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Oceanic Impact of Sea Fishing in the 21st Century

Paper Type: Free Essay Subject: Environmental Studies
Wordcount: 3425 words Published: 29th Jul 2021

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Sea Fishing first started to emerge back in the 15th century, and it exploded in the 19th century with the arrival of steam boats. These steam boats were large trawlers that could pull much larger nets, which in turn caused the amount of fish caught to rise. Fishing has caused large amounts of employment opportunities for people over the years and has provided a safe and secure income for many fishermen and employees of local fisheries. For as long as anyone can remember, fish have been one of the main food sources for us. As positive as this may seem, there is a dark and more sinister side to sea fishing. Like most things, everything isn’t as it seems. It’s no surprise that fish are being over-exploited by humans. But there is more than what meets the eye in terms of issues it causes. Automatically, I thought – okay, if we catch too many fish then there isn’t much left. Simple? Not quite.

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The over exploitation of fish is causing many issues both directly and indirectly to not only marine animals, but to us as well. Issues such as eco-system alterations are causing starvation amongst marine animals, low oxygen levels and the release of CO2 emissions into the atmosphere, (Stafford, 2016). The growth of new technology trawlers are ultimately killing marine life, destroying coral reefs/sea beds (which ruin marine habitats and species which are new to science), (Sample, 2010), and are catching extremely colossal numbers of fish in one given pass. This is essentially contributing to negative economic impacts also as seen in the Newfoundland Cod Fishery which had to close because there were no more fish left.

The growth of macro algal blooms within the waters is causing a large number of medical issues for both marine animals and humans alike. Since it’s linked to shellfish poisoning, I believe this is a wakeup call to all. It is important to take into deep consideration that the number of deaths by shellfish poisoning is around 351,000 people per year. (European Parliament, 2011). By overfishing, we are removing the species in which keep these blooms at bay, such as Pike, (Nature, 2009). Ultimately, we are causing harm to ourselves through greed.

This leads us to the question of what does the viability of sea fishing in the 21st century tell us about the future of human civilisation? How can a civilization thrive if we are causing harm to marine animals and ourselves?


As previously stated, there are many issues caused by the over-exploitation of fish. One of the largest issues is the alteration of the eco-system and the food chain. For reference, an eco-system includes various living things like animals, organisms, and plants which interact with each other. They also interact with non-living environments, which includes the earth, soil, weather, earth, climate and atmosphere. (eSchoolToday, 2018). The ocean food chain is made up of four different parts, produces, primary consumers, secondary consumers and decomposers. 

The food chain begins with producers, which are plants. These plants make their own food via photosynthesis. Then, the primary consumers consume plants, and secondary consumers consume primary consumers. Decomposers break down dead plants and animals, and the nutrients absorb into the environment for the consumption of other producers.  Each link within a food chain is extremely vital, and it is important that no links are disrupted, or it will impact the whole chain. (Moore, 2010). An example of a food chain, starting from the bottom, is that bacteria is eaten by zooplankton/jelly fish/krill etc. These are then consumed by small bait like fishes, which may include spot fish or sand perch, which are then consumed by large fish such as tunas and cods. The ‘’top predators’’ such as whales and big sharks consume these large fish. (eSchoolToday, 2018).

Issues are beginning to arise due to the fact that only one tenth of predators that once roamed the oceans remain due to overfishing. Species such as Skates that were once policed and consumed by predators such as Sharks, are exploding in population. In turn to this, they are wiping out scallops and a wide variety of shellfish, which is also causing the quality of sea water to suffer. (Gibbons, 2009) According to Canadian Scientist Julian Baum, “we have literally chopped off the top of the ocean food chain.” The removal of predators from the eco-system is causing carbon dioxide levels to rise into the atmosphere, and ultimately contributing to climate change, which in turn effects our lives in one way or another. The way to explain the reasoning behind this is simple – predators reduce the biomass of small fish and zoo plankton, which in turn ultimately begins to lower the amount of respiration occurring. When these are removed due to overfishing, the amount of carbon dioxide rises. (Stafford, 2016). The release of carbon dioxide into the atmosphere creates a large amount of greenhouse gases. These gases trap extra heat, which leads to melting ice caps and oceans levels rising. This, ultimately causes flooding as the heat of the planet rises, (Lamb, 2018).

The alteration of the food chain is having many negative effects on marine animals. Due to the depletion of top level species in the food chain, this influences future fish production levels. By ‘’fishing down the food chain’’ it ends up simplifying the entire marine eco-system and resentfully effects other species. For example, the decline of Stellar Sea-Lions within Alaska has been caused due to the overfishing of their main food sources which include Cod, Pollock & Mackerel. Without a food source, these species cannot survive. (US Department of State, 2003). The effects were shown when expert studies carried out of over 1288 fish species on Africa’s west coast which showed that 37 of these species were in a classification of being threatened, with 14 of them were classed as being close to threatened, (Johnson, 2017). In my opinion, this is not something that happens by accident, but is an outcome of years of greed by humans.

On a more medical based note, the growth of macro algal blooms is causing severe and even fatal issues for both humans and marine animals alike. For reference, a macro algal bloom is the name given to a rapid growth of algae and bacteria. With the growth of macro algal blooms, it can create toxins that can kill fish and other sea animals. This is normally seen with Lynbya Majes algae. Due to this, the toxins make their way up the food chain and begin causing harm other animals such as turtles and dolphins.  When death doesn’t occur, these toxins can block sunlight, causing habitat loss from low oxygen levels and even clog the gills of fish causing serious health issues. These algae often over-grow and replace seagrass, destroying coral reefs. (EPA, 2017)

The damaging of effect of these blooms, as stated, are not limited to marine animals, but to us humans also. Issues include serious rashes or other serious health problems associated with Shellfish Poisoning. European Parliament, 2011). Dinoflagellates is the name given to the harmful algae linked to various forms of Shellfish Poisoning. These types of shellfish poisoning can include paralytic shellfish poisoning (PSP), (NPS), also known as neurotoxic shellfish poisoning, ciguatera fish poisoning (CFP) and diarrheic shellfish poisoning (DSP), (European Parliament, 2011). This is extremely worrying, as around 351,000 people a year die with side effects associated with shellfish poisoning, (European Parliament, 2011). Due to species being over-exploited by humans, fish such as Parrot Fish and Pike are being greatly exploited. It’s been shown that overfishing is having an either direct or indirect cause. One, they are being fished and caught via trawls, or two, these species are being exterminated by fish that are no longer being policed by their predators, (Gibbons, 2009).

It was scientifically proven by Britas Klemens Erikson at the University of Groninge, that these fish are the key to controlling algae growth on reefs. The issue was raised once Britas noticed that where there was a decline of predators in the Baltic Sea, algae blooms were forming. Britas and a team carried out investigations and compared a year’s worth of data. The data covered over 700 kilometres of the Baltic Sea, and the data was from 9 different locations. His research found that where there was a large decrease in Pike, there was a huge increase in algae blooms, and that where Pike roamed, there was only a 10% chance of a growth of algae blooms, compared to 50% where Pike populations were reduced. (Nature, 2009). Due to the removal of these species by the over exploitation of fish by humans, these blooms are growing at a rapid pace which is adversely affecting our health.

The growth of new technology is normally something to be positive about. But what happens when we over-exploit these resources available to us? Well, according to survey of the world’s reefs and sea mounts, it was shown that bottom sea trawling carried out by humans is the leading cause of marine habitat destruction. Apart from the millions of deaths of marine animals by trawling, pristine habitats and species new to science are being destroyed due to the lack of respect humans have for the ocean, (Sample, 2010). For reference, a trawler is a commercial fishing vessel, which is the equivalent to a large fishing net, which is used by dragging the nets along the bottom of the sea bed via boat. They slice everything that is in their path, and some of the larger nets are even big enough to consume a Boeing 747 Jumbo Jet. (OCEANA, 2018).

Trawlers can process many fish in one given trip. A previously banned trawler which roamed the Irish waters back in 2015 named the Margiris, the second largest in the world, can process up to 250 tonnes of fish in one given day. (Ryan, N, 2015). Scientists within Europe have calculated that trawlers roaming within the North Sea are destroying 16 pounds of marine animals for every lb of sole that’s caught. (OCEANA 2018). In my opinion, that is a colossal amount. The effects that these trawlers have on marine life is extremely upsetting. They pose great harm to reefs, shellfish and coral. The “Firth of Forth” was once home to a large number of oysters. Now, none remain. Likewise, the “Firth of Clyde” was once overcome with whales, shellfish and fish. Now it is nothing more than an empty seabed, and the fish stocks have practically disappeared. According to Callum Roberts, this gives us all a vision of life without fish if this continues. (Mckie, 2014).

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The effect of these new technology trawlers is not only visible on marine animals, but for us also. This was seen when The Newfoundland fishery ultimately was closed by the government due to the fish stocks being so low. It was stated that The Grand Banks fishery was ruined by advanced technology in fishing techniques within the years 1950 and 1960, and this had a huge negative economic impact on the surrounding areas (Greenpeace, 2009).

On the note of economic impacts, it brings us to the question, how important are fish to us? First, we must take into consideration that it’s been proven that over 852 million people on this planet do not have enough food to eat. Millions of fish farmers in the world, big and small are extremely poor and depend on fish. Secondly, we must take into consideration that they directly enable people to a food source, and provide various nutrients in the process, which are vital to people’s health. Over 100,000 tonnes of fish are consumed annually worldwide. This shows that fish provides 2.5 billion people twenty percent of their average animal protein intake. (Food and Agriculture Organization of The United States, 2005).

Thirdly, fish provides an income, as fish farmers create income by selling their catch. (Food and Agriculture Organization of The United States, 2005) So, what’s the point in these statistics? The point is to show how important fish are to us, and how much we are disrespecting the availability of these species. To give a brief indication of how overfished most fisheries are, Oceana released a report stating that 80% of fisheries in the world are not capable of increased fishing activity, and 17% should be considered capable of any growth in catch at all.

Contrary to popular belief, the act of over fishing does have negative economic impacts for both fisheries and fishermen alike. As previously stated, The Newfoundland Grand Banks are a prime example. This was seen with the collapse of this fishery back in the 1990’s. It was stated that the collapse ultimately occurred due to trawlers such as the ‘Fairtry’ trawler being distributed. These trawlers enabled a great number of fish to be caught in one given pass. In 1968 the cod catch was around 810,000 tonnes, and by 1975 the annual catch drastically dropped by 70%. By the early 1990’s the fishery collapsed, and the government shut it down simply because the catch numbers were at an all-time low, (Greenpeace, 2009). It was stated this occurred due to overfishing, generated by the “greed of humans”, (Wikipedia 2018)

An estimation showed that around 19 thousand fishers along with plant workers were affected and up to twenty thousand other jobs were either harmed or loss during the closure. (Mason, 2002). The question that is raised from this is can it be recovered from? Can we as a civilisation recover from impacts like this? Well, over the past decade, the cod catch was dramatically rising. A report by the House of Commons showed that the stock was beginning to rebuild after the 1990’s collapse, which you would believe gave hope to us having a future of a civilization.

Despite this impressive comeback, my predictions for 2020 are not so positive. I concluded this prediction after scientists working with the Department of Fisheries and Oceans have released statements showing that between the years 2017 and 2018, cod within the fertile fishing area from Labrador to the Avalon Peninsula decreased by a staggering 30%. “This is a reminder that where we are in that critical zone is a very precarious place to be,” a quote, from Karen Dwyer, who is a stock-assessment biologist working with the department of Fisheries and Oceans. (DFO). “We have to be careful with all sorts of removals.” (Greenpeace, 2009). This is a prime example as to why I believe we will have a less positive outcome by 2020, and that we cannot have a future as a civilization. I don’t believe a civilization can thrive based on destroying the lives of marine animals, destroying oceans, and jeopardising livelihoods of ultimately, each other.


In conclusion, I believe that it is safe to say that we cannot continue to over-exploit fish and our resources at the rate we are doing so. I do believe that if we continue at this rate we will eventually see a world of empty oceans, overgrown with algae blooms, as is starting to show with the Firth of Forth and Firth of Clyde. Ultimately, it is shown that only one tenth of predators that once roamed the ocean remains. Various species are exploding in population due to their predators being overfished by humans and are consuming other species that are of great benefit to the oceans oxygen levels. Overfishing is realistically, in turn, causing the death of more marine animals either directly or indirectly.

By eliminating the species in which keep algal blooms at bay, marine animals are dying, & developing health issues from the toxins that arise from unattended algal blooms. Over 351,000 humans are dying on an annually from the bacteria they are digesting via shellfish, which arise from algal blooms. Within my research, I found this to be the most astonishing fact. Who would have known that we ultimately are causing our own ill-health?

In relation to the example of the Newfoundland Cod Fishery, it shows the importance of fish for our dietary requirements and for economic purposes. The new advances and technology in fishing such as these new technology trawlers are ultimately a downfall. If overfishing continues at the current rate, the population of fish will slowly decrease and eventually humans will not have the required access for their needs.

I believe education is the key to combatting these issues, as I do not believe that we are as educated in this area as we need to be. I certainly was unaware of the issues that arise from this over-exploitation, and it has given me a fresh new insight and appreciation for the marine life that roams below us. I think that if everyone knew what we now know from this essay, that the world would soon change their ways.


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