Ocean populations almost halved since 1970

Marine mammal, birds, fish and reptile populations have almost halved since 1970, according to a report which is a “wake-up call” to tackle the crisis in the world’s oceans.

The study by conservation group WWF and the Zoological Society of London looked at how 5,829 populations of 1,234 species of marine creatures had fared in the past 45 years and found a 49% drop in numbers in the face of over-fishing and habitat loss.

Some species people rely on for food are faring even worse, such as the Scombridae family of fish which includes tuna and mackerel have fallen by almost three quarters (74%).