The Environmental Food Crisis

IMPACTS OF ENVIRONMENTAL DEGRADATION ON FISHERIES

At present capture fisheries yield 110–130 million tonnes of sea- food annually. Of this, 70 million tonnes are directly consumed by humans, 30 million tonnes are discarded and 30 million tonnes converted to fishmeal. Aquaculture, freshwater and ma- rine fisheries supply about 10% of world human calorie intake – but this is likely to decline or at best stabilize in the future, and might have already reached the maximum. The primary and most important fishing grounds are found along the continental shelves within less than 200 nautical miles of the shores. The distribution of these fishing grounds is patchy and very localized. Indeed, more than half of the 2004 marine landings were caught within 100 km of the coast in depths generally less than 200 m covering an area of less than 7.5% of the world’s oceans, while 92% was caught in less than half of the total ocean area. Climate change and increased CO 2 assimilation in the oceans will result in increasing ocean acidification, die-back of up to 80% of the world’s coral reefs and disruption of thermoha- line circulation and other processes. It will particularly impact dense-shelf water cascading, a “flushing” mechanism that helps to clean polluted coastal waters and carry nutrients to deeper areas. Coastal development is increasing rapidly and is projected to impact 91% of all inhabited coasts by 2050 and contribute to more than 80% of all marine pollution. Increased development, coastal pollution and climate change impacts on currents will accelerate the spreading of marine dead zones, many in or around primary fishing grounds (Diaz and Rosen- berg, 2008). Overfishing and bottom trawling are reducing fish stocks and degrading fish habitats, and threatening the entire productivity of ocean biodiversity hotspots, making them more vulnerable to climate change. Up to 80% of the world’s primary fisheries stocks are exploited close to or beyond their optimum harvest capacity and large areas of productive seabeds on some fishing grounds have been partly or extensively damaged. For example, over 95% of the damage and change to seamounts has been caused by bottom trawling, which has been estimated to be as damaging to the seabed as all other fishing gear combined. Damaged from overfishing , bottom trawling and pollution, the worlds fishing grounds are increasingly becoming infested by

invasive species mainly through ballast water, with the pattern closely following the major shipping routes.

The result of unsustainable fishing practices are that we might no longer able to increase the landings from conventional fisheries, and might, in fact, be facing a substantial decline in the world’s fisheries in the coming decade. This will also have severe impacts on aquaculture production, which relies on fish for feed.

AQUACULTURE

Aquaculture production has increased more than seven-fold in weight (from 5 to 36 million tonnes) between 1980 and 2000. The value generated has grown from US$9 billion in 1984 to US$52 billion in 2000 (Deutsch et al ., 2007). In 2006, the world consumed 110.4 million tonnes of fish, of which 51.7 million tonnes originated from aquaculture. In order to meet the grow- ing fish demand, aquaculture will have to produce an additional 28.8 million tonnes – 80.5 million tonnes overall – each year, just to maintain per capita fish consumption at current levels. Aqua- culture growth rate is declining, however: a yearly growth rate of 11.8% from 1985 to 1995 slowed to 7.1% during the following de- cade, and to 6.1% for the 2004–2006 period. In October 2008, FAO cautioned that a series of emerging challenges need to be addressed if aquaculture is to meet increasing demand for fish. Almost 40% of all aquaculture production is now directly de- pendent on commercial feed. Most farmed fish that are con- sumed in the developing world, such as carps and tilapia, are herbivores or omnivores. But other species like salmon or shrimp – often raised in developing countries – are fed other fish in the form of fishmeal or oil. Salmon, shrimp and trout aquaculture alone accounts for almost 50% of all fishmeal used in aquaculture, but provides less than 10% of the production volumes (Deutsch et al ., 2007). In 2006, aquaculture con- sumed 3.06 million tonnes (56%) of world fishmeal production and 780,000 tonnes (87%) of total fish oil production. Over 50% of the sector’s use of fish oil occurs on salmon farms. Fish- meal and fish oil production has remained stagnant over the last decade and significant increases in their production are not THE FEED BOTTLENECK

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