Marine Science Virtual Lesson Biological Oceanography Photo credit: Getty Images • The study of how plants and animals interact with What is each other and their marine environment. • How organisms affect and are affected by chemical, Biological physical, and geological oceanography Oceanography? • Studies life in the ocean from tiny algae to giant blue whales Marine Environment Photo credit: Getty Images Biological Pump Some CO2 is • Carbon sink is part of the released through biological pump respiration • The pump includes upwelling that brings nutrient back up the water column • Releasing some CO2 through respiration Upwelling of nutrients Photosynthesis • Sunlight and CO2 is used to make sugar and oxygen • Can be used as fuel for an organism's movement and biological processes • Such as: circulatory system, digestive system, and respiration Where Can You Find Life in the Ocean • Plants and algae are found in the euphotic zone of the ocean • Where light reaches • Animals are found at all depths of the ocean • Most live-in the euphotic zone where there is more prey • 90% of species live and rely in euphotic zones • the littoral (close to shore) and sublittoral (coastal areas) zones Photo credit: libretexts.org Photo credit: Christian Sardet/CNRS/Tara Expéditions Plankton • Drifting animals • Follow the ocean currents (don’t swim) • Holoplankton • Spend entire lives in water column • Meroplankton • Temporary residents of plankton community • Larvae of benthic organisms Plankton 2.0 • Phytoplankton • Autotrophic (photosynthetic) Photo credit: Christian et Noé • Diatoms, cyanobacteria, dinoflagellates Sardet / Plankton Chronicles • Zooplankton • Heterotrophic • Some have locomotion to avoid predators • Flagella or cilia • Protozoan zooplankton • Foraminiferans, radiolarians and dinoflagellates • Metazoan zooplankton • Animals like krill and eggs and larval stages of fish • Grow into nekton such as fish Photo credit: ecomagazine.com Plankton Size • Different types of plankton based on size • Pico plankton <2 micrometers • Nano plankton 2-20 micrometers • Micro plankton 20-200 micrometers • Meso plankton .2-20 millimeters • Macro plankton 2-20 centimeters • Mega plankton 20-200 centimeters Photo credit: slideshare.net Nekton • Free swimming animals • Can move on their own • Don’t rely on ocean currents like plankton • Fish, turtles, marine mammals, and birds • Long distance migrations Benthos • Spend the majority of their lives on the ocean floor • Invertebrates • Mollusks • Crustaceans • Sea stars and relatives (Echinodermata) • Some are sessile like sponges • Don’t move at all Photo credit: Tui De Roy/Minden Pictures Migrations • Diel vertical migrations • Aka diurnal vertical migrations • Planktons migrate up and down the water column every 24 hours • Rise up during night and sink back below during the day • Reverse migration • Rise to surface during the day and fall to the bottom at night • Nocturnal migration • Night hunters • Avoid predators • Twilight migration • Dawn or dusk • Preference of light based on prey • Long distance migrations • Mating/breeding • Following food • Seasons Photo credit: iShutter • Many nekton have annual migrations Sunlight • Sunlight is super important • Starts the process that support life Photo credit: Getty Images • photosynthesis • Diel variation • Change from day to night • Affects when organisms are active throughout the day • Seasonal variation • Change between the seasons • Affects where organisms are active • migrations Photo credit: Getty Images Nutrients • Organisms travel to areas with nutrients • Animals tend to congregate in nutrient rich waters • Euphotic zone • Photosynthesis • Too much of nitrogen and phosphorous from runoff could inhibit growth • Harmful algal blooms • Low oxygen levels Photo credit: Wikipedia Photo credit: StoryboardThat.com Whale Falls • Whale falls provide nutrients to deep sea organisms • Whale falls are the carcasses of dead whales that have sunk to the bottom of the ocean • Deep sea organisms receive nutrients that trickle down from the surface • Whale falls contribute a lot of nutrients at once • As the whale decomposes, it provides nutrients for years • First scavengers consume the tissue • Whale bones become colonized by invertebrates and bristle worms • Fragments and detritus supplement the ocean Photo credit: nautiluslive.org floor for years Salinity • Osmoregulation • Balancing salt concentration • Fresh and saltwater fish regulate differently • Euryhaline • Tolerates a wide range of salinities • Stenohaline • Tolerates a narrow range of salinities Photo credit: bio.libretexts.org Turbidity • Amount of sediment • Affects clarity Photo credit: Getty Images • High turbidity means lots of sediments • Low turbidity means little sediment • No turbidity with pristine water isn’t a healthy ecosystem • No phytoplankton or algae • Too high of turbidity and light can’t get through for photosynthesis • Marine organisms adapt themselves and form niches to deal with various turbidity Photo credit: Active Blue Dive Centre Temperature • Determines adaptations species need Photo credit: iStock • Polar animals need to eb able to survive in the cold • Antifreeze in fish or blubber on polar bears and other marine mammals • Lose energy trying to stay warm • Tropical don’t need to worry about the cold Photo credit: Tim Man Lee • Over 70% of earth’s surface is covered in the oceans Why is it • Only 5% of the oceans have been explored Important? • So much more to learn • Biological oceanography helps us determine what animals and plants are doing in the ocean • Helps us understand how to protect the ocean.