Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Environmental Issues for the Marine Biome
Document related concepts
no text concepts found
Transcript
Environmental Issues for the Marine Biome Essential Questions How are humans impacting the marine biome? What is our role in protecting the marine biome? How are humans impacting the marine biome? One Ocean: The Changing Sea http://oneocean.cbc.ca/series/episodes/4the-changing-sea Questions provided 45:15 mins The 5 issues facing the Marine Biome Acidification Coral Depletion Deadzones Overfishing Pollution What is Acidification An increase in the pH level of the water of an ocean. The increase in pH is attributed to an increase in carbon Carbon interacts with other ions in the water to produce carbonic acid The pH scale A scale which measures from 0 to 14 7 = neutral = pure water 0.8 = acidic = battery acid Typically the ocean ranges from 7.9 to 8.2 pH Acid Test: The Global Challenge of Ocean Acidification http://www.nrdc.org/oceans/acidification/ aboutthefilm.asp 21:34mins What causes Acidification Use of fossil fuels Dependence on fertilizers We are dumping carbon dioxide into the atmosphere at a rate of 28 million metric tons per year What is the result of Acidification? The more acidic the water, the less ability it has to absorb CO2 Fish are starved for oxygen Corals and other marine species are deprived of calcium A proliferation of deadzones Ocean acidification (OA) is the quiet tsunami of environmental degradation. Within a few decades, OA may devastate some marine ecosystems and threaten the productivity of our fisheries. What is Coral Depletion? When the tiny organisms called coral die, they leave behind a skeleton in the form of bleached coral. As a bleached area spreads, the diversity of life in the immediate area decreases, effectively turning the skeletal remains of coral into a marine cemetery. ¼ of coral reefs are dead 60% of coral reefs are in trouble One Ocean: Footprints in the Sand Chp. 2 http://oneocean.cbc.ca/series/episodes/2footprints-in-the-sand 10mins What causes Coral Depletion? Rising temperatures Increased CO2 Increased acidity Development of tourism resorts Sediment Debris Chemical pollutants, fertilizers, pesticides Overfishing Bottom trawling fishing A single pass of a trawl removes up to 20% of the seafloor flora and fauna Coral mining Causes of Coral Depletion There is a lack of carbonate ions for corals to grow There is a lack of zooxanthellae which protect and feed corals Algal blooms smother the corals What is the result of Coral Depletion? ¼ of all fish spend some part of their life on a reef May loose these ecosystems in 20-30 years Fish and other sea life found in coral reefs feed between 30 million and 40 million people annually – providing jobs Coral reefs also form barriers around coastlines, protecting coasts (and the residences and business found there) from erosion caused by waves and currents. What are Deadzones? are areas where the bottom water (the water at the sea floor) is anoxic — meaning that it has very low (or completely zero) concentrations of dissolved oxygen An area of the ocean devoid of life 40 years ago there were <50 deadzones, 2003 there were 146 2008 there were 405! 2010 there were 415! Some are as small as a square kilometre (0.4 mi²), but the largest dead zone covers 70,000 square kilometres (27,000 mi²) What causes Deadzones? Human causes: Use of fertilizers Nitrogen Phosphorous Runoff from sewage Urban land use Can occur naturally in enclosed bodies of water or as a result of coastal upwellings and reduced winds and currents Nitrogen and phosphorous causes the increase reproduction of phytoplankton The result is algal blooms Blooms gobble up available oxygen as they spread When the blooms die, they sink to the bottom, as they decompose (by bacteria) they further deplete the oxygen Location of Deadzones What is the result of Deadzones? Bottom-dwelling species often die Reproductive problems in fish involving decreased size of reproductive organs, low egg counts and lack of spawning Fish are often quickly rendered unconscious and doomed Reports of baby octopuses climbing up crab-trap ropes in order to get air What is Overfishing? the harvesting a fish species at a rate exceeding the maximum harvest that would still allow the population to be replaced by reproduction 70% of the world’s fisheries are now fully exploited What causes Overfishing? Use of long-lines With 60 miles of hooks Bottom trawling Bycatch Illegal fishing Consumer demand Bottom Trawling Bottom trawlers drag giant weighted nets along the ocean floor, ripping up or scooping out whatever they encounter, including ancient coral forests, gardens of anemones and entire fields of sea sponges. Seamounts -- volcanic mountains and hills that rise from the ocean floor but do not break the surface -- are being damaged by these industrial fishing practices, and the wealth of flora and fauna clustered around sea mounts is being wiped out in the process. Bottom Trawling continued Many rare, ancient and even unknown species -some of which hold promise for biomedical research or are critical to undersea biodiversity -are at risk, including: Cold-water corals, which are as exotic and colorful as their warm-water counterparts. Sponges Red tree corals form ancient forests, stretching up to 7 feet tall and 25 feet wide, providing shelter for fish, shellfish, and sea stars. Corals on seamounts can live up to 8,000 years and tend to take branching, tree-like forms, making them particularly susceptible to trawl damage. form giant fields in the deep, creating stretches of habitat up to a mile long and 50 feet high. Fish including orange roughy, which take decades to mature and can live for 125 years. Bottom Trawling continued New species of flora and fauna tucked away on seamounts and other deep-sea habitats. Just like the creatures of the Galapagos Islands, many seamount species have evolved in isolation, resulting in unique species. Scientists studying a cluster of seamounts near New Caledonia have determined that nearly one-third of the species there have never been seen anywhere else. Novel chemical compounds that hold promise for the treatment of cancer and other diseases after their discovery by scientists investigating the biomedical properties of deep-sea organisms. By-Catch Unwanted and undersized fish hauled up by bottom trawlers are thrown back dead or dying -- in some areas, as many as four pounds of fish are discarded for every one pound brought to market. What is the result of Overfishing? If we don’t stop overfishing, all of the planet’s fish will have been caught by 2048 A chain reaction occurs when we overfish a particular species which can decimate other fish species and even an entire ecosystem What is Pollution? Every 2.59 square kilometers of the global ocean contains an estimated 46,000 pieces of floating plastic Farm and yard fertilizer runoff, sewage, and other land-based sources that contributes to harmful blooms of algae, which in turn lead to fish kills and swimmer illness, and ocean deadzones What causes Pollution? Discarded plastic bags, six pack rings and other forms of plastic waste Fishing nets, usually made of plastic, can be left or lost in the ocean by fishermen Toxic additives used in the manufacture of plastic materials can leach out into their surroundings when exposed to water Heavy metals are metallic chemical elements that have a relatively high density and are toxic or poisonous at low concentrations Examples are mercury, lead, nickel, arsenic and cadmium Oil spills – accidental, leaks, explosions It is estimated that approximately 706 million gallons of waste oil enter the ocean every year, with over half coming from land drainage and waste disposal Tracking the BP Oil Spill http://www.nytimes.com/interactive/2010 /05/01/us/20100501-oil-spill-tracker.html What is the result of Pollution? Plastic Fishing nets fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs, and other creatures, restricting movement, causing starvation, laceration and infection, and, in those that need to return to the surface to breathe, suffocation Plastic Additives Aquatic life can be threatened through entanglement, suffocation, and ingestion. Some plastic additives are known to disrupt the endocrine system when consumed, others can suppress the immune system or decrease reproductive rates Oil Spills If oil waste reaches the shoreline or coast, it interacts with sediments such as beach sand and gravel, rocks and boulders, vegetation, and terrestrial habitats of both wildlife and humans, causing erosion as well as contamination Immediate effects include mass mortality and contamination of fish and other food species Long term effects include poisons the sensitive marine and coastal organic substrate, interrupting the food chain on which fish and sea creatures depend, and on which their reproductive success is based The North Atlantic Garbage Patch is an area of marine debris found floating within the North Atlantic Gyre estimated to be hundreds of kilometers across in size, with a density of over 200,000 pieces of debris per square kilometer area shifts by as much as 1,600 km north and south on a seasonal basis The North Pacific Garbage Patch is an area of marine debris found floating within the central North Pacific Ocean located roughly between 135° to 155°W and 35° to 42°N estimates ranging from an area the size of the state of Texas to one larger than the continental United States high concentrations of pelagic plastics, chemical sludge, and other debris that have been trapped by the currents of the North Pacific Gyre The North Pacific Garbage Patch continued In samples taken in 1999, the mass of plastic exceeded that of zooplankton (the dominant animal life in the area) by a factor of six Ninety percent plastic, this debris accumulates on the beaches of Midway where it becomes a hazard to the bird population of the island. Midway Atoll is home to two-thirds (1.5 million) of the global population of Laysan Albatross. Nearly all of these albatross have plastic in their digestive system and one-third of their chicks die. An Ocean's Memory The Endless Voyage Series http://learning.aliant.net/Player/ALC_Play er.asp?ProgID=INT_ENDVOY12 Answer the Self-test questions after the video 27mins What is our role in protecting the marine biome?
