NR 150 1st Edition Lecture 15 Outline of Last Lecture I. Mammals (including marine mammals)II. Marine birdsOutline of Current Lecture III. Classification of Benthic marine environments by locationIV. The importance of competitionV. Benthic organisms live on or in the seafloorCurrent LectureI. Classification of Benthic marine environments by locationa. Littoral zone- intertidalb. Sublittoral zone- beyond the littoral zonec. Bathyl zone- slopes to great depthsd. Abyssal zone- below the bathyl zonee. Hadal zone- deepestII. The importance of competitiona. Organisms in a community compete with members of the same species and with members of other species for:i. Foodii. Lightiii. Spaceiv. Other resourcesIII. Benthic organisms live on or in the seafloora. Diversity of benthic habitatsi. Kelp forestsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. Seaweeds and marine plants are diverse and effective primary producers2. 2-5%of primary production by multicellular algae (seaweeds)3. True marine plants: mangroves and sea grassesa. Mangrovesi. Root system traps and holds sediment1. Subaerial roots of mangrove tree allow it to withstand rise and fall of tidesii. Stabilizing effect and expansion of delta and coastalwetlandsiii. Root system serves as a safe haven for organisms1. Prop roots serve as sanctuaryiv. Forests are facing a lot of destruction by humans4. Seaweedsa. Great variety in shape and sizesb. More than 7000 speciesc. Nonvascular plants because they don’t have to fight gravityi. Four requirements of CO2, water, nutrients, and sunlight to produce carbohydrates are simultaneously present in their bodiesd. Are held down by a holdfast, not a true roote. Lightweight structuref. Can use nearly all energy for photosynthesis; highly efficientg. Chlorophytes: green dye to the presence of chlorophyll and the lack of accessory pigmentsi. Accessory pigments assist with absorption of light and the transfer of its energy tot chlorophyll, aka masking pigmentsh. Phaeophytes: browni. Contain chlorophyll and secondary pigment (fucoxanthin)ii. Live in deep depth than chlorophytesiii. Include the species of kelpsiv. Sargassum weeds1. Spherical air bladders that keep small, leaf-like blades afloat near the surface2. Can also grow on rock3. Can float in hug patches offshore4. Sargossa sea named after sargassum5. Provides shelter and food for many organismsv. Rockweed1. Thick and leathery talli2. Can stand exposure to air3. Occurs in intertidal zones4. Providesa. Shelter for periwinkle snails and small crustaceans during low tideb. Feeding ground for small fish during high tide vi. Structure of a kelp1. Thallus (body) of a typical multicellular algae2. Blades (leaves) used for photosynthesis, absorb gases3. Stipes (stem) are strong, can also be used for photosynthesis, shock absorbent4. Holdfast (root) anchors but doesn’t take up water or nutrients5. Gas bladder assist seaweed in staying near the surface for sunlight and photosynthesisvii. Kelp1. Largest of brown algae2. Found below tide level in temperate and sub polar latitudes3. Provides food and shelter for many organisms4. Some kelp harvested for food5. Macrcystis is the largest kelp, about 100m-330ft6. Kelp forests are a biodiversity hotspota. Forest structures serve as a source of cover and foodb. Reduce current velocities, which allow for greater nutrient uptakec. Primary productivity in healthy forests is high enough to support more than 800 species7. Giant kelp, sea urchins, and sea otters are connected together in a food chaina. In 18th century, trappers began to hunt sea ottersb. Have very thick furc. By 1911, there were less than 2000 otters left in the worldd. Sea otters don’t have fat layer, unlikeother marine mammalse. No sea otters causes bald patches in the kelp foresti. When otter population goes down, kelp forest disappearsii. Sea urchins eat kelpiii. Sea otters live on diet of sea urchin, have purple stained teeth and skeletons8. Protect coastlines by absorbing wave shocka. Storms or swells can uproot entire plants and break away frondsb. Warm water and storms strong waveenergy caused high mortality in the southern California kelp forests9. Coastal developmenta. Sewage, industrial disposal, and coastal runoff might contribute to kelp forest degradationb. High sedimentation from coastal run-off may bury new plant shootsc. Reduce growth rates and reproductive success in more toxic water and sedimentsd. Studies on microscopic stages of kelp suggest that kelp is sensitive to sewage, industrial waste discharges, and other causes of poor water and sediment qualityi. Rhodophytesi. Get their red color from their accessory pigmentsii. Can live at a depth where human eyes cannot sea lightj. Economic importance of seaweedi. As a food sourceii. Produce gelatinous chemicals (phycocolloids) used in food processing1. Align (some uses)a. Emulsifier in dairy products (ice cream, cheese)b. Prevents frosting from drying outc. Thickener and emulsifier in tooth paste and shampoosd. Used in paper, paint, and cosmeticse. Printing paste in textile industry for sharper printsiii. Marine algae’s being considered for biofuels1. Fast growing2. Renewable3. Efficient primary producers4. Doesn’t need fresh water to growii. Rocky intertidal zones1. Between highest high tide and lowest low tide2. Sessile and motile organisms3. Problemsa. Wave shockb. Rapid temperature changec. Desiccation4. Opportunitiesa. Many habitats and nichesb. Many food sourcesc. Nutrient richiii. Sand beaches1. Communities exist in one of the Earth’s most rigorous habitatsa. Smaller organisms- few have adaptedi. Problems1. Sand (sharp, point, abrasive)2. Burrowing is difficult in swirling sand3. Exposed to predators4. Tidesii. Have adapted1. Sand crab2. Fast burrowing clams3. Sturdy polychete worms4. Interstitial animals2. Cobble beaches (even more uninviting)iv. Salt marshes1. Salt water mixes with freshwater runoff from landa. Advantagesi. Generally no wave shockii. High availability of nutrientsb. Disadvantagesi. Varying salinitiesii. Strong currents associated with tidesv. Areas around deep vents and seepsvi. Coral