How Trophic Cascades Are Powerful Forces That Have A Pronounced Effect On Ecosystems

Review Chapter 8 and pages 160–162 of Chapter 9 in Biology, 7th edition. Then complete the discussion by supplying or choosing the appropriate terms.

Correspondence concerning this article should be addressed to Katherine Valcin, Keiser University Biomedical Sciences Student, 5600 Lake Underhill Rd, Orlando, FL 32807. Email: K.valcin@student.keiseruniversity.edu

This investigative study included whether gray wolves, a natural top predator to white tailed deer, create a trophic effect by reducing the deer and how it may affect saplings and vegetation in the Great Lakes forest area. The study was not conducted for direct kills, instead it was done to see the effects of the deer population and the plant and vegetation systems surrounding them. The expected effects were that in areas where wolves are less dense in the region it causes an increase of deer having a negative impact on plants and vegetation in the surrounding area. The recolonization of wolves in the area is generating trait-meditated effects in the Great Lakes forest and are

Besides fishing for Nile perch, fishermen raise them in controlled cages underwater (Global Invasive Species Database). Fishermen do this to curb the possibility of not being able to catch Nile Perch in the Lake Victoria (Global Invasive Species Database). Communities surrounding Lake Victoria do not know exactly how to reverse the impact of Global Warming and overfishing (McDonnel). Serious economic damage would happen if Lake Victoria’s fish all died. Lake Victoria provides income for two million individuals (McDonnel). The shortage fish in Lake Victoria raises the market value (McDonnel). This causes food shortages because fish has become unaffordable for the lower class majority (Mcdonnel). Besides stirring up economic problems from the pond, the Nile perch impacts a much bigger picture. The nile perch is an oily fish (Lowe). Tree’s are cut down to make fires to dry out the catch (Lowe). The absence of trees has caused landscape erosion and habitat damage to Lake Victoria and surrounding areas

The following methods were taken from Carolina Biological Supply Company by Carolina Biological Supply Company (2012).

Prepare for your BIOL 200A Lab Quiz 1. It is going to be given on Thursday, February 2nd.

The role of predation is critical in shaping ecosystem structure and function (Berger et al., 2001; Hawlena and Schmitz, 2010). Predator-prey interactions can alter community composition (Kneite and Chase, 2004), mediate trophic cascades (Mooney et al., 2010), increase biodiversity (Letnic and Ritchie, 2012), and affect species invasions (Snyder et al. 2004). Furthermore, predators can control the dynamics of prey populations by influencing such aspects as survival, growth, behavior, size structure, and distribution (Beauchamp et al., 2007) while prey can likewise regulate predator populations (Yoshida et al., 2003; Ishii and Shimada, 2010). One of the primary components of predator-prey interactions is the behavior and subsequent survival of prey in the presence of predators which we focus on in this study.

A PROJECT PAPER SUBMITTED AS PARTIAL REQUIREMENT FOR THE DEGREE OF BACHELOR OF SCIENCE (BIOMEDICAL SCIENCES)

Shark populations continue to decline for of a number of reasons. Roff et al. (2016) reports a dramatic decrease in shark numbers as a result of over-fishing due to the rising demand for shark meat. In addition, it also been reported that increased levels of carbon dioxide (CO2) in the atmosphere results in ocean acidification, this has a variety of harmful effects on sharks (Pistevos et al. 2015). The increased temperature of the water has

californianus is restricted by biotic factors in how low in vertical elevation its tolerance is. During the study Paine concluded that Mytilus californianus lower tolerance range could be increase if its predator, Pisaster ochraceus, was removed from the system (Paine, 1974). From this study we are able to conclude that while interspecific competition between species (biotic factors) sets tolerance ranges, predation is also a key component in stress factors organisms living in the intertidal ecosystem

Determining animal behavior and abundance in the wild can be difficult and methods between researchers will vary. In many cases, different causes for "preferences" are found for similar groups due to the variety of methods. This is important because most models of animal abundance are based on previous findings on abundance and factors affecting area preference. With vulnerable animals these models are used to determine how to protect certain species by protecting particular areas. Therefore, truly understanding what influences an animal's preference to a particular area is critical to protecting certain species. The following two papers, Sheppard and Wirsing, assess two populations of Dugongs and their "preferences" in those areas.

Trivariate features were assessed using abundance and mean body mass data, as well as univariate, bivariate and trivariate patterns and interaction strength. Species averaged body mass were used to calculate consumer-resource body mass ratios, serving as proxies to estimate interaction strength (Emmerson & Raffaelli, 2004; Emmerson, Montoya & Woodward, 2005). This method is based on the well documents allometric scaling relationships between predator and prey body mass ratios aij~(Mj/Mi)*b, where Mj and Mi are mean predator and prey body masses, and aij the Lotka-Volterra interaction coefficient. Following the literature, we used a theoretical value of b=0.75 as scaling exponent (Emmerson & Raffaelli,

When sharks roam around regions of seagrass, major seagrass grazers, like sea turtles, do not approach, or leave the area out of fear of being eaten. In a study conducted by Biological Sciences professor, Mike Heithaus, and his colleagues, the importance of sharks in the presence of seagrass was proven prominent as the group of researchers observed significant differences with and without the presence of the Tiger shark in Shark Bay, Western Australia. For fifteen years, the group closely monitored the tiger shark lifestyle: their interaction within the environment and their prey. During the research period, it was observed that shark prey avoid area in which shark usually hunt, in this case the common hunting grounds were shallow areas in which seagrass grew. These prey animals are common grazers upon the seagrass, such as sea turtles and sea cows. Without the animals present, the gras was able to grow abundantly. In areas where sharks were not present, The meadows were over grazed and could not house the large fish populations that depend on its support (Heithaus). Besides protecting seagrass, sharks also help maintain a healthy ecosystem by preying on fish who bring the waters down, both through oceanic heath and diversity. As an appendix animal, sharks have major control over the food web, keeping the ecosystem balanced. They prey on the sick fish, protecting the region from diseases and animals who will do little to no benefit for the ecosystem. Also, they targeted animals who made the region unbalanced and unequally “by preventing one species from monopolizing a limited resource, predators increase the species diversity of the ecosystem” (Oceana). The greater the amount of sharks in an area or region, the more diverse and stable the environment would be. These animals are crucial to the the environments, hold strong roles in the way the ocean

8B06A37 Teaching Note FORMTEXT BIOMED CO., LTD. DESIGNING A NEW SALES COMPENSATION PLAN ADVANCE d 2 FORMTEXT Don Barclay prepared this teaching note as an aid to instructors in the classroom use of the case FORMTEXT Biomed Co., Ltd. Designing a New Sales Compensation Plan, No. FORMTEXT 9B06A037. This teaching note should not be used in any way that would prejudice the future use of the case. Ivey Management Services prohibits any form of reproduction, storage or transmittal without its written permission. This material is not covered under authorization from CanCopy or any reproduction rights organization. To order copies or request permission to reproduce materials, contact Ivey Publishing, Ivey Management Services, c/o Richard

Hinal Fifadra,TE student, Department of Biomedical Engg., D J Sanghvi College of Engg., Mumbai,India hinalfifadra28@gmail.com