Improving the ocean starts at our coast

A review of the Second World Ocean Assessment

The Second World Ocean Assessment was released in April, in connection with Earth Day 2021. The assessment involved contributions from more than 300 scientists from the UN’s group of experts chosen from around the world, and provides a comprehensive and integrated review of scientific information on the state of the marine environment.

The assessment is aimed towards people in all sectors who will be making decisions that affect the marine environment, and has a strong focus on the importance of coastal regions, including the coastal ocean and the land adjacent to the sea. The report, thousands of pages in length, covers the five principal drivers that are accelerating these changes: population growth; changes in economic activity, technological advances, changing governance structures, and climate change. Ocean heat content has more than doubled since the 1990s, severely affecting marine life and ecosystems; and marine litter is present throughout the ocean and along shorelines worldwide.

Professor Colin Woodroffe is a coastal geomorphologist at the University of Wollongong and contributed to the World Ocean Assessment. He says the coast is both the most productive part of the ocean, and the most impacted. However, many of our most significant gaps in understanding also occur in coastal waters.

“The latest assessment notes that the health of the ocean has not improved since 2015, and many of the benefits that the ocean provides to people such as food, jobs, medicine and climate regulation are increasingly being undermined by human activities.”

“A starting point to remedy this is a more thorough understanding of the state of the ocean across its many parts, including, indeed especially, the coast.” In launching the Second World Ocean Assessment, UN Secretary General, stressed that the ocean is the life-support system of our planet, but it is near its carrying capacity. Pressures from human actions are impacting important coastal ecosystems, such as mangroves and coral reefs. Processes on land are contributing pollutants to the sea, including plastics. Overfishing, much of which occurs in coastal waters, has resulted in enormous economic losses, and the carbon we are releasing into the atmosphere is driving warming and acidification, also threatening biodiversity with alarming consequences for coral reefs.

“There is broad consensus that more than 90% of the heat from global warming is stored in the ocean, which is becoming more acidic. The effects of increased heat and acidification on marine and coastal ecosystems urgently requires much more research,” said Professor Woodroffe, noting the recurrent bleaching of corals that has been endangering the Great Barrier Reef.

The Second World Ocean Assessment brought to light a whole range of issues relevant to the coast, many of which are being investigated by UOW researchers including the alarming pace of sea-level rise and coastal erosion, with many coastlines worldwide experiencing retreating shorelines. Professor Woodroffe points to a changing perspective on mangroves, which although being cleared and continuing to decrease in area in some parts of the world, are now recognised for the valuable role they play in coastal protection and in the sequestration of blue carbon.

Sylvia Earle, internationally-acclaimed oceanographer, scuba diver, and research scientist, notes that we have only seen about ten percent of the ocean floor, and most of the seabed is yet to be explored. She reiterates society’s dependence on the sea and its resources, saying “The ocean is in trouble. We need the ocean and the ocean now needs us to take care of the systems that make our existence possible.”

The assessment recognises the increasing impacts that population growth will have on offshore waters. With an estimated 71% increase in global population from 2000 to 2050, augmented by migration to coastal settlements, over 1 billion people will be living in coastal regions.

Coastal communities play a key role when it comes to the ocean economy, as a recent emphasis on the ‘blue economy’ has indicated. Ports support shipping which carries about 90% of the volume of international trade. Coastal tourism is growing, whether this comprises ‘sun, sea and sand’ tourists, or more focused ecotourism.

While the assessment raises several troubling insights, there were some positives. The report notes that some pressures have been reduced since 2015, partly through establishment of additional marine protected areas, and, in some regions, improved management of pollution and fisheries. However, these trends vary considerably from region to region.

“We have seen developments in coastal protection strategies that supplement structural engineering approaches with softer more environmentally sustainable forms of coastal stabilisation.”

“It is also encouraging to see that innovations in various remote sensing technologies have enabled the discovery of nearly 11,000 new marine benthic invertebrate species and more than 200 species of fishes since 2015.”

Professor Woodroffe says a clearer dialogue between scientists and policy-makers is needed and we are starting to see that relationship forming at both global and local level.

There are clearer processes by which local and state government look after coastal environments. The Coastal Reforms of recent years, particularly the Coastal Management Act of 2016 and its implementation through coastal management programs, has been effective. “Small steps are being made towards a better coast, and for the first time we might be able leave our coast in a better state than we found it.”

A key feature of the assessment was relating present understanding to the UN Sustainable Development Goals, which were developed to promote human aspirations for a sustainable and equitable future.

The UN Decade of Ocean Science for Sustainability also launched this year. The initiative sets a plan towards the 2030 Agenda for Sustainable Development focused on the theme: ‘the science we need for the ocean we want’.

“It is promising to see that the world is embarking on working towards a better ocean. It is a great goal to which to aspire, but the Second World Ocean Assessment indicates more needs to be done.”