Marine Ecology Marine ecology is the branch of
Marine Ecology Marine ecology is the branch of ecology dealing with the interdependence of all organisms living in the ocean, in shallow coastal waters, and on the seashore. The marine environment for all organisms consists of non-living, abiotic factors and living, biotic factors.
Abiotic The abiotic factors include all the non-living variables that have a bearing on the type of life that can exist in an area. Included are; water light temperature p. H salinity substratum • • • nutrient supply dissolved gases tides currents waves exposure to air.
Biotic The biotic factors are the interactions among living organisms. Zonation- Two major divisions in the marine world. Pelagic zone. . . waters of the world Benthic zone. . . the ocean bottom.
Pelagic zone The pelagic zone includes the productive coastal waters (neritic zone) and deep waters of the open ocean (oceanic zone) Another division in the pelagic zone is related to light penetration the photic and aphotic zones.
Benthic zone The benthic zone extends from the seashore to the deepest parts of the sea. The material that makes up the bottom is the substratum and the organisms living there are the benthos. If an organism resides primarily in or on the substrate and doesn't swim or drift for extended periods as an adult it is considered benthic
TROPHIC (FEEDING) RELATIONSHIPS Energy transfer is accomplished in a series of steps by groups of organisms known as autotrophs, heterotrophs, and decomposers.
Autotrophs absorb sunlight energy and transfer inorganic mineral nutrients into organic molecules. The autotrophs of the marine environment include algae and flowering plants and in the deep sea are chemosynthetic bacteria that harness inorganic chemical energy to build organic matter. . . AUTOTROPHIC NUTRITION- supply food molecules to organisms that can't absorb sunlight
HETEROTROPHS Heterotrophs are consumers that must rely on primary producers as a source of energy. Heterotrophic nutrition. The energy stored in the organic molecules is passed to consumers in a series of steps of eating and being eaten and is known as a food chain. Each step represents a trophic level and the complex food chains within a community interconnect and is known as a food web.
DECOMPOSERS The final trophic level that connects consumer to producer is that of the decomposers. They live on dead plant and animal material and the waste products excreted by living things. The nutritional activity of these replenishes nutrients that are essential ingredients for primary production. The dead and partially decayed plant and animal tissue and organic wastes from the food chain are DETRITUS. This contains an enormous amount of energy and nutrients.
ENERGY TRANSFERS IN MARINE ENVIRONMENTS Primary producers usually outnumber consumers and at each succeeding step of the food chain the numbers decrease. The numerical relationship is called the pyramid of numbers. Some energy is lost as it passes to the next level because (a) consumers don't usually consume the entire organism (b) energy is used to capture food (c) organisms used energy during their metabolism (d) energy is lost as heat. Generally only 10% will pass on to the next level.
FOOD RELATIONSHIPS Predator-prey - predator kills and eats another organism, the prey. Anti-predator defenses have evolved LIKE: POISONOUS SECRETIONS, SHARP SPINES AND THORNS THE HARD SHELL-LIKE CONSTRUCTION of Coralline algae also deters grazing sea urchins
Symbiotic refers to close nutritional relationship between two different species. commensalism- one benefits Mutualism- both benefit Parasitism- one benefits at hosts expense.
Population Cycles Density or numbers of individuals depends on 1. Natality or rate of production of new organisms 2. Mortality rate of death in a population.
Phytoplankton The major primary producers include: Diatoms. They dominate the temperate and polar oceans. Typical size is about 30 micrometers. They contribute about 60 per cent of the primary productivity in the oceans. Coccolithophores. They dominate in regions of moderate turbulence and nutrients such as mid-latitudes in late spring in subpolar regions and in equatorial regions. Typical size is 5 -10 micrometers in diameter. They are one of the world’s major primary producers, contributing about 15 per cent of the average oceanic phytoplankton biomass to the oceans (Berger, 1976). Cyanobacteria. Typical size is about 1 micrometer in diameter. The most common are prochlorococcus and synechoccis. Dinoflagellates. They tend to dominate in regions of low turbulence and nutrients, such as oceanic areas in late summer. Sizes range from 30 micrometers for some marine species up to 2, 000 micrometers (2 mm) for Noctiluca.
Phytoplankton Algae Growth Animation
Zooplankton The phytoplankton are eaten by the smallest floating animals, the zooplankton. They range in size from singlecelled organisms to larger multi-celled organisms. Small zooplankton are eaten by larger zooplankton. Zooplankton include Single-celled animals such as ciliates or amoeboid that never grow large. Copepods. Shrimp. Larval forms of barnacles, mollusks, fishes, and jellyfish, all of which grow to be much larger animals.
Zooplankton
Zooplakton Many zooplankton are larval stages of familiar animals. Yet they look little like their adult stages. Match up the larva with the adult.
Invent a Plankton
Scavengers feed on dead plants and animals that they have NOT killed. . . crabs ripping chunks of flesh from fish on the beach are scavengers. Most scavengers consume detritus rather than flesh and deep sea animals can feed on both.
Small Predators Zooplankton are eaten by small predators: Shrimp and krill. Immature stages of larger animals such as jellyfish and fish. Small fish such as sardines, menhaden, and herring.
Top Predators At the top of the marine food web are the large predators: Jellyfish, squid and octopus. Large fish such as sharks, tuna, and mackerel. Marine mammals including seals, walruses, dolphins, and some species of whales (some eat fish, others eat zooplankton directly). Birds such as pelicans, albatross, and penguins. People, the dominant top predator.
Top Predators
Food Web and Food Chains A food chain shows how each living thing gets its food. Some animals eat plants and some animals eat other animals. Most animals are part of more than one food chain and eat more than one kind of food in order to meet their food and energy requirements. These interconnected food chains form a food web.
Marine Food Web Game
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