LESSON TWO - The Needs of Living Things - OceanLink

The chemistry of a “black smoker.” After seawater seeps into the crust (1), oxygen and potassium (2) and thencalcium, sulfate, and magnesium (3) are removed from the water. As the water begins to heat up (4), sodium,potassium, and calcium dissolve from the crust. Magma superheats the water, dissolving iron, zinc, copper, andsulfur (5). The water then rises back to the surface (6), where it mixes with the cold seawater, forming blackmetal-sulfide compounds (7).Image courtesy of Woods Hole Oceanographic Institution.Text from Ocean Explorer:oceanexplorer.noaa.gov/explorations/02fire/background/education/media/ring_candy_chemo_9_12.pdf3. Exploring SymbiosisIf you have poked around in a tide pool, you have probably seen bright green sea anemones that lookmore like flowers than animals. The anemone is green because it has an algal partner (or symbiont)that is green! These giant green anemones, Anthopleura xanthogrammica, are an example ofsymbiosis. The anemone provides a secure home for the algae, and the algae make sugars byphotosynthesis for the anemone.There are three different ways in which organisms can engage in a symbiotic relationship. Mutualism isa close relationship between two organisms in which both organisms benefit. Parasitism is arelationship between two organisms in which one is harmed and the other benefits, and commensalismis a relationship in which two organisms live together where one benefits while the other is unaffected.In the deep-sea there are many relationships among organisms that may seem strange and unusual toyou. At hot vents and cold seeps, unique food chains were discovered completely reliant onchemosynthesis. When worms found at hot vents like the Giant Tubeworm, Riftia, were looked at,biologists found that this worm was “gutless”. It took a while, but what they discovered was a uniquechamber inside the animal, called a trophosome. The trophosome contains microbes that need sulfidecompounds to produce sugars. These sugars are then consumed by the tubeworm. The GiantTubeworm and the microbes are so interconnected that they cannot survive without each other. Whenhydrothermal venting stops and the tubeworm can no longer provide chemicals to the bacteria, bothorganisms die.Similar symbiotic relationships between tubeworms and microbes, and between clams and microbesexist at cold seeps like the one found in Barkley Canyon.. Deep-sea clams farm methane-munchingmicrobes in their guts providing the microbes with methane. The clams then harvest the sugars madeby the microbes, showing another example of producers and consumers living together to meet theirsurvival needs. Other clams, such as “V” clams (“Vesicomyid Clams”) commonly seen in vent fieldsand at cold seeps, live by sucking sulfide through their foot from the mud. Sulfide travels through the