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Biodiversity Crabs I/L

Hypoxic conditions are harmful to blue crab, a keystone species in the Chesapeake Bay


Johnson, Eric G. "Crab Species Team Background and Issue Briefs." (n.d.): n. pag. Sea Grant Maryland. Sea Grant Maryland, 2010. Web. 16 July 2014. .

One of the most widespread threats to estuarine and marine ecosystems is caused by low DO; ¶ anoxia (0 mg O2 L-1) and hypoxia (< 2 mg O2 L-1), which has occurred with increasing frequency ¶ and aerial cover historically in Chesapeake Bay (Diaz and Rosenberg 2008). Low DO events can ¶ arise daily (diel cycling due to nighttime respiration of autotrophs, particularly algae; Tyler et al. ¶ 2009), seasonally (after the spring phytoplankton bloom through autumn) or periodically (in ¶ relation to weather events or spring-neap tidal cycles; Diaz and Rosenberg 2008). Typically, ¶ hypoxic and anoxic zones of the Chesapeake Bay mainstem and major tributaries are associated ¶ with areas deeper than 10 m (Pihl et al. 1991). ¶ ¶ Responses by blue crabs to low DO are determined in part by the severity of such events and ¶ their tolerances to low oxygen levels. Blue crabs circumvent anoxic areas and readily detect and avoid hypoxic waters < 4 mg O2 L-1 (Das and Stickle 1994; Bell et al. 2003). Thus, crab densities are zero in anoxic waters and are greatly diminished in hypoxic areas. Typically, blue crabs move out of deeper water affected by low DO and into shallow areas during hypoxia or anoxia. ¶ In doing so, they become more concentrated in the shallows and are more susceptible to fishing gear, density-dependent predation and agonistic interactions.

Blue crab is a keystone species in the Chesapeake Bay, loss of the species would be harmful to the entire region


NOAA. "Chesapeake Bay Program." Bay Blog RSS. NOAA, 2012. Web. 16 July 2014. .

As both predator and prey, blue crabs are a keystone species in the Chesapeake Bay food web. Blue crabs also support the most productive commercial and recreational fisheries in the BayBlue crabs are an important link in the Chesapeake Bay food web¶ Blue crabs are both predators and prey in the Bay’s food web.¶ Blue crab larvae are part of the Bay’s planktonic community, and serve as food for menhaden, oysters and other filter feeders.¶ Juvenile and adult blue crabs serve as food for fish, birds and even other blue crabs. Striped bass, red drum, catfish and some sharks depend on blue crabs as part of their diet. Soft shell crabs that have just molted are particularly vulnerable to predators.¶ Blue crabs are among the top consumers of bottom-dwelling organisms, or benthos. Blue crabs are opportunistic feeders that eat thin-shelled bivalves, smaller crustaceans, freshly dead fish, plant and animal detritus, and almost anything else they can find.¶ Because blue crabs feed on marsh periwinkles, they help regulate periwinkle populations. Scientists are concerned that a drop in blue crab populations could harm salt marsh habitat, as periwinkle populations rise and the snails over-feed on marshgrass.

Biodiversity Impact

Dead zones lead to hydrogen sulfide production, which has been seen as the cause of multiple mass extinctions on earth.


Simmons, Amy. "Scientists Fear Mass Extinction as Oceans Choke." ABC News. ABC, 1 Dec. 2010. Web. 16 July 2014. .

Australian scientists fear the planet is on the brink of another mass extinction as ocean dead zones continue to grow in size and number.¶ More than 400 ocean dead zones - areas so low in oxygen that sea life cannot survive - have been reported by oceanographers around the world between 2000 and 2008.¶ That is compared with 300 in the 1990s and 120 in the 1980s.¶ Professor Ove Hoegh-Guldberg, of the ARC Centre of Excellence for Coral Reef Studies (CoeCRS) and from the University of Queensland, says there is growing evidence that declining oxygen levels in the ocean have played a major role in at least four of the planet's five mass extinctions.¶ "Until recently the best hypothesis for them was a meteor strike," he said.¶ "So 65 million years ago they've got very good evidence of the cretaceous exctinction event.¶ "But with the four other mass extinction events, one of the best explanations now is that these periods were preceded by an increase of volcanic activity, and that volcanic activity caused a change in ocean circulation.¶ "Just as we are seeing at a smaller scale today, huge parts of the ocean became anoxic at depth.¶ "The consequence of that is that you had increased amounts of rotten egg gas, hydrogen sulfide, going up into the atmosphere, and that is thought to be what may have caused some of these other extinction events."¶ Professor Hoegh-Guldberg says up to 90 per cent of life has perished in previous mass extinctions and that a similar loss of life could occur in the next 100 years.¶ "We're already having another mass extinction due to humans wiping out life and so on, but it looks like it could get as high as those previous events," he said.¶ "So it's the combination of this alteration to coastlines, climate change and everything, that has a lot of us worried we are going to drive the sixth extinction event and it will happen over the next 100 years because we are interfering with the things that keep species alive.¶ "Ocean ecosystems are in a lot of trouble and it all bears the hallmarks of human interference.¶ "We are changing the way the Earth's oceans work, shifting them to entirely new states, which we have not seen before."¶ He says while it is impossible to predict the future, in a century from now the world will be vastly different.¶ "A world without the Great Barrier Reef, where you don't have the pleasure of going to see wild places any more," he said.¶ "We might be able to struggle on with much lower population densities, but ultimately it won't be the world we have today.¶ "The idea of walking in the Daintree will be a forgotten concept because these changes have occurred."

The status quo makes mass extinctions inevitable absent change


Shah 1/19/2014 [Anup Shah, “Loss of Biodiversity and Exinctions”, January 19, 2014, http://www.globalissues.org/article/171/loss-of-biodiversity-and-extinctions#MassiveExtinctionsFromHumanActivity]

Despite knowing about biodiversity’s importance for a long time, human activity has been causing massive extinctions. As the Environment New Service, reported back in August 1999 (previous link): the current extinction rate is now approaching 1,000 times the background rate and may climb to 10,000 times the background rate during the next century, if present trends continue [resulting in] a loss that would easily equal those of past extinctions.” (Emphasis added) A major report, the Millennium Ecosystem Assessment, released in March 2005 highlighted a substantial and largely irreversible loss in the diversity of life on Earth, with some 10-30% of the mammal, bird and amphibian species threatened with extinction, due to human actions. The World Wide Fund for Nature (WWF) added thatEarth is unable to keep up in the struggle to regenerate from the demands we place on it. The International Union for Conservation of Nature (IUCN) notes in a video that many species are threatened with extinction. In addition, At threat of extinction are 1 out of 8 birds 1 out of 4 mammals 1 out of 4 conifers 1 out of 3 amphibians 6 out of 7 marine turtles 75% of genetic diversity of agricultural crops has been lost 75% of the world’s fisheries are fully or over exploited Up to 70% of the world’s known species risk extinction if the global temperatures rise by more than 3.5°C 1/3rd of reef-building corals around the world are threatened with extinction Over 350 million people suffer from severe water scarcity Is this the kind of world we want, it asks? After all, the short video concludes, our lives are inextricably linked with biodiversity and ultimately its protection is essential for our very survival: In different parts of the world, species face different levels and types of threats. But overall patterns show a downward trend in most cases. The reasons vary from overuse of resource by humans, climate change, fragmented habitats, habitat destruction, ocean acidification and more. Research of long term trends in the fossil record suggests that natural speed limits constrain how quickly biodiversity can rebound after waves of extinction. Hence, the rapid extinction rates mean that it could take a long time for nature to recover. Consider the following observations and conclusions from established experts and institutions summarized by Jaan Suurkula, M.D. and chairman of Physicians and Scientists for Responsible Application of Science and Technology (PSRAST), noting the impact that global warming will have on ecosystems and biodiversity: The world environmental situation is likely to be further aggravated by the increasingly rapid, large scale global extinction of species. It occurred in the 20th century at a rate that was a thousand times higher than the average rate during the preceding 65 million years. This is likely to destabilize various ecosystems including agricultural systems. …In a slow extinction, various balancing mechanisms can develop. Noone knows what will be the result of this extremely rapid extinction rate. What is known, for sure, is that the world ecological system has been kept in balance through a very complex and multifaceted interaction between a huge number of species. This rapid extinction is therefore likely to precipitate collapses of ecosystems at a global scale. This is predicted to create large-scale agricultural problems, threatening food supplies to hundreds of millions of people. This ecological prediction does not take into consideration the effects of global warming which will further aggravate the situation. Industrialized fishing has contributed importantly to mass extinction due to repeatedly failed attempts at limiting the fishing. A new global study concludes that 90 percent of all large fishes have disappeared from the world’s oceans in the past half century, the devastating result of industrial fishing. The study, which took 10 years to complete and was published in the international journal Nature, paints a grim picture of the Earth’s current populations of such species as sharks, swordfish, tuna and marlin. …The loss of predatory fishes is likely to cause multiple complex imbalances in marine ecology. Another cause for extensive fish extinction is the destruction of coral reefs. This is caused by a combination of causes, including warming of oceans, damage from fishing tools and a harmful infection of coral organisms promoted by ocean pollution. It will take hundreds of thousands of years to restore what is now being destroyed in a few decades. …According to the most comprehensive study done so far in this field, over a million species will be lost in the coming 50 years. The most important cause was found to be climate change. As explained in the UN’s 3rd Global Biodiversity Outlook, the rate of biodiversity loss has not been reduced because the 5 principle pressures on biodiversity are persistent, even intensifying: Habitat loss and degradation Climate change Excessive nutrient load and other forms of pollution Over-exploitation and unsustainable use Invasive alien species Most governments report to the UN Convention on Biological Diversity that these pressures are affecting biodiversity in their country (see p. 55 of the report). The International Union for the Conservation of Nature (IUCN) maintains the Red List to assess the conservation status of species, subspecies, varieties, and even selected subpopulations on a global scale. Extinction risks out pace any conservation successes. Amphibians are the most at risk, while corals have had a dramatic increase in risk of extinction in recent years. The UN’s 3rd Global Biodiversity Outlook report, mentioned earlier, notes that, About 80 percent of the world marine fish stocks for which assessment information is available are fully exploited or overexploited. Fish stocks assessed since 1977 have experienced an 11% decline in total biomass globally, with considerable regional variation. The average maximum size of fish caught declined by 22% since 1959 globally for all assessed communities. There is also an increasing trend of stock collapses over time, with 14% of assessed stocks collapsed in 2007. — Secretariat of the Convention on Biological Diversity (2010), Global Biodiversity Outlook 3, May, 2010, p.48 IPS reports that fish catches are expected to decline dramatically in the world’s tropical regions because of climate change. Furthermore, “in 2006, aquaculture consumed 57 percent of fish meal and 87 percent of fish oil” as industrial fisheries operating in tropical regions have been “scooping up enormous amounts of fish anchovies, herring, mackerel and other small pelagic forage fish to feed to farmed salmon or turn into animal feed or pet food.” This has resulted in higher prices for fish, hitting the poorest the most. As Suurkula mentioned above, mass extinctions of marine life due to industrialized fishing has been a concern for many years. Yet, it rarely makes mainstream headlines. However, a report warning of marine species loss becoming a threat to the entire global fishing industry did gain media attention. At the current rate of loss, it is feared the oceans may never recoverExtensive coastal pollution, climate change, over-fishing and the enormously wasteful practice of deep-sea trawling are all contributing to the problem, as Inter Press Service (IPS) summarized. As also explained on this site’s biodiversity importance section, ecosystems are incredibly productive and efficient—when there is sufficient biodiversity. Each form of life works together with the surrounding environment to help recycle waste, maintain the ecosystem, and provide services that others—including humans—use and benefit from. With massive species loss, the report warns, at current rates, in less than 50 years, the ecosystems could reach the point of no return, where they would not be able to regenerate themselves. Dr. Boris Worm, one of the paper’s authors, and a world leader in ocean research, commented that: Whether we looked at tide pools or studies over the entire world’s ocean, we saw the same picture emerging. In losing species we lose the productivity and stability of entire ecosystems. I was shocked and disturbed by how consistent these trends are—beyond anything we suspected. — Dr. Boris Worm, Losing species, Dalhousie University, November 3, 2006 “Current” is an important word, implying that while things look dire, there are solutions and it is not too late yet. The above report and the IPS article noted that protected areas show that biodiversity can be restored quickly. Unfortunately, “less than 1% of the global ocean is effectively protected right now” and “where [recovery has been observed] we see immediate economic benefits,” says Dr. Worm. Time is therefore of the essence. Declining Ocean Biodiversity It is not just fish in the oceans that may be struggling, but most biodiversity in the seas. This includes mammals (e.g. whales, dolphins, polar bears), birds (e.g. penguins), and other creatures (e.g. krill). Ocean degradation has been feared to be faster than previously thought. The health of the ocean is spiraling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth. — Professor Alex Rogers of Somerville College, Oxford, and Scientific Director of IPSO, Latest Review of Science Reveals Ocean in Critical State From Cumulative Impacts df formatted document, The International Programme on the State of the Ocean (IPSO), October 3, 2013 The factors affecting the ocean’s health includes: De-oxygenation Acidification Warming These impacts will have cascading consequences for marine biology, including altered food web dynamics and the expansion of pathogens, the IPSO also notes. These factors are also looked at in further detail on this site’s article on climate change and biodiversity as well as covered in more depth by IPSO’s report, State of the Ocean. The Census was able to determine, however, that over-fishing was reported to be the greatest threat to marine biodiversity in all regions followed by habitat loss and pollution. One of the summary reports also added that “the fact that these threats were reported in all regions indicates their global nature.” A collection of regional and overview reports were also published on the Public Library of Science web site The report also notes that “The number of observed ‘dead zones’, coastal sea areas where water oxygen levels have dropped too low to support most marine life, has roughly doubled each decade since the 1960s. Many are concentrated near the estuaries of major rivers, and result from the buildup of nutrients, largely carried from inland agricultural areas where fertilizers are washed into watercourses. The nutrients promote the growth of algae that die and decompose on the seabed, depleting the water of oxygen and threatening fisheries, livelihoods and tourism.” (p. 60) If ecosystems deteriorates to an unsustainable level, then the problems resulting can be very expensive, economically, to reverse. The Economics of Ecosystems and Biodiversity (TEEB) is an organization — backed by the UN and various European governments — attempting to compile, build and make a compelling economics case for the conservation of ecosystems and biodiversity.

Environment destruction destroys potential economic growth, destabilizes countries, and increases military vulnerabilities


Perkins 5/6/2013 [Skylar Perkins, “The Creation of Weath: Economics and the Environment”, May 6, 2013, http://www.izilwane.org/the-creation-of-wealth-an-inevitable-paradigm-shift-in-economics.html]

It is difficult to imagine any real solutions coming out of Congress right now. There is an ideological divide, a rift, a lack of understanding on critical issues and the power of big money. But there is a larger question: Is the system we have in place capable of solving the problems we currently face? Our economic and global circumstances are changing rapidly with globalization, climate change, resource depletion, and a rapidly evolving economic system. For elected officials it seems impossible to adapt when we have crises of debt and unemployment. Yet based purely on the health of our ecosystems, it seems we are left with two choices: make these changes ourselves or have large scale changes inflicted upon us. Economic growth has become synonymous with success, with freedom, with improvement, with the American dream. Yet, endless economic growth could ultimately be our downfall. Currently, we operate under a model designed for infinite economic growth. Our monetary system, our progress indicators, our investment structures; these are all based on the idea that our economy will grow forever. When there is no growth, there is unemployment, banks don't lend money, the economy does not innovate and we move toward collapse. Changing this foundation of our economy would be a leap from a cultural standpoint and a policy standpoint. Economic growth is based on one central assumption: The economy is a closed system. This is a fundamental concept that comes from physics. A closed system is self-contained, having no inputs or outputs. This conventional model of the economy has a gaping hole: the ecosystem. In modern economic flow charts, we never see the input of resources or the output of detrimental factors such as pollution. In other words, there is no value on the ozone and no cost of species extinctions. The Reality In the 18th century, moral philosopher Adam Smith theorized on the free-market in the context of what economists call an empty worldin which there were fewer people and nature was vast and plentiful. In that time period, the ecosystem could be entirely ignored and assumed to be infinitely abundant. Now, however, we are in a full world – a world in which population has increased ten-fold and consumption levels have skyrocketed. Though the economy has never been a closed system, this scientific fact has been historically ignored because natural resources were not yet scarce.ii Many of today's economists continue to assume that our economy is a closed system that contains an ever-substitutable supply of resources and pollution sinks. While times are changing fast, the fundamental basis of our economy was born 200 years ago during the Industrial Revolution. During this time, the wealth of ecosystems was basically ignored, and economists considered man-made wealth to be the primary focus. As we destroy our natural resource base, we are destroying collective wealth and the resiliency of our economy for short-term private gain. By assuming the economy is the whole and the ecosystem is merely a part, we are applying false economic precepts to the natural world. For example, in an ecosystem, not all parts and functions are substitutable; each segment has a unique niche that makes the system as a whole operate effectively. Through outright ignoring the physical dimensions of value, we are, in many cases, assigning value where we should not and neglecting to assign value where we should. We are calling losses profits and profits losses. Our economy does not completely reflect the values of the people, and therefore neither does the construction and destruction of the world around us. Here is an updated model of the economy The conventional economic model does not include the biosphere, natural recycling, wastes and pollution, industrial recycling, energy and natural resources, or solar energy. However, our economic system, based on this flow, interacts with our ecosystem on an inextricable level. Our Debt in Natural Capital In a paper published in Scientific American in 2005, ex-World Bank senior economist Herman Daly explains, When the economy's expansion encroaches too much on its surrounding ecosystem, we will begin to sacrifice natural capital (such as fish, minerals and fossil fuels) that is worth more than the man-made capital (such as roads, factories and appliances) added by the growth.iii The more we inhibit the environment, the less our economy benefits from these services. Despite its limitations, putting a monetary value on nature can be highly useful and informative for both macroeconomic policy and conservation efforts. The Economics of Ecosystems and Biodiversity (TEEB) has estimated that each New Year, economic activity costs the world approximately 6.6 trillion dollars in environmental benefits. Expanding economic growth and inhibiting nature growth is actually quite costly, given that our entire economy depends not only on services nature provides – outdoor recreation, education, and health, to name a few, each of which provides significant income for both local and national economies – but also on stocks of natural capital such as timber and fossil fuels. Pollution has created 246,048 square kilometers of dead zones in the ocean throughout the world. According to the Global Partnership for Oceans, approximately 35 percent of mangrove habitats have been lost in the last 30 years, which has had dramatic effects on the stability of coastal areas and increased negative impacts from storms on both local communities and ecosystems. This coastal wetland destruction may account for more than two percent of global CO2 emissions. Our current economy does not account for the benefits of healthy oceans, the services provided by mangroves or the economic benefits of a stable climate. It therefore cannot estimate the true cost of pollution. We have seen the tragic effects of rising ocean temperatures and climate change from Hurricane Sandy on the East Coast of the United States. From an economic growth perspective, Inger Andersen, vice president of sustainable development at the World Bank, notes that "without taking care of the environment we are shaving digits off GDP and, therefore, limiting our very potential for the future."iv Of course, protecting nature not only has the potential to save dollars from national expenditures; it also seems to be a key component in creating a fair and just society. For instance, while many conventional economists have used the trickle-down logic to promote unrestricted free enterprise internationally, reports can now put economic values on the unequal distribution of costs caused by waste and resource extraction in economic activity. While ecosystem services may provide directly for two-15 percent of a nation's Gross Domestic Product (GDP), TEEB has found that this often affects the poor disproportionately. Internationally, the poor are more directly tied to the ecosystem, depending more on local resources and food for income while being less protected from the consequences of climate change and pollution. The societal neglect for natural capital may cost them as much as 50 percent of their wealth.v Putting a monetary value on many basic ecosystem services illustrates the ecosystem service entitlements that corporations have been receiving. To a large extent, corporations have had the rights to destroy ecosystem services, pollute air and water, deplete resources, and harm the ecosystem at the expense of ecological flows and services for other producers and for present and future generations. A global calculation by Trucost for the United Nations Principles for Responsible Investment estimated that the top 3,000 companies in the world, which account for 33 percent of global profits, cost the global public 2.25 trillion dollars per year. That's 2,250,000,000,000 U.S. dollars each year in externalities. Externalities are consequences of economic exchanges not captured by the economy. For example, the negative effects of acid rain not paid for by a pollution emitter are externalities.vi National Security The economy is not a purely economic issue, as the ecosystem is not a purely ecological issue. Climate change, rising sea levels, extreme weather conditions, droughts, resource scarcity, biodiversity loss, desertification; these are potential threats to life around the earth and potential threats to peace internationally. The U.S. military understands this, noting in their 2010 Defense Department review that climate change is an "accelerant of instability and conflict"; they identify climate change and energy security as "prominent military vulnerabilities."vii There is ample evidence that climate patterns such as El Nino are as much of a factor in civil conflicts as any other geopolitical or economic factor.viii Despite evidence from our own military, recent presidential candidates neglected to make the connection between national security and the environment in any of the 2012 election's three debates.

Oceans are suffering worldwide-biodiversity loss, climate change, and dead zones will only get worse


Tirado 2008 [Reyes Tirado-Ph.D University of Exeter, UK, “Dead zones How Agricultural Fertilizers Kill our Rivers, Lakes and Oceans”, 2008, http://www.greenpeace.to/publications/dead-zones.pdf]

Fertilizer run-off from industrial agriculture is choking the planet’s oceans, rivers and lakes. Nitrogen and phosphorus pollution feed explosive algal blooms that suck the oxygen from the water as they grow. These algal blooms result in dead zones that have become a recurrent feature in every ocean and on every continent from the Gulf of Mexico to the Black Sea, from Canada’s Lake Winnipeg to China’s Yangtze Delta. As global warming heats our oceans, these problems will only worsen. Unless measures are put in place to control fertilizer usage, losses to biodiversity will continue to mount, coastal and inland fisheries will suffer and summer beaches could become toxic no-go zones devoid of life. Global warming could potentially exacerbate the occurrence of harmful algal blooms in future years, since higher temperatures tend to stimulate algal growth and favour toxic algal species (Chu et al. 2007). Other physical factors affected by climate change could stimulate nutrient flows and eutrophication. For example, referring to the Gulf of Mexico, a group of scientists recently stated: “Future climate change, within the range likely to occur in the 21st century, could have profound consequences to hypoxia in the northern Gulf of Mexico. If changes result in increased precipitation, river discharge and nitrogen loading, hypoxia is expected to be more extensive, persistent and severe” (Rabalais et al. 2007). Dead zones in the ocean form when the millions of minute floating plants and animals (phytoplankton and zooplankton) that are associated with algal blooms die and sink to the deep sea floor where they are consumed by microbes. In turn, these microbes also grow dramatically, and consequently use up the oxygen in bottom waters. The oxygen content in fully oxygenated seawater levels is about 10 parts per million (ppm); once water oxygen levels fall to 5 ppm, fish and other marine animals have trouble breathing (Diaz 2001, Dodds 2006). Hypoxic zones are defined as areas where the oxygen level has fallen below 2 ppm. While fish swim away when levels fall below 2 ppm, other less mobile animals cannot escape and they begin to die at around 1.5 ppm oxygen (Diaz et al. 2004). Biodiversity is thus diminished on the seabed as many animals cannot survive, even though closer to the water surface there is still sufficient oxygen to support animal life. Oxygen depletion around the world The worldwide distribution of coastal oxygen depletion is either centred on major population concentrations, or closely associated with developed river basins that deliver large quantities of nutrients (Diaz et al. 2004). In some regions, dead zones extend across vast areas, and the problem is growing worldwide. The number of dead zones has doubled every decade since the 1960s. The United Nations Environmental Programme estimated in 2006 that the number of dead zones has increased worldwide from 150 in 2004 to 200 in 2006—a 30% increase in just two years (UNEP 2006). The largest dead zones are found in coastal areas of the Baltic Sea (84,000–100,000 km2 ), northern Gulf of Mexico (21,000 km2 ), and until recently, the northwestern shelf of the Black Sea (40,000 km2 ). Smaller and less frequently occurring areas of hypoxia occur in the northern Adriatic Sea, the south North Sea and in many US coastal and estuarine areas (Rabalais et al. 2002). Recent research shows that hypoxic areas are now also occurring off South America, China, Japan, southeast Australia and New Zealand. Some of the more recent registered sites appear to be in the Archipelago Sea in Finland, the Fosu Lagoon in Ghana, the Pearl River estuary and the Yangtze River in China, and the western Indian shelf (see Figure 4) (UNEP 2006). The UNEP map above (Figure 5) shows dead zones in the oceans as of 2003, distinguishing between persistent and temporary dead zones. For example, some of the dead zones in the northern Gulf of Mexico are dominant from spring through to late summer, but rare in the autumn and winter, while the dead zones in the Baltic are permanent year-around (Rabalais et al. 2002). Dead zones and fertilizers Accelerated growth of the hypoxia zone in the Gulf of Mexico follows the exponential growth of fertilizer use beginning in the 1950s (Rabalais et al. 2002). In the Baltic, there is clear evidence that excess use of fertilizers is associated with dead zones in bottom waters (Karlson et al. 2002). The dead zone in the northwestern Black Sea in the 1970s and 1980s covered up to 40,000 km2 ; since then there has been some recovery, most likely due to the reduction in use of agricultural fertilizers. This occurred as a result of the economic collapse of the former Soviet Union and declining subsidies for fertilizers. Less fertilizer input to the Danube River was accompanied by signs of recovery of both open-water and seafloor ecosystems of the Black Sea. By 1999, the hypoxic area receded to less than 1000 km2 . However, according to a study published in 2001, there has been no recovery of seaweed beds and most fish stocks are still depleted (Rabalais et al. 2002). Dead zones in the Baltic and Black Sea led to the disappearance of bottom fisheries in these areas (Diaz 2001). Biodiversity loss and jellyfish invasions Besides the increased frequency and severity of HABs and dead zones, nutrient overloading has been also blamed for the disappearance of seagrass habitats and massive loss in coastal biodiversity (Diaz et al. 2004). Jellyfish invasions in coastal waters, like recent recurrent events in the Mediterranean, Chinese river estuaries and Japan coasts, are the result of a number of factors, but nutrient loading and eutrophication are at the root cause of the problem (Purcell et al. 2007). The consequences of overfishing can further exacerbate eutrophication impacts (Maranger et al. 2008). As humans continue to unsustainably exploit fisheries, jellyfish and plankton do not have to face their usual predators and competitors, which would usually regulate their population growth.

Species extinction snowballs-jeopardizes entire planet


Center for Biological Diversity 2008 [Center for Biological Diversity, “The Extinction Crisis”, http://www.biologicaldiversity.org/programs/biodiversity/elements_of_biodiversity/extinction_crisis/]

It’s frightening but true: Our planet is now in the midst of its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years. We’re currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago. Although extinction is a natural phenomenon, it occurs at a natural “background” rate of about one to five species per year. Scientists estimate we’re now losing species at 1,000 to 10,000 times the background rate, with literally dozens going extinct every day [1]. It could be a scary future indeed, with as many as 30 to 50 percent of all species possibly heading toward extinction by mid-century [2]. Unlike past mass extinctions, caused by events like asteroid strikes, volcanic eruptions, and natural climate shifts, the current crisis is almost entirely caused by us — humans. In fact, 99 percent of currently threatened species are at risk from human activities, primarily those driving habitat loss, introduction of exotic species, and global warming [3]. Because the rate of change in our biosphere is increasing, and because every species’ extinction potentially leads to the extinction of others bound to that species in a complex ecological web, numbers of extinctions are likely to snowball in the coming decades as ecosystems unravel. Species diversity ensures ecosystem resilience, giving ecological communities the scope they need to withstand stress. Thus while conservationists often justifiably focus their efforts on species-rich ecosystems like rainforests and coral reefs — which have a lot to lose — a comprehensive strategy for saving biodiversity must also include habitat types with fewer species, like grasslands, tundra, and polar seas — for which any loss could be irreversibly devastating. And while much concern over extinction focuses on globally lost species, most of biodiversity’s benefits take place at a local level, and conserving local populations is the only way to ensure genetic diversity critical for a species’ long-term survival. In the past 500 years, we know of approximately 1,000 species that have gone extinct, from the woodland bison of West Virginia and Arizona’s Merriam’s elk to the Rocky Mountain grasshopper, passenger pigeon and Puerto Rico’s Culebra parrot — but this doesn’t account for thousands of species that disappeared before scientists had a chance to describe them [4]. Nobody really knows how many species are in danger of becoming extinct. Noted conservation scientist David Wilcove estimates that there are 14,000 to 35,000 endangered species in the United States, which is 7 to 18 percent of U.S. flora and fauna. The IUCN has assessed roughly 3 percent of described species and identified 16,928 species worldwide as being threatened with extinction, or roughly 38 percent of those assessed. In its latest four-year endangered species assessment, the IUCN reports that the world won’t meet a goal of reversing the extinction trend toward species depletion by 2010 [5]. What’s clear is that many thousands of species are at risk of disappearing forever in the coming decades FISH Increasing demand for water, the damming of rivers throughout the world, the dumping and accumulation of various pollutants, and invasive species make aquatic ecosystems some of the most threatened on the planet; thus, it’s not surprising that there are many fish species that are endangered in both freshwater and marine habitats. The American Fisheries Society identified 700 species of freshwater or anadromous fish in North America as being imperiled, amounting to 39 percent of all such fish on the continent [9]. In North American marine waters, at least 82 fish species are imperiled. Across the globe, 1,851 species of fish — 21 percent of all fish species evaluated — were deemed at risk of extinction by the IUCN in 2010, including more than a third of sharks and rays. INVERTEBRATES Invertebrates, from butterflies to mollusks to earthworms to corals, are vastly diverse — and though no one knows just how many invertebrate species exist, they’re estimated to account for about 97 percent of the total species of animals on Earth [10]. Of the 1.3 million known invertebrate species, the IUCN has evaluated about 9,526 species, with about 30 percent of the species evaluated at risk of extinction. Freshwater invertebrates are severely threatened by water pollution, groundwater withdrawal, and water projects, while a large number of invertebrates of notable scientific significance have become either endangered or extinct due to deforestation, especially because of the rapid destruction of tropical rainforests. In the ocean, reef-building corals are declining at an alarming rate: 2008’s first-ever comprehensive global assessment of these animals revealed that a third of reef-building corals are threatened. MAMMALS Perhaps one of the most striking elements of the present extinction crisis is the fact that the majority of our closest relatives — the primates — are severely endangered. About 90 percent of primates — the group that contains monkeys, lemurs, lorids, galagos, tarsiers, and apes (as well as humans) — live in tropical forests, which are fast disappearing. The IUCN estimates that almost 50 percent of the world’s primate species are at risk of extinction. Overall, the IUCN estimates that half the globe’s 5,491 known mammals are declining in population and a fifth are clearly at risk of disappearing forever with no less than 1,131 mammals across the globe classified as endangered, threatened, or vulnerable. In addition to primates, marine mammals — including several species of whales, dolphins, and porpoises — are among those mammals slipping most quickly toward extinction.

Loss of ocean biodiversity threatens fish supply-jeopardizes millions of people around the world


UNEP 2/16/2009 [United Nations Environment Programme, “THE ENVIRONMENTAL

FOOD CRISIS-THE ENVIRONMENT’S ROLE IN AVERTING FUTURE FOOD CRISES”, February 16, 2009, http://www.grida.no/publications/rr/food-crisis/page/3558.aspx]



Aquaculture, freshwater and marine fisheries supply about 10% of world human calorie intake – but this is likely to decline or at best stabilize in the future, and might have already reached the maximum. At present, marine capture fisheries yield 110–130 million tonnes of seafood annually. Of this, 70 million tonnes are directly consumed by humans, 30 million tonnes are discarded and 30 million tonnes converted to fishmeal. The world’s fisheries have steadily declined since the 1980s, its magnitude masked by the expansion of fishing into deeper and more offshore waters (Figure 10) (UNEP, 2008). Over half of the world’s catches are caught in less than 7% of the oceans, in areas characterized by an increasing amount of habitat damage from bottom trawling, pollution and dead zones, invasive species infestations and vulnerability to climate change (UNEP, 2008). Eutrophication from excessive inputs of phosphorous and nitrogen through sewage and agricultural run-off is a major threat to both freshwater and coastal marine fisheries (Anderson et al., 2008; UNEP, 2008). Areas of the coasts that are periodically starved of oxygen, so-called ‘dead zones’, often coincide with both high agricultural run-off (Anderson et al., 2008) and the primary fishing grounds for commercial and artisanal fisheries. Eutrophication combined with unsustainable fishing leads to the loss or depletion of these food resources, as occurs in the Gulf of Mexico, coastal China, the Pacific Northwest and many parts of the Atlantic, to mention a few. FOOD FROM FISHERIES AND AQUACULTURE Current projections for aquaculture suggest that previous growth is unlikely to be sustained in the future as a result of limits to the availability of wild marine fish for aquaculture feed (FAO, 2008). Small pelagic fish make up 37% of the total marine capture fisheries landings. Of this, 90% (or 27% of total landings) are processed into fishmeal and fish oil with the remaining 10% used directly for animal feed (Alder et al., 2008). In some regions, such as in parts of Africa and Southeast Asia, increase in fisheries and expansion of cropland area have been the primary factors in increasing food supply. Indeed, fisheries are a major source of energy and protein for impoverished coastal populations, in particular in West Africa and Southeast Asia (UNEP, 2008). Here, a decline in fisheries will have a major impact on the livelihoods and wellbeing of hundreds of millions of people (UNEP, 2008).

Global warming dooms genetic diversity-one-third of species are at risk


Romm 9/20/2011 [Joe Romm- Senior Fellow at American Progress, holds a Ph.D. in physics from MIT, and an Assistant Secretary of Energy, “Global Warming May Cause Far Higher Extinction of Biodiversity Than Previously Thought”, September 20, 2011, http://thinkprogress.org/climate/2011/09/20/323639/global-warming-extinction-of-biodiversity/]

If global warming continues as expected, it is estimated that almost a third of all flora and fauna species worldwide could become extinct. Scientists … discovered that the proportion of actual biodiversity loss should quite clearly be revised upwards: by 2080, more than 80% of genetic diversity within species may disappear in certain groups of organisms, according to researchers in the title story of the journal Nature Climate Change.  The study is the first world-wide to quantify the loss of biological diversity on the basis of genetic diversity. That’s from the news release of a study, “Cryptic biodiversity loss linked to global climate change” (subs. req’d).  The recent scientific literature continues to paint a bleak picture of what Homo  ‘sapiens’ is doing to the other species on the planet. In 2007, the Intergovernmental Panel on Climate Change warned that “as global average temperature increase exceeds about 3.5°C [relative to 1980 to 1999], model projections suggest significant extinctions (40-70% of species assessed) around the globe.”  That is a temperature rise over pre-industrial levels of a bit more than 4.0°C.  So the 5°C rise we are facingon our current emissions path would likely put extinctions beyond the high end of that range. Last fall, the Royal Society ran a special issue on “Biological diversity in a changing world,” concluding “There are very strong indications that the current rate of species extinctions far exceeds anything in the fossil record.” I realize that the mass extinction of non-human life on this planet isn’t going to be a great driver for human action.  Most people simply don’t get that the mass extinctions we are causing could directly harm our children and grandchildren as much as sea level rise.  Such extinctions threaten the entire fabric of life on which we depend for food, among other thingsThis may be clearest in the case of marine life — see “Geological Society (8/10): Acidifying oceans spell marine biological meltdown “by end of century.”  And then there’s the worst-case scenario in Nature Stunner — “Global warming blamed for 40% decline in the ocean’s phytoplankton”:“Microscopic life crucial to the marine food chain is dying out. The consequences could be catastrophic.” Life matters.  Here’s more from the release: Most common models on the effects of climate change on flora and fauna concentrate on “classically” described species, in other words groups of organisms that are clearly separate from each other morphologically. Until now, however, so-called cryptic diversity has not been taken into account. It encompasses the diversity of genetic variations and deviations within described species, and can only be researched fully since the development of molecular-genetic methods. As well as the diversity of ecosystems and species, these genetic variations are a central part of global biodiversity. In a pioneering study, scientists from the Biodiversity and Climate Research Centre (BiK-F) and the Senckenberg Gesellschaft für Naturkunde have now examined the influence of global warming on genetic diversity within species. Over 80 percent of genetic variations may become extinct The distribution of nine European aquatic insect species, which still exist in the headwaters of streams in many high mountain areas in Central and Northern Europe, was modelled. They have already been widely researched, which means that the regional distribution of the inner-species diversity and the existence of morphologically cryptic, evolutionary lines are already known. If global warming does take place in the range that is predicted by the Intergovernmental Panel on Climate Change (IPCC), these creatures will be pushed back to only a few small refugia, e.g. in Scandinavia and the Alps, by 2080, according to model calculations. If Europe’s climate warms up by up to two degrees only, eight of the species examined will survive, at least in some areas; with an increase in temperature of 4 degrees, six species will probably survive in some areas by 2080. However, due to the extinction of local populations, genetic diversity will decline to a much more dramatic extent. According to the most pessimistic projections, 84 percent of all genetic variations would die out by 2080; in the “best case,” two-thirds of all genetic variations would disappear. The aquatic insects that were examined are representative for many species of mountainous regions of Central Europe. Slim chances in the long term for the emergence of new species and species survival Carsten Nowak of the Biodiversity and Climate Research Centre (BiK-F) and the Senckenberg Gesellschaft für Naturkunde, explains: “Our models of future distribution show that the “species” as such will usually survive. However, the majority of the genetic variations, which in each case exist only in certain places, will not survive. This means that self-contained evolutionary lineages in other regions such as the Carpathians, Pyrenees or the German Central Uplands will be lost. Many of these lines are currently in the process of developing into separate species, but will become extinct before this is achieved, if our model calculations are accurate.” Genetic variation within a species is also important for adaptability to changing habitats and climatic conditions. Their loss therefore also reduces the chances for species survival in the long term. New approach for conservation So the extinction of species hides an ever greater loss, in the form of the massive disappearance of genetic diversity. “The loss of biodiversity that can be expected in the course of global warming has probably been greatly underestimated in previous studies, which have only referred to species numbers,” says Steffen Pauls, Biodiversity and Climate Research Centre (BiK-F), of the findings. However, there is also an opportunity to use genetic diversity in order to make conservation and environmental protection more efficient. A topic that is subject to much discussion at present is how to deal with conservation areas under the conditions of climate change. The authors of the study urge that conservation areas should also be oriented to places where both a suitable habitat for the species and a high degree of inner-species genetic diversity can be preserved in the future. “It is high time,” says Nowak, “that we see biodiversity not only as a static accumulation of species, but rather as a variety of evolutionary lines that are in a constant state of change. The loss of one such line, irrespective of whether it is defined today as a “species” in itself, could potentially mean a massive loss in biodiversity in the future.”

Ocean biodiversity loss is happening at an unprecedented rates-sets the stage for mass extinctions


Burke and Selman 6/22/2011 [Lauretta Burke and Mindy Selman, “Shocking” New Report Confirms Threats to World’s Oceans and Reefs”, World Resource Institute, June 22, 2011, http://www.wri.org/blog/2011/06/shocking-new-report-confirms-threats-worlds-oceans-and-reefs]

A new report on the state of the world’s oceans is gaining considerable attention this week. The report by the International Programme on the State of the Ocean (IPSO) and the International Union for the Conservation of Nature warns that combined threats to oceans are creating conditions where there is “a high risk of entering a phase of extinction of marine species unprecedented in human history.” Dr. Alex Rogers, scientific director of the IPSO, calls the new findings “shocking.” While to some this language may seem extreme, the reality is that an unprecedented range of threats are coming together to challenge the health of oceans and underwater life. The report identifies the main drivers of these threats, including: climate change, overexploitation, pollution and habitat loss. The report also finds increasing hypoxia (low oxygen levels) and anoxia (absence of oxygen, known as ocean dead zones) along with warming oceans and increasing acidification are creating multiple stessors on the world’s oceans – and multiple stressors are, in their words, a precondition for other mass extinction events in the Earth’s history. The bottom line is that these combined threats– much of it caused by human activity— are undermining the sustainability of our fragile ocean ecosystems, sea life and the value they hold. The World Resources Institute has been working on these issues over its 30 year history— particularly focused on the threats to coral reefs and issues around eutrophication and hypoxia (commonly referred to as “dead zones”). Coral Reefs Coral reefs are an essential part of ocean ecosystems – home to over 25 percent of all known species of marine life. The new IPSO report finds that in the past 50 years, activities related to “overfishing, pollution, and unsustainable practices” have led to severe declines in many marine species and an unprecedented level of degradation and loss of critically important habitat types such as mangroves, seagrass meadows and coral reefs. These pressures are being compounded by global warming, which leads to coral bleaching and related threats from ocean acidification. These findings echo themes from WRI’s recent report, Reefs at Risk Revisited, which finds that 75 percent of the world’s reefs are already at risk. WRI found that the main local pressures include overfishing, destructive fishing and pollution are leading threats to coral reefs. Like the IPSO, WRI looked at global pressures as well, namely global warming, coral bleaching and ocean acidification. WRI found that unless these combined threats are turned back, more than 90 percent of coral reefs will at risk by 2030 and all the world’s reefs will be threatened by 2050. In addition, WRI found that in the past 10 years, threats to coral reefs increased by 30 percent – showing that the threats to reefs are increasing both in speed and intensity. Dead Zones The new IPSO report identifies hypoxia as one of the factors which is threatening ocean life. Last year, WRI worked with the Virginia Institute of Marine Science (VIMS) to identify and map areas around there world that are showing signs of eutrophication and hypoxia. The new research identified 535 low-oxygen “dead zones,” only 56 of which can be classified as improving; an additional 248 sites worldwide were identified as areas of concern that currently exhibit signs of marine eutrophication and are at risk of developing hypoxia. According to our analysis, the number of eutrophic or hypoxic areas have increased from 42 known hypoxic or eutrophic sites in 1950 to the 783 sites we’ve identified today. This represents an 1800% increase in eutrophic and hypoxic areas over the past 60 years. Dead zones are the result of over-fertilization of our coastal areas from sources such as runoff from agriculture, discharges from industry, and human sewage. When a dead zone forms, oxygen in the water is severely depleted– threatening animals, plants, and other sea life with it. A combination of stressors from climate change, fisheries, pollution and habitat destruction are leading to more dead zones, further comprising our oceans, including the fragile world of coral reefs.

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