“There are plenty of fish in the sea” is a widely used phrase that you’ve probably heard. It is an analogy that has been used to comfort humans for decades. However, there might not always be enough fish for everyone in the world, due to a serious issue: overfishing. There are two sides to the issue; one is that overfishing is not an issue at all. Many fishermen need to fish in large proportions to earn a living or support a family. Fish and seafood are in high demand in restaurants all around the world. It is thought that 70% of the world’s human population gets their main source of protein from seafood. However, overfishing is a violation of the laws of fishery, so therefore an issue is prevalent. Overfishing is threatening the marine environment in more ways than one: we are losing species and entire ecosystems. In ecosystems, many organisms rely on each other for survival, so overfishing is affecting multiple species of plants and marine animals and the environment surrounding them.
Different areas of the ocean have different types of marine ecosystems. An ecosystem can be described or defined as “a community and the interactions of living and nonliving things in an area.” There are ecosystems on land and under the sea. The ecosystems below the surface are called marine ecosystems. These marine ecosystems all have distinct organisms and unique characteristics. They result from the exclusive combination of physical factors, or abiotic factors, that create them. Some examples of marine ecosystems are: abyssal plain (deep sea coral, whale falls and brine pools), polar regions, coral reefs, the deep sea, kelp forests, mangroves, the open ocean, rocky shores, salt marshes and mudflats and sandy shores. The biotic factors include many marine animals and plants, for example: different species of fish, coral, seals, penguins, squid and octopi, sea anemones, plankton and porpoises. This diagram shows each of the biotic factors (living things) in the marine ecosystems and what they eat- it is a food web. Fish are a food source for many other creatures in the ocean. They also help some marine plant-life to grow, therefore helping creatures that eat coral and other marine plants, such crabs and turtles. This is an example of biotic relationships. Selected species of fish and the coral around them have relationships of mutualism, such as clownfish and anemones. Other fish relationships in the food web have one species be benefited and the other remain unaffected, like the barnacles on the shells of scallops; this is an example of commensalism. Sharks eating the fish are an example of predation; they seek out their prey as a food source. However, sharks are in competition for food with species of fish such as the northern pike- meaning that they have to sometimes fight for food that they both want. Fish of all species can be targeted by isopods. Isopods are ‘fish lice’, and they are an example of a relationship of parasitism as they will drain the fish’s body of all liquid and food, and will not leave until they choose to or the fish dies.
As there are many different species of fish and other organisms living in the ocean, they all have different life cycles. This diagram is a basic life cycle of a salmon and fish of similar size. Most fish begin as eggs, in time they develop into alevin. Alevin feed off a yolk sac, they don’t swim around yet. Once the fish become fry, then they start swimming. They are usually very small; some fish stay with their parents and some head off on their own. After this, the fish develop scales and markings and grow over a period of time: this can be between months and years. They will go through stages of growth, eventually becoming a sexually mature adult. Before natural death, the fish will spawn and lay eggs of their own. Then the cycle begins again, with the fish growing in the eggs.
Overfishing directly impacts population sizes of marine life, and there are many reasons why the population is so affected. Species can die out very quickly, as these gigantic super trawlers and other ships used to haul in tonne by tonne of fish often target the one area until no fish are left, then move on. By targeting large schools of fish and leaving hardly any fish left in that area to carry on the gene: when the last fish in that area dies, there will be no more of that species in that area of the ocean. If these super trawlers are departing from many countries around the world, and can hold thousands of fish each, they can wipe out entire species in a matter of weeks. The hooks that are used either alongside or instead of large nets are also very destructive. These hooks kill over 2700 sharks and marine turtles in the Coral Triangle alone every six months. Let’s not forget that marine life of all types are also caught in the huge nets, and are sold or discarded in terrible condition. With multiple species being affected as a result of these barbaric practices, it is obvious that our human impact is destroying the marine ecosystems.
Natural ecosystems such as marine ecosystems can be sustainable in many ways. One way to have a sustainable ecosystem is to have biodiversity. It is a crucial aspect of having sustainable natural ecosystems. Biodiversity refers to the sheer quantity of species that inhabit an ecosystem. A bio-diverse ecosystem is one where there are plenty of species at all sides of the food web, and animals and plants can easily rely on each other for survival. It also has genetic diversity, meaning that evolution and adaption can occur more easily. Having a food chain is another important aspect of a sustainable natural ecosystem. It is where a healthy, sustainable ecosystem allows for the unbroken movement of energy from species to species. An example of this is: plants convert solar energy into chemical energy. Animals eat the plants and convert the energy into kinetic and heat energy. When these animals die and decompose, their stored energy returns to soils to be used again by plants. It is a balance, popularly referred to as the circle of life, and is important in all sustainable ecosystems. Biogeochemical cycles are also vital parts of a sustainable ecosystem. This refers to the climate and geological changes, directly affecting an ecosystem’s stability. Every ecosystem, whether it be marine or not, relies on chemicals from the earth, light and heat from the sun, and the presence and movement of water. The movement of water through an ecosystem, a hydrologic cycle, is crucial in providing stability and a sustainable ecosystem. It is important in marine ecosystems as it often affects the balance of temperatures and nutrients in a body of water.
An ecosystem can feel the influence of overfishing in six months and not recover whatsoever. As of 2001, the population of marine life in the coral reefs of Guam is lower than it was in 1967 when authorities began monitoring the life. In the last decade, in the Atlantic regions, fish populations of cod, hake, haddock and flounder have fallen by up to 95%. It is statistics like these that urge us as humans to prevent overfishing. Overfishing has been occurring since colonial times, and has directly affected balance in ecosystems and their sustainability. Humans are the root cause of overfishing, not animals, as animals are creating a circle of energy and sustaining the planet. Humans, as we are an overpopulated species, are taking more than we need. So many humans rely on seafood as their source of protein, but the reality is how we are impacting ecosystems is disturbing and we need to have better practices. Oil spills, which can happen on these gigantic super trawlers used to fish in large amounts, affect thousands of species. Animals can instantly become ill and die as a result, if they survive being stuck in a net in the first place. As sustainable ecosystems have a distinct food web, the biodiversity is usually something that comes naturally. However, as a result of human activity, larger species are dying off. This allows smaller organisms, like bacteria, to flourish- and as these bacteria grow they kill off more fish as well. The bacteria kill other marine life too, such as coral, which then affects turtles and other animals consuming the plant life under the sea. When these fish and marine plants decompose under the sea, they affect the ocean floor- in which other marine life live. This puts other species at risk, especially sea cucumbers, which consume and excrete sand and other things on the bottom of the ocean. Finally when we consume this fish, we ourselves as humans are consuming more fungi and microorganisms than protein, all as a result of our own greediness and disregard for marine life as humans.
As overfishing is not exclusive to just one type of marine ecosystem, it is important that we look for strategies to sustainably fish in all marine ecosystems. Authorities plan on making fishing more sustainable by introducing plans such as Ecosystem Based Management, or EBM. This conservation work started by the World Wildlife Foundation aims to find innovative forms of management to conserve fish populations. By confronting people in positions of power about these issues, super trawlers are being banned from the waters in special areas that this EBM and other organisations (with the support of the governments of different areas of the world) have deemed protected. By protecting essential, bio-diverse marine ecosystems from these large fisheries, many species can breed there and then migrate to other areas in smaller groups. Then when people fish, they will target smaller groups rather than one large ecosystem where many species are harmed in the process. Safer traps and safer management will also help the industry, and now as it is very much illegal to overfish, most fisheries are monitored so as to make sure that they only take what is needed. The idea is to allow this biodiversity to remain, only fish in different areas, rather than just the one, target one small group of fish, implement safer practices and protect ecosystems. The EBM supports sustainable fisheries and smarter fishing choices, and more countries are beginning to take part in the EBM and are becoming aware of the issues surrounding overfishing as a whole- not just overfishing of whales and dolphins.
One interesting perspective of this topic is that overfishing is not an issue at all. In fact, overfishing can be compared to an industry such as owning a clothing shop. The more items of clothing you sell, the more money you make. If you sell expensive, designer items of clothing, you make even more money. The same goes with the fishing industry. The more fish you catch, the more money you make. If you catch heaps of big fish of rare breed and delicious taste, you make even more money. Money is an incredibly important factor in our world, and as many people in developing countries go hungry due to lack of money, it directly impacts and influences human life. The livelihood on over 500 million people in developing countries depends solely on fisheries and agriculture. Seeing as the average family size in developing countries is 7 people, which is a lot of mouths to feed, these men (rarely women from developing countries work in the industry) need their jobs to stay alive. The more fish caught by the men working in these industries, the more money they get to buy food for their family so they can live and be healthy like every human should. The men working in these large fisheries hardly get a wage, but they at least have a wage. To hold on to their jobs and feed the family, they have to catch fish in the thousands. Overfishing is hardly even an issue when you compare it to world hunger. If it means catching a few more fish, then why not solve an issue that affects so many people, like world hunger? Why kill humans so a bunch of fish can have a better life? It simply does not make sense in any way, shape or form.
Overfishing is not environmentally or economically smart. As a result of these huge businesses catching so many fish, small industries and local fisheries are shutting down, as they don’t stand a chance against the giant ships, hooks and nets. Many Australian fisheries have been affected by overfishing, especially up in the northern part of Australia. Small businesses cannot run as a direct influence, and as so many people in developing countries want a job in the industry- many get minimum or below minimum wage for working many hours in terrible conditions. The annual total global catch of fish is 124 million metric tons, which is equivalent in weight to 378 Empire State Buildings. This is not a sustainable way of fishing and it affects thousands upon thousands of marine species. The FAO has pointed out that about 25 percent of the world’s captured fish end up thrown overboard because they are caught unintentionally, are illegal market species, or are of inferior quality and size. This means that sick or disturbed fish are being thrown back into the ocean, harming other marine life around them, and our people in developing countries we talked about before do not get paid. The stability of ecological communities depends largely on the interactions between predators and prey, so to keep such biodiversity we have to prevent overfishing as much as possible to allow marine ecosystems to flourish. Overfishing has affected sharks and larger marine life as well as tuna, salmon etcetera. Recent reports suggest that over fishing has caused a 90% decline in shark populations across the world’s oceans and up to 99% along the US east coast. These are some disturbing numbers, and when you add them to the fact that the more fish we take the more our humans will get sick due to the spreading bacteria- you really think, what is the point?
In conclusion I definitely think that overfishing is a serious issue that we need to get a grasp on, and quickly. More people are becoming aware of this issue, and I think that in the future it will no longer be an issue. Sustainable fishing practices are key: obviously the fish industry is not going to end, but we need to fish in an environmentally safe way. If we do not prevent overfishing from happening, humans and marine life will be affected. Due to lack of biodiversity, we could consume unhealthy fungi and microorganisms too small for our eyes to see, therefore harming our bodies. Fundamentally, overfishing has a direct route to multiple problems, which could lead to the downfall of many jobs, and most importantly the health of human and animals. Although many people rely on fish as a source of income, I think that by practicing safe methods of catching the fish they will still benefit. Also, companies, fish shops and large supermarkets should always consider how their fish was caught before they sell it. We should try to buy fish that was caught using safe procedures and are keeping our marine ecosystems sustainable. People also need to consider that we can obtain protein from other foods, so that with our growing population we cease to take more than we need from our marine ecosystems. Sure, “there are plenty of fish in the sea”, and we should all agree to keep it that way.