Atlantic Ocean Grows, the Pacific Ocean Shrinks
Today’s oceans are relatively young geologic formations which are always changing their physical dimensions and size. Radiocarbon scans of submerged stone beds discovered that almost all sea floor is less than 180 million years old. While new oceanic bedrock is formed along oceanic ridges, it’s simultaneously crushed in subduction zones and remitted into magma.
Scans have also shown that planetary tectonic plates are moving, and fifteen major tectonic plates (as well as forty-one smaller ones) fit together like a temporary jigsaw puzzle. Sliding onto a molten layer beneath the lithosphere, both the oceanic and continental plates collide with one another continually.
Since the Atlantic Ocean grows, the Pacific Ocean shrinks. Within a few hundred million years, the surface of the planet will look considerably different than it does today. This oceanic geological sequence has been repeating itself for at least 3 billion years, and scientists predict it will keep doing so until the inside of the planet warms into a solid mass.
Other physical changes have happened to the oceans within a shorter period. Sediment and organic debris have accumulated and added layers to ocean and sea bottoms. In some places, this amounts to 15,000 feet (4,572 meters) of deposits, as in the Mediterranean Sea. The World Ocean has steadily worn away at the continental upland, carrying rock, sand, and minerals into the water.
As the polar ice caps have grown and shrunk according to shifts in surface temperatures, ocean water levels have fluctuated. During the Earth’s ice ages, the oceans became smaller, revealing features like the Siberian Land Bridge between Russia and North America.
Global warming historically has meant a decrease in polar ice and widespread flooding across lowland regions, leaving places like the Florida peninsula underwater for tens of thousands of years.
More recent changes like human-induced global warming have become threats to the current stability in the international ocean environment. Two of the biggest changes which are impacting the oceans today are melting polar ice from higher air temperatures and ocean acidification from an excessive amount of carbon dioxide pollution; both have been directly correlated with the significant increase in greenhouse gas emissions since 1850.
In 2007, the International Panel on Climate Change reported that the temperature increases could melt the whole northern ice cap in the Arctic Sea by the summer of 2040, and winter ice depth may shrink drastically. The panel also concluded that by the year 2100, carbon dioxide emissions likely will lead to ocean pH levels to decrease by up to 0.5 pH units the lowest they have been in the last 20 million years threatening tens of thousands of marine organisms such as corals, crabs, and oysters, which rely on available calcium to form shells or exoskeletons.
Scientists theorise that rising temperatures may cause oceans to expand away from the equator and toward the poles. Most of the expansion will take place in the North Atlantic Ocean, near the North Pole. Because the poles are closer to the Earth’s
Rescuers use a crane, fitted with giant slings, in an attempt to transport this long-finned pilot whale (Luciocephalid melas) back out to sea from Hamelin Bay, which lies south of the city of Perth, Australia.
This whale and ten others survived a mass beaching on Australia’s west coast that claimed ninety-nine long-finned pilot whales and ten bottlenose dolphins (Tursiops truncates).
The reason behind this 2003 and other similar events isn’t known, even though some scientists suggest a widespread bacterial infection or excessive underwater sonar use by military operations as possible causes axis of rotation, having more mass in these locations could accelerate the planet’s rotation.
Scientists theorise that at least 1 million species that inhabit ocean waters will continue to change in population as they either adapt or fail to adjust to a complex set of pressures like weather fluctuations, food shortages, chemistry changes, and temperature elevations.
Protecting the Ocean Environment
Governments, nongovernmental organisations and global groups are making a concerted effort to protect the world’s oceans. A “World Ocean Day” was proposed by Canada at the United Nations Earth Summit in Rio de Janeiro in 1992 to coordinate educational and advocacy events on a global scale.
In 2005, Ocean the largest international organisation focused solely on ocean conservation reached agreements with commercial and recreational fishermen, federal fishing management council members. Them and the U.S. National Oceanic and Atmospheric Administration (NOAA)’s National Marine Fisheries Service staff to protect deep-sea coral and sponge communities in North America from destructive trawling and dredging fishing gear.
In November 2008, Healthy Reefs for Healthy People, an international, multi-institutional effort tracking the health of the Mesoamerican Barrier Reef, released an Eco-Health Report Card for the reef its first complete health assessment. The beach stretches from the northeast tip of Mexico’s Yucatán Peninsula into Amatique Bay, Guatemala, Which Makes It the second-largest coral reef system in the world after the Great Barrier Reef in Australia. The Eco-Health Report Card found that over development in several communities had caused nearly 48 percent of the reef system to be in poor condition and 6 per cent of the system to maintain a critical condition where species loss is imminent.
In 2009, the National Marine Fisheries Service staged federal regulations that prohibited large scale fishing for krill in U.S. Pacific waters to be able to avoid a devastating gap in the food chain through overfishing. Also in 2009, the United Nations General Assembly, after seventeen years of casual yearly parties, designated June 8 as World Oceans Day.
A weekend earlier that day’s first official observance, the governors of the states of Delaware, Maryland, New Jersey, New York, and Virginia signed an agreement committing the countries to a concerted effort to protect the sea waters of the mid-Atlantic.
Around the world, such organisations and groups are working independently and collectively to protect corals, stop illegal oil dumping, halt destructive trawling, save endangered species like sea turtles and whales, and advocate for improved management and protection of the sea for its long term health.
In 1950, there were a dozen sparkling ocean research facilities, virtually all of which were associated with government agencies or universities. By 2009, the number of investigation services had increased to thirty-two large centres spread across Africa, the Americas, Antarctica, Asia, and Europe.
Their accomplishments include studying the ocean’s influence and ocean phenomena, mapping ocean bottoms, analysing water, inventorying thousands of species, and learning the essentials of this massive environmental biome.
Scientists and educators have shared this information with the government and public officials, leading to new policies and laws meant to protect oceans and their biota.
Even though the global community has protected up to 12 percent of combined upland (forests, fields, wetlands, and mountains) from development, it has not done the same for ocean territory. Less than 1 percent of worldwide saltwater habitats are designated as protected.
The end of the twentieth century and the start of the twenty-first century have seen a push to set aside larger regions of the world’s oceans as preserves, where human development might be heavily regulated or even entirely banned.
Two outstanding examples of efforts to create and manage marine preserves include those in the Caribbean and the USA. The preservation area, which spans 6.8 miles (11 kilometres) of coastline was carved into zones with five distinct levels of protection.
The USA took a bold step in 2006 when it created a Pacific Ocean sanctuary known as the Papahanaumokuakea Marine National Monument that spans 131,250 square miles (339,938 sq km) of ocean waters, islands, and atolls in the Hawaiian Islands.
This area featured stronger federal protections to boost conservation efforts for its endangered monk seals, nesting green sea turtles, and some 7,000-other species. All recreational fishing is banned within the monument, and, by 2011, all commercial fisheries in the region will end, marking a five-year phase-out period.
Although numerous scientific studies are conducted to catalogue up to 215,000 species from the oceans over the last 200 years, no new inventory was undertaken until 2000.
The project plans to describe and catalogue up to 14 million species, including those that may be extinct but can be sampled from bottom debris. In its first couple of years, the census added some 5,600-new species while completing fourteen field projects to assess major habitat areas.
The initial reports of seventeen projects spanning six ocean locations will be published in late 2010.
Nearly all international electricity comes from five sources: coal, hydropower, nuclear fission, oil, and wood. Almost all rely on land-based sources and generate much pollution or otherwise affect the environment. The oceans, however, provide a promising resource for considerable renewable energy with far.
The Seagen tidal power generator is shown here with its turbine blades from the water at the narrows of Strangford Lough in Northern Ireland. Marine Current Turbines, the company that created the alternative-energy power plant, eventually hopes to attain significant commercial production.
This 209-megawatt facility comprises ninety-one turbines and generates enough power to support 200,000 homes.
The Wind provides almost 20 percent of the nation’s power. In 2009, the Danish government began a project to grow this system by 50 percent by 2025 to reach a target of providing 70 percent of the country’s power through wind.
Oceans also offer sources aside from the wind for power. The Rance Estuary in northern France has harnessed tidal flow since 1966, giving a daily average of 68 megawatts of power through a set of hydro-turbines. This system currently provides less than one percent of France’s power.
The SeaGen turbine in Strangford Lough in Northern Ireland was constructed in a North Sea location that has a lot of narrow channels between open water and fast-moving currents that exceed 13.1 feet per second (4 meters per second).
In 2000, new technology utilising wave energy was put to use on the island of Islay, off Scotland’s western coast. Each Islay turbine looks like a large floating buoy. The centre rides up and down on the passing waves, and the motion causes air pressure to turn a turbine, which generates electricity.
The first large-scale business project using this technology, the Agucadoura Wave Farm, was constructed in 2006; it is situated in the Atlantic Ocean, 3 miles (5 kilometres) off the shore of northern Portugal near the city of Povoa de Varzim. Three energy converters can generate 2.2 megawatts of power. A total of thirty-one converters is planned to be installed in the region in 2010.
The Future of Ocean Resource Management
The collapse of an ocean fishery has occurred many times around the world since the 1980s. It begins with reduced catch levels. Regions or countries often end up in conflict over dwindling fish stocks. A system of quotas might be agreed upon by industry or government leaders to manage the population better.
At times the quota system is imposed too late, and because reproductive pools already are too small, fish stocks barely improve or continue to shrink in population. Occasionally, the community challenge of one species (like Atlantic striped bass, Morone saxatilis, in the North Atlantic) is associated with the overfishing of another species (like Atlantic herring, Clupea harengus) in precisely the same area.
Because of this, governments have turned to other techniques of managing their ocean resources, including strict fish lengths and quotas, closing waters, buying out fishing fleets, financially supporting the aquaculture (aquafarming) industry, and passing other laws to protect entire ecological regions.
Catch Limits and Fishing Closures
Ocean managers and government officials have learned that nothing is as beneficial as restricting catch amounts or stringent fishing closures to help ecosystems naturally repopulate. This perspective has been applied to multiple places, including waters between Canada and the United States in the North Atlantic (for cod) in 1992, waters between New Zealand and Australia (for orange roughy) in 2007, and in European Union waters (for bluefin tuna) in 2007.
Sadly, the effects of a sudden closure can be devastating economically. The fishing fleets may have the ability to modify their gear and pursue unique species, but often, they are just forced out of business.
Government subsidies of fishing fleets have helped them through difficult financial times, but these grants also have been shown to contribute to bloated fishing fleets and exploitive fishing practices. A 2009 study of the U.S. fisheries, Quantification of U.S. Marine Fisheries Subsidies, found that annual subsidies exceeded $713 million and could be worth as much as a fifth of the value of the fish caught.
The analysis also concluded that some 56 percent of subsidies to fishers lead to overfishing, by lowering overhead costs like fuel prices (by eliminating federal and state taxes). The western United States received particular attention in the report, since the region catches only 2 percent of the total U.S. catch, but receives up to 23 percent of the total subsidies.
Governments sometimes initiate Buyouts as an incentive to switch the business. One buyout included $46 million to purchase ninety-two of the 260 ground-fishing boats in the northern Pacific, from the states of Alaska and Washington, to protect flounder, snapper, and whiting stocks.
Saltwater organisms (such as fish, molluscs, crustaceans, and aquatic plants), a practice called aquaculture, is performed in the major coastal pens, indoor pools, or outdoor ponds. Throughout the last half century, the industry has grown as a whole, especially in the total amount of fish that’s farmed due to reduced fishing in the open oceans.
Tons of farmed fish were provided globally; since 1985, the industry has grown steadily by nearly 9 percent annually. As of 2010, aquaculture accounted for approximately a third of the whole fish harvest.
Without its challenges, including complex water quality and disease management difficulties. By way of instance, farmed salmon meat often loses the bright pink colour typical of wild salmon.
The Marine Stewardship Council, a non-profit organisation, created in London, England, in 1997, was formed “to safeguard the world’s seafood supply by promoting the best environmental option.”
Each certified location has to undergo an intricate review (every one or two years), proving that fish are being removed at a rate that’s sustainable. One example, in the stormy These mackerel, grows in three years to their maximum size of about ten inches (25 centimetres) long.
(The government changes this number each year, raising it to as large as 2,980 tons in 2002 or dropping it to as low as 42 tons in 2006.) Each area certified by the council is re-inspected at least annually to be certain it’s in compliance with agreed-upon management targets and catch limits.
Treaties and Laws
The overarching international Treaty which offers a structure of law and procedures for oceans is the United Nations Convention on the Law of the Sea (UNCLOS, also referred to as the Law of the Sea Convention or the Law of the Sea Treaty). The first convention laid out a sovereign territory that extended up to 12 miles (19 kilometres) off the coast of any ocean-bordering nation.
In 1958, the United Nations also Created a Convention on the High Seas, a global treaty designed to codify the rules of world law and speech sea procedures outside territorial waters. High seas (defined as water bodies out of any territorial or jurisdictional claim) were open to all countries for navigation, fishing, and economic development efforts like laying cables or drilling for oil.
Due to competition among nations since the mid-twentieth century, in 1982, the United Nations expanded the sovereign limit of jurisdiction to a 200-mile (322-kilometer) Exclusive Economic Zone.
This revision also established some standards to safeguard the marine environment, allowed scientific research throughout the world’s oceans, and addressed the dilemma of deep-water mineral drilling by producing a new International Seabed Authority to regulate such practices.
Although UNCLOS is a Wide-reaching treaty that brought business and standards into the worldwide community, it didn’t erase disputes between nations in particular areas. Even though some arguments centred over island possession, most were more than fishing grounds and worried the expansion of sovereign territory.
The 1950s and 1970s saw cod wars between Great Britain and Iceland. The 1980s brought tuna conflicts between France and Great Britain. In 1992, a dispute between Morocco and the European Union resulted in Morocco imposing fishing tariffs and limits on European fishing trawlers in that nation’s territorial waters.
Several European countries, citing actual ownership of parts of Morocco, felt that the government’s claim of a 200-mile (322-kilometer) exclusive economic zone was unjust. In 1995, a Canadian government boat seized a large Spanish trawler for illegally fishing in its coastal waters. As a consequence of such actions, many fishing fleets necessarily found themselves seeking their catch in deeper waters.
UNCLOS was amended in 1982 and Again in 1995 with a set of regulatory measures titled the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish. These successive modifications set new international standards to reduce both coastal and deep-sea catches.
Even though most countries have Imposed fishery management plans in their 200-mile (322-kilometer) economic Zones to safeguard stocks, unregulated deep-ocean fishing is not uncommon. Enforcement Is extremely tough, despite satellite imaging. These deep-water ocean harvests pose the next challenge for long-term fisheries conservation and the health of marine ecosystems.