Marine resources: ph ysical and biological resources, marine energy

IntroductionMarine resources are physical and biological entities that are found in seas and oceans that are beneficial to man. They include fish, coral reefs and crabs, fungi, etc. A lot of conservation effort is required to protect these resources from human destruction activities like pollution and over fishing. Marine natural resources include both biological and physical sources. Biological sources include anything attributed to life forms whereas physical sources are considered to be those things that are not part of life processes. In a few instances some resources are both biological and physical. In considering the outlook of our oceans it is important to first identify the main natural resources and their status.

Importance of marine resourcesThere are many marine resources like salt, seaweed, fish, etc. and the importance is that it would make life more comfortable. Each has its own importance but it remains for the same possible concept for your comfort in living. A marine protected area (MPA) is essentially a space in the ocean where human activities are more strictly regulated than the surrounding waters - similar to parks we have on land. These places are given special protections for natural or historic marine resources by local, state, territorial, native, regional, or national authorities. Authorities differ substantially from nation to nation. Marine conservation, also known as marine resources conservation, is the protection and preservation of ecosystems in oceans and seas. Marine conservation focuses on limiting human-caused damage to marine ecosystems, and on restoring damaged marine ecosystems. Marine conservation also focuses on preserving vulnerable marine species. The ocean is one of Earth's most valuable natural resources. It provides food in the form of fish and shellfish; about 200 billion pounds are caught each year. It's used for transportation; both travel and shipping. It provides a treasured source of recreation for humans. It is mined for minerals (salt, sand, gravel, and some manganese, copper, nickel, iron, and cobalt can be found in the deep sea) and drilled for crude oil. Marine Resources are living organisms that can be found in water such as lobster, fish, crab, and sponges.

There are many marine resources some of them are given below-

1 . Physical

  a.      Petroleum

b.      Sand and Gravel

c.      Evaporative salts

  d.      Fresh water

  e.      Methane hydrates

2.      Biological

3.      Energy

a.       Waves, currents, and tides

b.      Thermal gradient

Physical resources The oceans hold an enormous reservoirs of minerals. The oceans also hold reservoirs of fossil fuel or the potential for harnessing forces for energy development. For example:petroleum and natural gas, methane hydrate,sand and gravel,salts,manganese nodules,freshwater. Some of them given below-

Petroleum

Petroleum (L. petroleum, from Greek: πέτρα (rock) + Latin: oleum (oil) is a naturally occurring, yellow-to-black liquid found in geologic formations beneath the Earth's surface, which is commonly refined into various types of fuels. It consists of hydrocarbons of various molecular weights and other liquid organic compounds. The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and subjected to intense heat and pressure.

Petroleum is recovered mostly through oil drilling. This comes after the studies of structural geology (at the reservoir scale), sedimentary basin analysis, reservoir characterization (mainly in terms of the porosity and permeability of geologic reservoir structures).It is refined and separated, most easily by boiling point, into a large number of consumer products, from gasoline (petrol) and kerosene to asphalt and chemical reagents used to make plastics and pharmaceuticals. Petroleum is used in manufacturing a wide variety of materials, and it is estimated that the world consumes about 90 million barrels each day.

Manganese nodule

Polymetallic nodules, also called manganese nodules, are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. The core may be microscopically small and is sometimes completely transformed into manganese minerals by crystallization. When visible to the naked eye, it can be a small test (shell) of a microfossil (radiolarian or foraminifer), a phosphatized shark tooth, basalt debris or even fragments of earlier nodules.

Fig:Manganese nodule Fig:Nodules on the SeabedNodules vary in size from tiny particles visible only under a microscope to large pellets more than 20 centimetres (8 in) across. However, most nodules are between 5 and 10 cm (2 and 4 in) in diameter, about the size of potatoes. Their surface is generally smooth, sometimes rough, mammilated (knobby) or otherwise irregular. The bottom, buried in sediment, is generally rougher than the top

 Biological Resources

BenthosBenthos are bottom-dwelling organisms that generally live non-mobile lifestyles, though some mobile species such as crabs do exist. In the Bay Area, many benthic invertebrates live within sedimentary or soft-bottom habitats, usually within the top 2 to 3 centimeters of the soft sediment. Some benthic invertebrates also live on hard substrates, which are much less common in the Bay compared to sedimentary habitats.

Three major benthic species assemblages (groups of organisms that inhabit a location or locations at a certain time or over a period of time) are present in the Bay Area: fresh-brackish, estuarine, and marine assemblages. Fresh-brackish assemblages are found in the delta, with a transition assemblage extending into Suisun Bay. Estuarine assemblages are prevalent in San Pablo Bay. The Central Bay harbors marine assemblages. Assemblage characteristics, such as species composition and abundance, are affected by many physical factors, including salinity and sediment grain size, or by biological factors such as competition and predation. Changes in these factors can influence individual benthic species differently.

Many of the more common benthic species in San Francisco Bay today are accidentally or intentionally introduced species. Most of these non-native species were transported here in ballast water of ships or on the oyster shells brought from the east coast for commercial farming purposes in the late 19th century. Some of these non indigenous species serve ecological functions similar to those of the native species that they have displaced. Examples of these include the eastern oyster (Crassostrea virginica), the Japanese littleneck clam (Tapes philippinarum), and the soft-shelled clam (Mya arenaria), all of which have supported commercial or sport fisheries. However, other species, such as one of the so-called Asian clam species (Potamocorbula amurensis), have a negative effect on phytoplankton and zooplankton populations and organisms that depend on them. Though P. amurensis may serve as a food source for diving ducks and sturgeon, their high feeding rates can remove much of the

phytoplankton from the water column and may have an adverse effect on zooplankton and other organisms that in the food chain that feed on them.

Fish

More than 100 species of fish inhabit the San Francisco Bay system. The majority of species are native, but there are also many introduced species. A large portion complete all life stages within the Bay. A smaller portion, anadromous fish, migrate from ocean waters, through the estuary, and into a series of freshwater streams where they spawn. Common fish species found in the Bay are include northern anchovy, topsmelt (Atherinops affinis), jacksmelt, striped bass, white croaker (Genyonemus lineatus), Pacific herring, and English sole (Parophrys vetulus).

Fish population trends can be determined by analyzing the data resulting from the monitoring efforts of CDFG. An analysis of these data from a monitoring study between 1980 and 1995 suggests a general distribution of fishes in the Bay as follows

North Bay – Fish species typically found in the North Bay include sharks, rays, longfin smelt, staghorn sculpin, starry flounder, topsmelt, arrow goby (Clevelandia ios), yellowfin goby (Acanthogobius flavimanus), stickleback (Gasterosteus sp.), mosquitofish (Gambusia affinis), green sunfish (Lepomis cyanellus), Pacific herring, Chinook salmon (Oncorhynchus tshawytscha), and steelhead (Oncorhynchus mykiss).

Central Bay – Typical fish species occurring in the Central Bay include Chinook salmon, striped bass (Morone saxatillis), white croaker, Pacific herring, and northern anchovy.

Federally Managed Fish Species

Under the Magnuson-Stevens Fisheries Conservation and Management Act, the Pacific Fisheries Management Council (PFMC) is responsible for managing commercial fisheries resources along the coasts of Washington, Oregon, and California. Managed species are covered under three fisheries management plans:

Coastal Pelagic Fishery Management Plan (includes species such as sardines and anchovy)

Pacific Groundfish Fishery Management Plan (includes species groups such as flatfish and rockfish)

Pacific Salmon Fishery Management Plan (includes Chinook and other salmon)

Most of the federally managed species in these plans are not found in San Francisco Bay.

Birds

San Francisco Bay provides diverse habitat for many species of waterfowl and shorebirds. Open water, Bay flats, and tidal marsh are just some of these habitats.Roughly 120 species from 16 avian families occur in the Bay. Of these birds, approximately two-thirds are represented by three families: Anatidae (waterfowl), Laridae (gulls and terns), and Scolopacidae (sandpipers and phalaropes).

The Bay serves as an important staging and wintering ground on the Pacific Flyway for numerous species of water birds. The Pacific Flyway is a bird migration corridor along the Pacific Coast that stretches as far north as northern Canada and Alaska, and as far south as the southern tip of South America. In the Bay, the greatest water bird abundance and species diversity is seen in winter, as birds migrate along the flyway. Each year, nearly one million waterfowl and more than one million shorebirds pass through this area. No other site within the Pacific Flyway supported more than 16 to 32 percent of these species. Tidal Bay flats in particular offer important habitat and a migratory staging area for shorebirds.

The most predominant birds in the open Bay are diving ducks, including scaup, scoter, and canvasback.

Marine Mammals

The waters off California support an abundance and diversity of marine mammals, primarily because of the numerous upwelling centers that stimulate primary production, the central location between arctic and subtropical areas, and the diversity of habitats. Some species migrate through the area on their way to summer feeding or winter breeding areas; others reside in the area year-round. San Francisco Bay, like many estuaries, serves as a nursery for some species of marine mammals (e.g., harbor seals), provides protected waters for resting ashore and in the water (e.g., California sea lions and harbor seals), and is used as a foraging area (e.g., harbor seals and, occasionally, gray whales).

Several marine mammal species can be found in San Francisco Bay including the harbor seal (Phoca vitulina), California sea lion (Zalophus californianus), and more recently, the gray whale (Eschrichtius robustus).

Harbor seals are the most common and abundant marine mammal in the Bay and are the only marine mammals that are permanent residents in the Bay. All harbor seals use resting areas (called haul-out sites) that are free from frequent disturbance and near channels or open water. Habitats used as haul-out sites include tidal rocks, mudflats, sandbars, and sandy beaches.

Other marine mammal species that have been seen very rarely in the Bay include the humpback whale (Megaptera novaeangliae), harbor porpoise (Phocoena phocoena), northern elephant seal (Mirounga angustirostris), Steller sea lion (Eumetopius jubatus), northern fur seal (Callorhinus ursinus), and the southern sea otter (Enhydra lutris). The species occur frequently off the California coast and occasionally enter the Bay either mistakenly, or while searching for food.

Aquatic Plants

Substrate in much of the Bay consists of soft mud, making it difficult for many macroalgal species to colonize. Some types can initially attach to a hard substrate such as a small rock or piece of shell, and, as they become larger, move with the small attachment. Common Bay species include the green algae Enteromorpha clathrata, E. intestinalis, U. lactuca, and Cladophora sericea and the aquatic plant eelgrass (Zostera marina).

Eelgrass (Zostera marina)

Eelgrass is a native marine vascular plant indigenous to the soft-bottom bays and estuaries of the Northern Hemisphere. The species is found from middle Baja California and the Sea of Cortez to northern Alaska along the west coast of North America and is common in healthy shallow bays and estuaries. Eelgrass serves as a food source for a number of invertebrates, fish, and some migratory birds. It also provides habitat for many commercially and recreationally important finfish and shellfish species. Pacific herring regularly spawn on eelgrass leaves, and juvenile salmonid and smelt often spend extensive amounts of time within eelgrass habitats prior to heading for the open ocean.

Marine energy: Wind, waves and currents etc.

Potential of ocean energy

The theoretical potential is equivalent to 4-18 million ToE.Capacity

(GW)Annual gen.

(TW·h) Form

5,000 50,000 Marine current power20 2,000 Osmotic power

1,000 10,000 Ocean thermal energy90 800 Tidal energy

1,000—9,000 8,000—80,000 Wave energy

Indonesia as archipelagic country with three quarter of the area is ocean, has 49 GW recognized potential ocean energy and has 727 GW theoretical potential ocean energy.

Forms of ocean energy

RenewableThis section requires expansion.

The oceans represent a vast and largely untapped source of energy in the form of surface waves, fluid flow, salinity gradients, and thermal.

Marine current powerMain article: Marine current power

The energy obtained from ocean currents

Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity.

The operating principle behind tidal energy converters is that the energy contained within the moving current is harnessed by a device that extracts kinetic energy from the flow and imparts this into a mechanical motion of a rotor or foil. The device then converts the mechanical motion of the structure into electrical energy by means of a power take-off system. Before connection to the electricity grid, the electrical power output from the device will need to be conditioned in order to make it compliant with grid code regulations. In essence, tidal device operation is synonymous to that of a wind turbine, albeit operating within a different fluid medium.

Osmotic powerMain article: Salinity GradientAt the mouth of rivers where fresh water mixes with salt water, energy associated with the salinity gradient can be harnessed using pressure-retarded reverse osmosis process and associated conversion technologies. Another system is based on using freshwater upwelling through a turbine immersed in seawater, and one involving electrochemical reactions is also in development.

Ocean thermal energyMain article: Ocean thermal energy

The power from temperature differences at varying depths.

Tidal powerMain article: Tidal power

The energy from moving masses of water — a popular form of hydroelectric power generation. Tidal power generation comprises three main forms, namely: tidal stream power, tidal barrage power, and dynamic tidal power.

Wave powerMain article: Wave power

Wave energy forms as kinetic energy from the wind is transmitted to the upper surface of the ocean. The height and period of resulting waves will vary depending on the energy flux between the wind and the ocean surface. Much work has been carried out in the field of research and development of technology capable of harnessing energy from the waves. At present there is limited design consensus surrounding the design of wave energy technology, and there are several areas in which a wave energy converter can be placed in order to harness the energy most efficiently.

The wave energy sector is reaching a significant milestone in the development of the industry, with positive steps towards commercial viability being taken. The more advanced device developers are now progressing beyond single unit demonstration devices and are proceeding to array development and multi-megawatt projects.[7] The backing of major utility companies is

now manifesting itself through partnerships within the development process, unlocking further investment and, in some cases, international co-operation.

At a simplified level, wave energy technology can be located near-shore and offshore. Wave energy converters can also be designed for operation in specific water depth conditions: deep water, intermediate water or shallow water. The fundamental device design will be dependent on the location of the device and the intended resource characteristics.

Non-renewable

Petroleum and natural gas beneath the ocean floor are also sometimes considered a form of ocean energy. An ocean engineer directs all phases of discovering, extracting, and delivering offshore petroleum (via oil tankers and pipelines,) a complex and demanding task. Also centrally important is the development of new methods to protect marine wildlife and coastal regions anbgainst the undesirable side

Conclusion:Marine environment is rich in marine resources. These are utilized by man for many reasons .So we should have proper knowledge about them. This knowledge is necessary to establish an effective strategy for protection. Public education and appreciation for marine resources is needed for protection. An educated public understands how to interact in the environment to avoid damaging marine resources and will help to promote the main conservation messages.

References:

Accurso, L.M. 1992. Distribution and abundance of wintering waterfowl on San Francisco Bay, 1988-1990. Master's thesis, Humboldt State University, CA. May.

Berry, W., N. Rubenstein, B. Melzian, and B. Hill. 2003. The biological effects of suspended and bedded sediments (SABS) in aquatic systems: a review. Internal report to U.S. EPA, Office of Research and Development, National Health and Environmental Effects Laboratory, Narragansett, RI.

Boffa Miskell Partners. 1988. High Voltage Direct Current Inter-island Transmission System Expansion Environmental Impact Assessment.

Wyllie-Echeverria, S. and P.J. Rutten. 1989. Inventory of Eelgrass (Zostera marina L.) in San Francisco/San Pablo Bay. National Marine Fisheries Service Administrative Report SWR-89-05. October 1989.

Baxter, R., K. Hieb, S. DeLeon, K. Fleming, and J. Orsi. 1999. Report on the 1980-1995 fish, shrimp, and crab sampling in the San Francisco Estuary, California. California Department of Fish and Game Technical Report 63. Interagency Ecological Program for the Sacramento-San Joaquin Estuary.

Glover, A. G.; Smith, C. R. (2003). "The deep-sea floor ecosystem: current status and prospects of anthropogenic change by the year 2025.". Environmental Conservation 30 (3): 21–241.

Abramowski, T.; Stoyanova, V. (2012).

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Cronan, D. S. (1980). Underwater Minerals. London: Academic Press. Cronan, D. S. (2000). Handbook of Marine Mineral Deposits. Boca Raton: CRC Press.