INTRODUCTION Corbicula fluminea is a freshwater species of clam that is invasive to the United States. This clam is often used as a food source in the Asian countries to which it is native, and is postulated to have been introduced in the late 1930s to the state of Washington by Chinese immigrants (Dresler 1980). C. fluminea has since spread throughout the majority of the U.S., and has become particularly prolific in the Chesapeake Bay region since the 1970s (Dresler 1980). While C. fluminea may be an invasive species, its presence can be beneficial to the waterways in which it is found. These clams play an important role in nutrient cycling and the filtration of phytoplankton and seston out of the water column (Hakencamp and Palmer 1999). …show more content…
Algae were then measured using the ocular micrometer and the previously determined conversion factor was used to calculate the true algal cell size. The diameter of the cell was measured in the species Chlorella sp., Haematococcus sp., Chlamydomonas sp. The length and width of the cell were measured in Scenedesmus sp. Average cell size and the standard deviation were then calculated for each species of algae, based upon the longest dimension of the …show more content…
fluminea were placed in water containing Chlorella sp., the filtration rate decreased in comparison to clams given Chlamydomonas sp. and Haematococcus sp. This was unexpected, as I anticipated filtration rates of Chlorella sp. to be higher than Chlamydomonas sp., but lower than Haematococcus sp. Because Chlorella sp. is of a spherical shape, similar to Chlamydomonas sp. and Haematococcus sp., and is within the size range of particles that C. fluminea are capable of filtering, it is likely that particle size is not the only factor that influences particle selection. The presence of chemoreceptors has been noted in other species of bivalves (Ten Winkel and Davids 1982). While no studies have confirmed the presence of chemoreceptors in C. fluminea at this time, the low filtration rates of Chlorella sp. in this study indicate that C. fluminea may be selecting algae for filtration based upon chemical signals in conjunction with cell size. Scenedesmus sp. was also filtered at a lower rate than Chlamydomonas sp. and Haematococcus sp. In addition to this species being at the upper end of the range of cell size that C. fluminea is known to filter, Scenedesmus sp. was the only species of algae used in the study that had a non-spherical cell shape. It is unknown at this time if the shape of algal cells significantly impacts filtration capabilities in C.
The Zebra Mussel (Dreissena polymorpha), is a small freshwater mollusk that is an invasive species. It has slowly been making its way into the United States. It has done this by showing up in lakes and in rivers. The mussels get their name due to the striped pattern on their shells. They are a relatively small species, only growing to the size of a human finger nail but there have been cases of larger (“Zebra Mussels,” 2013, para. 2). Mussels live a short life span of 4-5 years and most do not make into adulthood. They live in freshwater at depths of 6 to 24 feet. The female produces 30,000 to 1,000,000 eggs per year starting at the age of two. Zebra Mussels are free moving and can move with an external organ called the byssus (“Zebra Mussels,” 2013, para. 3). But they can be moved around by currents and other objects too. Zebra Mussels are a threat to ecosystems. They damage the natural habitat of lakes and rivers and cause negative effects to the native aquatic life. They multiply in vast majority casing a lake of food and space for other animals. And also the U.S. has spent millions on the removal of these pests from our water (“Zebra Mussels,” 2014, para. 8). The Zebra Mussel has now made its way into Colorado. Just a few has been found in the waters of Colorado but a few is enough to cause a big stir. Extreme precautions have now been put into effect to make sure that the threat of Zebra Mussels is under control.
A common inference made by scientists predicts that the zebra mussel will continue spreading passively, by ship and by pleasure craft, to more rivers in North America. Trailered boat traffic is the most likely cause for invasion into North America. This spread can be preventable if boaters thoroughly clean and dry their boats and associated equipment before transporting them to new bodies of water. Since no North American predator or combination of predators has been shown to significantly reduce zebra mussel numbers, such spread would most likely result in permanent establishment of zebra mussels in many North American waterways.
The nonnative species of the lionfish, living in tropical waters to depths far below is an unseen threat by first glance. Truth behold, this fish is a serious pest since the first sighting in Dania Beach back in the 1980s. Presently, it has grown out of its bounds and causes harm not only to the sea life but trouble to humans as well. An unmatched appetite with a fast and large reproduction to spawn its species in a matter of only a short time, makes this invasive fish at the top of a sounding alarm. Clever biological adaptations have made this fish a tough fighter to the ecosystem and only in the past few years have we learned to take effective measures to control their population to save our coral reefs.
One of the Bays biggest resources is its oysters. Oysters are filter feeders which mean they feed on agley and clean the water. The oysters feed on agley and other pollutants in the bay turning them into food, then they condense the food down to nutrients and sometimes developed pearls. Filtering the water helps the oysters to grow, and also helps clean the Chesapeake Bay. One oyster can filter 50 gallons of water a day, Oysters used to be able to filter the Bay in about a week. However, these creatures are now scarce in the bay. The Chesapeake Bays Oyster (crassostrea virginica) Population has declined severely because of over harvesting, agricultural runoff, and disease. Now the Chesapeake Bay is becoming polluted without the oysters and the water is not nearly as clean as it once was. The Chesapeake Bay was the first estuary in the nation to be targeted for restoration as an integrated watershed and ecosystem. (Chesapeake Bay Program n/d). This report will show the cause and effect of the Chesapeake Bay's Oyster decline on the Bay.
They also look after the quality of coastal waters by watering down, sifting, and settling deposits, left-over nutrients and contaminants. They are highly productive ecosystems and provide habitats and act as nurseries for all manner of life.
Tropicalia is not only know as a form of music in Brazil but as a rebellion. Its theme of cultural non conformity was strengthened by the idea that Brazil had lost its way. Tropicalia took a stand against the social and musical hierarchy of Brazil. Though mainly known as a form of Brazilian pop music Tropicalia is deeply rooted in the political and cultural background of Brazil.
The understanding of Saballaria cementarium's diet has not been thoroughly examined in much detail. Qian and Chia (1990) examined the role of detritus, form of eelgrass, as a food source for developing larvae of the organism. It is not known whether they are food limited. The experiment was conducted to reveal some facts about the feeding habits of the larvae in determining the development and growth of it. The invertebrate larvae's primary food source comes from the phytoplankton that is found in abundance at the bottom of the sea floor. The larvae fed with detritus were compared with those fed on equal concentrations of phytoplankton. Other tests were conducted to compare the degrees of survivorship among the larvae using varying concentrations of phytoplankton. Higher concentrations of phytoplankton, consumed by the larvae, yielded
... ethanol present. Due to the fact that there has been a distinct correlation between the levels of ethanol present and the mortality rate of certain aquatic life forms, it was expected that when a higher concentration of ethanol was present in the artificially constructed environment, the brine shrimp would have a lower rate of hatching and a higher mortality rate. It was anticipated that if the brine shrimp cysts were exposed to levels of ethanol in 0%, 0.1%, 0.15%, and 0.2%, than the brine shrimp cysts exposed to higher levels of ethanol would develop more slowly due to the fact that ethanol changes the shape of proteins when it permeates the membrane of a call. Thus, the brine shrimp’s exposure to 0.2% ethanol would yield higher mortality rates and more developmental problems than when the brine shrimp were exposed to 0.15% ethanol, 0.1% ethanol, and 0% ethanol.
Lionfish are not currently listed as threatened in their native range. However, the increase in pollution in coral reefs can negatively affect the lionfish's primary food sources (NOAA, 2011). If lionfish are unable to adapt to declines in their prey species, their numbers will decrease. Although between the increasing reef pollution and the Lionfish’s voracious appetite reef populations will more than likely be damaged beyond repair, they may even be close to elimination by the time the Lionfish population actually declines (Albins, 2013).
Reason Two: Daphnia are also an able to be used in bioassays because they are very sensitive to any changes within the water and a very simple and cheap. They mature in a very short period of time, so it does not take long to grow them to maturity and test. ”Bioassays are procedures that can determine the concentration, purity, or biological activity of a substance such as vitamin, hormone, or plant growth factor by measuring the effect on an organism, tissue, cells, enzyme, or
The outer layer of a reef consists of living animals, or polyps, of coral. Single-celled algae called zooxanthellae live within the coral polyps, and a skeleton containing filamentous green algae surrounds them. The photosynthetic zooxanthellae and green algae transfer food energy directly to the coral polyps, while acquiring scarce nutrients from the coral. The numerous micro habitats of coral reefs and the high biological productivity support a great diversity of other life.
Coral reefs are the most biodiverse ecosystem on the planet. There are more than 25,000 known species of organisms and countless others that have yet to be identified (Helvarg, 2000). Reefs thrive on the shallow edge of tropical seas, most often on the eastern edge of continents along warm water currents that brush the coasts. Reefs cannot live in cold waters and are limited by ocean depth and available sunlight. Coral is the foundation of the reef community, providing a three-dimensional structure where thousands of species of vertebrates and invertebrates live and feed. Some species of coral are hard, while others soft. Some are branched, yet others are compact and rounded. Coral is made up of large communities of tiny jellyfish like polyps. These polyps absorb calcium from the sea water and secrete a hard limestone skeleton. At night the polyps extend sticky, stinging tentacles from their skeletons to capture and consume small floating organisms such as zooplankton. Every coral has a two-stage life cycle: the larva, and the polyp. The larval stage is free swimming, and the polyp is stationary. Ocean currents carry the larva from the stationary parent polyp to any hard, clean, silt-free surface where, if the conditions are perfect, the larva grows into a coral forming polyp, never to move again (Levin, 1999). One of the most valuable resources for coral polyps are algae. Some live on the coral skeletons, but one type in particular, zooxanthellae, lives inside the tissue of the polyps. Zooxanthellae makes up about half the weight of the fleshy polyps and are not only a valuable food resource, but they are responsible for the brilliant colors associated with coral. When coral looses these prec...
There are several types of treatment methods present but biological treatment methods have gained much traction in the recent years due to their low operation costs, comparatively benign effects on the environment and their ease of handling and maintenance. Biological wastewater treatment methods can be subcategorized into dispersed growth systems and attached growth systems. Biofilms fall under the latter category (Sehar & Naz, 2016)
Introducing exotic species has been a highly debated issue. Why should we bring another animal or plant into a region to eradicate another species? That’s the question that people have been asking for ages. Of course, there are positives to bringing in another species, but many times, there are just as many negatives. Also, these species can be introduced accidentally or intentionally. The new organism may cause no obvious problems and eventually, it will be considered “native” to the area. For example, corals are “perhaps the oldest animals on the planet, and these long-lived corals have evolved in one of the Earth’s most stable environments” (Eichenberg, p.2). If a new type of fish were to be put into the ecosystem with the corals, the coral would be affected. First, the fish might eat the coral. Second, they could use the coral for shelter, and possibly damaging it that way. Third, the fish could bring predators that might also eat the coral. Introducing an exotic species has the “rippling affect” of dropping a stone into a pool of water. Everything outside the epicenter is affected. A study was done at Cornell University, and they estimated that $120 billion per year are spent fixing the problems caused by exotic species” (Chiras, p.