Abstract
The purpose of this term paper is to provide information about the different kinds of algal blooms and their effect on our environment and ourselves. There are still a lot of things that are not known about the algal bloom phenomenon, and many different hypotheses have been presented to explain these. Throughout the course of this paper those hypotheses will be presented and discussed, allowing the reader to derive their own opinion about the origin of algal blooms and what will happen in the future.
table of contents
Table of Contents
I. Harmful Algae
II. What are Algal Blooms and Red Tides?
III. Why do Algal Blooms occur?
IV. What are the effects of Algal Blooms?
V. Where and how often do Algal Blooms occur?
VI. Resources
I. Harmful Algae
All algal species are not harmful. Only a few out of the thousands of species are associated with the phenomenon known as an algal bloom. These algae fall into two categories. The first category of harmful algae produces toxins that are released when ingested by animals or humans.
The dinoflagellate Alexandrium tamarense (left) and the diatom Pseudo-nitzschia australis (right) are examples of toxin producing alga.
The other category of harmful algae kill without toxins. These are equipped with structures such as spines and serrated edges that allow them to lodge in fish gill tissues. When this occurs it causes irritation which leads to overproduction of mucus which eventually leads to death.
This Chaetoceros species (above) is an example of an algae that kills by using specialized serrated structures.
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II. What Are Algal Blooms and Red Tides?
Algal blooms are when algae grows at a fast rate and accumulate near the surface, hence the term "algal bloom". The term "Red Tide" is a misnomer because it has nothing to do with the tides. It refers to a specific type of algal bloom that occurs when certain species of phytoplankton that contain red pigments "bloom" causing the water to look red. Red Tides are usually not harmful.
The California Noctiluca Bloom is an example of a Red Tide
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III. Why Do algal blooms Occur?
Scientists aren't exactly sure of how or why algal blooms get started. One theory is that when temperature, salinity, and nutrients reach certain levels there is a massive increase in the amount of algae.
Nitrogen and nitrates relate to Hypoxia via the process of eutrophication. Since Nitrogen is a limiting nutrient in most waters, the added input of nitrate causes massive growth in algae. The algae rapidly consume all available N, and once the nutrient is limited again, the alga dies en masse. As the alga decomposes, oxygen is depleted in the water. This lowers dangerously lowers the level of dissolved oxygen in the water, which harms living organisms in the area. Small organisms and organisms that are immobile or unable to escape low-oxygen areas are particularly vulnerable. Hypoxia and resulting “dead zones” are harmful to local fishing and shrimping industries and algal blooms hurt the tourism industry. Hypoxia has lead to a decrease of about 25% in the brown shrimp habitat, forcing shrimping operations further offshore. As the hypoxia issue continues to grow, negative human effects will only increase. Since nitrate runoff from ag. has been proven to be the dominant source of hypoxia, policies could be enacted to effectively deal with “point-source” pollution. This makes enacting environmental policy more easily adapted, possibly included in past policy such as the Clean Water Act.
The Chesapeake Bay is the nation’s largest estuary with six major tributaries, the James, the Potomac, the Susquehanna, the Patuxent, the York, and the Rappahannock Rivers, feeding into the bay from various locations in Maryland, Virginia, Pennsylvania, and the District of Columbia (Chemical Contaminants in the Chesapeake Bay – Workshop Discussion 1). These areas depend on the Bay as both an environmental and an economic resource. Throughout the last 15 years the Chesapeake Bay has suffered from elevated levels of pollution. Nitrogen and phosphorous from wastewater treatment plants, farmland, air pollution, and development all lead to reduced water clarity and lowered oxygen levels, which harm fish, crabs, oysters and underwater grasses (Key Commission Issues 1). There are other types of pollution in the bay such as toxic chemicals, but because nutrient pollution is the most significant and most widespread in the Bay its effects are the most harmful to fisheries. Nitrogen and phosphorous fuel algal blooms which cloud the water and block sunlight from reaching underwater grass beds that provide food and habitat for waterfowl, juvenile fish, blue crabs, and other species (Blankenship 11-12). Algae plays a vital role in the food chain by providing food for small fish and oysters. However, when there is an overabundance of algae it dies, sinks to the bottom of the Bay, and decomposes in such a manner that depletes the oxygen levels of the Bay (11). The reduced oxygen levels in the Bay reduce the carrying capacity of the environment and these “dead areas” sometimes kill off species that can not migrate to other areas of the Bay, such as oysters (11). Increased abundance of algal blooms also led to the overabundance of harmful and toxic algae species and microbes such as the microbe Pfiesteria, which was responsible in 1997 for eating fish alive and making dozens of people sick (12). The heightened awareness of diseases that can be contracted through consumption of contaminated fish also has an economic impact. Therefore, the excess levels of nitrogen and phosphorous have fueled an overabundance of algal blooms, which has reduced water clarity and lowered oxygen levels, affecting many species within the bay and ultimately the industries that rely on these species.
Amoebae of the genus Naegleria are identified in part by their ability to create a temporary flagellate phase once exposed to nutritional scarcity. N fowleri is confirmed to be a typical eukaryotic protist by electron microscopy examination (Patterson et al., 1981).
Because of farm fertilizer, an excess quantity of nitrogen and phosphorus can be wash down becoming runoff into rivers. From this, marine algal blooms cause the water to turn green from the chlorophyll (Reed, 2011). Eutrophication then becomes a dilemma in the system causing either an increase of primary production or an expansion of algae. An enormous expansion of phytoplankton on the water’s surface is then established. At the same time the water column is also stratified, meaning things such as the temperature and salinity are not sync from top to bottom. The seasonal warm surface water has a low density forming a saltier layer above while the cooler and more dense water masses near the bottom layer is isolated from the top cutting off oxygen supply from the atmosphere (Overview, 2008).
Ocean Pollution is a serious issue in today's global politics. The delicate balance of Earth's ecosystem is put in jeopardy when the ocean is not clean. Problem evolving from ocean pollution directly harm marine life and indirectly affect human health and the Earth's many valuable resources. Ocean Pollution is a Broad term that encpompasses any and all foregin matter that directly or indirectly makes its way into the ocean. This includes everything from the extreme: oil spills, Toxic Waste dumping and industrial dumping-- to the small scael: human activities and basic carelessness. Because the oceans and all other water bodies are invariably, somehow connected, and because they account for 3/4 of the Earth's surface, they are an ideal method of transportation for pollution, allowing the rapid spread of seemingly far away toxins into a river near you! It is increasingly important that we educate ourselves as to what, exactly, ocean pollution is, so that we can identify the causes at their source and take action in small and large ways, and hopefully, prevent this terrible form of pollution from getting any worse than it is today.
The Chesapeake Bay has faced an excessive amount of pollution over the past century. The water in the bay has become so highly polluted that It is capable of causing harm to humans coming in direct contact with the water. Although algae serves a vital role in the bay’s ecosystem, it also creates a problem that is causing a large amount of the problem.
Red Tide, commonly labeled as Harmful Algal Blooms (HABs), is a natural phenomenon that is caused by an explosion of algae in coastal waters. The algae are single celled protists; plant-like organisms. Because the algae reproduce expeditiously, they manage to alter the color of coastal oceans. However, the name "Red Tide" is a misnomer; many times, the ocean can be multiple colors, ranging from green to blue to yellow. Overall, Red Tide has many negative effects on the environment as well as the health of both humans and animals alike.
With the moon’s strong gravitational pull it makes the earth’s water gravitate towards the moons direction. However as the bottom section of figure 2 shows, when the moon and the sun are perpendicular from each other the high tide and low tide are not as far apart, resulting in lower high tides, and higher low tides. When that occurs it is called a neap tide, and when the sun and moon are parallel with the earth and the high tide is very high, and the low tide is very low, that is called a spring tide. Although gravity is the number one cause of tides there are also some other smaller factors that can result in varying tide
At this moment in time, eutrophication is causing worldwide devastation to not only aquatic life, but the fishing industry. The release of nutrients into fresh water lakes, rivers and reservoirs leads to excessive growth of three different plant species:
How often also does a human use or eat algae in his daily life? When most people think of algae, they probably think of something that is slimy, gross, and dirty. Algae may irritate people because it grows in unwanted places like swimming pools and boats. Algae can be toxic and it is slimy, but algae benefits people in all aspects of life. Humans obtain algin from algae to help make ice cream, pudding, face cream, and shoe polish. Algae is present in hamburgers, yoghurt, and cakes. Algae also helps make explosives, insulation, and paint. Algae produces most of the oxygen that animals breathe and without it the world would suffocate. Also, according to Helen Challand, "It is now believed that the oil and gas formed millions of years ago in the ground were created by algae" (20).
Tides are common features of the ocean. Tides occur when large bodies water rise and fall, because of the gravitational pull of the moon and the sun. Spring tides are especially strong tides; in spite of the name they have nothing to do with the season spring. They occur when the Earth, the sun, and the moon are in a line. Spring tides occur during the full moon and the new moon. Neap tides are especially weak tides. They occur when the gravitational forces of the moon and the sun are perpendicular to one another. When water moves from side to side, it is called a current. Currents move warm and cold water to different parts of the ocean.
These results agree with the hypothesis that our “untouched and super-productive world” is affecting marine life ecosystems (Vannela, 2012). All of these results combined confirm the overall hypothesis that pollution is getting worse in the ocean and more marine life ecosystems are being affected, but there
Some of the algae are flat some are branched, blood red sheets but majority are succulent. Red algae seaweeds are basically from phylum rhodophyta, that are different from other seaweeds due to presence of red and blue pigment, phycocyanin and phycoerythrin, in addition to chlorophyll a. The red and blue pigment in this seaweeds make a great advantage so that it absorbs blue-green light in deep water by passing the energy to the chlorophyll for food production by photosynthesis. Red algae live in both high on the shore and at great depth. Algae that are present in deep water having the red pigment but the algae present in inter tidal water having the yellowish, reddish brown or almost black pigment, that’s why many of red algae are confused of brown algae that are yellow
...eochemical cycles. By increasing the amount of crops that are removed from the soil and the subsequent soil erosion, phosphorus levels in the soil have dropped. The phosphorus lost from the soils travels to aquatic ecosystems which then can cause massive algal blooms. The increased use of nitrogen based fertilizers has also altered that cycle. The fertilizers add high levels of nitrates to the soil, and in natural ecosystems, nitrates will undergo denitrification and be returned as atmospheric nitrogen. This is not the case because the nitrate levels exceed the levels of denitrification that bacteria can handle. Additionally, much of the denitrifying bacteria is found in marshes and wetlands, which are currently being destroyed at incredible rates. In some areas, the excess nitrate has made it into the ground water system and contaminated the drinking water system.