3.10. Conservation of target species
As world populations increase and economies expand more pressure is being placed on the natural resources of the planet, which in turn will affect the environment for us all. One major issue is the development of tourism. Increasing boat traffic and the removal of coastal habitats through coastal development poses problems of pollution and physical disturbance to the marine environment. Recreational boat traffic increasingly poses a noise and physical disturbance to cetaceans.
Recreational boat traffic (Blue World Institute) Overfishing is a worldwide issue and also a threat for the animals in the Mediterranean area. Virtually all commercially valuable marine species are overexploited. Many cetacean species and human fishing fleets are fishing for the same prey species. Reduced availability of food naturally also affects the marine top predators, marine mammals, causing changes in population number, behaviour and distribution.
For decades various pollutants have been dumped into the oceans. It is known that some pollutants, such as mercury and organochlorines accumulate through the aquatic food chain, and can be passed on to top predators such as marine mammals, turtles and even humans. Highly industrial and agricultural countries surround the Mediterranean Sea and contaminants regularly enter the sea from the land, rivers and the atmosphere. From urban trash to abandoned fishing gear, marine debris is one of the world’s most pervasive marine pollution problems. Every year it injures and kills thousands of marine animals that swallow it or become entangled in it. Marine debris also degrades important aquatic habitats, like coral reefs and seagrass beds. Fishing line and nets, rope and other rubbish can wrap around fins, flippers and limbs of other animals causing drowning or amputation. Discarded nylon nets may also pose a threat as ghost nets, catching large animals and destroying fragile habitats through entanglement.
Sea turtles as a group are recognised as one of the most endangered in the world and all species have an IUCN Red List status. Sea turtles come across dangers from the moment they hatch. They have to avoid many animals on their way to the sea including natural predators (crabs, sea birds) and ones introduced by humans (dogs, foxes, rats, wild boars). Sandy beaches are very popular among people creating all sorts of noise, sufficient to deter female turtles searching for an appropriate nesting site. Huge hotel resorts have a devastating effect on the quality of the habitat with their artificial light confusing hatchlings on their way to the sea. Floating debris presents a threat to sea turtles as well. Turtles mistake plastic bags swaying in the current for jellyfish, and ingest them. They can often die as they are unable to excrete or digest the plastic. These animals get tangled in nets, rope and other floating rubbish that had been thrown away. Unable to free themselves, it is easy for them to suffocate or die from exhaustion. Many sea turtles are struck by boats while sunbathing on the surface. These animals have broken bones and large wounds on the carapace, flippers and the head.
Video 3.10.3. The survival of the sea turtle. By TED- Ed Originals, https://ed.ted.com/lessons/the-survival-of-the-sea-turtleThe greatest threat to sea turtles is the interaction with humans. Although all marine turtles have a protection status they still suffer from being caught in fishing activities. Bycatch in fishing nets and trawlers is the major threat to sea turtles. In Mediterranean, 132.000 animals are accidentally caught each year with a mortality of 33%. Turtles tangled in nets are unable to reach the surface, they become comatose due to lack of oxygen and die. However, some of them can be rescued by application of recovery techniques. During winter, turtles are often in a lethargic state and are moving slowly due to low body temperature. This is why we need to make sure these animals are active when released in order to avoid drowning. Sometimes, they require recovery in the rescue centre. Long-line fishing is also a major factor in sea turtle mortality. The hook can be embedded in their mouth or some other part of the gastrointestinal tract, and the ingested line can cause intestinal obstruction and necrosis. However, relatively inexpensive changes to fishing techniques, such as slightly larger rounder hooks, shorter soaking time, correct recovery on board trawlers and Turtle Excluder Devices can dramatically cut the mortality rate.
Due to their common life-history characteristics of slow growth, delayed maturity, long life spans, and low fecundity, sharks are highly sensitive to anthropogenic threats including pollution, habitat destruction, and fishing impact in particular. Elasmobranchs are generally considered commercial species, except for the basking shark (Cetorhinus maximus) and the great white shark (Carcharodon carcharias) that are fully protected from all fisheries. For other species of Elasmobranchs quotas are set in some northern European fishing areas. Nevertheless, sharks are heavily exploited, with catches ranging in hundreds of tonnes. Consequently a number of species are now listed as Critically Endangered on the IUCN Red List – meaning they have an elevated risk of extinction in the Mediterranean.
In order to enjoy natural and undamaged environments in the future a form of sustainable use and development of our marine habitats has to be adopted and implemented. Effective conservation measures rely on relevant and up-to-date information about the area or species that we want to protect. There are different ways how you can contribute to conservation of marine habitats and species. Strategies and techniques for marine conservation tend to combine theoretical disciplines, such as population biology, with practical conservation strategies, such as setting up marine protected areas (MPAs). These protected areas are established with the aim to limit the impact of human activity. Other techniques include developing sustainable fisheries and restoring the populations of endangered species. Recognizing the economics involved in human use of marine ecosystems is key, as is education of the public about conservation issues. Moreover, it is important to realise that it is not too late for individuals, groups and communities to make a difference. As more people become involved in environmental projects and public awareness the faster we can change the current unsustainable use of the world’s resources. Be part of the solution, not part of the problem.
3.10.1 Turn down the noise: Cetaceans are drowning in a noisy ocean
For whales , ‘listening’ is as important as ‘seeing’ is for humans. Noise pollution threatens whale and dolphin populations, interrupting their normal behaviour, driving them away from areas important to their survival, and at worst injuring or sometimes even causing the deaths of some whales. These mammals live in a world of water and sound. They feed, communicate and find their way around their world using sound. If you pump high levels of unnatural noise in their world, then they will suffer. Seismic noise used to find oil and gas, conducting loud military exercises at sea and increases in boat traffic can all put whales and dolphins in danger, cause them to strand on coastlines, and even kill them. Amazingly, there are currently no accepted international laws regarding noise pollution in our seas. We don’t know what damage all these activities are doing to whales so we have to act now to find out before it is too late.“The only good thing about ocean noise pollution is that noise disappears once you stop making it.”In order to prevent this marine noise pollution we have to get the ships in a certain route that will have no harm to he marine environment. To achieve that we have to employ some researchers to get enough information about whales and their habits.The good news: Better technology can dramatically reduce the noise. Oil and gas drillers, for example, usually use airguns with massive dynamite-like explosions to map the sea floor. But it’s possible to use marine vibroseis, a technology that’s thousands of times less invasive, instead. Some shipping companies are beginning to use technology for quieter ships. In the USA, ferries are now using quieter propellers (which, what do you know, also happen to be more efficient and save fuel). Ships can also reduce noise just by slowing down.We have to respect animal life as well as marine environment so that we can have a balanced future.
3.10.2 Who's eating all the fish? Overfishing means marine animals are starving
Marine animals live in a hidden kingdom almost below our feet, a kingdom where humans are hard to access,but yet they manage it's destruction with many different means without them knowing. Fish are becoming more and more extinct because of the rapid change of the weather and the careless acts of humans. Nowadays ,biodiversity is in crisis and needs our help. People all around the globe eat fish and enjoy the life oceans are offering to us. But do they really know, because of there ignorant acts the water and fish are getting infected and then we digest what we just contaminated. Fishes are consumed a lot by humans but that doesn't answer the question: Who's eating all the fish? Firstly, over-fishing plays a big role. Because of it, marine animals don't have many fish to eat and that leads to there starvation and death. Secondly, after the few of the fish that are kept alive by luck, die from a lot of trash that's left in the sea and by the gasoline,petrol etc. Although! even in the darkest times, there is hope. There are teams all over the world who ain't ignorant and are trying to save this before it becomes uncontrollable and unchangeable. They are trying to show the world how much of an impact their simplest acts have on the environment and create programs for helping resolve the problem. They organise trash collecting teams so oceans can be kept cleaner and marine animals have a healthier environment to live in. Another example is ALL, who is targeting education and teaches the young leaders of the new world what is needed to be done this time so the past is not repeated. People often think that the food chain contains only what lives in land. What they don't know is that it is consistent by marine life also. According to science '' Humans first came out of the water and later evolved into what we are today'' so let's not forget our origins.
3.10.3 Chemical pollutantsbring ocean health at risk
Over the last one hundred years, humans have introduced a significant number of chemicals into the environment. While some chemicals are designed to get rid of weeds and pests, a significant amount of chemicals are waste from industrial and agricultural processes. Although awareness around marine plastic pollution has grown, the impacts of chemical pollutants in the oceans is still largely being ignored. This is partly because chemical pollutants are mostly "invisible" to the naked eye and their health and ecological consequences are complex and long-term.
While it may seem fine for industrial plants or manufacturers to dispose of two inert chemicals, when those chemicals are mixed the result could be a serious pollutant to the water supply. As streams, rivers and oceans become polluted, aquatic life can suffer. Already two-thirds of aquatic life is considered to be endangered species because of improperly disposed chemicals. However, businesses do not have to dump chemicals into water sources for the effects to be seen. Anyone who dumps or releases chemical waste can affect the problem. As it rains, those chemicals are washed into rivers which feeds the waterfalls and then goes into the ocean.
Humans can suffer as well, and that's because chemicals aren't disposed properly and end up in the water supply. Animals higher in the food chain - humans - accumulate these these harmful toxins in significantly high concentrations. Simply put, predators higher on the food chain are much more likely to have genetic mutations, diseases, birth defects, and several other deleterious effects of improper certified product destruction. This may result in boil water advisories to protect human health.
Chemical production is growing everyday while global programmes have not been fully implemented and are not achieving their objectives. Every human needs to be aware of the problems chemicals can cause to life on earth and thus we all have to do something to prevent them.
3.10.4 Harmful marine debris: Struggle for marine animals
Marine debris is one of the most pervasive and solvable pollution problems plaguing world's oceans and waterways. Nets, food, wrappers, cigarette filters, bottles, resin pellets and other debris items can have serious impacts on marine wildlife. Successful managemment of the problem requires a comprehensive understanding of both marine debris and human behavior. A plastic bag may look flimsy, but in a fight against a sea turtle , its often wins. There are many ways that marine debris can impact marine animals. Animals may unintentionally eat debris along with their meal, or intentionally ingest trash due to its resemblance to real food,For example, a plastic bag can win a fight with a sea turtle using its resemblance to a jellyfish when it's floating in the water. Jellyfish are a favorite snack for sea turtles and the pastic bag is often swallowed before the turtle knows the difference. Since plastic is not real food, the turtle is not getting the nutrients it needs and once that plastic is in its guts, it can sometimes get stuck there, making the turtle very sick. All sea turtle species eat debris and unfortunately, turtles aren't the only animals that mistake plastic for food. Many marine animals ingest marine debris. This is an especially big problem in seabirds. Recent studies estimated that 90% of seabirds have ingested plastic and predisted that number would increase substantially by 2050. Unfortunately, the impact of marine debris doesn't stop there. Entanglemment and ghostfishing also pose a threat. Marine life can get range from slightly uncomfortable to lethal. Derelict fishing gear such as nets and crab potscan also be a big problem. Large or heavy debris can smother or crush sensitive habitats, such as corals reefs and sea grass. The solution is to reduse, reuse and recycle to decrease the amount of trash that is adding to marine debris problem.
3.10.5 Turtles in trouble: Why are sea turtles one of the most endangered groups in the world?
Even though sea turtles have been living on earth for millions of years, the past few decades their population has been decreasing dramatically. Nowadays, they are characterized as one of the most endangered species. In fact, six of the seven sea turtle species are classified as threatened or endangered. Many studies have shown that there are several factors which threaten sea turtles’ survival.
Firstly, sea turtles almost everywhere are affected by fisheries. Catching fish for food is a big business. Fishing gear accidentally captures thousands of sea turtles every year. This problem is called bycatch, which occurs when fishing equipment (nets, trawls, hooks...) catch animals that were not meant to be caught. In addition, Sea turtles and their eggs are killed by people throughout the world for food, and for products including oil, leather and shell. Therefore, sea turtles suffer from poaching and over-exploitation. Pollution is considered as a significant factor which jeopardizes the lives of sea turtles. Plastics, petroleum by-products, and other debris harm and kill sea turtles through ingestion. Light pollution disrupts nesting behavior and causes hatchling death by leading them away from the sea. Chemical pollutants can weaken sea turtles’ immune systems, making them vulnerable to disease. Furthermore, surveys have shown that climate change will increase the frequency of extreme weather events, result in loss of nesting beaches, and cause other alterations to critical sea turtle habitats and basic oceanographic processes.
3.10.6 Deadliest catch: Thousands of sea turtles are unintentional victims of fisheries in Mediterranean
Man’s greedy appetite for over the top quantities of fish has had a huge unintentional impact on species like the sea turtle. A new report says that between the year 1990 and 2008, supposedly 85,000 marine turtles were officially reported killed by accidentally wandering into the fisheries’ nets. If one is to take into account the unreported fatalities, the numbers would raise up to millions.
Like all reptiles the sea turtle requires air to breathe so sea turtles occasionally emerge to the surface for air. This would mean that if a sea turtle was to get caught in a fisherman’s net or hook, it would not be able to go up for air and would result in it drowning. Additionally, sea turtles often swallow hooks which get stuck in their throats or stomachs, leading to internal bleeding. Some of the most lethal fishing equipment for sea turtles include gillnets, longlines, and trawls.
The Mediterranean Sea has some of the highest unintentional marine turtle killings due to fisheries. The Green turtle and Loggerhead turtle are two charismatic Mediterranean species with dangerously low populations. A disturbing fact is that a rate of up to 200,000 Loggerheads get killed by fisheries every year. Efforts have been made to rescue these endangered species in countries such as Italy, Greece and Spain with the help of rescue centres and first-aid stations.
In reality, the most effective way to rescue these desperate species is by changing the way fisheries operate and having better management. This would not only help reduce the number of unintentional sea turtle killings, but other species as well. Some suggestions are having on-board observer programs that document marine turtle fatalities and enforce regulations. Another suggestion is implementing area closures that prohibit fishing during peak sea turtle presence.
Marine turtles are some of the most beautiful creatures on earth. It would be unfortunate to see them cease to exist. Let us take action before it is too late.
3.10.7 What species of shark is for dinner?Elasmobranchs are heavily exploited
Are sharks edible?Well this is a difficult question because there are sharks who are more edible than others,and the meat of sharks it has some secrets before it becomes edible.First of all everything starts from the moment you hook the shark and this is because the more exhausted a shark gets, the more lactic acid and carbon dioxide there is in the blood and muscles and this can affect the taste of the meat.Secondly as a shark deteriorates the urea in their blood immediately begins to break down into ammonia which then gets absorbed in the flesh and expelled through the skin of the animal. In other words, sharks urinate through their skin.This is why shark meat that hasn’t been prepped quickly and effectively can smell and taste like ammonia. So to avoid ammonia taste in the meat, once you land a shark, it’s imperative you bleed it, gut it and clean it as soon as possible.Now as i mentioned before not every specie of shark is edible.The most edible sharks according to the anglers are porbeagles and Mako sharks which belongs to the Lamnidae family and looks like tuna.Also Thresher sharks who belongs to Alopiidae family are edible such as requiem sharks which belongs to the Chondrichthyes family. Sevengill, Soupfin, Leopard, Dogfish, Shovelnose, and Blacktip sharks are also edible.Shark meat is very common to the Assian countries and it is a traditional food for them and because many sharks who are edible belongs to Elasmobranchs a subclass of Chondrichthyes sharks which also includes rays, skates, and sawfish are highly exploited due to the overfishing of these sharks because of the high demand of shark meat in the Assian countries.