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=Observation of the animal=
=Observation of the animal=
=Interviews=
=References=
=References=
Dolphin Societies, ''discoveries and puzzles'', edited by Karen Pryor and Kenneth S.Norris <br>
Dolphin Societies, ''discoveries and puzzles'', edited by Karen Pryor and Kenneth S.Norris <br>

Version du 21 août 2009 à 12:10

Draft Plan:

  • Introduction
  • Orcas:
    • Classification
    • Morphology
    • Habitation and Distribution
      • The different groups
    • Communication
    • Nutrition
    • Hunting
    • Reproduction
    • Spatial and behavior structure
    • The population growth
  • Pollution:
    • Definition
    • Human activity
      • Traffic
      • Farming
      • Hunting
    • Chemical pollution
  • Observation of the animal
    • The different techniques to observe the animal


Introduction

In this project I would like to make my own research by using different kinds of resources as books or even by interviewing searches working on Orcas for years. My project talks about the huge problem, that is each year increasing, pollution and in what it influences marine mammals, more precisely Orcas. I will write about these incredible animals which are constantly attacked by different pollution factors and in conclusion which influence different domains of their life. The main goal of this work is to show in what and by what the different kinds of pollution influences and degradates Orcas life. This will also determine how big is this impact and that all the marine mammals are touched by pollution. I will first write on pollution on one side and on the other on Orcas. Than I take the both subject and mixed them together by seeing what kind of impact there will be and happen maybe in few years. After on I went to a specific place which is Vancouver to do an outside experiment and will discuss and deal with the different problems pollution causes on killer whales. This will show and prove certain of the points I have mention in the first part of my work. M y project is so organize in a way of writing about Orcas ,by presenting this animal, about pollution, presenting the different kinds and by what are the provoct, making and hypotheses of what's happened when we have these different factors that tuches Orcas and finnaly by having an exterior experiment in a certain area that will give a certain matier to my work by prooving certain of my hypothese or by myself seeing a beginning of some problem pollution causes.

Classification: Orcas, Orcinus orca

In common life we give the names of animal according to our own language. However we use a system call binomial nomenclature to have no mal entendu between scientific coming from different language. This is why we use a a scientific language to give names to animals. The binomial nomenclature uses 3 laws. First we say the genus and the specie of the animal in Latin. When we write the scientific name of the animal the first letter of the genus is written in uppercase letter and the hall name is written in italic. The scientific name of the killer whale is Orcinus orca. Each animal is classified in a specify way according to there characteristics. We use for this a system call hierarchic classification.
Here is the hierarchic classification of the Orca:
Domain: Eucaryote
Reign: Animal
Crotch: Stringed
Class: Mammals
Order: Cetacean
Family: Delphinia
Genus: Orcinus
Specie: Orca
Genus, species: Orcinus orca

Morphology

The Orcas as often been merged with whales because of his extraordinary size. However Orcas are the biggest ever known dolphins. There other name killer whale can also bring confusion of there real origins which are dolphins.
The size of an orca changes choosing it's sex and also it's geographic location.
Size:

  • Male:

When a male orca reaches it's maturity, it can be 9.8 m long. It wises in average 3.6 and 5.5 tone, it can even wise 11t. The back, codal and pectoral fin can be in average 2 meter.

  • Female:

When a male orca reaches it's maturity, it can be between 5 and 7.7 meter long. It wises in average an1.3 and 3.6 tone, it can even wise 7.4t. The back, codal and pectoral fin can be in average

  • The young:

At the birth the the young measures between 1.8 to 2.7 choosing it's location birth. The weight of the new born is in average 180 kg.


Coloration:
We can easily recognize an Orca because of his distinctive corporal black and white pigmentation. He has a white oval pigmentation just behind his two eyes. His dorsal and pectorals flippers are black. On the buttom of the animal his body is white and elongates itself between his pectoral flippers and his fluke. In addition orcas have each of them a distinct grey stain behind their dorsal fin. This stain is call the saddle and has different kind of forms chosing the individu. Reaserchers use the saddle to recognise an individu from a group. While I was on a whale watching boat I made photos of orcas. On the boat I was able to have a book in which there is the photo of the dorsal fin and saddle of each orca from a certain group. This permitted me to compare my photos we those and find out which orca I had taken a photo of. I could so determin that the orca on this photo is call capucino and that I was observing the K pod, who is part of the southern residential group.


Body shape: Orcas have an elongated body that permit them to easily swim fast in the ocean. This shape is comon for dulphins and also similar to whales. However killer whales have been built for hunting as all the other dulphins. This is why they are much smaller than wahles and have a more sharp body.

Habitation and Distribution

The different species

It is quite hard to regroup the different kind of killer wahles groups as their names and the groups change chosing which part of the world they can be found. For example in british columbia where I have work for the marine mammal rescue and observes orcas their are 3 kinds of groups.

  • The residents killer whales: This groups is seperated into two communities call the southern resudent, which is composed of 81 induvuduals and the northern resident, which is composed of 172 individuals. The residential group is seperated in two because the northern lives in the north of the B.C area while the southern lives in the south. It is important to know that these two goups never intersept or have any contacts together.In addition of this seperation of 2 groups theirself are seperated into pods. The J,k and L pod for the southern reseidential group and i will not name all the northern pods as they are an amount of sixteen pods.
  • Transient killer whales is a groups call transient because we less see them in the area of the B.C during the year. However we can still observ them in these regions. This groups is composed of 79 individuals and is seperated into 30 pods. They are in conclusion less than the residential group. One of the reason why is because they mainly eat mairne mammal, which is not the case of the residential groups. We will more explain this in the chapter of nutrition. The transient groups travels in the area of both southern and northern resident, but never interact socially with them. However as I discussed with M..., who worked in the marine mammal rescue with me and who hade pass more than 25 years catching, coaching and observing orcas, he told me that ons there had been an observation of residents killer wahles attaking a southern resident killer whale. Neverthless this is the only time we observed it.

However you have to be carfull with the name of resident and transient, because the resident are not less transiant in the area of B.C than the so call transient group. In fact most of the time the resident do not stay much more longer than the transient orcas in the B.C area. However we still call them this way because researchers start it this way and will not change it. For shure what seperates the transient to the reident group is their nutrition.

  • The Off-shore killer whales is a newly known groups. We know really few of it, a part from the fact that they live off shore and that they never come to costs.

Location:

  • North Atlantic
  • North Pacific
  • South hemisphere

http://www.orcaresearch.org/akwic.htm

Adaptation to this middle

Nutrition

Orcas are one of the biggest predator in the world. There shape, there teeth are specialy fit for hunting. There exist different groups of orcas who eat different nutrition. As we said many times before there exists different groups, which are all blood relatives and have their own language. An other element that differentiates these groups is nutrition.

We also have in British Columbia’s water 2 distinguish Orcas, the inshore and the offshore. During year the searchers noticed, by looking in orca’s stomach and by observation that there was really two different groups defined by their nutrition. The first one, inshore, eat 89.7% marin mammals, 7.1% squid and 3.2% fish. These groups are consisted of 10 to 15 individuals. Their number is in taken account of their hunting strategy. This group is consisted of the most dangerous predator, as it can even attack blue whales and hunt a human thinking it is a seal. The offshore orcas eat 98.5% fishes, 1.1% squid and finally 0.4% marine mammals.

The nutrition of orcas can also be defined by their age and sex. Generally the older males will more eat big prays and the one that are the harder to hunt as they have more experience of hunting than the young orcas.

Hunting

Reproduction

The Orcas have a close reproduction mode to the non aquatic mammals and including ours.

Spatial and behavior structure

During expedition we can observe that dolphins member and so Orcas are structured as a herd. In fact these animals stay in group together and stay closer to each other than to an animal from an other group. We can observe one or two leaders in the herd and the presence of a constant central group. These leaders are stronger and larger than the others. These dominant member observed the area for potential danger or investigates if there is something new happening near the group.We sometimes have also two or three members of the group that are more in front of the others to watch for inshore areas or danger. When there is a danger the animals immediately regroups there self in a packed group with the youngest in the middle protected by the other members. There movement are synchronize and in harmony. The group structure of orcas allows them a good use of the space around them as for hunting in several different conditions.

+ Herd = family !

Communication

Sounds for marine mammals is very important,as in water the visibility is greatly limited. Even though killer whales have a good vision in water, can see below and above it this capacity is limited by the time of the day and the clarity of water.This is why thanks to their capacity of communication and producing sounds killer whales are no more limited by these limitations. Killer whales use sounds to naviguate,locate their preys and to communicate with each other.What's special with these mammals is that each group has his own languange. Sounds of each of these groups is the same with some special differatiations. Thanks to this we can generaly recombine the family tree of some groups and fine the lien de parenter between them.

The population growth

Identification

Searchers mostly identifiy orcas by observing specific characteristic on one individu]]. Some of these specific characteristic are natural marking that we can find on the animal dorsal fins or marks all around the body. This identification is the most used as it is the easiest technic to recognise an individu.

Pollution

We are dealing here with the marine pollution. In fact orcas live in ocean and are influence by the pollution which is taken place in oceans. 71% of the earth surface is occupied by water and 97% of this water is found in ocean. On earth we have 5 million animals and plants. Even though only 5% of these animals and plants live in the ocean, because of the so important place water has on our blue earth we are touch and cetacean even more than us by the marine pollution, which is increasing. Pollution is a big factor in the degradation on earth’s water health. It is fluent and can quickly extend as it print itself in the water and cannot after be clean. This is a great problem as it also causes diseases and when the pollution is chemical it prints itself in plants which pollute each animal that eats them.

Let’s start by the beginning of food chain. First in the marine’s food chain starts with the phytoplankton (plant plankton). This miniscule plants absorb the sun’s rays which are use to make photosynthesis and thus to produce energy. They are the energy resource of the entire living animal, this is why they at the beginning of the food chain. In addition the phytoplankton represents a huge mass of the vegetal spicy thus it is the regulator of the earth’s oxygen. They allow us to live and breathe. Any tiny variation in the ocean temperature as 1C° can cause huge problems, as it alters the phytoplankton’s growth and in consequence changes the entire marine’s live. We than, have the Krill, which is in the second place in the food chain.-., This zooplankton is bunch of very small and tiny shrimps which are 3 to 7 cm long. All together they can weight 500 million tones which represents even more than the weight of the total human population on earth. They essentially grow in zones where the conditions are perfect for phytoplankton growth which is their nutrition. We can so find them in the north pole and mostly in the south pole. The krill represents 80% of the nutrition of sea birds, 100% of certain whales a fanon, of most fishes, also of some penguins and finally of some squid.This is one of the only example on earth were only one nutrition exists for so many species and which shows us how important they are and how big the impact on the marine worlds would it have if there was no more krill and zooplankton. In addition we can see that the krill is fragile and if the pollution kills it all the cetacean, fishes and other ocean mammals will disappear with it.

Different kinds of pollution: Our earth is a fragile matiere and can be easily degradated by anything as pollution. During these last 100 years the human activity has destroyed the earth’s nature and oceans. This is caused by the constant increase in the development of industries and also the high and rapid increase of the earth’s demography and plenty of other factors. For example every day, every month and every year huge quantity of use water not treated, of oil, industriel rejet and déchets. All these examples and other pollutants are brought in the oceans essentially by the atmosphere, rivers and marin corents. Even tgou there is 1’370 milliards metre cube of ocean’s water, which permits it to diluate easily pollution, they is still a major problem. In fact when there is a big ecological catastrophe it can easily spread everywhere as marin corants and so water l’emporte. This affects a lot of marine species and marine plants as they live in water and are attacked by the pollutants agent. Pollution kills each day a lot of marine animals or living in the oceans and this is, for most of the factors, or fault. Each country pollutes oceans at different levels and by a certain way. Domestic pollution: Most of the earth’s population, more precisely 60%, lives at less than 60 km of the ocean and seas costs. This results to the reason why, the zone mostly touch by pollution, are the cost zones. In fact because of the presents of human activity as we explained before pollutes a lot and by different ways. In addition this population is in a constant growth which makes that we are having even more than before pollution near these sectors. One of the reasons of these results is the sewages.


New resent research has prove that the antartic’s orcas are the most polluted animals in the Antartic. The amount of chemical pollutant as BCP, the pesticides and the brominated retarders of flame in their graisse is huge. One of the most dangerous pollutants comes from fire retardants which is the deca-BDE. In addition in contrary to the BCP and the pesticides, it is not forbidden, so they are constantly . This pollutant can cause central nervous system disorders, behavioral and reproductive to animals. The daily life contaminates the marines faun. Pollutants are not directly brought by human to the animal but taken around the ocean by different marine and air currents. The amount of pollutants in the artic is huge. The reason for this amount it that the winters in the artic are long and dark and the low temperatures empeche the degradation of pollutant ones they have been fixed in the soil’s and water’s artic.


Human activity

Ports, Harbours and Marinas

One of the biggest sources of pollution in our ocean is ports. These places are constantly rebuilding themselves and have to be constantly maintained. They receive million of boats, which fuels a lot and destroys the environment all around them. The port has to maintain and take care of some ships by repairing and repainting them. When these factors are not properly measured they can occur to a huge environment disaster. In consequence, these places products chemical storage, air emission, solid waste generation and disposals, that will pollute the marine environment around them.

In addition of ports marinas and harbors also reject a lot of contaminants in the ocean. They also pollute as ports but sometime in different ways. Marinas are little ports, they will so reject a smallest amount of pollutants. Harbors also pollute the ocean with some identical pollutants than ports and marinas. Marinas and harbors are smallest sources of pollutants than ports. They emit, in the marine environment, hydrocarbons, organic waste and persistent chemicals such as PCPs, TBT, and PAHs. They can also be the cause of the presence of certain toxic metals, such as mercury, copper, lead, nickel, cadmium, silver and arsenic, in the ocean.

Industries

The industry pollution exists since years. However since the industry revolution happened, around 1800s, there is a constant increase in production and at the same time of pollution. Most of the pollution made by industries comes from the use of some fuels like coal. However in our case we are more interest in the pollution that industries cause in the ocean. This happens because industries dump their wastes such as organic, nitrogenous products or phosphoric and toxic products in waterways. However choosing the type of industry, its type of treated water, its waste water management, the characteristic and quantity of the waste water cause by the industries changes. The dumping of the wastes in the waterways contaminates them and will than contaminate the water in which waterways flow. Which is even more dangerous is that some of these organic wastes are persistent and hardly degraded.
One of the other reasons of pollution in the ocean cause by industries is the mixing of their wastes with groundwater (potable water) and waterways. This happens when industries do not use enough efficient containment in which they store their wastes. Because of this their waste will leak into the groundwater and waterways. Furthermore by contaminating groundwater industries pollution is as bad for us than the marine mammal life.
Industries make two kinds of wastes: liquid and solid. They take rid of liquid wastes by throwing it into wastewater systems. When they have solid waste they discharged it in landfills. Furthermore because liquid waste is discharged into wastewater system, the wastes of domestic and commercial activities are mixed together. In consequence sewage has a high level of chemicals and heavy metals.
Some waste that has been treated still contains some bad substance. These ones will be carried into rivers and coastal water. They will not be degraded during the travel and will contaminate the ocean. These chemicals substance can also reach the ocean and pollutes it via pipeline discharged. They can also be discharged accidentally by a boat accident that was caring them and also by leaking underground storage tanks.
Searchers can find chemicals made by pollution and other pollutant product by the industries in ice cores. These ice cores are taken from Antarctica and the arctic, which show us how far pollutant can travel in the ocean and how high industry’s pollutants are in the ocean. Sewage comes mostly from commercial, domestic, and industrial sources. Sewage comes from different water that we use for our common days activity: bath water, toilet flushing, laundries, from kitchens, dishwashing in which there is detergents, greases solvent and finally organic waste. There is also sewage coming from animals, vegetable and from food preparation that are sometimes throw into an in-sink garbage.
Before being directly throw away sewage generally have to be treated. There are two methods for sewage discharged: first they can be put underground after treatment in septic tanks or, after being treated in a sewage treatment plant, to surface- water bodies (river, lakes, stream and coastal outlet). Nevertheless when septic tanks are malfunctioning or badly designed sewage will contaminates surface water, groundwater and also coastal waters. Furthermore even treated sewage contaminates the environment. When sewages are treated in sewage treatment plants there is a formation of a semisolid byproduct called biosolid. This disposal is commonly named sludge. During a certain time most of American’s coastal sewage treatment plant discharged the treated sewage into the ocean. However this contaminates most of the marine environment around the discharging and produces disease-causing microbes. The government had even to prohibit some beach in which the water was too much contaminated. In consequence America prohibited any sludge into the ocean. However a lot of countries do not prohibit it, which makes that the ocean is still polluted by sludge.
Nevertheless not all of the sewage are treated before being discharged. In addition the infrastructure and organization of the sewage are sometime quiet bad and leak. In addition there can have malfunctions or inundation cause by storm water which makes lots of problems. Explanation in pollution 1 in organic waste.
In developed countries non-treated sewage continue to be discharged into opening water in harbors, bays and coastal water. Moreover developing countries, who cannot afford themselves sewage organization, have to throw the raw sewage, waste into surface water and coastal water.

Agriucltur pollution

There is more than 340’000 composed synthesis that the agriculture domain use for their different activities. They so use pesticides such as DDT, herbicides, fungicides and manures for their lands. All these elements will create wastes with also the waste created by animals. In addition agriculture wastes contain nitrogen, phosphorus and other nutriments. All these elements can leak into rivers, lakes, coastal waters and even into groundwater. Wastes that will leak into lakes, rivers and coastal waters will enter into the ocean and contaminate marine life. However as you can read the wastes can leak also into groundwater and in conclusion contaminate also human health. waste: One of the waste in the agricultur domain is made by animals. These waste are not treated as there a made by animals and so reach waterbodies trough the surface layers or by crossing the land surface via runoff. Animal waste can also reach the ocean by leaking into rivers that reaches the ocean.

Domestic pollution

Because the purgation station are rare near costal zones, most of the sewage throw in the ocean are not clean.

Coastal Eutrophication: Plants, animals and human sewages have nutrients and organic materials which reach the ocean. These materials provoke in the water a biological, physical and chemical stimulation.When sewage not pure enter the water it oxydfies itself. This phenomena is call eutrophisation.This progression is commonly observed in bays, estuaries and marginal seas. The human activity accelerates this process, because of the inputs in the ocean of fertilizers, sludge, waste containing nutrients like nitrogen and phosphorus. One of the observations of the eutrophication process is the increasing growth of alga and other plants created by the increase of nutrients. The accumulation of these plants and alga in a certain area will avoid the transmission of into the water. There is a possible decay of marine plant’s bacterial which can make the dissolve oxygen in the water decrease.
 Limitation of orcas area  Also: This is a dangerous process as some species can take the place of other, making this spicy disappear. The disappearance of this specie can provoke the disappearance of the specie that eats it and inconsequence makes it also disappear until the higher spicy of the chain food. In addition sometimes the alga that take place of the ancient ones can produce biotoxins (natural poison) that can be transported to the different levels of the chain food and potentially kill the highest spicy of the chain. We see the same observation we contamination of the nutriments of some spicy that accumulates until the highest spicy of the chain.

Most of the time sewage contains human dejection, which have some microbes. These pathogens will contaminate the ocean when the sewage leaks in it. We will explain in the chapter of ‘’effects’’ what happens then.
In addition human just throw in their sewage heavy metals, plastic, meds, acids, diluents, detergents and oil of emptying.These different elements will simply enter the water via the flow of our sewage and damage the marine life in the ocean.

Floating waste: One of the biggest pollution made by domestic activity near the costs is floating waste. It is more and more observe on beaches plastic or other kind of waste on the ground or floating in the water. A lot of animals die because of these waste. Scientists say that 80% of these wastes come from coastal areas. These objects reach the ocean by being directly thrown in it or by being push by the wind or rivers. The other 20% of these wastes arrive in the water by being thrown overboard of boats and even some time come even from air planes.
This kind of pollution is persistent for a certain period in the water and will so disappear after a certain period. However, a plastic bottle for example takes more than 4 centuries to be degraded, which leaves a long time for the pollutant to make damages. Most of these wastes are not biodegradable and are thrown in the water for more than 30 years. In addition our sewage can sometimes carry some microbes known as pathogens and can cause disease.

Boats and traffic pollution

How ports, marinas and harbors pollute the ocean: Boat reparation and boat grids: One of the major source of pollution coming from these 3 places is the activity of boat reparation and when the boats needs a hull reparation, boat grids.

Organic waste and sewage: Another kind of pollutant discharge in the ocean is organic waste. These wastes are mostly rejecting by small recreational vessels. These vessels don’t have sewage-treatment or holding tanks. They will in consequence directly throw their wastes in the marine environment. Most of these pollutants are found near small crafts harbors as they usually have more small vessels. Some boats that have holding tanks sometimes are not able to correctly throw the sewage in pumping sewage. For a result they throw directly raw or treated sewage in the ocean. Finally in most of the world’s ocean there is no restriction for no-dumping zones which makes that there is an accumulation of wastes and sewage mostly in marinas and harbors. This is also because these places are not fit to receive or take sewage and wastes from boats in comparison to ports, that receive a lot of cruises and big boats.

Fuel oil: In most harbor’s and marina’s water, there is a huge amount of fuel oils and lubricants. There is two kind of oil pollution: the acute, which is for example an oil spilling and the chronic one, which is little amounts of oil leaking. In these areas there is more likely chronic oil pollution, the oil accumulates itself in the water and slowly destroys the marine environment of the area. In these places there are a lot of small boats as we said before. They are not often new and so pollute much more than new boats. They reject fuel from their carburetors and lubricating oil as their old engines easier chock than new ones. These two pollutants can also leak into water because of over-priming. Old boats also pollute a lot as they have not changed their engines to cleaner-burning ones. In addition, when boats have to be refueled or when there is a fuel transfer, there are often hydrocarbons lost, that mostly leaks into the ocean. Finally marinas and harbors have a big amount of fuel and lubricants in their areas, because boats start their cold engines in these places, which make that they will more likely prime or choke. Engines of boats also reject exhaust, more precisely call gasoline. In ports there is more pollution, because there is much more activities made on boats and big boats that need reparation or fueling. These activities contribute to chronic oiling in the environment. There is oil that leaks from the pipelines while the tanks are filled up or when they are emptied. Moreover some hulls where the pipelines enter are outside of the boats, the oil that leak from it, will so directly leak in the water. This structured is often seen on old boats, while in new boats the hull is on board of the boat. When I went on a whale watching boat I was able to observe the fueling of the boat. On this boat which is part of a new boat had his hull on board, as you can see on the photo. The oil even leaks when the tanker is broken or just because the tanker does not keep well the product. The oil can also leak in the ocean when the tank is washed. While fueling some of the fuel can leak in the ocean. In addition often little ports are not equipped for waste disposal or even oil wastes. They will so sometime illegally mix it with the ballast water (explain ballast water??) of ships, which treatment machine is not equipped to handle and clean. The waste unclean will so after all leak in the ocean and destroy it. Ballast water itself polluted the ocean, when not clean. This is because it can carry some pathogens that come from the ballast. Bilge water is the water that is on the deck that does not leak overboard and so goes to the bilge. This water will be clean and then throw in the ocean or be throw in the water without be treated. Not only old boats pollute a lot. In fact in ports there are a lot of activities that reject oil in the water.

Traffic: In this case traffic causes pollution by throwing their sewage and wastes in the ocean. They are created by the routine operation of the crew on the boat. The boats also create solid wastes. They come from the exhaust of the boat’s engines. It is exactly the same kind of pollution that happen in ports, a part from certain activities such as the pollutants use for painting a boat or other kinds of activities made only in ports. In addition of all these pollutants thrown in the water by boats engine or the crew on it, there is also the pollutant liberated by boat accident. More precisely oil spills. Each year more than one million of tones are release in the ocean. A big oil tanker can carry more than 40 million of liters of petroleum. In reason of his fragility he has to travel near costs and if he has to stop, he needs a stopping zone. In consequence if there is any problem on his path it becomes a massive problem. Oil spills occur when the boat enter in collision with something, explode, takes fire, groundings and hull failures.

Toxic waste: Heavy metals are one kind of toxic wastes. They are considered, in our case, as common transition metals such as lead, copper, and zinc. These metals pollutes and contaminants oceans. They come from industries that just throw them or let them to leak in the ocean. Even acid rains make the metal ions that are in the soil to leak into lakes and ocean. How does city garabage go into ocaean waters ? Garbage dumping are composed of human waste, water from bathing, ground up garbage and plastics. When there is a rainfall the sewage pipes ten (tende) to over-flow, which mixe them with the storm water drain. When sewage pipes are in the same space than storm water drains they commonly flow into lakes or rivers. The rivers will than flow into the ocean and will transmit into it the city garbage they contained.

Noise pollution

Noise: The boat traffic causes a lot of noise in the water and disturbs the cetacean. The engine while working creates a huge amount of noise that spreads than in the water. Tanker and bulks can create sounds levels over 170 dB, while small and pleasure boats produce 145 to 160 dB. Cetaceans have an incredible hearing and can hear 10 times more than a human. In addition noise spreads very fast and far in the water. In conclusion a cetacean can easily hear a boat engine when it is at ………………………………?
Military experience also disturbs the cetacean. In fact they generally make bombs experience in the ocean, which creates a huge noise that can disturb cetacean the same way as they are disturb by boat’s engine. Further more of these experience militaries create noise with their submarine that make exactly the same kind of noise than boats.

Sonar: Boats while they are working use a lot of sonar machines, to know the depth of the water under them, to know if there is a further obstacle in front of them for example a boat or even, under water, a submarine. These sonar machines creates waves that will than disturb the cetacean that use the same kind one technique to find their food.
In the military case, submarines make a lot of waves also because of their sonar. It has the same influence than the boats sonar machine. However submarine always make disturbance with their sonar, while little boats do not have sonar machines. Moreover these experiences (which also take in account seismic surveys) create twice more dB than boats. In fact they emit 240 dB. Furthermore for a while military used low frequency active (LFA) to repair, from far away, silent submarines. These emissions create really low infrasound LFA, so low that they can even kill a marine mammal in a perimeter of 200km. They can also disturb them in other many ways, that I will explain later on in the chapter of ‘’effects’’.
We should not forget the disturbance on cetacean cause by oil and gas exploration. These exploration cause disturbance to the marine life, because they emit high-pressure sound waves in the ocean to a seabed. Than these ways jump back to the oil explorers machine at different speeds and intensity, which will let them make a conclusion, if in the area there is a presence of oil or not.

Air pollution

Industries can also pollute the ocean by polluting the air. The smokestack of sulfur dioxide made by factories is released in the air and pollutes it. The mixture of this air with humidity creates airborne sulfuric acid. This will produce acid rain that falls on land and water, sometimes changing the chemistry and ecosystem of a marine environment.

Human contamination

Aborigines are the human the most contaminated by pollution. This is because their nutrition is mainly base on whales and fish. These animals carry pollution in their bodies and transmit it to the higher specimen in the chain food, who is aborigines, in this case. This brings us to think about our case. The highest specimen in the chain food where orcas live is themselves. They have the same nutrition as aborigines. They, in conclusion, have to be as contaminated as aborigines.

Traffic

Boats: Marine pollution cause by boats comes from their engine while it turns. The engine rejects chemical exhaust in the water that will then poison the marine faun.

Farming

Hunting

Chimical pollution

Observation of the animal

Interviews

References

Dolphin Societies, discoveries and puzzles, edited by Karen Pryor and Kenneth S.Norris
The Ecology of whales and dolphins, edited by D.E.Gaskin
http://www.seaworld.org/infobooks/KillerWhale/home.html http://www.motherjones.com/politics/2006/03/marine-pollution-how-ocean-became-toxic-waste-dump

maybe you should start putting all the references somewhere on the wiki...--Pierre.brawand 2 février 2009 à 22:59 (MET)