This paper was written as part of the 2009 Alaska Oceans Sciences Bowl high school competition. The conclusions in this report are solely those of the student authors.

The Effects of Ocean Acidification on Meroplanktonic Organisms

Authors

Laurel Stark
Tyler Emerson
Carly Casipit
Seth Brickey-Smith
Ross Douglas

Team Coo-Coo for Coccolithophores

Juneau-Douglas High School
10014 Crazy Horse Dr
Juneau, Alaska 99801-8529

Abstract

Ocean acidification is the acidification of the world's ocean due to the increasing amounts of carbon dioxide (CO2) and the absorbing of the CO2 into the ocean. The absorption is making the ocean more acidic by releasing hydrogen (H+) ions and thus lowering the pH. Up to half of the global carbon emissions are being absorbed by the oceans. When the ocean is acidic it makes it very difficult for marine calcifiers because the H+ ions combine with carbonate forming bicarbonate; this creates a shortage of carbonate which then makes a shortage of calcium carbonate that some organisms use to make their skeletons. Here, we looked at meroplankton and how ocean acidification might impact them. Meroplankton are plankton that live part of their lives as plankton, a lot of these organisms have calcium carbonate skeletons. Meroplankton are found the same places holoplankton and up to 50% of zooplankton can be meroplankton in some places. They are a food source to many organisms in their plankton and adult stages. Meroplankton will not be able to grow and develop if the pH continues to decrease and calcium carbonate concentrations diminish even further. The loss of meroplankton will be detrimental to the fisheries of Southeast Alaska. Reducing emissions of CO2 will be the best mitigation for the long-term large scale effects though it would not help the ocean in our lifetime because it would take tens of thousands of years to get the chemistry of the ocean back to the way it was before the industrial revolution. State and federal governments need to make and enforce laws so big industries and emitters of CO2 reduce their impact on the environment. But it can not be just an American effort, it has to be world wide because it is a global problem.

Introduction

Before the Industrial Revolution, atmospheric conditions and concentrations of naturally occurring greenhouse gases such as carbon dioxide, methane, nitrous oxide, and ozone remained relatively stable for the last 10,000 years (Figure 1). During this period, net incoming solar radiation was balanced with net outgoing infrared radiation. However, the growth of a fossil fuel dependant industry, increased energy demands of modern consumers, and carbon emitting intensive agricultural methods have drastically altered the composition of the atmosphere as we know it. This accumulation of greenhouse gases has, based on a vast majority of scientific studies, resulted in greater absorption of outgoing infrared radiation and a subsequent increase in global mean temperature as energy is re-radiated to the Earth's surface.

The most prominent anthropogenic greenhouse gas is CO2, primarily released in fossil fuel combustion and cement production. While chemically neutral in the atmosphere, carbon dioxide in the ocean is chemically active. As it dissolves in seawater, it reacts with water molecules to form a weak acid called carbonic acid then the carbonic acid releases hydrogen ions into the solution, leaving behind both bicarbonate and carbonate ions in the solution (Alfred Wegener Institute for Polar and Marine Research, 2007).

One important consequence of the release of hydrogen ions is that they combine with any carbonate ions in the water to form bicarbonate, thus removing substantial amounts of carbonate ion from the solution. The uptake of human made carbon dioxide in the ocean has already resulted in a 10% decline in carbonate (Burns, 2008). The saturation of seawater with carbonate ion is extremely crucial for marine species that construct their shells or skeletons with calcium carbonate. These species include meroplanktonic organisms, most corals, mollusks, echinoderms, foraminifera, calcareous algae, and crustaceans. The shells and skeletons of these species do not dissolve because the upper layers of the ocean are saturated with calcium and carbonate ions. However, as the pH of the oceans drops, it ultimately results in an under saturation of carbonate ions which in turn disrupts the calcification process (Burns, 2008).

Meroplankton, a group of organisms that spend part of their life in a planktonic stage, use calcium carbonate to create their skeleton. These organisms include creatures such as, sea urchins, starfish, sea squirts, most of the sea snails and slugs, crabs, lobsters, octopus, and marine worms (http://www.amonline.net.au/exhibitions/beyond/meroplankton/index.htm). These organisms also serve as the base of the food chain in some areas and if they are not able to survive it will have lasting consequences for many other creatures that directly or indirectly rely on them as a source of food.

Ocean Acidification

Over the past 200 years humans have been releasing greater and greater amounts of carbon dioxide into the atmosphere by burning fossil fuels, producing cement, and removing carbon sequestering organisms by destroying vegetation and forests (http://www.science.org.au/nova/106/106print.htm). The CO2 released into the atmosphere has two major pathways, it is either absorbed into the ocean, causing ocean acidification or it stays in the atmosphere, causing climate change. For the past 400,000 years, since pre-industrial times, the concentration of carbon dioxide in the atmosphere has fluctuated between 200 and 280 parts per million (ppm). In the past 50 years, there has been an increase of 22% in atmospheric carbon dioxide levels (http://www.akmarine.org/our-work/address-climate-change/ocean-acidification). This change has coincided with human industrial development. Currently, the concentration of CO2 is 380 ppm, and it is increasing rapidly (Feely, 2004). As a result of these increasing CO2 levels, CO2 will more rapidly dissolve into the ocean and consequently lower the pH level. It is hypothesized that if the pH level stays the same, in 50–100 years only half of the coral reefs will still be in existence, and if the concentration of CO2 goes up to 450ppm, only 10% of all coral reefs on the planet will still be in existence (Cao and Caldeira, 2008).

Numerous studies have been conducted. Based on them, it is predicted that within 50 years the concentration of CO2 will be around 560 ppm in the polar and sub-polar regions (http://www.akmarine.org/our-work/address-climate-change/ocean-acidification). If these studies prove to be correct the effects would be catastrophic for all species of calcifying organisms and the food web that they support.

Since pre-industrial times the overall ocean pH has dropped from 8.21 to 8.1. By the end of the century it is expected that the pH level could drop another 0.4. That value may not seem large, however, the pH scale is logarithmic and lowering the scale by 0.1 represents a 30% increase in acidity. If this decrease occurs as predicted, the calcium carbonate (CaCO3) levels available will decline by 50%. The lower pH and lower CaCO3 numbers will not only affect the current population of the ocean, but also those for the next few thousand years, because the oceans cycle at a slow pace. Many species dependent on CaCO3 will most likely diminish or die off completely unless something is done (http://www.akmarine.org/our-work/address-climate-change/ocean-acidification).

Calcification uses bicarbonate instead of CO2, as expressed by the equation Ca2++2HCO3-→CaCO3+CO2+H20. The CO2 produced throughout calcification cannot be used again, increasing the CO2 levels, and therefore decreasing the overall pH (Hays, 2005).

However, the main formula used to explain ocean acidification is CO2+CO32-+H20→2HCO3. This shows the decrease in the availability of carbonate ions (CO32-), leading to a condition known as under saturation. In addition, this process increases the of availability of CO2, which then lowers the pH of the ocean even further, starting with the surface waters and moving deeper as the waters mix (Gattuso, 2007).

Under saturation of carbonate is a problem in the intermediate waters of the North Pacific Ocean, as well as parts of the southeast Atlantic and north Indian oceans because there are fewer carbonate ions available for shell precipitation. Aragonite is 1.5 times more soluble than calcite, and so has a shallower saturation depth than calcite (Feely, 2004). The under saturation zone has expanded since the pre-industrial times by 50–200 meters in depth, and is expected to continue (Takahashi, 2004). This is expected to begin in the northern subarctic waters in the winter, when the water is coldest, and continuing toward the equator, however it is unlikely that under saturation will be a huge problem in tropical waters (Feely, 2004).

Currently the photic zone is absorbing the greatest amount of CO2. Most of the life in the ocean lives in the photic zone, and this is where the greatest change in pH will occur causing these creatures lives to alter drastically unless mitigation occurs. However, it is possible that the biota living in the lower parts of the ocean will be more sensitive to change (Caldeira, 2003).

Alaska Waters

The Gulf of Alaska and Bering Sea have an average pH of 8.05 (Sigler et al., 2008). These waters are more acidic than the 8.1 pH average of the world's oceans (http://www.akmarine.org/our-work/address-climate-change/ocean-acidification). The data shows that in both areas the waters are slightly alkaline, but the pH scale being logarithmic the difference of 0.05 is a noticeable difference.

The Alaska waters are also colder than average, because they are so far north. The average temperature of Icy Straight, southeastern Alaska surface water is 6.5–13.5°Celsius while the average temperature of the ocean is between 5 and 20°Celsius (Garrison, 1999; Park et al., 2004).

Owing to the fact that Alaska waters are more acidic and colder, they will absorb more CO2 from the atmosphere to begin with, and will be affected by ocean acidification sooner than other areas.

In Alaska, our waters are thriving with organisms that need CaCO3. We have cold-water coral reefs, a large king crab (Paralithodes camtschaticus) fishery in Alaska, and a large Dungeness crab (Cancer magister) population that provides large amounts of commercial and subsistence food for Alaskans in Southeast. Echinoderms, shellfish, and crustaceans living throughout all Alaska provide important commercial and subsistence fisheries and they need CaCO3 to make their skeletons.

Meroplankton Biology

Meroplankton are organisms that live part of their lives as plankton and the other as an adult life form. Echinoderms, crustaceans, barnacles, and shellfish all have meroplanktonic larvae. They all use CaCO3 (calcium carbonate) to form their shell/exoskeleton in their adult life form. All of these species are being affected by ocean acidification due to increasing amounts of carbon dioxide in the ocean. These species are all very susceptible because if there is not a high enough concentration of CaCO3 they will not be able to create an exoskeleton and will most likely not be able to survive. Another problem they face is that when the exoskeletons of calcite or aragonite organisms are combined with magnesium, it makes the dissolving of their shells more rapid in acidified oceans.

Meroplankton (including decapod larvae) makes up as much as 50% of the total zooplankton population and as much 40% of the total biomass of zooplankton in Auke Bay, Alaska in the spring bloom. Barnacle nauplii and bivalve larvae were the most abundant, both of which are calcareous. The decapod larvae made up about half the biomass of meroplankton in Auke Bay (Coyle and Paul, 1990).

Calcareous meroplankton affect the whole ecosystem because they are distributed throughout the area and are a food source for many different species and trophic levels. Pink and chum salmon eat decapod and mollusk larvae, herring feed on bivalve and barnacle larvae, sea otters eat adult forms of echinoids (sea urchins), and crustaceans and shellfish both eat calcareous plankton. If the prey species population decline, sea otter populations will most likely subsequently drop, along with most salmon species that represent a large portion of the Alaskan economy. If salmon are not able to find an alternative food source the consequences could be disastrous for the economy of Alaska.

Barnacles are odd arthropods because they are fixed to a rocky surface in their adult life form. The adult has six to eight calcareous plates which is their cover and has two plates that move on the top so the cirri can come out to obtain food. Barnacles don't release their gametes into the water like other organisms because they are hermaphroditic and fertilize one another. One adult can release 10,000 larvae (Davey, 2000). Nauplii, which are crustaceans, are released into the water and molts several times before reaching the cyprid larvae stage then settles on its permanent home using their cement glands to attach themselves. Barnacles are reliant on CaCO3 to protect themselves and survive.

King crab females carry thousands of eggs underneath their tail flap for about a year time and when they hatch they become larvae (meroplankton). They feed on plankton for several months, and molting many times, change their body forms until they sink to the bottom and become the non-swimmers that look like crabs but at this point are smaller than a dime. Crabs must molt their shells in order to grow and females must molt their shells in order to mate. King crab eat a range of food dependent on species, size, and the depth they live at; prey include: worms, clams, mussels, snails brittle stars, sea stars, sea urchins, sand dollars, barnacles, other crabs, other crustaceans, fish parts, sponges, and algae (Blau, 1997). Not only will king crabs be directly affected by an increasingly acidified ocean, but also indirectly because their main prey also have calcium carbonate shells. If they don't have enough calcium carbonate they won't molt properly due to the low concentration. This will affect the growing process and mating process since females have to molt in order to mate. Some of the organisms that eat king crab are: pacific cod, sculpins, halibut, octopuses, other king crabs, sea otters, and some nemertean worms have been found with king crab embryos in their stomachs. These organisms will be affected indirectly because, if they can not find an alternative food supply they may starve. This is vital to Alaska as king crab is the second largest fishery in Alaska, second only to the sockeye salmon fishery.

Dungeness crab have similar characteristics with the king crab. The number of eggs the female produces is directly correlated to the size of the female. Before the eggs are hatched they are carried in the female's shell for seven to ten months (Rogers et al., 1980). A juvenile crab can molt six times in the first year, this causes rapid growth. If they can't molt they won't grow and develop correctly. Femails reach sexual maturity before males. Females mature in two years, while males mature in three years. Like king crabs the female has to molt and have the sperm transfer before the shell hardens again. Dungeness crab frequently eat crustaceans, clams and polycheates. The Dungeness crab fishery is one of the oldest in Alaska. It would be detrimental to commercial fishing in Alaska if Dungeness crab populations decline.

Echinoderms also have a meroplanktonic larvae stage and have a calcium carbonate (CaCO3) endoskeleton. The endoskeletons are made up of ossicles (bony plates), some are rigid and locked together and have no room to move, like sea urchins; some are flexible and have gaps in the structure, like sea stars; and sea cucumbers only have remnant ossicles. The spines on an echinoderm are the endoskeleton covered by the epidermis. Echinoderms make these skeletons by extracting calcium and bicarbonate ions from the water and then incorporating them in their body. The echinoderms go through many stages on their way to becoming an adult; they are bilaterally symmetrical until they become an adult when they change to radial symmetry. Male and female reproductive systems are in separate individuals. Sea cucumbers remain planktonic for two to four months. All organisms with shells or skeletons made with calcium carbonate are going to be at risk. They are not going to develop correctly, they won't be able to grow, and some won't be able to mate unless the calcium compensation depth is held and doesn't continue to rise.

Indirect Effects

Two of the species that may be seriously affected indirectly by ocean acidification are humpback whales (Megaptera novaeangliae) and sea otters (Enhydra lutris).

Humpback whales are an endangered species and it is estimated that there are only about 30,000 in the entire world. They can live up to 95 years, reach 35–48 feet and can weigh up to 65 tons with the females usually being larger. Humpback whales live in pods and are migratory, breeding in tropical areas and then migrating to feed in the polar region. Humpbacks are generalized feeders; they eat what are in big groups or schools, such as surface plankton and schools of fish. They like to feed on zooplankton, especially krill, and smaller fish like herring. Humpback whales are found in all oceans, and seen in coastal and shelf waters. Humpbacks reach the age of reproductive maturity around 4–5 years. The gestation period is 11 to 11.5 months and the embryo grows 17–35 cm per month. Females usually only have one ovulation period a breeding season. They usually get pregnant twice every three years. When the calf is born it is 4–5 meters long and nurse for the first five months. Currently humpback whales are listed by the Endangered Species Act and are protected in most of the world's oceans.

Sea otters are a very important species in the food web. They exert a lot of direct and indirect effects on coastal ecosystems. They play a major role in communities by controlling where herbivorous invertebrates inhabit. An example is sea urchins and kelp forests; where there are no sea otters there are usually an abundant amount of sea urchins and no kelp forest because sea urchins graze on kelp. Where otters are present, the limited abundance of sea urchins help promote kelp forests, which in turn reduce the amount of CO2 in the water.

Sea otters are one of the few marine mammals to use tools to break open their food like clams and crabs. They need to eat 20–25% of their body weight a day (Gunderson, 2002). Sexual maturity is reached in four to five years and pregnancies last 4–12 months. This wide variation of time is due to delayed implantation.

Sea otters are distributed from Baja, Californis to Alaska to the eastern part of Kamchatka, and even around Japan. Sea otters can reproduce year-round but the numbers of births peak in May–June in the Aleutian Islands. Females usually give birth once a year unless they lose a pup, then they will go into estrus sooner. The life span of a sea otter is approximately 23 years.

Sea otters will eat anything they can find in their habitats, which are usually kelp forests. Their diet is comprised of invertebrate herbivores and filter feeders such as mussels, sea urchins, snails, and bivalves. They are also known to eat crab, squid, octopus, sea stars and fish. All of these prey species will be directly or indirectly affected by increasing ocean acidity. Every otter tends to be different in their choice of prey. Known predators include: great white sharks, orcas, sea lions, bald eagles, and humans.

Many other indirect affects on other animals and ecosystems could yet be seen.

Economy

The resources harvested from Alaska marine ecosystems are vital to the supply of seafood to the world, as well as the state's economy. According to an Alaska Job Service survey, 38% of all America's commercial fishing income is derived from Alaska. In 2000, the total catch of tradable fish and shellfish amounted to 2.1 million metric tons (4.5 billion pounds) and brought a total of $2 billion in economic activity to the state of Alaska (Alaska Department Of Fish And Game Season Evaluation). Alaska exports contributed $1 billion to United States Balance of Trade. A total of $956,650,686 was reported by the Alaska Commercial Fisheries Entry Commission in year 2000 and 41% of that went to Alaska residents. Along with significant profit to the state through tax revenue and general economic stimulus, the fishing industry offers many jobs to state residents. An Alaska Job Service survey reported a total of 65,000 jobs associated with either fish processing or work aboard fishing vessels. Also, 105 seafood processing sites operating in Alaska.

Southeast Alaska (SEA) has a significant role in commercial fishing. In 1994, Southeast Alaska's economy consisted of 2.7% mining, 26.2% wood products, 30.8% tourism and 40.2% seafood catching, exporting and processing (Hartman, 2000). Also in 1994 the Southeast fishing industry contributed $223.6 million to personal income and $114.56 million went directly to commercial fishers and processers (Hartman, 2000). Chief exports of SEA fisheries are salmon, crab, shrimp, bottom fish, and finally urchins and sea cucumbers, respectively. In 2000–2004 the SEA fishing industry brought in approximately 157 million salmon (about 742 million pounds) (Woodby, 2005). The average yearly income of the 2000–2004 harvest period was in excess of $230 million in salmon alone. The grand total of noted species in 2000 is 6,938,000 pounds with a value of $16 million. In contrast the 2005 season harvest was 12,070,000 pounds worth $22,460,000 million. This shows significant growth monetarily and poundage of seafood harvested (see tables one and two for specifics).

All of these species are either meroplanktonic or are indirectly affected by a decrease in population of meroplanktonic organisms, and therefore the effects of ocean acidification will be a vital factor in their survival. If they can not survive it will have detrimental effects on Alaska's economy. With many small communities in SEA being dependent on the well-being of the fishing industry, if it fails many of the residents may be forced to move and find new work elsewhere.

Mitigation

Although many technologies and ideas exist that could potentially slow the absorption of carbon dioxide in to the ocean, currently, no single approach could be implemented that would successfully mitigate the huge amounts of carbon that are constantly being released from anthropogenic sources. However, if different strategies were to be applied, their combined effect could possibly slow or even halt the effects of Ooean acidification.

Carbon Capture and Storage

One of the most promising technologies that could significantly affect the net amount of CO2 being emitted into the atmosphere is carbon capture and storage (CCS). CCS is an idea, which promises to capture and store CO2 from large stationary emitters of carbon such as power plants powered by fossil fuels.

Carbon capture and storage built into a modern conventional power plant would most likely reduce CO2 emissions by approximately 80–90% compared to a plant without CCS. However, capturing and compressing the carbon is a very energy intensive process and would increase the fuel use of a coal-fired plant with CCS by 25–40%, this and other system costs are estimated to increase the energy costs from a power plant with CCS by 21–91% (Metz et al., 2005). If CCS were successfully implemented, captured CO2 would then have to be transported either by pipeline, boat or truck to geological sites such as saline formations, coal seams that cannot be mined, basalt formations, or oil fields.

Deep saline formations have shown large potential for storing significant amounts of CO2. These common geological features are layers of porous rock that contain minerals that could react with the CO2 to form solid carbonates, some estimates have shown that enough of these features exist to potentially store up to 12,200 billion metric tons of CO2 (http://www.netl.doe.gov/technologies/carbon_seq/core_rd/storage.html).

Coal seams that cannot be mined are another option for long term CO2 storage. These seams are either too deep or too thin to be mined economically. Also, all coal has varying amounts of methane adsorbed onto pore surfaces, and wells can be drilled into coal beds that cannot be mined to recover this coal bed methane (CBM). Initial CBM recovery methods, dewatering and depressurization, leave a fair amount of CBM in the reservoir. Additional CBM recovery can be achieved by sweeping the coal bed with nitrogen. Carbon dioxide offers an alternative to nitrogen. It preferentially adsorbs onto the surface of the coal, releasing the methane. Depending on the coal, three to thirteen molecules of CO2 are adsorbed for each molecule of methane released, thereby providing an excellent storage site for CO2 along with the additional benefit of enhanced coal bed methane recovery. The recovered methane could be sold to help offset the cost of the sequestration. More than 180 billion metric tons of CO2 sequestration potential have been identified in existing coal seams that can't be mined, distributed over 24 states and 3 Canadian provinces (http://www.netl.doe.gov/technologies/carbon_seq/core_rd/storage.html).

Another possible storage possibility exists in basalt formations, geologic formations of solidified lava. Basalt formations have a unique chemical makeup that could potentially convert all of the injected CO2 to a solid mineral form, thus permanently isolating it from the atmosphere. Research is focused on enhancing and utilizing the mineralization reactions and increasing CO2 flow within a basalt formation. Although oil- and gas-rich organic shales and basalts research is in its infancy, these formations may, in the future, prove to be optimal storage sites for CO2 emissions (http://www.netl.doe.gov/technologies/carbon_seq/core_rd/storage.html).

Another possible storage medium resides in oil and gas fields, these formations have held crude oil and natural gas over geologic time frames. Usually, they are a layer of porous rock with a layer of non-porous rock above such that the non-porous layer forms a dome. It is the dome shape that trapped the hydrocarbons. This same dome offers great potential to trap CO2 and makes these formations excellent sequestration opportunities. As an added benefit, CO2 injected into a mature oil reservoir can enable incremental oil to be recovered. When injected into depleted oil bearing formation, the CO2 dissolves in the trapped oil and reduces its viscosity. This "frees" more of the oil by improving its ability to move through the pores in the rock and flow with a pressure differential toward a recovery well. Typically, primary oil recovery and secondary recovery via a water flood produce 30–40% of a reservoir's original oil in place. A CO2 flood enables recovery of an additional 10–15% of the original oil in place. Research has shown that more than 88 billion metric tons of geologic storage potential exists in 9,667 oil and gas reservoirs distributed over 27 states and 3 Canadian provinces (http://www.netl.doe.gov/technologies/carbon_seq/core_rd/storage.html).

Although many problems must be solved before CCS can be widely implemented, the IPCC estimates that it could potentially account for 10–55% of the total carbon mitigation effort until year 2100 (Metz et al., 2005).

Iron Fertilization

Another possible strategy in sequestering large amounts of carbon is iron fertilization. Throughout the ocean, about one third of surface phytoplankton growth is limited by the amount of dissolved iron in the area (Alfred Wegener Institute, 2008). This concept takes advantage of this fact by intentionally adding iron to areas with abundant nutrients and lack of iron thus triggering phytoplankton blooms. Plankton that generate calcium or silica carbonate skeletons such as diatoms and coccolithophores absorb carbon in the creation of their skeleton and later sink through the thermocline at a rate of about 75 feet per day (Markels, 2001). The sinking biomass is trapped in the cold, dense waters where it is eaten by animal life and bacteria, which slowly converts the biomass back to carbon in the deep waters. Where high concentrations of biomass are generated and reach the ocean floor undisturbed, they can be covered in mud and debris, which could sequester the carbon for centuries and possibly thousands of years.

Biological Sequestration

Biological sequestration of CO2 in forests and soils could possibly remove 350 billion tons of CO2 cumulatively up to 2050 (Schellnhuber, 2006). Land availability is very important for sequestering carbon by forestation and need for land and water for agriculture may restrict potential.

Conservation of Resources and Renewable Energy

Along with the efforts to remove carbon from the atmosphere, more investment must be put into using renewable energy, along with finding ways to use fossil fuels more efficiently.

At current levels of efficiency and cost, wind and solar power could replace some fossil fuel based electricity production. As application of these technologies increase the price would go down, allowing for even greater use. Currently wind and solar energy account for less than 2% of world electricity production (http://unfccc.int/essential_background/feeling_the_heat/items/2908.php). Studies have shown that there is enough wind power worldwide to satisfy global demand seven times over, even if only 20% of the wind power could be captured (http://news-service.stanford.edu/news/2005/may25/wind-052505.html). Also, expanding the use of hydro-electric power generation, at sites which the ecosystem would be minimally affected could also make a major contribution in reducing the use of fossil fuels for electricity production. Currently, hydroelectric plants account for 723 gigawatts of electricity, the theoretical potential is 2,800 gigawatts, however, this figure will most likely never be attained due to environmental and economic constraints (http://www.erg.com.np/hydropower_global.php).

If carbon related emissions in the transportation industry are to be decreased, the widespread use of renewable fuels such as bio-diesel and ethanol must be implemented. In the short term, vehicles need to be designed smaller and lighter, and possibly with hybrid power trains for maximum efficiency. Also, cleaner burning fossil fuels such as natural gas are a better alternative to petroleum based gas and diesel.

Conclusion

It is now apparent due to the predicted effects of ocean acidification on the marine ecosystems of Alaska that some combination of mitigation strategies must be put into effect as soon as possible in order to avoid the decline of the currently sustainable seafood industry in Alaska. The most practical and promising of theses strategies would perhaps be carbon capture and storage due to the huge potential mitigation effect it could have if widely implemented. Steps should be taken to apply it as soon as possible so it can be scaled up to make observable changes in net carbon output.

We feel that research on all organisms in Alaska and the effect ocean acidification is having on them would not be economically feasible. It would be useful if the Alaska Department of Fish and Game made it a priority to continue monitoring and devote further studies to finding the effects of ocean acidification on the species of the lower levels of the trophic web, especially those dependent on CaCO3. It would also be important to do same for the commercially viable species of Alaska that a tremendous population of residents depends upon for either a subsistence source of food or a source of income. If a decline in these populations is seen it would be necessary to draw on the Alaska State Constitution which states that it must do anything in it's power to maintain sustainable levels of natural resources. Legislation could be passed to require companies and possibly individuals to comply with mitigation/conservation efforts in order to prevent harm to the ecosystems that support these natural resources. This could also be brought to the federal level if it is proven that ocean acidification is harming any endangered species that reside here in Alaska. In any case, the U.S. government should pass legislation that gives incentives to companies and individuals who comply with yet to be determined regulations on carbon emissions. This could prove very efficient in decreasing our carbon emissions, which is necessary in the long term sustainability of human life on this planet as we know it. It is also necessary that the entire world reduces its carbon emissions because it is a world wide problem. Hopefully as a country and as a world we will start to see the destructive path that we have set ourselves on and move into a new era of environmental consciousness where everyone works together to save energy, reduce waste, and think about their actions and their subsequent effects on the environment.

Tables and Figures

Fishery

Catch (pounds)

Value (dollars)

King Crab

500,000

2,000,000

Tanner/Snow Crab

170,000

3,830,000

Dungeness Crab

228,000

3,900,000

Shrimp

1,670,000

1,960,000

Sea Cucumber

1,570,000

3,160,000

Sea Urchin

2,670,000

1,120,000

Geoduck

200,000

320,000

Total

6,938,000

16,000,000

Table 1.Southeast Alaska Fisheries Catch and Value 2000 (ADFG, 2008)


Fishery

Catch  (pounds)

Value (dollars)

King Crab

770,000

3,420,000

Tanner / Snow Crab

800,000

1,840,000

Dungeness Crab

4,210,000

5,140,000

Shrimp

2,420,000

5,600,000

Sea Cucumber

1,370,000

2,980,000

Sea Urchin

1,800,000

500,000

Geoduck

700,000

2,980,000

Total

12,070,000

22,460,000

Table 2.Southeast Alaska Fisheries Catch and Value 2005 (ADFG, 2008)


carbon dioxide variations over the years

Figure 1.Shows pre-industrial atmospheric carbon dioxide levels and blowup of recent, unprecedently fast rise in these levels (http://www.globalwarmingart.com/wiki/Carbon_Dioxide_Gallery).


References