To answer this question we need to ask ourselves why this issue has arisen in the first instance, and where and how it originated. Firstly I need to find out what farming is concerned with and what the current world food situation is. This will provide a basic background knowledge on which I can base my study. The environmental issues of farming on and off land will need to be compared in a range of farming techniques to establish the cause and effect of threats to the environment.
In the oceans I will be looking into the over fishing of global fisheries and the impacts that this has on the marine, social and economic environments, of areas worst hit. I will be looking at a case study of a Canadian Cod based in fishery New Found land as an example of causes and effects of over fishing on the environment. As new technology is ever growing, the new wave of aquaculture and Salmon farming in Scottish lochs that is emerging will provide an alternative viewpoint of the effects on the environment to traditional methods of fishing.
Along side aquaculture I will be looking at effects of genetically engineered fish on wild stocks again using salmon as a prime example, this should give me an insight into the effects it has on biodiversity in the sea. On Land I will use the effects of overgrazing in Nepal as a comparison to over fishing, as both are concerned with the overuse of an environment and improper management. I will use the effects of GM crops as a comparison to genetically modified fish and look at the effects it has on biodiversity.
In recent years the amount of people that farming has had to provide for has risen very quickly and has risen dramatically in recent years. This is mainly due to the human race’s exponential population increase; in the year 2000 the human race exceeded a population of 6 billion1. Increasing rates of consumption of resources and waste production, altogether magnify the human impact on the environment. Other species when they reach their carrying capacity crash but humans use technological advancements to increase that carrying capacity and often resulting in negative effects on the environment.
There are 92 million tonnes of fish caught each year worldwide and of the 3000 or more species in the sea only a few hundred are fished2. This may not sound too much of an issue but it is the individual species that are in danger of becoming extinct. For example 2/3 of the fish stock in the North east Atlantic and most of the fish stock in the north sea are over exploited and in danger of disappearing1. One particular fish species that is in most danger is the North Sea cod, there had been bans implemented by Brussels on fishing particular areas of the North Sea especially cod spawning areas.
This came As a result of declining catches of cod during and leading up to 1999. Fishermen had only been able to catch 60% of the 1999 quota of 81 000 tonnes3. “The main threat when concerned with biodiversity in oceans, and a threat said to be greater than global warming or pollution, comes from over fishing”1. Fish are the only wild animal we still-hunt and consume on a large scale, but the problem is they are still seen as a renewable source, rather than an animal that could very well become extinct in the near future.
Between 1950 and 1990 the world’s annual fish catch increased nearly five fold. 2 According to the FAO most major fisheries are fully to over exploited. 3 The reason for this over exploitation is the large demand for fish from MEDC, but also the advances in modern technologies that embellish the fishing ships. The modern day fishing fleets are the most destructive to the marine ecosystems; they use props such as airplanes, video Sonar, Seafloor maps and radio to track down the fish, which stand little chance of avoiding detection.
The nets that they use such as bottom trawls and dredges, are extremely destructive to the sea bed trawling up everything in its path including Corel, bottom dwelling organisms and other fish referred to as by catch. The by catch are thrown over board and have a profound effect on ecosystems. It is estimated that across global fisheries there is an estimated 27 million tonnes of by catch each year. 4 Poor management of fisheries can often lead to threats to the marine environment, this was the case for a Canadian cod fishery off New Foundland in 1992 where 40, 000 people lost there jobs and the cod stocks were left at an all time low. The cause according to Bernard Martin a Canadian fisherman was “too much industrial fishing technology.
The culprits are the draggers (the boats that haul nets along the sea bed)” In the 1950’s the technique of dragging took of and the cod stocks were nearly wiped out, in 1977 Canada brought the stocks under control but because of new technologies stronger draggers were introduced and the cod did not have time to fully recover and so in 1992 the fishery collapsed. Another problem with the draggers was the time that they caught the fish, targeting them when they were spawning a time when the population is highly vulnerable to capture.
Campaigners against the trawling technology claim that the trawling negatively affects the reproductive behaviour of the cod and in addition the trawling activity is thought to cause dispersion of eggs and milt, resulting in a higher fertilisation failure. When placed alongside farming on land, a comparison can be made to a problem known as over grazing. I wanted to raise this issue as it is concerned with the over use and exploitation of a natural resource like over fishing.
Over grazing is a form of soil erosion caused mainly in LEDC’s where land for grazing is not adequately maintained and managed, the cattle are free to roam wherever uncontained. In Nepal the farmers used to be nomadic so the cattle did not over use one particular area of land, but due to frequent droughts and political issues farming patterns have become more sedentary. Larger volumes of cattle than the grazing area of land can cope with, cause the soil erosion; this is amplified by the dry climate as new seedlings take longer to take hold and the winds blow the topsoil away.
But it is not just the soil erosion that is linked to over grazing, before the cattle can graze, areas of forest have to be removed causing the further destruction of habitats and wild life. The effects of over grazing come in the form of increased risks of landslides on the steep hills where the farmers are forced to farm due to the lack of space. As with fishing, cattle farming does not just affect one thing, many other animals and habitats are affected in the process, much like a domino effect.
Deforestation>Loss of forest habitat/animals>food for cattle (grass)>Overgrazing (soil erosion>Land slides (loss of human life? >Flooding of Rivers. Another process that started due to the dwindling fish stocks was aquaculture and fish farming. At present over 1/3 of all fish for human consumption is produced by aquaculture. 6 7 Five kilos of ocean fish are needed to produce one kilo of farmed fish, a very uneconomical method. As with cattle ranches in Nepal which have cleared acres of rainforests, Thailand has lost nearly half of its Mangrove forests due to shrimp farming.
The encaged fish also produce waste equivalent to that generated by half a million people. And in one season in Scotland, fish farming can create waste equivalent to 8 million people, which is deposited into Scottish waters. The preferred feed for salmon is shrimp because of its ability to turn the skin of the salmon pink, but due to its scarcity the salmon are fed a pigment. On top of this they may also be fed hormones, colourings and vaccines. 8 This makes the fact that, in Scotland an average of 15000 salmon escape each month, even more alarming. Escapee salmon compete and breed with the wild salmon, weakening their immune systems and gene pools. This occurrence in the sea is symptomatic of the GM crop issues on land.
The problem on land is also with the effects that GM crops will have on other ecosystems. The worry is that pest resistant crops could breed insecticide resistant insects, which would then destroy the supposedly insect resistant crops. The knowledge about G. M crops and the effects they will have are very similar to that of the knowledge of the consequences of the whole effect over fishing has on marine ecosystems, there is little of it. The major concern in farming is to provide enough food for the world, but in their mission to provide they seem to overlook the environmental consequences that bestow their trade, until it is too late.
The plight of the Cod stocks in Canada is an example of the shortsighted views of the governments that manage the seas. If they continue to do nothing then many ecosystems will be lost. Ocean floors bear the brunt of the trawlers who indiscriminately haul every single life form up from the bed including marine habitats like coral. The huge proportion of by catch may have profound effects on food chains and the amount of young fish from a species that are left to reproduce.
The aquiculture trade also has vast negative effects, in the coastal areas and in the locks of Scotland, threatening the genetic makeup of some of the marine wildlife. The social and economical environments of the humans is vastly effected by farming as a whole, The farmers of Nepal rely solely on farming and so if the continued ill managed farming techniques was left unchanged their welfare would be at steak. In much the same respect many countries rely heavily on fishing as their main revenue, and many of the restrictions that could be imposed would be catastrophic for them.
We know very little about the oceans and therefore cannot predict the consequences of our actions. This is the main problem caused by fishing; we have only explored and understand about 2% of the oceans9. There are so many varying problems caused by fishing that when fully understood appear to have far more devastating affects than farming the land. The fact that we know vast amounts more about the land provides a huge advantage when coming to manage farming techniques, which makes it a much more sustainable industry.