World Population Essay

The United States is the third most populated country in the world. This country holds about 4.5% of the world’s population. The U.S. population is currently estimated to have 308.7 million persons. This number is more than double of the population from 1950. Besides the fact of the population has doubled its size, the population has also become qualitatively different from the one from 1950. As noted by the Population Reference Bureau, “The U.S. is getting bigger, older, and more diverse.” The growth of the population is the result of the trends over time in the relationship of increased births, decreased deaths, and increased net immigration.

     Colonization by zebra mussels has devastating ecological impacts on native bivalves (Mackie, 1991; Haag et al., 1993), frequently driving them to local extinction. Zebra mussels readily, perhaps preferentially, settle on native bivalves and eventually cover them over. They filter the water so efficiently that they can lower the amount of suspended food organisms below levels needed to sustain native unionids.

Jason performed a semi-quantitative survey for federally listed mussels on the mainstem of the Apalachicola River near the Estiffanulga boat launch. Side-scan sonar imagery was integrated with aerial imagery to design a stratified random survey design for estimating densities of two federally protected mussel species.

First of all, these shellfish get their name from the Zebra like stripes that cover its “D shape” shell. It is approximately two inches or less in length and have “sticky byssal threads that they use to attach tightly to any hard surface” (3.). When it comes times for them to reproduce, the female may produce up to 500,000 eggs in a single year. These eggs eventually develop into a small microscopic larva that will ultimately begin to form their own shells. These Zebra Mussels first landed on the map in the late 1980’s by hitching rides in the ballast waters of cargo ships. First they started showing themselves in the great lakes and from there they spread.

The purpose of this report is to examine the data from an observational study of abalone in Tanzania. The intent of the

The environment is full of invasive species, some more invasive than others, but this is about zebra mussels and garlic mustard. Zebra mussels are small clams that attach to solid surfaces in water. They have D-shaped shells, yellow and brownish colored stripes. They are native to Eastern Europe and Western Russia and were brought over to the Great Lakes from ships in 1988. Garlic Mustard begins as a kidney-shaped garlic-smelling leaves in the first year. The second-year plants grow a stem up to 4 feet tall with triangular barbed leaves and small white four-petaled flowers in clusters at the top of the stem. It is invading our lawns, woodlands and other areas and poses a severe threat to native plants.The first recorded observation of garlic mustard in the United States was on Long Island, New York in 1868. Since 1868 garlic mustard has spread to thirty U.S. states and three Canadian provinces. Zebra mussels are worse compared to garlic mustard.

Zebra mussels are an extremely large species of mussels that are notorious for causing problems for animals, sea creatures, and even humans. They have the ability to cling and adhere to any man made, living, natural object, or creature when placed or growing in the acceptable conditions and habitat. Zebra mussels have many characteristics, traits, and ways of thriving, surviving, and of course, unknowingly creating problems for most of life on Earth. These fascinating and compelling critters have an intriguing story to tell about how they reached the U.S. and why they generate complications and issues for mankind and our environment.

Chile also exports giant mussels, chilean oysters, red abalone, lobsters, sea urchins, clams, sea snails, seaweed and many more of the seas delicious

The reading states that the Zebra mussels' invation to North American cannot be stopped and that poses a serious threat to freshwater fish populations in all of North America and provides three reasons of support. However, the professor states that there are ways to control the Zebra mussel spreading and doesn't have a serious threat in the environment and refutes each of the authors' reasons.

Zebra Mussels are omnivores and can be a primary or secondary consumer. Zebra Mussels consume plankton and algae.

P. oceanica meadows are met in transparent and pure waters of Mediterranean area. The prevalence of Posidonia meadows in clear water is a useful tool for biomonitoring the clearness of the desired area. Along with Mytilus galloprovincialis, the Mediterranean mussel, Posidonia is a natural reservoir of different metals acquired from the environment. These metals are released from industrial, agricultural and urban activities in the coastal area and are one of the most persisting pollutants in the environment (Bethoux et al. 1990). Due to its sessile property, Posidonia is an ideal organism for biomonitoring. In a study conducted to compare the bioaccumulation level between M. galloprovincialis and P. oceanica, for cadmium, cobalt, chromium, nickel and lead, P. oceanica

The current global population of 7.6 billion people is expected to reach 11.2 billion in 2100 (UN DESA), and as the Earth’s population continues to grow exponentially, the topic of environmental sustainability is being debated with increased urgency. In the past few years, many large-scale environmental issues have emerged due to human activities: climate change, air and water pollution, rising sea levels, habitat loss, species extinction, and worsening natural disasters are all becoming more and more prevalent. But perhaps our most immediate concern should be whether or not we will be able to continue feeding this ever-increasing population.

North America is home to approximately 300 species of mussels; however approximately 70% of these species are extinct, endangered, or otherwise of special concern. Mussel population decline cannot be attributed to a single factor, but rather a combination of often interacting factors from land use change (e.g. water quality degradation, habitat loss, altered streamflow, and sedimentation), direct channel modification (e.g. dam building), host fish availability (more on this later), and invasive species impacts (e.g. predation and zebra mussel infestation). Because mussels are long lived (some species can live 50 + years), relatively sedentary, and have a complicated life cycle that requires suitable host fish populations, they are often used as indicators of river ecosystem wellbeing. A kind of “canary in the coalmine” organism, mussel response to environmental conditions can signify an early warning for a degraded ecosystem. In fact, instrumented mussels are being used as biomonitors for water quality. Mussels are filter feeders, and they have the ability to close their shells for a period of time when a contaminant is present. By monitoring mussel gape (i.e the rate which they open and close their shells), water resource managers can tell, for example if all mussels close up quickly, that there is likely potentially harmful

The aim of this experiment is to investigate the relationship between sampling area, sampling size, and precision. The hypothesis of this experiment is that a larger transect and a higher number of replicates will reduce imprecision. The objective of this experiment is to choose an appropriate transect size and optimum number of replicates for a study of population density of Holothuria scabra at Trikora Beach based on a pilot study from Pulau Jemaja, Riau, Indonesia. Holothuria scabra sea cucumbers are harvested in South East Asia for food. They are highly sought after by local fisheries in the region and are under threat of extinction due to increased levels of harvesting and collection. Hence, precise estimates

Microalgae have immense applications in biotechnology as source of food, feed additives, coloring substances, antioxidants, cosmetics, toxins and isotopes (Pulz and Gross 2004). They are critically important in aquaculture industry as they are the natural food source of larval stages of many aquaculture organisms including fish, crustaceans, and mollusks