The impact of human activities on sharks in the northwest atlantic Essay Example for Free

The impact of human activities on sharks in the northwest atlantic Essay The earth is a finite space. Everyone and everything on it must share its vast yet limited resources, and the actions of one species effects many, if not all, others. Over time, we have come to realize that human activities are having disproportionately negative effects on the global environment. An excellent example of this within the marine biome can be seen in analyzing shark populations of the Northwest Atlantic. In their study, â€Å"Collapse and Conservation of Shark Populations in the Northwest Atlantic† (2003), Julia K. Baum, et al. traced the changes in the populations of eight shark species from 1986 to 2000 (two species were only recorded from 1992 onward). They looked at the areas comprised of the â€Å"Caribbean, Gulf of Mexico, Florida East Coast, South Atlantic Bight, Mid Atlantic Bight, Northeast Coastal, Northeast Distant, Sargasso/North Central Atlantic, Tuna North/Tuna South. † In this region, they noted an 89% decline in the hammerhead shark population over a period of 14 years. Similarly, white sharks declined 79%, tiger sharks 65%, and thresher shark populations declined by 80% between 1986 and 2000. In fact, each of the eight species saw a population decline over the course of the study. The study concludes that â€Å"The magnitude of the declines estimated†¦suggests that several sharks may also now be at risk of large-scale extirpation. † The study goes on analyse the causes of such drastic decline over such a short period of time. Citing overfishing as a significant culprit it claims, â€Å"In the past half century, as fishing fleets expanded rapidly in the open ocean, have large marine predators been subject to this intense exploitation. † Overfishing however is not a new phenomenon, and has indeed been a factor in depleting populations of marine species historically as well. In his 2001 colloquium paper, â€Å"What was natural in the coastal oceans? † Jeremy B. Jackson cites 19th century overfishing in cause â€Å"live coral abundance declined to 1-2% cover from values of 50% or more† in the 1908s. He claims that while this was noted in the 1980s it is the result of historical trends by determining, â€Å"Coral communities did not change noticeably until the epidemic mortality of Diadema antillarum in the 1980s because ecological redundancy of herbivores obscured the potential effects of the loss of large herbivorous fishes for well over a century. Macroalgae were not able to overgrow corals until the last major herbivore was lost from the system. † The ramifications for sharks and other carnivorous species as is significant because declining herbivore populations means there is a food scarcity and thus will result in a decline in predator populations as well. The Baum study notes that their finding of â€Å"large and rapid declines†¦are in addition to substantial historical reductions. Overexploitation of elasmobranchs (sharks, skates, and rays) is known to have already nearly eliminated two skate species from much of their ranges. † They then engage in a discussion of appropriate measures that could be adopted to counteract the declines their study revealed. They particularly examine marine reserves an â€Å"increasingly popular tool for marine conservation and resource management worldwide† (2002). Using â€Å"simple models to analyze the implications of large-scale marine reserves for shark conservation. They ran each of these models with two likely scenarios â€Å"(i) after the closure, fishing effort is displaced and changes such that the same total swordfish quota is caught (constant-quota scenario); or (ii) fishing effort is displaced but remains constant overall (constant-effort scenario). † Surprisingly, the study found that â€Å"marine reserves can indirectly cause harm if fishing effort is merely displaced. † They found that while closing one region of the study area benefited some species of that region, it had the potential to harm other species both within the closed region and in other regions of the Northwest Atlantic. Their findings suggest that â€Å"if marine reserves are to be effective, their placement is of critical importance, and conservation initiatives must explicitly consider impacts on the whole community of species. † They concluded that â€Å"emphasis on single-species conservation, without controlling effort, simply shifts pressure from one threatened species to another and may actually jeopardize biodiversity. † This scenario would be much like that of 19th century overfishing in that its results would be indirect and thus their effects might immediately be masked but could show up to be catastrophic in the long-term. A more recent study further indicated that ensuring species survival would require a 40-80% reduction in fishing mortality, and that â€Å"rapid recovery of community bio-mass and diversity usually occurs when fishing mortality is reduced. † This recovery was noted to be â€Å"more variable for single species, often because of the influence of species interactions. † Thus, the study concluded that multi-species management must be targeted toward the needs of the most sensitive rather than the most robust species in the system. Finally, in order to most effectively aid in the recovery of predator species of the Northwest Atlantic, the effort must include â€Å"reductions in fishing effort, reduction in bycatch mortality and protection of key areas to initiate recovery of severely depleted communities† (Myers Worm, 2005). Analysis the potential outcomes of any activity is significant because all human activity, not just actions determined to have a negative effect such as fishing, affects the environment. Even activities whose goal is to benefit another species can have unforeseen ramifications, some of these could even result in further harm to the species or environment they are seeking to aid. Rather than merely rushing to the conclusion that marine regions should be designated as reserves, it is important to examine not only the effects on one species, but look to the larger biome and scrutinize the impact that one variable is likely to have on countless other factors with which it interacts directly and indirectly. Within the finite space of the earth, any one action regardless of its intent is likely to reverberate throughout the environment and especially be felt within a specific region or biome. Thus, humans must consider all of there actions when working with the marine biome so as to ensure the least possible harm to its species and the larger world in general. References Baum, J. K. , Myers, R. A. , Kehler, D. G. , Worm, B. , Harley, S. J. , Doherty P. A. (2003).Collapse and Conservation of Shark Populations in the Northwest Atlantic, Science, 299 (5605), 389-392. Halpern, B. S. and Warner R. S. (2002). Marine Reserves Have Rapid and Lasting Effects, Ecology Letters, 5, 361-366. Jackson, J. B. C. (2001). What Was Natural in the Coastal Oceans? , Procedures of the National Academy of Science U. S. A. 98, 5411-5418. Myers, R. A. , Worm, B. (2005). Extinction, Survival or Recovery of Large Predatory Fishes, Philosophical Transactions of the Royal Society B: Biological Sciences, 360 (1453), 13-20.

English Speech Against Physical Punishment of Children :: Papers

English Speech Against Physical Punishment of Children Good Morning/Afternoon ladies, gentlemen and chairperson. I am also arguing against the motion that states, this house believes that physical punishment including smacking young children is wrong. I am a firm believer that a short, sharp smack can keep children under control. This doesn’t mean they should be beaten up or even marked, but strict and fair punishment will benefit a child in the long run. Please picture this scene: a young child of around 3 years is having a temper tantrum in the middle of a busy high street because his mum won’t buy him a toy car. He tries to run away from his mother, screaming and shouting at the same time. To stop the noise the mother gives in a buys the toy car. Now ask yourself who is in charge here, the mother or the child? After all, the child gets his own way and now knows exactly what to do next time he wants something. In these circumstances, parents may have to resort to a smack to one, get the child listening and doing what they are told, two, stop the noise and temper tantrum and finally, for the child’s benefit and own safety. Also, what or who is going to stop an out of control child running out into the middle of a busy road? A quick smack is a lot less pain full then getting knocked down by a car or even a bus! There are many in favour of the government leaving the law as it stands that parents have the right to smack their children. Groups such as Family and Youth Concern feel politicians should let parents get on with bringing up their children as they see fit, and warn that any change in the law would risk turning thousands of parents into criminals. They also feel a ban on smacking would be impossible to enforce. The opposition may argue that there are other forms of punishment which are just as effective as smacking. For example, ignoring the

Creation Myth Compare and Contrast

Usually, creation myths have a lot of similarities and seem to convey the same message. A creation myth is a symbolic narrative of how the world began and how people first came to inhabit it. There are many different creation myths that have been passed down from generation to generation and in â€Å"Enuma Elish† â€Å"Osiris, Isis and Horus† and â€Å"Genesis† you are able to see just how similar they are, but also slight different. One of the first things you will notice in these myths is that they are all based on gods.Each myth has an evil entity that helps set the myth to tell a story on what happened and to get the message across. Each evil entity plays a big part in the myth and eventually loses the battle to show that good always prevails.1. Osiris, Isis and Horus – Set was the son of Geb and Nut who chose to be born on the third day. Set was aggressive from the very beginning choosing the time and manner of his birth. Osiris became king of Upper a nd Lower Egypt. Set wanted to take over the country and established a plan to trick Osiris by showing a beautiful wooden box during the feast.Set said that anyone who can fit in the box perfectly was able to keep the box – little did everyone know that Set secretly measured the box to fit Osiris. Once Osiris had his turn to fit in the box, it was nailed shut with him inside. They then poured melted lead to make sure that he suffocated. Isis eventually was able to bring Osiris back to life and in the mean time their son, Horus, was born. Horus was born to avenge his father’s death and kill Set. Isis would not allow Horus to kill Set, so they battled each other, and Horus won each time.2. Enuma Elish – Tiamat was encouraged by her son Kingu to seek revenge her children to avenge the death of Apsu and for creating a fourfold wind that kept them awake and disturbed their bodies. Tiamat created monsters to help her win this battle against the other gods, but they had something else in mind. They made Marduk fight the battle against Tiamat because the others were not strong enough and Marduk was the wisest and strongest of all of the gods. Marduk won the battle against Tiamat and killed her to make the heavens and the earth from her body.3. Genesis – The evil entity in Genesis is the serpent that convinces Eve to eat the apple off of the tree of wisdom. God specifically told Adam and Eve not to eat this fruit as it was forbidden. Eve gave in and ate the fruit and then had Adam do the same. Because of the serpent, Adam and Eve ate the fruit and they were all punished and put out of the Garden of Eden. As you can see, each myth’s evil entity lost their battle during the story. None of them achieved what they wanted to, which shows that good always overcomes evil, even though there are conflicts raised from it.Sometimes you have to fight for what you know is right, but eventually, the good always shines. Enuma Elish and Genesis are mo st similar in a few different ways. With these myths, you are really able to tell that most creation myths are a foundation on the way different cultures are made up. Some of the similarities between Enuma Elish and Genesis are;1. Both myths imply that there was nothing in the beginning. In Genesis it states, â€Å"In the beginning God created the heavens and the earth.Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. † The myth of Enuma Elish starts by stating â€Å"In the beginning, only water and the mist that hovered above it existed. † As you can see, both myths beginning started with nothing until the Gods created something.2. The Enuma Elish is recorded on seven tablets where as Genesis states that everything was created in seven days.3. In both myths, water is divided into upper and lower waters.Both of these creation myths have a similar beginning as well as a similar plot †“ they both created human life to worship God and the gods, to serve them. Both had an evil entity in them that tried to cause chaos to the gods. Although I do think that all three myths are very similar, I believe that Enuma Elish is most different from Osiris, Isis and Horus. The difference between the two is shown when it comes to the creation of the world around them. The difference between the two myths is;1. In Osiris, Isis and Horus doesn’t mention anything about the creation of the heavens, earth, etc.  in the beginning.The myth starts out with the parent’s of Osiris and Isis and the story of how Nut was not allowed to give birth in any month of any year.2. The beginning of the the Enuma Elish starts out with what all existed and how the waters were split between gods.Each myth has a lot of similarities as well as differences but they each tell a story on how things were created. All of the myths had gods that tried to do good for the other gods and had an evil entity try to change that. Each of the explained how good will always outweigh evil even though evil is always in the world.

Heat of Formation Definition - Chemistry Glossary

In chemistry, heat of formation is the heat released or absorbed (enthalpy change) during the formation of a pure substance from its elements at constant pressure (in their standard states). Heat of formation is usually denoted by ΔHf. It is typically expressed in units of kilojoules per mole (kJ/mol). Heat of formation is also called enthalpy of formation. The pure substances in question may be elements or compounds. However, the heat of formation of a pure element has a value of 0. Sources Kleykamp, H. (1998). Gibbs Energy of Formation of SiC: A contribution to the Thermodynamic Stability of the Modifications. Berichte der Bunsengesellschaft fà ¼r physikalische Chemie. pp. 1231–1234.Zumdahl, Steven (2009). Chemical Principles (6th ed.). Boston. New York: Houghton Mifflin. pp. 384–387. ISBN 978-0-547-19626-8.