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| | | Environmental emergencies affecting fisheries |
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|  Storm-related damages to capital assets, including boats and fishing gear, means the loss of income and livelihood, especially for poor fishing households. Poor households who depend on fishing for their livelihood may not have adequate saving to replace their capital, and are likely to face the risk of food insecurity in the aftermath of storms unless their capital is replaced immediately through public support. The disruption of fishing activities by such households could also affect the livelihood and food security of other households, for instance, small traders who buy and sell fish in small local retail markets.There are three types of environmental uncertainties affecting fisheries: (1) natural environmental oscillations, (2) global environmental change and (3) environmental emergencies. Natural oscillations affect fish abundance and availability: seasonal oscillations are usually forecasted with reasonable accuracy and exploited by fishing industries whereas inter-annual oscillations that occur with a range of frequencies (such as 11 to 50-60 year cycles) are less predictable and are only slowly being understood (e.g. El Niño and La Niña phenomena). Environmental emergencies correspond to environmental crises emerging as a consequence of an unforeseen combination of circumstances with results that call for immediate action in the form of contingency plans or mitigating action, such as assistance or relief. These include fish kills, harmful algal blooms and oil spills (caused by tanker accidents or from incidents related to offshore development). | | | | Complex and extensive systems of underwater pipelines, amounting to thousands of kilometres, are among the greatest environmental risk factors during offshore oil developments, along with tankers and drilling operations. Causes of accidents range from defective material, pipe corrosion, ground erosion, tectonic movements, ship anchors and bottom trawls. Depending on the damage, the pipeline may become a source of leakage or of an abrupt (even explosive) blowout of hydrocarbons near the bottom. The intensity and scale of toxic impacts on the marine biota in the accident zone varies depending on a combination of many factors. It is important to consider that, in a number of cases, the accidental oil and gas spills and blowouts of mainland pipelines threatens coastal marine ecosystems. This can occur when such accidents take place, for example, near big rivers where river pollution eventually affects the sea zone near the river mouth. | | | | Drilling accidents | | | | Drilling accidents are usually associated with unexpected blowouts of liquid and gaseous hydrocarbons from the well. Only tanker oil spills compete with drilling accidents in regularity and severity. Some rare occurrences could lead to catastrophic situations involving intense and prolonged hydrocarbon gushing. Often they involve hydrocarbon spills and blowouts during drilling operations. Usually, these accidents do not attract any special attention. Nonetheless, the ecological hazards and associated environmental risks can be considerable - especially given their frequency - and could ultimately lead to chronic impacts on the marine environment. | | | | Fish kills | | | | Massive fish kills affecting large biomasses across relatively large aquatic areas are often triggered by unpredictable environmental conditions resulting from accidental (or sometimes illegal) events such as the release of toxic substances from industrial waste storage facilities (e.g. following a fire or mine tailing impoundment after heavy rains or from malfunctioning waste treatment facilities). As well, heavy winds, resulting in up-welling of oxygen-depleted bottom water, can be the cause of fish kills in stratified coastal waters and great lakes. The fish kills themselves may aggregate oxygen depletion as large amounts of dead organisms accumulate on the bottom. Fish kills can also result from cold spikes (e.g. in the Northern Adriatic) when exceptionally cold atmospheric conditions reduce water temperature in coastal areas, provoking massive kills of sessile or benthic populations (e.g. Norwegian lobsters). | | | | Harmful Algal Blooms | | | | About 300 hundred species of micro-algae can form mass occurrences at times, nearly one fourth of which produce toxins. Scientifically referred to as 'Harmful Algal Bloom' (HAB), they are commonly called "red tides" as the large patches of planktonic concentration may appear red on the surface. Such proliferation of micro-algae - thought to be activated by environmental changes - in marine or brackish waters can cause massive fish kills, contaminate seafood with toxins and alter ecosystems in harmful ways. A broad classification of HABs distinguishes two groups of organisms: the toxin producers, which can contaminate seafood or kill fish, and the high-biomass producers, which can cause anoxia and indiscriminate kills of marine life after reaching dense concentrations. The impact of harmful micro-algae is particularly evident when marine food resources, such as mussels grown in aquaculture facilities, are affected. Shellfish, and in some cases finfish, are often not visibly affected by the algae but nonetheless accumulate the toxins in their organs. The toxins may subsequently be transmitted to humans through consumption of contaminated seafood and become a serious health threat. | | | | Tanker accidents | | | | Tankers carry about 1 000 million tonnes of oil per year, about 50% of which is extracted on the continental shelf. On some offshore oil fields shuttle tankers are the main way of delivering hydrocarbons to the onshore terminals. The principal causes of tanker accidents that lead to large spills include running aground and into shore reefs, collisions with other vessels, and cargo fires and explosions. More recently, a number of accidents occurred when vessel structures collapsed during severe weather conditions. | | | | Tanker accidents often result in vast oil spills or massive release of harmful chemicals transported in bulk. According to the International Maritime Organisation (IMO), the amounts of oil spilled during tanker accidents in 1989 and in 1990 were 114 000 and 45 000 tonnes, respectively. Some of the most substantial oil spills have been: the Torrey Canyon in 1967 with 95 000 tonnes of oil spilled on the French and British shores; the Amoco Cadiz in 1978 with 220 000 tonnes of oil spilled, the Exxon Valdez in 1989 with 40 000 tonnes and the Braer in 1993 with 85 000 tonnes of oil spilled. The most dangerous are accidents involving underwater storage tanks that contain dangerous substances such as methane. Such incidents will be possible in the area of Shtokmanovskoe field developments in the Barents Sea where over 3 000 tonnes of methane are planned to be stored underwater. The resulting spills could have disastrous effects on coastal ecosystems, fisheries, aquaculture installations and, in some instances, on human life. Major impacts of oil spills on fisheries and aquaculture are the smearing of nets and fish cages and the tainting of fish and shellfish, rendering them unfit for marketing. Longer-term impacts on the ecosystem depend on the nature of the pollutant and the ecological characteristics of the area. | | | | Pipelines accidents | | | | |
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