Populations of fish species for human consumption have fallen by half, with some of the most important species experiencing even greater declines. For example tuna and mackerel have fallen by 74%.
The worrying fact is revealed in WWF’s new Living Blue Planet report that focuses on species, habitat and human well-being. The authors analysed more than 1,200 species of marine creatures in the past 45 years. Sadly, the populations of marine mammals, birds, fish and reptiles have declined by 49% since 1970.
3 billion’s source of protein
Given that three billion people rely on fish as their main source of protein and the 60% of the world’s population lives within 100 km of the coast the decline in fish stocks are concerning.
One of the key reasons for the decline in fish stocks are overfishing. 29% of marine fisheries are overfished. What is interesting is to note Stockholm Resilience Centre’s research on overfishing, which found that only 13 companies control 40% of the largest and most valuable “keystone” fish stocks.
This gives hope that if one can influence these 13 companies one might be able to turn around the negative trend before it is too late.
Decline in marine habitats
In addition to human activity such as overfishing, the report also says climate change is having an impact. Carbon dioxide is being absorbed into the oceans, making them more acidic, damaging a number of species.
For instance, tropical reefs have lost more than half their reef-building corals over the last 30 years. If current rates of temperature rise continue, the ocean will become too warm for coral reefs by 2050. Worldwide, nearly 20% of mangrove cover was lost between 1980 and 2005.
The decline of habitats – such as coral reefs, seagrass areas and mangrove cover – are concerning as they are important for food and act as a nursery for many species.
And with a rapidly growing population, the pressure on the world’s ocean are likely to become even greater.
Huge economic contributions
Additional concerns for the marine life includes seabed mining licences that cover 1.2 million square kilometres of ocean floor; more than five trillion plastic pieces weighing over 250,000 tonnes are in the sea; and oxygen-depleted dead zones are growing as a result of nutrient run-off primarily from agriculture.
All these damages are problematic for the ocean that generates economic benefits worth at least USD 2.5 trillion per year. Despite the massive economic contribution, only 3.4% of the ocean is protected, and only part of this is effectively managed.
The report recommends increasing marine protected area coverage to 30% as it could generate up to USD 920 billion between 2015 and 2015. It would be fantastic if one could achieve even half of that.
Read the full Living Blue Planet report.