Turn the tide
If humanity continues to destroy the oceans, we will ultimately destroy ourselves in the process, says marine biologist Callum Roberts
Oliver Purcell
© Getty Images
On the surface, the world’s oceans look much as they have done for thousands of years. Yet, underneath, the seas are changing faster than ever before. Ocean of Life – the fate of man and the sea , a challenging book by Callum Roberts, describes the past, present and future states of the world’s oceans in relation to global fishing practices, mass pollution and protection of endangered marine areas.
FROM PLENTY TO SCARCITY
For thousands of years humans battled the oceans of the world in pursuit of fish. Old oil paintings and photos provide historical evidence of the bountiful catch sizes of the past. However, in recent decades, species numbers have dramatically dwindled and some species forced to extinction as humankind developed the necessary skills to trawl the oceans to their very depths.
Today, while each advance in fishing techniques and technology has made it easier to harvest the oceans, there is a price to be paid. Stocks continue to drop rapidly. “Further increases in efficiency won’t spare the fishing industry from its demise when there’s nothing left to catch”, says Roberts in a recent interview with PROJECT M.
As a marine scientist and conservationist at the University of York, he is a frequent keynote speaker at environmental conferences around the globe. His experience and research in studying years of fishery statistics buttresses his findings in his most recent book. Ocean of Life (Penguin,), a grim account of the state of the oceans.
CHANGING EATING HABITS
We need to act now in order to protect future generations from the impacts that we are causing today
According to Roberts, the degree of degradation caused by fishing varies around the globe. For example, the Mediterranean – the origin of the fishing industry – has been exploited for thousands of years, so shows more signs of damage than the South Pacific, which has been fished less intensively for a shorter amount of time.
Listen to the interview with Callum Roberts.
But the impact of human activities has reached every corner of the globe, even to the deepest recesses of the oceans. Modern fishing techniques like bottom trawling and dredging – when a trawl net is dragged across the seabed – cause immense damage to anything living near or on the ocean floor.
Trawler catches are falling as fish numbers decline. In the past, human eating patterns adapted to such changes. Once considered bait to catch larger-sized fish, such as cod and halibut, lobster and prawns have become main course dishes. Now, as stocks of these crustaceans decline, jellyfish is being consumed regularly in some Asian cultures.
World Oceans Day
In, the United Nations General Assembly passed a resolution officially recognizing June 08 as World Oceans Day. The goal is to highlight the important role played by the world’s oceans in the lives of billions of people, plants and animals around the globe, and how the oceans can be protected.
JELLYFISH JOYRIDE IN ACIDIC WATERS
Climate change, named after its known influence on the Earth’s weather systems, has led to a steady increase in ocean temperature. And warmer waters hold less oxygen. As oxygen levels fall, the growth rate of fish slows affecting not only their physical size but also the amount of offspring produced.
This leads to less of the oxygen loving bigger fish such as tuna and more organisms that can live under hypoxic conditions. Scientists predict that jellyfish, one such creature, will thrive throughout the 21st century. Water-soluble carbon dioxide released into the atmosphere mainly from the burning of fossil fuels not only causes global warming but can increase ocean acidity levels.
Shell-bearing creatures will suffer most from ocean acidification as their calcium carbonate shells weaken in such waters. Even more worrying, says Mr. Roberts is that, “any acidification that we produce in the coming decades is going to be irreversible on a timescale of centuries.”
We have to continue to curb and reduce pollution of all kinds
Yet there is hope. Countries around the globe are taking positive steps towards protecting and cleaning the oceans. The Stockholm Convention, signed by 50 countries in, focuses on eliminating or reducing releases of 12 persistent organic pollutants, the so-called ‘Dirty Dozen.’ Sewage and nutrient inputs to the oceans are continually being reduced, especially among developed countries, while the latest advancements in technology include carbon capture and storage where lethal emissions of carbon are extracted from the atmosphere.
Callum Roberts is optimistic stating “knowing the alternative is self-destruction and encouraged by efforts over the last decade, humankind can and will change.”
