ocean and freshwater. Marine farming involves raising these diadromous fish.
Farmed finfish are first born in hatcheries and are then put into tanks and transferred to growth sites after the fertilised eggs hatch.
Finfish can be grown in pens, cages and large tanks. Pens are anchored to the sea floor in shallow waters. Cages can be located inshore or offshore. Inshore cages are usually in shallow waters with more protected areas that have less water circulation compared to offshore cages that are in deep water which has better water circulation and more exposure to storms.
The fish can also be grown in ponds that feature canals and dikes to help supply and drain water from pond compartments. Recirculating systems are used to control the water supplied to these ponds and factors such as temperature, as well as physical and chemical properties are taken into consideration.
Finfish are also subject to methods of growing called enhancement and ranching. At the inception, the fish are released at a young age to help restock free-living populations. Afterwards, the fish are captured in open waters that are artificially enclosed. Sea ranching is a method of mariculture that is also used to grow molluscs, crustaceans, marine plants and other marine organisms.
Over time, the raising of fish in cages close to the shore or in bays has caused severe ecological issues including contamination, disease, increased fish mortality, and severe damage to marine ecology, quality of the environment, and tourism.
To conclude, although world fish production from capture fisheries levelled off during the 1990s, demand for seafood continues to increase rapidly. This is because of the growth of the human population and the widespread view that seafood is healthy food. Scientists believe that the natural products from the ocean will not increase so to meet the rise in demand for seafood, both mariculture and fresh-water aquaculture will have to increase significantly. However, while several species are being reared successfully by marine culturists, various desirable species such as crabs and lobsters are very difficult to rear due to their life cycles being difficult to control under culture conditions or simply because they are way too complex.
Header Image: A fish farm off the coast of Greece. Photo by Artur Rydzewski
By Samudra De Silva
From the shallow seagrass beds of the Indian Ocean, and vivid reefs of coral triangle to sandy coasts of the Eastern Pacific, seven different species of sea turtles swim through our ocean waters. As a highly migratory species, turtles periodically come ashore to nest, and spend the most of their lives in the ocean. For more than a hundred million years, sea turtles have played a crucial role in sustaining the balance of our marine ecosystems. They fortify productive coral reefs and transfer nutrients from the ocean to coastal dunes. Over the last two centuries, human activities have growingly challenged the survival of these ancient mariners.
Today Sea turtles are being completely erased from some parts of the planet and pushed to the verge of extinction. Nearly all seven existing species of sea turtles are now classified as endangered, with three of them being critically endangered. But at the same time, sea turtles are one of the most loved and discussed among marine animals. There is hardly anybody who hate these graceful flippers. It is important to review how we knowingly or unknowingly have doomed their lives.
Sea turtles are victims of poaching and over exploitation. They have been slaughtered for human consumption and their meat, skin, and shells are traded as food, medicine, collectibles, and spiritual artifacts over the years in unsustainable levels. Turtle eggs are collected from nesting sites as food and for their alleged aphrodisiac effect. Hawksbill turtles are hunted for their unique gold and brown shells used in making jewelry and other collectibles. Many other sea turtle species are killed for their skin, which is sold as a raw material for leather accessories. A global assessment on illegal marine turtle exploitation, demonstrate that over 1.1 million sea turtles were exploited from 1990-2020 against existing laws prohibiting their use in 65 countries with over 44,000 turtles exploited annually over the past decade. Exploitation across the 30 years dominantly consisted of green (56%) and hawksbill (39%) turtles when identified by species. International trade of all species of sea turtles and their parts is prohibited under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), a global agreement among 173 governments to regulate or ban international trade in species under threat, yet illegal trafficking persists, especially in parts of Africa, Asia and the America.
Bycatch or the incidental capture by fishing gear is lethal to most sea turtles, especially endangered loggerhead turtles, greens turtles, and leatherback turtles. Worldwide, hundreds of thousands of sea turtles are caught up in shrimp trawl nets, gill nets, and on longline hooks every year. Since sea turtles need to reach the water surface to breathe, many drown once entangled in the nets or hooks. This threat is increasing alarmingly as fishing activity expands. However, some relatively inexpensive changes in fishing gear, such as using larger hooks from which sea turtles can escape, is observed to bring down the mortality rate. Turtle excluder devices (TEDs) could reduce sea turtle bycatch in nets as well.
Along with many other species, sea turtles face habitat loss. Feeding grounds of turtles such as sea grass beds and coral reefs are continually deteriorated by natural and human activities including sedimentation, nutrient run off from agriculture, and beach restoration through sand filling. Human development projects such as beach nourishment, parks, rock jetties, and buildings on beaches can reduce the amount and quality of available nesting sites for sea turtles. Human generated light is a serious threat to newly hatched sea turtles. Hatchlings are naturally attracted to light as the brightest area on a natural beach is the horizon over the ocean. Bright light emitted from streetlights and building on beaches causes hatchlings to become disoriented, crawling towards the light on the land and away from the water. Some beaches with high turtle nesting density have lost thousands of hatchlings due to impact of artificial light. There are recorded cases where large number of hatchlings were run over by vehicles after disorienting and crawling onto roadway. Noise and human activity on the beach also may cause females turtles to return to the sea instead of nesting.
Pollution, both chemical and physical, has become fatal. Trash in ocean and along coastlines, lowers the quality of their feeding grounds and nesting sites. Turtles seem to confuse solo drifting debris with their diet, and many turtles are dying from intestinal blockage due to ingestion of balloons and plastic bags which resemble their gelatinous translucent prey (jelly fish). A recent study shows that loggerheads ate plastic 17% of the time they encountered it, mistaking it for jellyfish. It escalated to 62% for green turtles, likely on the lookout for algae. The chemicals ingested from the plastic can leach into their eggs and affect offspring. A high level of phthalates has been measured in Leatherback turtle eggs’ yolks, which can disrupt endocrine activity in hatchlings. In 2015, an Olive Ridley sea turtle was found with a plastic drinking straw lodged inside its nostrils. Sharp objects found in marine debris can cause both internal and external injuries in sea turtles, which turns lethal. Sea turtles are vulnerable to oil spills because of the oil’s tendency to linger on the water’s surface, and affect them at all stages of their life cycle.
Climate change which is a long term and inevitable outcome of pollution has an impact on turtle nesting sites, as alterations in sand temperatures of the nest which determines the sex of hatchlings. Unusually warm temperatures are disrupting the normal ratios, biasing towards females resulting in fewer male hatchlings, or even preventing any of the eggs from hatching. The right balance between sexes is a determining factor for the continued procreation of this critically endangered species. Warmer sea surface temperatures can also lead to the loss of important foraging grounds for sea turtles, while increasingly severe storms and rising sea levels can destroy nests and erode beaches, making safe nesting sites severely scarce. Altering ocean currents, which are the highways that sea turtles use for migration, cause them to possibly have to shift their range and nesting time.
Unregulated leisure activities organized by travel and tourism businesses, such as “swim with sea turtles” followed by tourists feeding the animals, are exposing them to health risks. Too much of human intervention can disturb beaching turtles and scare them away. Often such activities are conducted with primitive knowledge on the behavior of these sensitive marine creatures, and only focuses on the financial gain. There are recorded cases where captive turtles are used for such businesses. Not only is it unethical and illegal, keeping away a mature animal that could reproduce, and stopping it from contributing to the genetic pool is ill- fated for the survival of a species, specially an endangered one.
Mismanaged conservation efforts such as sea turtle hatcheries seem to impact sea turtles in an opposing way than what they are planned for – which is to protect, rehabilitate and release back into the wild. Usually the turtle eggs are collected from the beach so as to avoid the risk of poachers and predators. Once the turtles hatch, they are monitored and released in to the ocean. Research demonstrates that relocating eggs alter hatchling gender ratios as well as the hatchling rate, possibly due to unusually warmer temperatures and overcrowding. In natural circumstances, the hatchlings are supposed to enter sea as soon as they hatch. Unfortunately, commercial turtle hatcheries act as tourist bait until an entrance fee is paid to release the sea turtles to the ocean, and they are kept in cement tanks until then. The cement tanks cannot simply replicate a sea environment in terms of salinity and the space that the sea turtles are habituated to, as highly migratory animals. Overpopulated, unhygienic and poorly maintained tanks caused spread of diseases among captive hatchlings, and allowing tourists to touch them further increases the risk of contamination and diseases. Hatchlings lose their stored energy by swimming continually in tanks at its critical stage of development, downgrading their survival rate when they eventually swim out to the deep ocean. Rehabilitation through hatcheries also interfere with the unique imprinting mechanism of sea turtles which naturally guide them to return to their natal beach to lay their own eggs someday.
Such human generated threats to sea turtles are escalating along with the rising human populations around the world. In-situ conservation, strengthening protected areas around nesting beaches, raising public awareness on the behavior of sea turtles, promoting ecotourism, lobbying for turtle friendly fishing practices, and minimizing of plastic debris and chemical contaminants which end up in the sea, will be helpful to ensure the tomorrow of those unique and graceful mariners who share the planet with us.
Header Image: NPS Photo via US National Park Service
Janya Edirisinghe
Global warming is an aspect of climate change and refers to the long-term rise of the planet’s temperatures. It is caused by an increase in concentrations of greenhouse gases such as carbon dioxide (CO2) in the atmosphere, which is mainly derived from human activities such as burning fossil fuels and farming.
In recent times, the planet’s temperatures have been rising at an alarming rate, which imposes a threat to mankind. Mentioned below are graphs/maps prepared by NASA on the changing global temperatures.
The graph above illustrates the significant rise in temperatures between the years 1880 and 2020. Continuing this trend in rising temperatures, the global temperature increase was 1.6 degrees Fahrenheit (0.89 degrees Celsius), making the year 2022, the Earth’s 5th warmest year since 1880, and the last 9 consecutive years have been the warmest 9 years on record. This means Earth in 2022 was about 2 degrees Fahrenheit warmer than the late 19th-century average.
The colour-coded maps above show how global temperatures have progressed between 1884 and 2022. Dark blue indicates areas cooler than average. Dark red indicates areas warmer than average.
As per the maps above, we can see how global temperatures in 1884 and 2022 were in two extremes where global temperatures in some areas were cooler than average in 1884 as opposed to global temperatures being warmer in some areas than average in 2022.
The extra heat is driving regional and seasonal temperature extremes, reducing snow cover and sea ice, intensifying heavy rainfall, and changing habitat range for plants and animals—expanding some and shrinking others. Many communities from around the world are experiencing the impacts brought about by climate change. For example, within the last year, Pakistan was devastated by heavy torrential monsoon rains and a persistent megadrought was brought about in the U.S. Southwest. In September of 2022, Hurricane Ian became one of the strongest and costliest hurricanes to ever strike the US.
In conclusion, research has shown that global temperatures are expected to rise further in the years to come.
Header Image: Flood victims from monsoon rain use a makeshift barge to carry hay for cattle, in Jaffarabad, a district of Pakistan’s southwestern Baluchistan province, on Sept. 5, 2022. (AP Photo/Fareed Khan)
By Janya Edirisinghe
Glaucus Atlanticus, commonly known as the blue dragon/blue glaucus are a species of nudibranches (sea slugs). However, unlike terrestrial sea slugs, these sea slugs are very brightly coloured. These colours have inspired a series of nicknames, such as blue dragon, sea swallow, and blue angel.
CHARACTERISTICS AND APPEARANCE
The Blue Dragon species is pelagic which means that they float on the water surface, due to the air stored inside their stomachs, which is not a common characteristic of most nudibranchs. The creature often floats on its backside, showing its brightly coloured underbelly to airborne predators. The bright and dark blue colour camouflage against the backdrop of ocean waves, and the animal’s silvery grey dorsal blends in with the bright sea surface, concealing it from predators below. The deep blue colour may also help reflect harmful UV rays. This phenomenon is called countershading where the animal is built in a way to help it avoid being attacked by both flying and swimming predators while floating in open water.
Additionally, the Blue Glaucus has a flattened, tapered body, along with six appendages that branch out into finger-like cerata – they almost look like horns. Cerata are long, slender structures that sting when hunting or when the Blue Glaucus feels threatened.
FOOD AND DIET
Like other sea slug species, the blue glaucus isn’t venomous by itself. They store venom in their bodies mostly derived as they feed on other pelagic, venomous creatures including the Portuguese Man o’ War and the Blue Button Jelly. These sea slugs will then store these toxins within their own tissues. The blue dragon has hard disks inside its skin and a protective layer of mucus that shields them against these stinging cells – of which it can accumulate a significant amount. This ability provides the blue glaucus with a defence mechanism against predation. Cannibalism is also very common between this species – these slugs won’t hesitate to eat other Blue Glaucus if they are unable to find other pelagic creatures to feast on.
HABITAT
Glaucus Atlanticus thrive in warm temperate climates and are usually found in tropical/subtropical waters. These sea slugs are passive swimmers which means that they are carried along by the winds and ocean currents. A group of blue glaucuses floating together is called a ‘blue fleet’. Since they float with the current, these ‘blue fleets’ can end up being stranded in beaches accidentally and they can be found in almost every ocean – there are several records of these creatures being found along Indian coastlines. Humans handling the slug may receive a very painful and potentially dangerous sting, hence it is not advisable to have close contact with these creatures. One thing to keep in mind is that the venom of the Blue Glaucus remains active even after it dies!
Interestingly, Blue Glaucus are now appearing in regions where they have never been seen before and scientists theorize that this may be due to the cyclical changes in the Portuguese Man o’ War populations, warming oceans and increased storm activity.
LIFESPAN AND REPRODUCTION
The life expectancy of the Blue Dragon is short and ranges from between one month to one year.
The Blue Glaucus, like all nudibranchs, is hermaphroditic – each individual produces both egg and sperm. An individual cannot fertilize its own eggs, however, and hence pairs must still mate. Long, spiral-shaped eggs are produced by both males and females and often float freely in the open water or stick to nearby surfaces.
THREATS
Many people want to add these creatures to aquariums all around the world, but keeping the Blue Glaucus in confinement is impractical because of its diet, as it is nearly impossible to obtain the required number of Portuguese Man o’ War, and those kept as pets often starve to death.
Moreover, ocean acidification caused by an increase in C02 levels due to global warming has led to a reduction of food that the Portuguese man o’ war eats (such as shrimp and small adult fish), eventually threatening Blue Glaucus populations.
Additionally, pollution represents an ongoing threat to the survival of Blue Glaucus. Harmful objects can be fatal to this sea slug as well as the toxins in the trash.
As mentioned above, cannibalism is common among this species, so other Blue Glaucus impose a threat to this sea slug. Few studies that have been conducted on the Blue Glaucus, show that loggerhead sea turtles may be one natural predator. A study on this species found that 42% of their stomachs contained remnants of blue dragons.
In conclusion, like most marine invertebrates, there is little information available regarding the conservation status of the Blue Glaucus, therefore, more research has to be done into this area, so that these creatures do not go into extinction.