Can countries end overfishing and plastic pollution in just 10 years?

Henrik Österblom, Stockholm University

In my career as a marine biologist, I’ve been fortunate enough to visit some of the most remote islands in the world. These beautiful places continue to remind me why I have this job in the first place, but they also bring home the pervasive influence of human societies. Uninhabited bird colonies on the Canadian West Coast, remote tropical Japanese islands, and tiny bits of land in South East Asia all have one thing in common: plastic waste on the beach.

When at home in Sweden, I regularly swim and sail in the Baltic Sea. But agricultural fertilisers and other types of pollution have created dead zones where fish either leave or suffocate. Meanwhile, offshore fisheries and aquaculture farms in many parts of the world overharvest and pollute the water. We know what proper management of these activities could look like, but political will has so far not been equal to the challenge.

That may be about to change. A recent agreement between 14 heads of state – together representing 40% of the world’s coastline – promised to end overfishing, restore fish stocks and halt the flow of plastic pollution into the ocean within a decade.

A tropical beach strewn with plastic waste. — Ocean problems implicate every country – and demand coordinated solutions.
Musleemin Noitubtim/Shutterstock

Interconnected problems

Pollution, plastics and unsustainable seafood may look like isolated problems, but they influence each other. As nutrients run off farmland and into the sea, they affect the conditions fish need to thrive. Pollution makes our seafood less healthy and overfishing is pushing some fish stocks beyond their capacity to renew themselves.

All of these stresses are amplified by global warming. The ocean has been acting as a sink for CO₂ emissions and excess heat for decades, but there is only so much that marine ecosystems can take before collapsing. And we shouldn’t think these problems won’t affect us – stronger storms, fuelled by warmer ocean waters, are happening more often.

It’s in everyone’s interests to protect the ocean. Clean seas would be more profitable and research suggests that better managed fisheries could generate six times more food than they do currently. The exclusive economic zones of coastal states would be more productive if every country agreed to protect the high seas. And sailing in the Baltic Sea would be much nicer if the boat didn’t have to plough a thick, green sludge.

So how can the world make progress – and what’s holding us back?

International solutions

As part of the recent agreement between 14 heads of state, the participating countries – Australia, Canada, Chile, Fiji, Ghana, Indonesia, Jamaica, Japan, Kenya, Mexico, Namibia, Norway, Palau and Portugal – committed to a number of goals within their national waters, including investment in zero-emission shipping, eliminating waste and ensuring fisheries are sustainable. The aim is to ensure all activity within these exclusive economic zones is sustainable by 2025.

The countries agreed to fast-track their plan for action, rather than work through the UN. Their combined national waters roughly equal the size of Africa. They each have clear stakes in the continued functioning of ocean ecosystems and economies, so this pragmatic approach makes sense. That’s a sentiment that businesses could no doubt respect. After all, there are no economic opportunities in a dead ocean.

The agreement is an encouraging message from political leaders, and these states can leverage vast sums of money and resources to effect change. But the ocean is home to a dozen global industries, and around 50,000 vessels traverse it at any one time. Clearly, we need more than governments to deliver on this ambitious agenda.

Colourful shipping containers and cranes fill a bustling seaport. — Shipping accounts for nearly 90% of all global trade.
Harmony Video Production/Shutterstock

My scientific colleagues and I have been developing a global coalition of businesses concerned with sustainable seafood. Our strategy is to find “keystone actors” within the private sector – companies with a disproportionate ability to influence change due to their size and strength.

The seafood industry is vast, and includes some of the largest companies in the world – from entire fisheries, to aquaculture farms and feed processors. After four years of working together, change within the participating companies is accelerating. For example, Nissui, the world’s second-largest seafood company, has evaluated their entire production portfolio for sustainability challenges.

Collaboration between scientists and businesses is vital to delivering commitments made by governments. Scientists can help define the problems, and business can develop, pilot and scale solutions. For instance, we’re developing software that can automatically detect which species of fish are caught on vessels, to radically improve the transparency of seafood production.

The ocean has been a source of inspiration, imagination and adventure since the beginning of time. It has fed us and generated livelihoods for billions. Politicians have stood serenely on the sidelines for some time now, content to be passive observers of deteriorating ecosystems. But the era of passive observation may finally be coming to an end.

Henrik Österblom, Professor of Environmental Science, Stockholm University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We’ve just discovered two new shark species – but they may already be threatened by fishing

One of the newly discovered sixgilled sawshark species (*Pliotrema kajae*).
Simon Weigmann, Author provided

Per Berggren, Newcastle University and Andrew Temple, Newcastle University

Finding a species that’s entirely new to science is always exciting, and so we were delighted to be a part of the discovery of two new sixgill sawsharks (called Pliotrema kajae and Pliotrema annae) off the coast of East Africa.

We know very little about sawsharks. Until now, only one sixgill species (Pliotrema warreni) was recognised. But we know sawsharks are carnivores, living on a diet of fish, crustaceans and squid. They use their serrated snouts to kill their prey and, with quick side-to-side slashes, break them up into bite-sized chunks.

The serrated snout of a sixgill sawshark (*Pliotrema annae*).
Ellen Barrowclift-Mahon/Marine MEGAfauna Lab/Newcastle University., Author provided

Sawsharks look similar to sawfish (which are actually rays), but they are much smaller. Sawsharks grow to around 1.5 metres in length, compared to 7 metres for a sawfish and they also have barbels (fish “whiskers”), which sawfish lack. Sawsharks have gills on the side of their heads, whereas sawfish have them on the underside of their bodies.

A sixgill sawshark (*Pliotrema annae*) turned on its side, showing gills and barbels.
Ellen Barrowclift-Mahon, Author provided

Together with our colleagues, we discovered these two new sawsharks while researching small-scale fisheries that were operating off the coasts of Madagascar and Zanzibar. While the discovery of these extraordinary and interesting sharks is a wonder in itself, it also highlights how much is still unknown about biodiversity in coastal waters around the world, and how vulnerable it may be to poorly monitored and managed fisheries.

The three known species of sixgill sawshark. The two new species flank the original known species. From left to right: *Pliotrema kajae*, *Pliotrema warreni* (juvenile female) and *Pliotrema annae* (presumed adult female).
Simon Weigmann, Author provided

Fishing in the dark

Despite what their name might suggest, small-scale fisheries employ around 95% of the world’s fishers and are an incredibly important source of food and money, particularly in tropical developing countries. These fisheries usually operate close to the coast in some of the world’s most important biodiversity hotspots, such as coral reefs, mangrove forests and seagrass beds.

For most small-scale fisheries, there is very little information available about their fishing effort – that is, how many fishers there are, and where, when and how they fish, as well as exactly what they catch. Without this, it’s very difficult for governments to develop management programmes that can ensure sustainable fishing and protect the ecosystems and livelihoods of the fishers and the communities that depend on them.

Small-scale fishers of Zanzibar attending their driftnets.
Per Berggren/Marine MEGAfauna Lab/Newcastle University, Author provided

While the small-scale fisheries of East Africa and the nearby islands are not well documented, we do know that there are at least half a million small-scale fishers using upwards of 150,000 boats. That’s a lot of fishing. While each fisher and boat may not catch that many fish each day, with so many operating, it really starts to add up. Many use nets – either driftnets floating at the surface or gillnets, which are anchored close to the sea floor. Both are cheap but not very selective with what they catch. Some use longlines, which are effective at catching big fish, including sharks and rays.

In 2019, our team reported that catch records were massively underreporting the number of sharks and rays caught in East Africa and the nearby islands. With the discovery of two new species here – a global hotspot for shark and ray biodiversity – the need to properly assess the impact of small-scale fisheries on marine life is even more urgent.

*Pliotrema kajae*, as it might look swimming in the subtropical waters of the western Indian Ocean.
Simon Weigmann, Author provided

How many other unidentified sharks and other species are commonly caught in these fisheries? There is a real risk of species going extinct before they’re even discovered.

Efforts to monitor and manage fisheries in this region, and globally, must be expanded to prevent biodiversity loss and to develop sustainable fisheries. There are simple methods available that can work on small boats where monitoring is currently absent, including using cameras to document what’s caught.

A selection of landed fish – including sharks, tuna and swordfish.
Per Berggren, Author provided

The discovery of two new sixgill sawsharks also demonstrates the value of scientists working with local communities. Without the participation of fishers we may never have found these animals. From simple assessments all the way through to developing methods to alter catches and manage fisheries, it’s our goal to make fisheries sustainable and preserve the long-term future of species like these sawsharks, the ecosystems they live in and the communities that rely on them for generations to come.

Per Berggren, Marine MEGAfauna Lab, Newcastle University and Andrew Temple, Postdoctoral Research Associate in Marine Biology, Newcastle University

This article is republished from The Conversation under a Creative Commons license. Read the original article.