BBC – Future – Science & Environment – How the world’s oceans could be running out of fish.
Entire species of marine life will never be seen in the Anthropocene (the Age of Man), let alone tasted, if we do not curb our insatiable voracity for fish. Last year, global fish consumption hit a record high of 17 kg (37 pounds) per person per year, even though global fish stocks have continued to decline. On average, people eat four times as much fish now than they did in 1950.
Around 85% of global fish stocks are over-exploited, depleted, fully exploited or in recovery from exploitation. Only this week, a report suggested there may be fewer than 100 cod over the age of 13 years in the North Sea between the United Kingdom and Scandinavia. It’s a worrying sign that we are losing fish old enough to create offspring that replenish populations…
The policy of subsidising vast fishing fleets to catch ever-diminishing stocks is unsustainable. In Spain, for example, one in three fish landed is paid for by subsidy. Governments, concerned with keeping jobs alive in the fishing industry in the short-term, are essentially paying people to extinguish their own long-term job prospects – not to mention the effect on the next generation of fishermen. Artisanal fishing catches half the world’s fish, yet it provides 90% of the sector’s jobs...
Clearly, industrialised countries are not about to return to traditional methods. However, the disastrous management of the industry needs to be reformed if we are to restore fisheries to a sustainable level. In the EU alone, restoring stocks would result in greater catches of an estimated 3.5 tonnes, worth £2.7 billion a year…
In severely depleted zones, the only way to restore stocks is by introducing protected reserves where all fishing is banned. In other areas, quota compliance needs to be properly monitored – fishing vessels could be licensed and fitted with tracking devices to ensure they don’t stray into illegal areas, spot-checks on fish could be carried out to ensure size and species, and fish could even be tagged, so that the authorities and consumers can ensure its sustainable source…
Humanity is not limiting its impacts to fish most commonly found on menus. Exotic sea creatures from turtles to manta ray to marine mammals are being hunted to extinction. Shark numbers, for example, have declined by 80% worldwide, with one-third of shark species now at risk of extinction. The top marine predator is no longer the shark, it’s us.
A decline in shark numbers has a significant impact on the marine ecosystem: it can lead to an increase in fish numbers further down the food chain, which in turn can cause a crash in the population of very small marine life, such as plankton. Without the smallest creatures, the entire system is threatened.
One of the repercussions, which I have discussed before, is an increase in jellyfish numbers, but overfishing, pollution, climate change and acidification also affect the marine ecosystem. Warmer waters are pushing species into different habitats, causing some to die off and others to adapt by creating entirely new hybrid species. Meanwhile, trawlers are netting bycatch that include marine mammals and even seabirds – as many as 320,000 seabirds are being killed annually when they get caught in fishing lines, pushing populations of albatrosses, petrels and shearwaters to the edge of extinction.
Some solutions are easier than you might think. Seabirds can be protected by using weighted lines and scaring off birds with lines that have flapping streamers attached – these methods alone have reduced seabird deaths by more than 85-99% where they are used…
[Solutions?] For example, one study found that designating just 20 sites – 4% of the world’s oceans – as conservation zones could protect 108 species (84%) of the world’s marine mammals.
The rivers in many European cities were so overfished, polluted and dammed up by the mid 20th century that they emptied of fish, and many species went locally extinct. But thanks to clean-ups, riverbank restoration and fishing restrictions, fish are returning to waterways, even in inner cities. A decade ago, few people would have imagined that salmon would return to my local river, the Thames. If it is possible to bring back fish to ‘dead’ rivers, there is surely hope for the world’s oceans.
