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.

Can buying up fishing licences save Australia’s sharks?

Christopher Brown, Griffith University and Samantha Munroe, Griffith University

The World Wildlife Fund (WWF) recently raised over A$200,000 to buy shark fishing licences in Queensland’s waters. They estimate the licences, for operating nets in and around the Great Barrier Reef Marine Park, could have been used to catch 10,000 sharks each year.

Retiring these licences is a new development in Australian shark conservation, but may also limit locally caught seafood.

But do Australia’s sharks need saving, or can we eat them? It depends on where you look.

Sustainable sharks

Sharks in general are much more vulnerable to overfishing than other fish. Compared to most fish, sharks have far fewer offspring over their lifetimes. As a result, shark populations cannot tolerate the same levels of fishing that fish can sustain.

Globally, there is great reason for concern over the status of sharks. About a quarter of all sharks and rays are threatened with extinction. The high value of shark fins in Asian markets drives a large and often unsustainable shark fishery that reaches across the globe.

Australia has an important role to play in combating this trend. Many species that are globally threatened can find refuge in the Great Barrier Reef Marine Park, which has an extensive system of protected areas and comparatively low fishing effort. Despite this potential safe haven, some species in Australia still rest on an ecological knife edge.

A white-tip reef shark in the Great Barrier Reef Marine Park.
Christopher Brown

For example, the great and scalloped hammerheads (which the WWF says will benefit from the licence purchase) are both by-catch species in the Australian fishery and are listed by the International Union for Conservation of Nature as endangered.

Australian fishermen don’t head out to catch hammerheads intentionally; most people do not consider the meat palatable. However, their hammer-shaped head is easily entangled in nets. Therefore hammerheads may be highly susceptible to any increase in fishing pressure.

Commercial fishers are legally required to have a licence. By buying the licences, WWF can limit the number of active nets in the water.

However, not all shark species are as vulnerable to fishing as the iconic hammerhead. Several shark species in Australia are well-managed. For instance, the spot tail shark is fast-growing and has many young, making it relatively resilient to fishing pressure. Many Australians regularly enjoy these species with a side of chips.

Species targeted by Queensland’s shark fishery are likely sustainable. The latest fishery assessment published by the Queensland government in 2014 found that catches of most shark species were well within safe limits.

Supporting our local shark fisheries is therefore far better than importing shark from overseas where fisheries may be poorly managed.

But it is not all good news in Australia. Both the assessment and an independent review found that while Queensland’s shark catch likely is sustainable, we need to be cautious about allowing any increases.

Importantly, Queensland’s 2014 shark assessment relies on very limited data. A crucial fishery observer program was cut in 2012. The limited data mean that regulations for Queensland’s shark catches are set conservatively low. Any increase in catch is risky without an assessment based on higher-quality data.

Scientists use tag-and-release programs to track the movements and population size of sharks. But more direct fisheries data are needed.
Samantha Munroe

A win for fishers and fish

Buying up licences in an uncertain fishery may be an effective way to prevent the decline of vulnerable species. Although buying licences is a new move for marine conservation groups in Australia, elsewhere it has proven an effective strategy for conservation and fisheries.

For instance, in California the conservation group Nature Conservancy bought fishing licences for rockfish, some species of which are endangered.

The Nature Conservancy now leases those licences back to fishers that promote sustainable fishing methods. The fishers themselves can charge a higher price for sustainable local catches of fish. What started as a move purely for conservation has had benefits for those employed in fisheries.

The lesson here is that conservation organisations can be the most productive when they work with, not against, fisheries. The recent shark licence purchase in Australia could be a great opportunity for fishers and conservation organisations to work together to maintain healthy ecosystems and fisheries.

But if Australians are serious about protecting sharks, there are other steps we still need to take. Queensland should reinstate the fishery observer program so we have reliable data to assess shark populations. For instance, currently we don’t know how many sharks are caught as by-catch in other fisheries.

A lemon shark seeks its fish prey in the shallow waters on Australia’s Great Barrier Reef. Lemon sharks are caught by our fisheries, but are not a target species.
Megan Saunders

Shark control programs designed to protect bathers are also a threat to endangered shark populations. However, data on deaths from shark control in Queensland were not accounted for in the government’s catch limits.

Accounting for these missing deaths could make a serious dent in our sustainable catch, an independent review found.

There is an opportunity to address these issues in Queensland’s upcoming fisheries management reform. Have your say here.

If conservation groups can work with fisheries, a more consistent and sustainable shark-fishing strategy may emerge. Australians can continue to be proud of our efforts to protect marine life, but can still enjoy shark for dinner.

Christopher Brown, Research Fellow, Australian Rivers Institute, Griffith University and Samantha Munroe, Postdoctoral research fellow, Australian Rivers Institute, Griffith University

This article was originally published on The Conversation. Read the original article.

Banning fishing has helped parts of the Great Barrier Reef recover from damage

Camille Mellin, Australian Institute of Marine Science; Aaron MacNeil, Australian Institute of Marine Science, and Julian Caley, Australian Institute of Marine Science

The world’s coral reefs face unprecedented threats. Their survival depends on how well they can cope with a long list of pressures including fishing, storms, coral bleaching, outbreaks of coral predators and reduced water quality. Together, these disturbances have caused the Great Barrier Reef to lose half of its coral cover since 1985.

One often-used way of protecting marine ecosystems is to close parts of the ocean to fishing, in no-take marine reserves. From research, we know that by reducing fishing you end up with more and bigger fish (and other harvested species such as lobsters).

But other benefits of protection might be more surprising. In a new study, we show that no-take reserves helped the Great Barrier Reef’s corals to resist a range of disturbances, such as bleaching, disease and crown-of-thorns starfish, and to recover more quickly from damage.

More exposure, but better protection

Our study used observations between 1993 and 2013 of 34 types of coral and invertebrates and 215 fish species on 46 reefs spread across the Great Barrier Reef. Among the 46 study reefs, 26 were open to fishing and 20 were in no-take marine reserves.

During the study period, several occurrences of coral bleaching, coral disease, storms and outbreaks of crown-of-thorns starfish were recorded.

The total number of disturbances affecting our study reefs increased in recent years (2010-12), mostly due to severe storms affecting the central and southern sections of the Great Barrier Reef. Among our study reefs, those located inside no-take marine reserves were more exposed to disturbance than those outside no-take marine reserves.

Our study showed that, inside no-take marine reserves, the impact of disturbance was reduced by 38% for fish and by 25% for corals compared with unprotected reefs. This means that no-take marine reserves benefit not only fish but entire reef communities, including corals, and might help to slow down the rapid degradation of coral reefs.

Damaged coral reef around Lizard Island a few days after cyclone Ita.
Photo by Tom Bridge, http://www.tethys-images.com

Faster recovery

In addition to greater resistance, reef organisms recovered more quickly from disturbance inside no-take marine reserves. After each disturbance, we measured the time that both coral and fish communities took to return to their pre-disturbance state.

We found coral communities took the longest to recover after crown-of-thorns starfish outbreaks. Outside no-take marine reserves, it took on average nine years for these communities to recover. It took just over six years inside no-take marine reserves.

Although there is more work to be done, one reason that reefs inside no-take zones are able to cope better with disturbances is that they preserve and promote a wider range of important ecological functions. Where fishing reduces the numbers of some species outside protected areas, some of these functions could be lost.

Coral reef showing signs of recovery.
Photo copyright Tom Bridge/www.tethys-images.com

Knowledge for conservation

Marine reserves (including no-take zones) currently cover 3.4% of the world’s ocean, which is still well below the 10% target for 2020 recommended by the Convention on Biological Diversity. The slow progress towards this target is partly due to the perceived high costs of protection compared to true ecological benefits, which can be difficult to gauge. While some surprising benefits are beginning to be revealed in studies like ours, such benefits remain little understood.

Our results help to fill that gap by showing that no-take marine reserves can boost both the resistance and recovery of reef communities following disturbance. In ecology, resistance plus recovery equals resilience.

Our work suggests that the net benefit of no-take marine reserves is much greater than previously thought. No-take marine reserves host not only more and bigger fishes, but more resilient communities that might decline at slower rates.

These results reinforce the idea that no-take marine reserves should be widely implemented and supported as a means of maintaining the integrity of coral reefs globally.

Our conclusions also demonstrate that we need long-term monitoring programs which provide a unique opportunity to assess the sustained benefits of protection.

Camille Mellin, Research Scientist, Australian Institute of Marine Science; Aaron MacNeil, Senior Research Scientist, Australian Institute of Marine Science, and Julian Caley, Senior Principal Research Scientist, Australian Institute of Marine Science

This article was originally published on The Conversation. Read the original article.