Seabird Ecology Food Chains Food Webs and Ecological Pyramids o Food Chain A succession of organisms in an ecological community that constitutes a continuation of food energy from one organism to another as each consumes a lower member and in turn is preyed upon by a higher member Begins with the primary producers They are autotrophs self feeders Organism capable of making organic compounds such as carbohydrates from inorganic material such as carbon dioxide and water o Photoautotrophs such as plants use solar energy to help make these compounds in a process known as photosynthesis 6CO2 6H2O C6H12O6 O2 Primary producers are consumed by primary consumers Primary consumers or secondary producers are heterotrophs other feeders Organisms incapable of making organic compounds from inorganic material they obtain their nutrition by consuming autotrophs and derive energy through respiration C6H12O6 O2 6CO2 6H2O Primary consumers are consumed by secondary consumers a k a tertiary producers And so on Food chains vary in length Terrestrial Example Plant seed primary producer is eaten by a mouse primary consumer that is eaten by a cat secondary consumer Marine Example Seaweed primary producer is eaten by sea urchins primary consumer that are eaten by sea otters secondary consumer o Food Web A bunch of interconnected food chains Primary consumers often eat more than one type of primary producer and secondary consumers often eat more than one type of primary consumer Leads to interrelated food chains that schematically appear as a web o Ecological PyramidThe flow of energy through an ecosystem can be visualized as pyramid with each level representing a different trophic level and the size of that level is proportional to the biomass in that trophic level Trophic Level an energy storing level in a food chain or pyramid The primary producers constitute the first trophic level and the primary consumers constitutes the second trophic level Because not all of the biomass of the preceding trophic level is used in the next trophic level the higher trophic levels have less biomass Ecological efficiency percentage of energy taken in as food by one trophic levela dn then passed on as food to the next highest trophic level Ecological efficiency for most ecological communities is about 10 o 100 grams of plants will sustain 10 grams of mice which will sustain 1 gram of cat o An ecological argument for vegetarianism The Marine Food Web o Primary Producers Oceanic primary productivity Light is only available for photosynthesis in the upper 100m or so of the ocean Below that there isn t enough light to support plant growth o Everything that lives below 100m in the ocean lives off of the production in the upper 100m Nutrients such as nitrate phosphate and silicate are often limiting in the upper 100m Consequently most of the ocean tends to be oligotrophic few food Very little productivity o Not a lot of biomass especially compared to land Biomass the amount mass of living material Open Ocean Phytoplankton leaf wanderer planktonic photosynthesizers in aquatic habitats the plants of the sea o Plankton any organism living in the water column that cannot swim against a current It goes where the water goes 1 100 m one millionth of a meter Produce of the world s oxygen Live only in the upper 100 m or so of the ocean Examples Dinoflagellates Diatoms Coastal Environments Phytoplankton Algae Seaweeds and seagrasses o Macroscopic primary producers Live attached to the substrate bottom Only found in shallow areas where light can reach the bottom o Primary Consumers secondary producers Open Ocean Zooplankton animal wanderer planktonic animals o Feed on Phytoplankton Detritus the remains of once living tissue Examples Krill Copepods Larval stages of many invertebrates crab lobster etc Larval fish Jelly fish Coastal Environment Zooplankton Benthic Macroinvertebrates Invertebrates you can see o Feed on phytoplankton as well as Algae seaweed and seagrass detritus o Examples Worms Clams Sea Urchins Limpets Some seabirds may be primary consumers Ducks eat duckweed o Secondary Consumers tertiary producers Open Ocean Large Zooplankton small fish some seabirds some whales Coastal Environment Large macroinvertebrates o Sea stars predatory welks Large zooplankton bigger fish many seabirds some whales Seabird Diet o Fish 200 of 270 species of seabirds have fish as part of their diet Fish is a great source of protein oil and fat Fats and proteins have a higher concentration of calories than carbohydrates and are therefore more efficient forms of energy o Zooplankton animal wanderer 138 of 270 species of seabird eat zooplankton as part of their diet Zooplankton are also a good source of fats and protein Zooplankton biomass is greater than fish biomass Remember the Ecological Pyramid Because zooplankton exist at a lower trophic level than fish most of the time their biomass is greater o Examples of Planktivorous Birds Penguins eat a lot of krill It turns their stomach linings red which they must periodically must regurgitate Seabird Habitats Habitat Where an organism lives Habitats provide food shelter and water Marine Habitats o Pelagic The Open Ocean Ocean beyond the continental shelf usually 200 miles from shore Continental Shelf shallow 200m areas of the ocean that are exposed during glacial maxima Deep ocean average depth 4000m or 12 000 ft Tends to be oligotrophic few food Very little productivity Not a lot of biomass especially compared to land o Biomass the amount mass of living material The pelagic realm which is the vast majority of the ocean is often referred to as a Blue Desert This blue water is due to the absence of high concentrations of phytoplankton Distribution to food tends to be very patchy Must travel long distances sometimes 100 s of km between feedings Common Seabirds Albatrosses Shearwaters Storm Petrels Gulls Terns and Alcids o Shelf Environments Nearshore Ocean over the continental shelf usually 200 miles from shore Shallow 200m deep More productive than the pelagic Sometimes referred to as Green Water because the abundance of phytoplankton as well as other algal detritus turns the water green Common Seabirds Loons Grebes Guillemots Cormorants Some Gulls and Terns o Seashores and estuaries Sandy Beaches Constantly shifting environments that offer little protection Most residents burrow in the sand o Below the High Tide line Crabs shrimp mollusks and worms Common Shorebirds Sanderlings Plovers and Sandpipers o