The importance of seas and oceans cannot be overstated. They play a crucial role in supporting various plants and animals, offering valuable resources and habitats. Furthermore, they are vital for the well-being and economies of nations. Unfortunately, human activities have had a significant negative impact on marine and coastal ecosystems.
Despite this, the planet greatly benefits from ocean resources, as they provide food through fish and shellfish. The annual catch of these marine species weighs approximately 200 billion pounds. Moreover, the ocean is indispensable for transportation purposes, serving both travel and shipping needs.
The ocean serves multiple purposes for humans. It provides opportunities for leisure activities and is a valuable source of minerals like salt, sand, gravel, manganese, copper, nickel, iron, and cobalt that are located in the deep sea. In addition to this, it is used for drilling crude oil. There is an image showing an oil rig near Santa Barbara (© Wolcott Henry 2001). Furthermore, the ocean plays a crucial role in removing carbon from the atmosphere and supplying oxygen while also regulating Earth’s climate. Moreover, it is increasingly significant as a source of biomedical organisms that have great potential in fighting against diseases.
The significance of the ocean for life on land is demonstrated by these examples, highlighting the need to preserve its health for future generations. Fishing Facts reveal that the oceans have always been crucial to human society, with fish playing a vital role in the global economy throughout history. This importance can be seen from cod trade during Viking times to fisheries in various regions including Lofoten, Europe, Italy, Portugal, Spain, and India.
Fisheries account for approximately 16% of the global protein supply, particularly higher in developing countries. They are essential not only for food production but also have a significant impact on the economy and well-being of communities. An exemplary instance is the Fish Market in the Philippines (© Wolcott Henry 2001).
The term “shipping” pertains to the conveyance of cargo between seaports via ships. Although certain vessels use wind power, most depend on steam turbines or diesel engines. Merchant navies, primarily comprising naval ships, facilitate the majority of international trade transportation among nations.
There are various types of ships, including container ships, tankers, crude oil ships, product ships, chemical ships, bulk carriers, cable layers, general cargo ships, offshore supply vessels, dynamically-positioned ships, ferries, gas and car carriers, tugboats, barges and dredgers. In the 1950’s, mining humans began to extract diamonds, gold, silver, metal ores such as manganese nodules and gravel mines from the ocean floor. This mining activity was initiated by Sam Collins’ establishment of the company Tidal Diamonds. While the ocean contains a greater abundance and higher quality of diamonds compared to land, mining them is significantly more challenging.
The extraction of valuable gems from the sediment on the ocean floor, known as diamond mining, presents challenges in bringing up the sediment. However, advancements in technology offer potential for this industry to thrive. Moreover, various other valuable resources such as metal compounds, gravels, sands, and gas hydrates are also extracted from the ocean. In the United States, sand and gravel extraction is commonly employed to protect beaches and address erosion.
Mining the ocean has detrimental effects on natural ecosystems, resulting in severe damage. Any type of dredging disturbs the ocean floor, causing extensive destruction of habitats and a significant decrease in fish and invertebrate populations. The excavation of the ocean floor also disrupts photosynthesis among phytoplankton and other marine organisms by suspending sediment in the water. Furthermore, this process introduces heavy metals that were previously harmless into the food chain. Moreover, as mineral resources on land are depleted, there is a growing inclination towards mining the ocean floor.
Marine life serves multiple purposes, such as providing food, medicine, and raw materials. It also plays a crucial role in supporting global recreation and tourism. Additionally, marine organisms contribute significantly to the oxygen cycle and regulation of Earth’s climate. They also assist in shaping and safeguarding shorelines, with some even aiding in land formation. The field of marine biology encompasses the study of various habitats ranging from the ocean-atmosphere interface to deep-sea trenches thousands of meters below. These habitats include coral reefs, kelp forests, tidepools, muddy/sandy/rocky bottoms, and the pelagic zone of open oceans. Despite the unknown quantity of life in our oceans due to undiscovered species, they host a substantial portion of Earth’s biodiversity.
Despite covering approximately 71% of the Earth’s surface, the oceans offer a significantly greater livable space than land habitats due to their depth. Within the ocean, there exists a wide range of plant life including plants and algae, which display an impressive species diversity underwater. It is worth noting that microscopic photosynthetic algae contribute more to global photosynthesis than all terrestrial forests combined. Surprisingly, macroscopic seaweeds like Sargassum and kelp take on the ecological role typically occupied by land plants, forming kelp forests.
Plants that are not algae, such as eelgrass (Zostera) and turtle grass (Thalassia), can survive in the sea. These plants are usually found in shallow waters and have adapted to high salt levels. The intertidal zone also supports plant life like mangroves, cordgrass, and beach grass. Microscopic algae and plants are important for marine organisms as they provide shelter and food for larval forms of larger fish and invertebrates.
Marine invertebrates, such as jellyfish and sea anemones, are vital components of the marine ecosystem and can be categorized into various phyla. These phyla encompass Cnidaria, Ctenophora, Platyhelminthes, Nemertea, Annelida, Sipuncula, Echiura,
Chaetognatha, Phoronida,Mollusca, Arthropoda,Porifera,Bryozoa,Echinodermata,and Urochordata. The ocean food chain is essential for maintaining equilibrium in the marine environment as many species consume different organisms within their own group. It’s important to note that the marine biome is Earth’s largest biome. Within this biome,
phytoplankton play a crucial role. Phytoplankton are single-celled plants that inhabit the sunlit upper layers of water known as the “euphotic zone.” Examples of phytoplankton include dinoflagellates,coccolithophores,and diatoms.
Phytoplankton play a crucial role in marine ecosystems as the main food producers. They use solar energy to convert carbon dioxide and other nutrients into carbohydrates, which are vital for the survival of marine creatures. In fact, 95% of their primary food source is derived from phytoplankton. Zooplankton, including shrimp, copepods, jellyfish, and mollusks, depend on phytoplankton for sustenance. Larger zooplankton feed on smaller zooplankton. Additionally, small bait fish like sardines, crabs, lobsters, and herrings also contribute to the marine food chain.
The ocean food chain is composed of distinct layers. Smaller fishes, including sharks, swordfish, tuna, and octopus, feed on zooplankton while being hunted by larger fishes. These larger fishes depend on smaller fishes as their source of nourishment. Additionally, the fourth layer of the ocean food chain consists of whales, sharks, killer whales, and other predators. During their feeding season, they consume not only larger fishes but also those within their own species or groups. Sea mammals like seals, walruses, sea lions, and dolphins also play a critical role in maintaining this complex web of life in the ocean. The study of oceanography and marine science helps unravel the mysteries surrounding this intricate system.
