Bio 105 1st Edition Lecture 27Past lecture (26)Ocean Planet (Earth)- Our life support systemWhy are they important?- Climate and temperature regulation- It stimulates our health both psychologically and physical.- Food (Most people in world live near coast)- Precipitation- Regulate gases in atmosphere- Most of life on planet is in oceans- Human economy (tourism, ecotourism)Marine ImpactIndicator species – species used to assess the conditions of a habitat or ecosystem, e.g. sea turtles.When did turtles evolve? Triassic periodWhen did sea turtles evolve?A hundred million years ago during in Cretaceous period. The sea turtles survived the K.T. extinction. They have been on Earth for a very long time. They can adapt to change. They undertake great migrations and very widespread and found everywhere. All seven species are threated and five are found in NC coastline.NC loggerheads reach maturity at ~37 years.Natal homing – The female sea turtle will mate at/near the beach where she was born. Pregnancy is so demanding on turtle physically that she can’t nest every year.Role:1. As prey (for raccoons, seagulls)2. Epibionts (Life on shells) There are 100 species that are dependent on sea turtles. The Green Sea Turtles are vegetarians as adults and will keep the pastures clean. 3. Eggs that do not hatch, add nutrients to the sand and supports life on beach.Current lecture (27)These 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.Importance of oceansBlue carbon: carbon that is locked up in marine life. Not bad.Sea grasses- Shallow green habitat- Supports 50% of world’s fisheries- C-sink (sequesters 30x more carbon than tropical rainforests, “blue carbon”)- Stabilizes coastlines (leaves are baffles)- What harms sea grass bedso Overgrowth (lack of grazing, also fertilizer runoff)o Sedimentso Shade- Sea grass blades grow long when aren’t chopped short. The shade bottom gets slimy andleaves decompose and slime increases.- Healthy sea grass is cropped short and supports many marine life.Back to sea turtles - They are grazers in sea grass pastures- Historic population is 91 milliono Consumed 45% of annual sea grass growth.o Transmits nutrients to annual food chain.- Modern population is less than 300,000o Consumes less than 0.1% of annual sea grass growth.o Uneaten sea grass buried in sediment.o Sea grass wasting diseaseo More sea turtles = more productivity, less dense.- Stranding: turtle washed up on beach. Most likely dead, or dying.- Causes of Moralityo Cold stunning – gets caught in cold currents, or bad weather. Natural causeo Increased intensity of storms. Natural causeo Sea level rise. Natural cause with human influenceo Garbage. Human cause. 4/5’s of garbage in ocean comes from the land.o Marketingo Pollutiono Beam armoring o Bycatch - What can you do?o Reduce disposable plasticso Recycleo Voteo Garbage pickups- Gill nets – “curtain of death” They catch anything that doesn’t fit in the nets.Shrimping – trawling destroys ocean
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