Excessive pressures on ocean resources
The cumulative impact of human activities have pushed the oceans’ carrying capacity almost to its limit, according to “The First Global Integrated Marine Assessment” carried out under the United Nations and released on January 22.
The report, which assesses the state of the world’s oceans from the scientific as well as socio-economic point of view, was presented at and endorsed by the UN General Assembly in December 2015.
It warns that climate change, over exploitation of marine living resources, increased uses of ocean space, rising pollution and other factors have placed excessive pressure on oceans. It also states that sustainable use of oceans cannot be achieved without coherent management of all sectors of human activities affecting the oceans and addressing the delay in implementing known solutions. “Human impacts on the sea are no longer minor in relation to the overall scale of the ocean. A coherent overall approach is needed,” the report says.
Headed by a 22-member Group of Experts, the report brings together findings from the world over with the aim of providing scientific evidence so that governments and other policy makers can make informed decisions. UN Secretary-General Ban Ki-moon writes in the foreword that the assessment report will help in the implementation of the recently adopted Sustainable Development Goals (SDGs), particularly SDG14 which pertains to conservation and sustainable use of oceans, seas and marine resources. “It is clear that urgent action on a global scale is needed to protect the world’s oceans from the many pressures they face,” Ban Ki-moon writes.
Human impacts on oceans
Some 361.9 million square kilometres of ocean area is divided among 7.3 billion of the world’s population. The report explains that each of us have only one-fifth of a cubic kilometre of ocean out of which we derive our annual oxygen supply, lifetime freshwater supply and all the seafood we eat. Our dependence on the oceans has influenced the location of our settlements, economic activities and social rules, including national and international oceans laws and treaties. But with the dramatic rise in human activities, we are placing an increasing burden on ocean resources. By the year 2050, global population is estimated to touch 10 billion, leaving only one-eighth of a cubic kilometre of the ocean for each person’s needs.
We are also subjecting oceans to negative impacts of our activities. The report highlights stratospheric fall-out from atmospheric nuclear-weapons testing as a prime example. Testing of large nuclear weapons leads to long-term and nearly worldwide deposition of deposition of radioactive materials, even if it is limited to a particular area. Man-made hazards such as oil spills and economic activities like overfishing and unregulated tourism on beaches harm marine life. In this way, the report has examined and listed some human pressures as follows:
- Climate change (ocean acidification and changing salinity and oxygen content, among others)
- Inputs to the ocean (such as toxic substances, plastics, waterborne pathogens)
- Human-induced mortality and physical disturbance of marine biota (such as capture fisheries, including by-catch)
- Demand for ocean space and changes in use of coasts and seabed
- Underwater noise (from shipping, sonar and seismic surveys)
- Interference with migration from structures in the sea or other changes in routes along coasts (wind farms, barrages, coast reinforcement)
- Introduction of non-native species
Gaps in management of human impacts
Availability of comprehensive data is critical for governments and other bodies to make informed decisions about the impact of human activities on oceans. This may pose a challenge, says the report, because it requires bringing together a large number of different sets of data. The assessment reveals that while we have a general qualitative understanding of impacts on oceans, more quantified information is needed to make the information more acceptable.
Techniques for collating all this information are still a work in progress, the report adds. It gives the example of theOcean Health Index which is an attempt to produce a comprehensive numerical assessment of the ocean at the highest possible level. The Index, however, suffers from the lack of reliable data and ends up counting estimates and allowing subjectivity to creep in.
Hence, the report makes a case for developing methods for integrated assessments, which not only take into account all scientific, social and economic aspects but also give quantified information about oceans in all parts of the world.
Impact of fisheries on marine biodiversity
Harnessing the ocean’s fish and shellfish reserves for human consumption and industrial purposes achieves record-breaking proportions each year. FAO data shows that production of fish from capture fisheries and aquaculture has grown at the rate of 3.2 percent in the past 50 years, from about 20 to nearly 160 million tonnes by 2012. Of this, capture fisheries accounted for around 80 million tonnes. Eleven Asian countries—led by China, Indonesia, Japan and India—and seven others together were responsible for 76 percent of production from capture fisheries.
An estimated 3.7 million fishing vessels operate in marine waters globally; 68 per cent of these operate from Asia and 16 per cent from Africa. The fisheries and aquaculture sector employs around 58.3 million people.
First recognised in the 19th century, the impacts of capture fisheries—catching of naturally occurring fish and other aquatic organisms—were given a proper formal platform with the establishment of Food and Agriculture Organization (FAO) in 1946.
Overfishing remains a critical problem with FAO stating that 29 per cent of assessed stocks are presently overfished.
(The views expressed are strictly personal)