Keywords: biosphere, bioaccumulate, biodiversity, food web, ecology, abiotic factors, and biotic factors. Lesson II: The Ocean Biosphere: From Microbes to Mammals Planet Earth is truly a water environments is called ecology. planet! We have a connection to all Living things such as plants and living things in the ocean, from the animals in the environment are called microscopic floating plants that biotic factors, or biota. Nonliving supply us with the oxygen we breathe, things in the environment, such as to the huge blue whale that fills its soil, water, temperature, light, belly with a ton of krill. This circle of salinity, chemical composition, and life is called a biosphere. The earth’s currents are abiotic factors. biosphere is composed of all living Together, these factors interact and things, from the deepest oceans to the function as an ecosystem. An upper atmosphere. It includes all the ecosystem is a community of different air, land and water where life exists. organisms interacting with the abiotic All living things depend upon and parts of its environment. Ecosystems interact with each other and with the may be as small as a beehive, or as non-living things in their large as the Atlantic Ocean. With the environment. aid of technology, we are discovering The study of interactions entire new ecosystems that survive in between organisms and their our biosphere. Our Ocean Biosphere Look at an atlas of the world animals. A few abiotic factors are and identify one of the major oceans temperature, salinity, pressure, found on planet earth. In short, the dissolved gases and depth. ocean itself is composed of the basin, The components are not that water, and biotic and abiotic factors. easily summed up. We will not dive The basin is composed of oceanic deeper into the formation of the crust made at the mid-oceanic ridge. oceanic basin, or the rain that fills the The water is supplied from rainfall basin, but we will explore deeper into and run off from the land. The biota the biotic and abiotic factors found in in the ocean is all living plants and the ocean. As said before, the biota are all plankton, feeding and growing, before living things in the ocean. The they become adults. They usually smallest organisms in the ocean look quite different from the adult belong to the same group that are the forms, probably because of the smallest on land, the viruses. They different mode of life. cause diseases in different organisms, Staying afloat is crucial to any and infect bacteria and phytoplankton. member of the plankton. There are Viruses may play a role in the demise many interesting adaptations found of phytoplankton blooms and keep within the plankton that help them bacterial populations under control. keep afloat. Many organisms have Researchers believe that viruses, by wings, flat plates, or spines that causing the cell of phytoplankton and increase resistance to sinking. Many bacteria to burst, are true recyclers of have floats full gases or air and some nutrients. Bacteria are found have special oils or fats in their everywhere in the marine bodies. environment. They are larger than the Some viruses. Researchers now believe that zooplankton are they too utilize available nutrients also single found in, and are important for celled, such as recycling nutrients for other the Foraminifera organisms. Plankton include all of the and the organisms that drift passively in the Radiolarian. Zooplankton, gain their ocean. They are divisible into nutrients by grazing on the phytoplankton, the plant plankton, phytoplankton. The Crustacea, such and zooplankton, the animal as euphausiids (krill), and copepods, plankton. Phytoplankton are the are the most numerous of the primary producers, or autotrophs, of zooplankton, comprising 70% or the open ocean. They take inorganic more. Life cycles of the zooplankton nutrients, CO2 and energy from are usually closely related with sunlight and convert it into a seasonal blooms of phytoplankton. carbohydrate source that is utilizable These blooms provide food for the by other organisms. They are the start developing zooplankton. Organisms of the food web, providing carbon to that feed on the zooplankton have life all other ocean organisms. cycles that correlate zooplankton Some animals spend only some mass. The blue whale migrates of their life stages in the plankton, through the temperate and polar these are called meroplankton. Fish waters during times of maximum larvae are a good example. Some fish zooplankton mass for feeding spend many months floating in the purposes. The Nekton There are not as many marine Some zooplankton can swim reptiles as there are terrestrial reptiles. well enough to move independently of The sea turtles are probably the most the currents. These creatures are familiar of this group. The known as nekton. These include the Leatherback grows up to 9 feet long fishes, octopods, squids, marine and can weigh up to 1900 pounds! It mammals and reptiles. is the most widely distributed of all There are almost 25,000 species living reptiles. Green sea turtles of fishes, more than any other group undertake long arduous journeys from of vertebrates. They have an amazing their feeding grounds to their nesting array of adaptations and live in a wide sites, which may be as far as 1,250 variety of habitats. There are fishes miles away. with cartilage instead of bone (sharks and rays), fishes that have discs on The Benthos their backs used for attaching to other There are numerous marine organisms (remoras), fishes with organisms that spend a large part of trunk like snouts (elephant fish), and their lives associated with the ocean fishes that walk on the bottom with floor. Reef building corals are their pectoral fins (tripod fish)! Fish benthic organisms that require sand or that live in the open ocean are called hard bottom, and very clean, clear, pelagic fishes. Some of these fishes warm waters. There is also a live their entire lives and may never seemingly endless array of infauna or come in contact with any type of organisms that actually live burrowed boundary, not the bottom, not the into he sediment, such as surface, just endless water! roundworms, flatworms, annelids, The nekton also contains the ribbonworms, and bivalve mollusks. whales. The largest animal to ever Many mollusks such as snails and have existed on the earth is the blue slugs move slowly across the benthos, whale. They can grow up to 110 feet both rocky and alone and weigh up to 200 tons. The muddy. Still baleen whale can eat up to 4 tons of other mollusks, krill a day. The sperm whale is a such as oysters toothed whale. It doesn’t eat krill, but and mussels are instead cephalopods make up most of sessile living and its diet. It is one of the deepest diving permanently whales, and can dive to a depth of attached to hard almost 4,000 feet in its quest for giant substrates. Arthropods spend much of squid. Some of the squid can get their time associated with the bottom quite large. They are known to reach substrate. Examples of these would lengths of almost 60 feet. be the horseshoe crab and of course many crustaceans such as lobsters and factor that could affect the crabs. phytoplankton is the amount of When most people think of fish available nutrients. Nitrogen and associated with the ocean floor they phosphate are the primary nutrients think of the flatfish, such as flounder for phytoplankton. But for these and sole. These are bottom- nutrients to be effective, they must be associated fish, however, there are in the right ratio to one another. To many others. Most skates and rays photosynthesize, phytoplankton need are predominantly bottom-oriented carbon dioxide. Carbon dioxide is the fish. Garden eels earn their name base of life. The materials that the because they look like a garden of phytoplankton produce (carbon), is eels that have been planted by their the food for all other systems in the tails. They sway in the current and ocean. Those of the basic needs for feed on the plankton that floats by. the autotrophs. This is just a small sampling of Heterotrophs require additional the biota found in the ocean. There gases, and are affected much more by are too many to list and many more pressure. Pressure increases with that have yet to be discovered and depth. For heterotrophs to survive, given a name. Not only is the biota they have many adaptations in their important, but the abiotic factors in bodies to withstand the 1 atmosphere the ocean are also important because increase with every 10 meters of both groups work together. water depth. The abiotic factors in the ocean Finally, both autotrophs and help the ocean to ‘work’. For heterotrophs are influenced by example, phytoplankton (autotrophs) salinity. Salinity can determine where need light, nutrients, CO2 (dissolved organisms can or cannot survive. gases) to photosynthesize. All of Some organisms are more adapted to these factors are crucial to the primary live near freshwater input, while producer! The Ocean is not a perfect others are meant to live in the blue world, it is composed of many things ocean where salinity is much higher. that act upon, and change the abiotic Other abiotic factors that factors. For example, the amount of influence organisms, and that light penetration changes with depth influence the nature of the ocean’s and turbidity. This could affect the waters include; winds, currents, and primary producers. Another abiotic tides. The Marine Food Web All organisms get their energy Heterotrophs eat autotrophs, thus either from making their own food, or gaining energy from the food source.