Exploitation and Pollution of Marine Resources Chapter 13

Transcription

1 OS 101 Marine Environment Winter 2007 Exploitation and Pollution of Marine Resources Chapter 13 I. Introduction - Exploitation of Marine Resources includes exploitation of both living marine organisms, and also of non-living (mineral) resources, as well as many intangible resources. - Examples include: - Living Resources - Fisheries - Marine mammals - Marine reptiles - Shellfish - Marine algae - Non-living Resources - Oil and gas (90% of the mineral value exploited from the oceans) - Sand and gravel (2nd in value to oil) - Magnesium, salts - Copper sulfide ores - Manganese nodules and sulfide deposits - Cobalt-rich manganese crusts - Sulfur, phoshorite, coal - Intangible Resources - tourism - biodiversity - ecosystem functioning II. Laws and Regulations - Humans have always exploited the marine environment, and ever since there were laws, there have been laws about the sea , the first territorial sea was agreed upon as the distance a cannon could fire from land , British set this distance at 1 league (3 nautical miles) , a series of United Nations treaties were established to set the Law of the Sea

2 A. Law of the Sea - This is a multilateral treaty between the nations of the world to establish regulations regarding the use of the resources of the sea that was arrived at by consensus (all agreed to provisions). - It was signed by 130 countries of the world in 1982 (without the US because of disagreements with provisions regarding deep sea mining). - It was ratified in 1993 and in force 1994, but without the US endorsement (but after further discussion, the US has now signed). - Features: - EEZ - Rights of ship passage - Deep ocean mineral resources - Arbitration of disputes. - One of the most important features with respect to living marine resources is the exclusive economic zone (EEZ). - The EEZ extends 200 nautical miles out from coast. - In the US, each Coastal state is responsible for managing fisheries within their own EEZ. However, this regulation has largely proved inadequate, with resulting overfishing problems still continuing. - For example, the recent wars between Washington state and Canada over the rights to fish in and around that area have resulted in disagreements at all levels (local, state, federal, international) B. Pollution Laws - There have long been laws about pollution as well, but we have often vastly underestimated the danger of the things we dump, and vastly overestimated the resilience of ocean ecosystems , Rivers and Harbors Act banned dumping in certain waterways , the first Clean Water Act was passed , Ocean Dumping Act was passed - Before 1972, there was no US Federal standard for clean water - It was thought that the oceans would provide infinite dilution - This regulation was supposed to make water swimmable and fishable - It required the removal of total suspended solids (TSS), nutrients, and contaminants before entry to the ocean, and to dispose of harbor dredge materials as landfill - It wasn t until 1991 that all dumping of sewage and industrial waste was banned

3 III. Fisheries A. History - Fisheries have historically been thought to be a limitless resource. - Up to the 1950s, most fish taken were for human consumption (>90%), and only a small fraction for industrial purposes. - However, this changed after WWII when there was a food shortage. There was a tremendous demand for poultry and pork, and fish were seen as a cheap protein source. - This did not work because this was not ecologically efficient (if we had all eaten anchovies it would have been efficient), and a larger percentage of fish stocks were being used for fish meal production rather than human consumption. - Due to demand and technological improvements, our harvest increased. - Most fisheries are OVERFISHED (=harvested at a rate faster than adult fish can reproduce to replenish the population) to point that is beyond the MAXIMUM SUSTAINABLE YIELD (= population size or # individuals necessary for population to maintain itself). B. Recent Trends - World fishery production is now over six times what it was in Marine fisheries still provide only about 5% of the protein consumed by the world's population. - However, fisheries yields have recently seemed to reach a peak, even though the size of fishing fleets has continued to increase, many species have been fished beyond the maximum sustainable yield to the point of commercial extinction. - the Georges Bank fishery off the coast of New England has essentially been closed and there are many other examples. - Twenty countries account for about 80% of the world's total production while ten countries account for almost 70%. - Nearly 1/3 of all fish for food is produced by aquaculture. - US fisheries account for ~6% of the world total catch. 58% of the US catch comes from Alaska IV. Pollution A. Definition 1) introduction into the ocean by humans of substances or energy that causes harmful effects to marine life, human health, and a hindrance to marine activities.

4 2) changes the quality of the water and affects the physical, chemical or biological environment of marine life and threatens human health. B. Effects of Pollution - A big problem is that these effects can be difficult to identify: a. Cellular level: Immediate b. Organism level: hours to months c. Population level: months to decades d. Community level: years to decades - In the US, we ve eliminated many of the point-source pollutants; it is much more difficult to eliminate all of the non-point-source pollutants - Some examples of common pollutants include: 1. Petroleum and Oil Spills - Oil (hydrocarbons) are organic substances biodegradable by (some) microorganisms; but they are complex compounds containing O, N, S, and trace metals in addition to hydrocarbons - Oil spills (Torrey Canyon off English coast in 1967; Exxon Valdez off Alaska in 1989) are obvious point-source oil pollutants, but only a small percentage of oil input to the ocean is from tanker oil spills - Chronic low-level pollution is from: - leaks at marine terminal - disposal of drilling muds - city & industry waste - urban runoff - atmospheric fallout - used motor oil 2. Plastics - In 1960, there was 2.7 x 109 kg plastic ; by 1990, 27.3 x 109 kg plastic , US law enacted to implement an International Convention: The Marine Plastic Pollution and Control Act - No dumping of plastics is allowed at sea 3. Sewage and Solid wastes - Sewage = A mixture of human waste, oil, zinc, copper, lead, silver, mercury, PCBs, and pesticides

5 - Solid waste = trash + garbage dumped; dredged materials from ports; industrial waste; obsolete military hardware and arms; toxic gases; sludge from water treatment plants - Solid waste is no longer dumped in the ocean (in the US) 4. Radioactive waste - Bomb testing (atmospheric fallout) - Nuclear power plant fuel reprocessing - Nuclear weapons - Where is a safe deposit site? 5. Toxics - Oils and Grease; Residues from industry - Organics (e.g., DDT, PCB, pesticides & fertilizers); PCBs are fat soluble, long-lived, accumulate in the food chain - Bacteria (coliform), viruses (see the Seagrant handout from a previous class) - Metals (Mercury [Minimata Disease]; Copper ) 6. World Population - as world population continues to increase, all of these issues will continue as well. - An interesting website with up to the minute statistics can be found at: