Marine Science Chapters


Marine Natural Resources

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

Biological marine natural resources include food and chemicals, as well as the living organisms themselves - including the products they secrete.

Seafood Counter
Seafood Counter. (GA image)
Food resources from the ocean have been taken for centuries and include mainly fish, shellfish, and plants that are used for direct consumption. Many species have been overfished in recent years particularly starting about 1970. As popular seafood species have become harder to find their price has increased until it may not be economically feasible anymore. Many popular species have become delicacies now because of this or disappeared entirely from the market.

New fisheries have opened up as older ones have become depleted - only to follow the same path as they too become depleted. For example, as the abalone fishery crashed in California in the 1970s the sea urchin fishery opened up and many abalone fishermen simply switched their catch.

Mariculture (marine aquaculture) farms sometimes try to replace and/or restore a depleted fishery. For example, in California the abalone fishery crashed (probably due to natural causes as well as overfishing) in the 1970s. This made the abalone cost between $30 and $70 per pound. During the 1960s abalone meat was similar in price to hamburger. Currently the only market abalone are produced by mariculture farms because it is illegal to fish abalone commercially in California (and there is no take at all, even by sport fishermen, in California below San Francisco). See the next lesson on Abalone for more details. Similar things have happened with other species such as salmon (see the Salmon lesson in the Water Dwellers chapter).

Kelp CutterProducts made with chemicals from seaweeds
Kelp cutter in southern California (left). (Image, with permission, from Western Marine Lab) Products made with chemicals from seaweeds - algin, agar, and carrageenin (right). (GA image)
Chemicals from living marine resources include drugs, and additives. Many species of marine organisms produce chemicals that have use in the drug industry. Several sponge species recently have been found to produce a cancer fighting compound. There is continued research on marine organisms from all over the world in search of new chemicals to fight diseases. Three products (agar, algin, and carrageenin) have been extracted from seaweeds for many years and used in a variety of ways. Agar is primarily used by the medical field as this is the culture medium for bacteria. Algin is used as a thickener in foods as well as a stabilizer. Carrageenin is used in many milk products as well as beer, lunch meats, pet food and toothpaste.

Most of the world's algin used to come from California. This is where large kelp beds provide a natural source of the brown algae (a type of kelp) within which is found algin. This particular resource was harvested for over 40 years by a company (now based in Chile where there are large kelp beds). This company carefully monitors its take so that it will not deplete its resource - during its 40 years in California it has shown that it can do this without damage to the kelp beds. Recently small kelp cutters have been built to harvest kelp in California for some of the abalone mariculture farms (see lesson 6.4.2).

Aquarium in Morro Bay, California. (GA image)
Aquarium ShopShell Shop
Aquarium store in Goleta, The Ocean Floor, (left), no longer in business. Shell shop (right) in Morro Bay (one of the best on the coast, in the author's opinion). (GA images)
Living organisms themselves are one of our newest natural resources. This includes the use of live animals in natural settings for human enjoyment like aquariums as well as the selling of live marine species in aquarium stores. This resource also includes the products that marine organisms secrete such as shells and fur. It could also include the growing industry of ecotourism where trained people take groups out into nature to view the natural life forms. Whale watching is a type of ecotourism that has replaced whaling (the killing of whales for their oil, bones and meat) in most countries (see the Whaling lesson at the end of this section).

Many aquariums, aquarium stores and shell shops are sensitive to the environmental effects their trade produces. A number of the larger aquariums raise their own specimens (like the Monterey Bay Aquarium in California raises most of its own jellyfish for its jellyfish displays). They also take great pains to create a natural environment for their captive species so that they live a long life. Aquarium stores often augment their living organisms with species that are raised particularly for this purpose. Shell shops often purchase their shells only from countries and suppliers who certify that the shells were taken without the living organisms inside. This is helpful in the big picture of marine ecology but is not always possible. In aquariums, aquarium stores, and shell shops there is a large amount of education that goes on with most of the people who are their clients. This education is very important in helping the public understand the importance of the health of the oceans. So, sometimes the value of education can seem to offset some of the negative impacts related to the taking of the natural marine resources used in these pursuits.

Physical marine natural resources include products from the ocean as well as the ocean itself. A few of these could also be considered partially biological.

Salt taken from the deep ocean off the big island of Hawaii at the NELHA. (GA image)
Sand, gravel, and salt are physical products taken from the ocean. The sand and gravel mines are along the continental shelves in areas where these materials are present and not impacting cities. Salt is taken from seawater by several companies around the world. One example of salt extraction is now found in Hawaii at its Natural Energy Lab (see lesson 2.4.5).

Bottled Water from the Ocean
Bottle water (from desalination) is a product of the deep water brought up at NELHA. The image above shows the position of their deep-sea pipeline and an inset with some of the products that result from this - including bottled water for Japan. (GA image)
Ocean water itself is a natural resource and can be used to make freshwater, as a coolant or for the production of energy. Desalination plants around the world create drinkable freshwater from ocean water in areas where there are not sufficient supplies of freshwater. Ocean water is taken in by many power plants and used to cool parts of the plants. This ocean water does not leave the pipe, it just is pumped through hot areas of a power plant and the cool pipes keep the plant cool. The water leaves the plant pretty much unchanged except a few degrees higher. This is sometimes thought of as 'thermal pollution.' Finally a process is used to take cold, deep water and turn it into energy (OTEC). This process is currently operated at NELHA in Hawaii. [Note: At NELHA a company is bottling freshwater from the deep ocean water and creating a product that is highly valued in Japan because it is from the depths of the oceans.]

Oil Rig

Oil rig off the coast of Santa Barbara, California (left). (Image, with permission, from Western Marine Lab)

Oil and gas are resources that can be considered physical as well as biological. These resources are nonrenewable resources. This means that oil and gas are currently not being produced even close to the rate that they are being used. A renewable resource is one that can be used up at about the same rate that it can be replenished (such as cutting trees down but planting new ones). Oil and gas are 'fossil fuels' - that is they are products of the bodies of organisms that died millions of years ago but did not decompose. Instead the bodies were compressed by layers of sediment (mostly under the ocean) and they changed into the petroleum products we value so much nowadays - oil and gas. Currently there just are not any areas in the ocean that we know about where the bodies of dead organisms are piling up and not decomposing. The ocean basins millions of years ago where these layers developed did not support decomposition but this has changed today.

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(Revised 2 June 2009)
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