More and more people eat more and more fish (see: fish dilemma). As a result, the world oceans are depleted. Although numerous fish populations are already close to extinction, high-tech conventional industrial fishing fleets keep on scouring the oceans and catch more fish of a population than can be reproduced.
Their often non-selective and destructive fishing practices put nearly all marine creatures at danger: Many million tons of them are thrown overboard every year as unexploited by-catch, dead or dying. According to estimates of the Food and Agriculture Organization (FAO), in addition to the approx. 90 million tons of marketable fish, several million tons of by-catch end up in the giant nets every year – including juvenile fish, whales, dolphins, sea birds, and sharks. On top of that, common fishing techniques destroy the marine environment.
Fishing with bottom trawls is one of the most destructive fishing methods in use: A net is dragged along the seabed, completely ploughing up the delicate ground. Fishes are shooed into the nets in the process. Deep-sea ecosystems are exceptionally susceptible to the ploughing of the sea bottom, in particular deep-sea coral forests. On the high seas, up to 300 trawlers from industrialized countries use bottom trawls for fishing. They plough up an area of about 1,500 square meters every day. Bottom trawls can also be used in a depth of 2,000 meters. This is particularly dangerous as deep-sea fish have a life expectancy of up to 200! years, do not become sexually mature before they reach the age of 25, and their populations can thus hardly recover from overfishing.
Its principle is similar to bottom trawls. Beam trawl fishing is common in the North Sea and produces enormous amounts of by-catch: per kilogram of sole, 10kg of other marine animals are killed; per kilogram of shrimps, the number even amounts to 15kg! According to expert estimates, the seabed of the North Sea is ploughed up 5 times per year for the purpose of plaice fishing.
“Trawling” is the most common method of high sea fishing in the free water zone (Pelagial) to catch schooling fishes such as herrings, mackerels, and sea bass. The nets have an opening of up to 23,000 square meters and can catch up to 600 tons of fish and other marine animals. In the process of trawling with two boats, the so-called pair trawling, many dolphins get killed in the English Channel by French and English fishermen.
Once a school of fish is discovered, this up to 2,000 m long and 200 m deep net is cast around it in a circle and pulled tight like a sack from the bottom. It is the most common fishing method for canned tuna and skipjack tuna. Its increasing use threatens the survival of vulnerable species given that large amounts of by-catch end up in the nets. Artificial swimming objects, so-called Fish Aggregating Devices (FADs), do not only lure skipjack tunas into the nets but also juvenile fish, sea turtles, sharks, bigeye tuna, and yellowfin tuna.
These nets are made of fine, transparent, and extraordinarily tear-proof synthetic fibers and often drift underneath the ocean’s surface for days, where they are attached to buoys. Millions of marine animals, such as dolphins, sharks, sea birds, sea turtles, and sperm whales get entangled and die in the nets. This is why the United Nations globally banned this particular fishing method in 1992. Still, it took the European Union until 2002 to put a ban on drift nets in its waters. Nonetheless, countless drift nets are still being used illegally – particularly in the Mediterranean Sea – by up to 400 boats.
These up to 15 kilometer long and fine synthetic nets are anchored to the ground. Small cetaceans are not able to locate their thin cords with their echo sounders and thus get entangled in them and drown. In the North Sea and the Baltic Sea alone, 10,000 porpoises die in bottom-set gillnets every year.
Similar to a beam trawl, a dredge is made of a stable steel frame that is dragged over the seabed. This is how crustaceans such as mussels and crabs are harvested. Suction and hydraulic dredges shoot water into the sediment and then collect the stirred-up crustaceans in a net (hydraulic dredge) or suck them to the surface with a tube (suction dredge). This method again ploughs up and destroys the entire seabed.
The harmful variant of dynamite fishing is very popular in tropic regions. It is illegal and destroys many coral reefs.
Industrial fisheries attach longlines with a length of more than 100 kilometers and up to 3,000 baited hooks (mackerel or tuna) to the ocean floor in order to catch tuna, sharks, swordfish, Patagonian toothfish, and halibut. Longline fleets put out 4 million hooks around the globe every day, intended to catch tuna. Among the victims of by-catch, that can account for up to 20-35%, are sharks, rays, sea birds, and turtles.
Longline fishing also serves the purpose of shark finning. This technique involves cutting off the dorsal fin of the caught (and still living!) sharks. Afterwards, the animals are thrown back into the sea where they bleed to death and drown. The cut-off shark fins are used to make shark fin soup, which is considered a delicacy notably in Asian countries. Blue sharks and oceanic whitetip sharks are the main targets of longlines. In this way, up to 100 million sharks die a painful death every year. The actual fin does not taste like anything at all and is often cooked in chicken soup...
Furthermore, sharks are caught and killed for their dentures, their teeth, their leathery skin, as well as cosmetic ingredients. On the French island La Réunion in the Indian Ocean, living dogs and cats are used as bait for shark fishing. Fishermen stick fish hooks through their snouts and paws and simply cast them into the water.
Norway, Japan, and South Korea are countries that, despite a global moratorium, still hold on to whaling today. As a pretext, they refer to the fact that it is legal to catch whales for the purpose of research. In this way, they have killed more than 25,000 whales since 1986. Their meat is sold profitably on the market. It is a tortuous fishing method and whale meat is often of inferior quality and entirely unfit for human consumption due to its high share of heavy metals.
In the Japanese bay of Taiji, up to 15,000 dolphins and small cetaceans are slaughtered as part of a festive traditional ceremony every year that takes place from September to January. Their blood often colors the ocean red for many days.
Between April and July, when pilot whales visit the cooler waters around the Faroe Islands in the North Atlantic to bear and raise their young, the inhabitants of the half-autonomous island state organize a whale hunt in which thousands of them are driven into bays and killed with knives and hooks. Their meat, highly contaminated with mercury and PCB, is later distributed among the inhabitants.
Environmental pollution, caused by the discharging of untreated wastewater and garbage contained within, dumping, the industry – i.e. crude oil and natural gas production and resulting accidents like oil pests –, tanker accidents, and disasters involving oil platforms or mineral extraction, poses a threat to all the oceans and their inhabitants.
Crude oil and natural gas are extracted on nearly all coastlines. They are brought to the surface with the aid of oil rigs, which poses a danger to the local fauna. With regards to the last crude oil reserves, a global competition has broken out among the largest corporate groups. The local flora and fauna as well as the local people are completely disregarded in the process.
The amount of plastic waste in the oceans keeps on growing every day. Instead of decomposing biologically, plastic is ground and split up into ever smaller pieces. These so-called “tears of the mermaids” can already be found in all parts of the oceans and leave animals to starve if they mistake them for food. As plastic cannot be digested, it accumulates and constipates the stomachs of fishes, birds, and marine mammals. Animals can get entangled with larger plastic parts, such as plastic bags or can holders, and choke to death on them or end up with flesh wounds. It is assumed that not a single cubic meter of seawater is free of plastic.
The discharging of untreated wastewater can promote the development of algal bloom. Owing to the nutrients contained in the wastewater, the algae grow in an uncontrolled manner and use up all the oxygen in the water. Starved of oxygen, these areas become death zones where life is no longer possible.
Poisonous substances contained in wastewater are absorbed by plants and animals and can thus also end up in human foods via the food chain. Most notorious in this respect may likely be the Minamata Bay. This is where, in the Fifties, wastewater containing mercury was discharged into the ocean by the Chisso corporation. It was absorbed by the fishes that were subsequently fished out of the ocean and eaten by the local population. Cats were the first to drop dead. Later, many people got sick and died of the consequences of mercury poisoning.
Today, it can be proven that about 1.2 million tons of polychlorinated biphenyls (PCBs) were released into the environment (ocean, atmosphere, ground water, and land). Roundabout 100,000 tons were disposed of in the Atlantic Ocean alone, making it the global ocean most contaminated with PCBs. PCBs are contained in plastics, plasticizers, and insulating agents. They are considered carcinogenic and highly poisonous.
As they filter their aliments from the seawater, mussels absorb poisonous substances and in particular heavy metals; the same goes for big marine mammals such as whales, dolphins, and seals. There is another problem with consequences that will only start to show after several years: the accumulation of medication in natural watercourses. Many drugs that are swallowed and absorbed through the stomach are so highly overdosed that the human body partly excretes them later-on. However, the current state of knowledge is still insufficient and, in spite of numerous research efforts, is it still not known which risks they entail for human health and aquatic life. Drugs should thus be used in a conscious manner. Old drugs must be disposed of separately.
Whales and dolphins are increasingly confronted with noise in their habitats (building sites on the coast, shipping traffic, etc.). As they are highly dependent on their fine hearing and their susceptible echo sounder to explore their surroundings, to search for food, and to communicate, there is a direct link between the high amount of noise pollution, the resulting malfunctioning of their echo sounders, and the stranding of countless whales and dolphins.
The growing shipping traffic also contributes to noise pollution; moreover, collisions of ships with whales and dolphins are not uncommon in highly frequented maritime regions. The northern right whale, also called the black or Biscayan right whale, is particularly threatened by shipping traffic as it is exceptionally slow and thus cannot dodge fast ships and boats in time.
The acidification of the oceans via an accumulation of CO2 in the water (from the atmosphere) reduces their calcium carbonate content, which is needed by corals, mussels, and crustaceans to build their shells and skeletons.
Leading environmental groups publish yearly fish guides. These guides specify which fish species are not yet overfished and therefore suited for consumption to a limited extent. They provide an orientation for your everyday shopping.
The guides partly also include information from the FAO (Food and Agriculture Organization of the United Nations) on large fishing regions and their fish populations.
Bei den Ratgebern fließen teilweise auch Informationen der FAO, der Welternährungsorganisation der Vereinten Nationen über große Fisch-Fanggebiete und somit über deren Fischbestände mit ein.
Aquacultures offer an alternative to conventional fishing. In 2010, forty percent of all fish products came from such fish farms. Unfortunately, diseases can spread more quickly there, given the confined space. Hence, additional medication such as antibiotics must be fed. These antibiotics can enter the open oceans where they are then absorbed by other fish and dolphins. As a consequence, the chemical loading in intensive breeding is enormous.
Breeding basins for prawns have already destroyed more than one million hectares of mangrove woods and other ecologic areas around the globe. Salmon farming companies in northern Europe also have a negative impact on the local fjords and coastal waters. Escaped salmons displace the natural local salmon stocks.
Moreover, the feed for aquacultures is made of fishmeal that was fished from the ocean with non-selective fishing methods beforehand. A kilo of farmed fish consumes roundabout 5 kilos of fishmeal. The fry used in fish farming, that is the juvenile fish, is mostly wild-caught. Hence, to be accurate, a fish species is simply converted into another seemingly sustainable fish species.
The MSC label (Marine Stewardship Council) is an international and independent label that stands for sustainable fishing, strict fishing quotas, and gentle fishing methods. Fish from sustainable and organic farming is marked with organic labels.
Selective fishing for tuna – without high amounts of unwanted by-catch – is possible with a fishing rod and a line. This technique leaves juvenile fish in the water. The so-called pole & line method for catching skipjack tuna is being used, for instance, by fishermen on the Maldive Islands. A fleet of a thousand ships was built for this purpose, providing an income to 20,000 fishermen as well as thousands of additional jobs in fish factories and boat construction.
Further information on the ocean and what we can do for it (as water sports enthusiasts: Green Room Surfing
The ocean is a gigantic and interconnected ecosystem that covers about 70% of the earth’s surface. The Pacific Ocean, the Indian Ocean, and the Atlantic Ocean as well as the Arctic Ocean and the Antarctic Ocean are linked together by ocean currents. In addition, there are smaller inland seas, such as the North Sea and the Baltic Sea, as well as the Mediterranean Sea, the Caspian Sea, and the Black Sea. Inland seas are side arms of former oceans.
The different regions of the oceans are subdivided into four groups according to their water temperature: polar, cold temperate, warm temperate, and tropical. The ocean’s habitat is divided into two larger categories, the pelagic Zone, also called the high sea, and the benthic zone on the seabed.
Biodiversity is determined by the sunlight. The uppermost water layer is flooded with enough light which contributes to photosynthesis in plants. It is called the euphotic zone and extends downwards to a water depth of 200 meters. This zone is were most living beings are found. It is home to whales, sharks, and all sorts of fish. From a depth of 200 to 1,000 meters, the light becomes weaker and no longer suffices for plants to grow. This zone is called the disphotic zone. From 1,000 meters onwards, it is pitch black. This aphotic zone is the preferred habitat of deep-sea animals. Prevailing temperatures average at 4°C.
Coastal areas separate the oceans from the land masses. They are influenced by the tides, a significant factor for the quality of waves. The different types of coast are home to various animals. They have adapted to the inhospitable conditions of rocky coasts, sandy coasts, and Wadden Sea, defying tides, wind, and waves. Estuaries, partly enclosed water bodies where fresh water and ocean water mix, also form part of the coastal areas. Mangrove woods can be found in tropical coastal areas. They offer ideal conditions for many small aquatic organisms. However, they are threatened by environmental pollution and aquacultures. Salt marshes are primarily located in temperate latitudes.
The area between the coast and the continental slope, where the ocean plunges into the depth, is called the shallow sea or shelf sea. This area is shallow, flooded with much light, and constitutes the beginning of the Pelagial – the high sea. Seagrass meadows and kelp forests offer an ideal habitat for roundabout 230,000 species here. Flat tropical shelf seas are home to the snapper, an important edible fish for many coastal inhabitants.
Warm and shallow waters allow for the formation of coral reefs. Some of the best waves for surfing break above coral reefs. There are three different kinds of reefs altogether: fringing reefs, barrier reefs, and atolls. The water temperature around these reefs never drops below 21°C. Moreover, there are coldwater coral reefs in the temperate zones. All coral reefs are biodiverse and colorful habitats that are irretrievably being destroyed by environmental pollution and acidification.
The open sea begins where the shelf seas end. This is where the ocean floor drops down to the deep-sea plains. It is home to the oceanic whitetip shark, different tuna species, as well as numerous whale species who are still threatened by whaling nowadays. In the deep sea, only few species can survive given its inhospitable conditions. However, they are severely threatened by deep-sea fishing with bottom trawls.
The polar seas – the Arctic and the Antarctic Ocean – are the oceans located at the poles. This is where ocean life is regulated by ice.
The Arctic Ocean, also called the North Polar Sea, is the smallest ocean of the world. It is enclosed by Russia, Asia, North America, and Greenland and covered with a thick layer of ice during most of the year. Is is the habitat of polar bears, walruses, seals, and whales as well as the target of deep-sea fisheries and the greed of crude oil companies due to its sizable oil and gas resources. Previously, the North Pole was the hunting ground for English, Dutch and German whalers.
The Antarctic Ocean, also called the South Pole or Southern Ocean, is the ocean located around the continent Antarctica and the second smallest ocean after the North Polar Sea. This is where the biggest penguin species, the emperor penguin, lives under hostile conditions. Even today, countless whales are caught by the Japanese every summer when the pack ice retreats.
The Atlantic Ocean is the second largest ocean and covers more than a fifth of the earth. It is also the youngest ocean and expands by about 25 mm every year. Many large rivers flow into the Atlantic, such as the Mississippi, the Amazon River originating from South and North America, as well as the Congo and Niger rivers originating from West Africa. The Rhine, the Loire, and the Elbe flow into the Atlantic Ocean from the European continent. It is also connected to the Mediterranean Sea via the Straits of Gibraltar and to the North Sea via the English Channel. The Atlantic Ocean is home to countless fish populations due to its nutrient-rich waters above the continental shelf; however, they are close to collapse due to overfishing.
The warm waters of the South Atlantic is where the best-known great white shark population lives, around the South African “Seal Island”. Great whites are exposed to severe hunting, which, among other things, is due to their bad reputation.
Cape Horn is where the Atlantic meets the Indian Ocean. The latter is completely bounded by the Asian land mass to the north. Moreover, it is the only ocean whose main current, the Somali Current, changes direction with the seasons. Commercial industrial fishing in the Indian Ocean poses a threat to local fishermen and destroys coral reefs through overfishing.
The Pacific Ocean is the largest ocean as well as the birthplace of numerous earthquakes due to its “ring of fire”. Tectonic plate movements break open the deepest trenches of the earth. The Pacific Ocean comprises among other things the Hawaiian Islands and the Galapagos Islands with their unique flora and fauna. Both archipelagos still show volcanic activity today and keep on growing. The Pacific is home to numerous fish populations and of high significance for the crude oil and natural gas industry. Its inhabitants are severely threatened, in particular by illegal fishing. The Sea of Japan, bordering the Pacific Ocean, is the hub of the shark fin industry.
Responsible for the content: Ridehere-Ridenow, Association for Conscious Living in the Here and Now, ZVR: 437983246