Many of the sea food favourites such as common octopus, pink conch and orange roughy are in rapid decline, according to a new study.
The researchers at the University of British Columbia, GEOMAR Helmholtz Centre for Ocean Research Kiel and the University of Western Australia looked at the biomass (weight of a given species’ population in water) and came up with the findings. They looked into the biomass of over 1,300 fish and invertebrate populations. As per the study, they found a steep decline in the population.
The researchers found that 82 per cent of the fish were far below levels that can produce maximum sustainable yields. They said that this was because of over fishing and the catch was beyond re-growth.
They found that 87 populations were in “very bad” category, with biomass levels at less than 20 per cent needed to maximize sustainable fishery catches. Moreover, the fishermen also catch less of these fishes even if they venture into the sea for longer periods.
Lead author Maria Deng Palomares said that it was the first time that such a global study of in the population biomass of exploited marine fish and invertebrates was conducted. She said that they looked at how the marine population have been doing in the past 60 years. The biomass found to have come down below the level that can produce optimal catches, she added.
The researchers made the calculations through computer intensive stock assessment methods such as CMSY and BSMY. Y noted the greatest decline in the southern temperate and polar Indian Ocean and the southern polar Atlantic Ocean. The population of marine wealth shrunk by over 50 per cent since 1950, they said. On the contrary, they found an increase in biomass or fish wealth in Northern Pacific Ocean. They found an increase by 800 per cent of the biomass in its polar and subpolar zones, and about 150 per cent in its temperate zone.