Pacific Island nations will no longer stand for Australia’s inaction on climate change


Michael O’Keefe, La Trobe University

The Pacific Islands Forum meeting in Tuvalu this week has ended in open division over climate change. Australia ensured its official communique watered down commitments to respond to climate change, gaining a hollow victory.

Traditionally, communiques capture the consensus reached at the meeting. In this case, the division on display between Australia and the Pacific meant the only commitment is to commission yet another report into what action needs to be taken.

The cost of Australia’s victory is likely to be great, as it questions the sincerity of Prime Minister Scott Morrison’s commitment to “step up” engagement in the Pacific.




Read more:
Can Scott Morrison deliver on climate change in Tuvalu – or is his Pacific ‘step up’ doomed?


Australia’s stance on climate change has become untenable in the Pacific. The inability to meet Pacific Island expectations will erode Australia’s influence and leadership credentials in the region, and provide opportunities for other countries to grow influence in the region.

An unprecedented show of dissent

When Morrison arrived in Tuvalu, he was met with an uncompromising mood. In fact, the text of an official communique was only finished after 12 hours of pointed negotiations.

While the “need for urgent, immediate actions on the threats and challenges of climate change”, is acknowledged, the Pacific was looking for action, not words.

What’s more, the document reaffirmed that “strong political leadership to advance climate change action” was needed, but leadership from Australia was sorely missing. It led Tuvaluan Prime Minister Enele Sopoaga to note:

I think we can say we should’ve done more work for our people.

Presumably, he would have hoped Australia could be convinced to take more climate action.

In an unprecedented show of dissent, smaller Pacific Island countries produced the alternative Kainaki II Declaration. It captures the mood of the Pacific in relation to the existential threat posed by climate change, and the need to act decisively now to ensure their survival.

And it details the commitments needed to effectively address the threat of climate change. It’s clear nothing short of transformational change is needed to ensure their survival, and there is rising frustration in Australia’s repeated delays to take effective action.

Australia hasn’t endorsed the alternative declaration and Canberra has signalled once and for all that compromise on climate change is not possible. This is not what Pacific leaders hoped for and will come at a diplomatic cost to Australia.




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Response to rumours of a Chinese military base in Vanuatu speaks volumes about Australian foreign policy


Canberra can’t buy off the Pacific

Conflict had already begun brewing in the lead up to the Pacific Islands Forum. The Pacific Islands Development Forum – the brainchild of the Fijian government, which sought a forum to engage with Pacific Island Nations without the influence of Australia and New Zealand – released the the Nadi Bay Declaration in July this year.

This declaration called on coal producing countries like Australia to cease all production within a decade.

But it’s clear Canberra believes compromise of this sort on climate change would undermine Australia’s economic growth and this is the key stumbling block to Australia answering its Pacific critics with action.

As Sopoaga said to Morrison:

You are concerned about saving your economy in Australia […] I am concerned about saving my people in Tuvalu.

And a day before the meeting, Canberra announced half a billion dollars to tackle climate change in the region. But it received a lukewarm reception from the Pacific.

The message is clear: Canberra cannot buy off the Pacific. In part, this is because Pacific Island countries have new options, especially from China, which has offered Pacific island countries concessional loans.




Read more:
As Australia’s soft power in the Pacific fades, China’s voice gets louder


China is becoming an attractive alternate partner

As tension built at the Pacific Island Forum meeting, New Zealand Foreign Minister Winston Peters argued there was a double standard with respect to the treatment of China on climate change.

China is the world’s largest emitter of climate change gasses, but if there is a double standard it’s of Australia’s making.

Australia purports to be part of the Pacific family that can speak and act to protect the interests of Pacific Island countries in the face of China’s “insidious” attempts to gain influence through “debt trap” diplomacy. This is where unsustainable loans are offered with the aim of gaining political advantage.

But countering Chinese influence in the Pacific is Australia’s prime security interest, and is a secondary issue for the Pacific.

But unlike Australia, China has never claimed the moral high ground and provides an attractive alternative partner, so it will likely gain ground in the battle for influence in the Pacific.

For the Pacific Island Forum itself, open dissent is a very un-Pacific outcome. Open dissent highlights the strains in the region’s premier intergovernmental organisation.

Australia and (to a lesser extent) New Zealand’s dominance has often been a source of criticism, but growing confidence among Pacific leaders has changed diplomatic dynamics forever.




Read more:
Climate change forced these Fijian communities to move – and with 80 more at risk, here’s what they learned


This new pacific diplomacy has led Pacific leaders to more steadfastly identify their security interests. And for them, the need to respond to climate change is non-negotiable.

If winning the geopolitical contest with China in Pacific is Canberra’s priority, then far greater creativity will be needed as meeting the Pacific half way on climate change is a prerequisite for success.The Conversation

Michael O’Keefe, Head of Department, Politics and Philosophy, La Trobe University

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

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Can Scott Morrison deliver on climate change in Tuvalu – or is his Pacific ‘step up’ doomed?



Pacific leaders don’t want to talk about China’s rising influence – they want Scott Morrison to make a firm commitment to cut Australia’s greenhouse gas emissions.
Mick Tsikas/AAP

Tess Newton Cain, The University of Queensland

This week’s Pacific Islands Forum comes at an important time in the overall trajectory of Prime Minister Scott Morrison’s very personal commitment to an Australian “stepping up” in the Pacific.

To paraphrase the PM, you have to show up to step up. And after skipping last year’s Pacific Islands Forum, Morrison has certainly been doing a fair amount of showing up around the region, with visits to Vanuatu and Fiji at the beginning of the year and the Solomon Islands immediately after his election victory.

Add to this his recent hosting of the new PNG prime minister, James Marape, and it is clear there has been significant energy devoted to establishing personal relationships with some of the leaders he will sit down with this week.

An ‘existential threat’ to the region

Regional politics and diplomacy in the Pacific are not for the faint of heart. It’s clear from the tone of recent statements by Foreign Minister Marise Payne and the minister for international development and the Pacific, Alex Hawke, that there is some disquiet ahead of the Tuvalu get-together.

And with good reason. For some time, the leaders of the region have been becoming increasingly vocal about the lack of meaningful action from Canberra when it comes to climate change mitigation.




Read more:
Yes, Morrison ‘showed up’ in the Pacific, but what did he actually achieve?


Most recently, ten of the Pacifc Islands Development Forum (PIDF) members signed the Nadi Bay Declaration, which advocated a complete move away from coal production and specifically criticised using “Kyoto carryover credits” as a means of achieving Paris targets on reducing emissions.

While this body does not have the regional clout of the Pacific Islands Forum, its membership includes key players, notably Fiji, Tuvalu, and the Republic of the Marshall Islands, whose leaders have all spoken out strongly on the need for stronger action on climate change.

In a speech last month, Fijian Prime Minister Frank Bainimarama urged his fellow Pacific leaders to withstand any attempts to water down commitments on climate challenge in the region and globally.

Bainimarama’s warning: ‘Our region remains on the front line of humanity’s greatest challenges’

Bainimarama is attending this year’s Pacific Islands Forum for the first time since 2007, and has already made his presence felt. Earlier this week, he urged Australia to transition as quickly as possible from coal to renewable energy sources, because the Pacific faces

an existential threat that you don’t face and challenges we expect your governments and people to more fully appreciate.

Losing credibility on its ‘step up’

Given the state of Australia’s domestic politics when it comes to making climate change action more of a priority, it is hard to see how Morrison can deliver what the “Pacific family” is asking for.

The recent announcement of A$500 million to help Pacific nations invest in renewable energy and fund climate resilience programs is sure to be welcomed by Pacific leaders. As is the pledge for A$16m to help tackle marine plastic pollution.

But none of this money is new money – it’s being redirected from the aid budget. And it does not answer the call of Pacific leaders for Australia to do better when it comes to cutting emissions.

An aerial view of Funafuti, the most populous of Tuvalu’s country’s nine atolls.
Mick Tsikas/AAP

Why does this matter? Because it’s becoming increasingly obvious that the inability – or refusal – to be part of the team when it comes to climate change is undermining Australia’s entire “Pacific step-up”.

If Morrison, and the Australian leadership more broadly, want to reassure Pacific leaders that Australia’s increased attention on the region is not just all about trying to counter Chinese influence, this is where the rubber hits the road.

This is not about whether China is doing better when it comes to climate change mitigation than Australia. The Pacific has greater expectations of Australia, not least because Australian leaders have been at pains to tell the region, and the world, that this is where they live – that Pacific islanders are their “family”.

And for Pacific islanders, if you are family, then there are obligations. This week, as has been the case previously, Pacific leaders will make clear that addressing climate change is their top priority, not geopolitical anxieties over China’s increasing role in the region.




Read more:
Everything but China is on the table during PNG prime minister’s visit


There is little doubt that Australia’s “Pacific step-up” is driven by concerns about the rising influence of China. But Morrison knows better than to voice concerns of that type – at least in public – while in Tuvalu.

Numerous Pacific leaders have made it clear that as far as they are concerned, partnerships with Beijing (for those that have them) provide for greater opportunity and choice.

While they welcome renewed ties with traditional partners like Australia and New Zealand, they maintain a “friends to all and enemies to none” approach to foreign policy. That is unlikely to change any time soon.

Tuvalu’s Prime Minister Enele Sopoaga has warned Australia that its Pacific ‘step up’ could be undermined by a refusal to act on climate change.
Mick Tsikas/AAP

Will Tuvalu prove a turning point?

Tuvalu Prime Minister Enele Sopoaga may well be hoping that when Morrison sees for himself how climate change is affecting his country, he will be so moved personally, he will shift Australia’s stance politically.

Indeed, on arrival in the capital of Funafuti this week, leaders are being met by children sitting in pools of seawater singing a specially written song “Save Tuvalu, Save the World”.

So what can Morrison realistically be expected to achieve during the summit? He will be able to demonstrate Australia’s commitment to other issues that are important to regional security, such as transnational and organised crime and illegal fishing.

He can also hope the personal relationships he has cultivated with Pacific leaders deliver returns by way of compromise around the wording of the final communique, if only to avoid a diplomatic stoush.

But if there is no real commitment to cutting greenhouse gas emissions, he will leave plenty of frustration behind when he returns to Australia.The Conversation

Tess Newton Cain, Adjunct Associate Professor, School of Political Science & International Studies, The University of Queensland

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

Australia Institute analysis adds to Pacific pile-on over Morrison’s climate policy


Michelle Grattan, University of Canberra

An analysis from The Australia Institute accuses Scott Morrison of planning to exploit a “pollution loophole” equivalent to about eight years of fossil-fuel emissions from the rest of the Pacific and New Zealand.

The “loophole” is using Kyoto credits to help the government meet its emissions reduction target.

The progressive think tank issued its salvo ahead of the Pacific Island Forum in Tuvalu, which Morrison is attending and starts today.

Anxious to sandbag the Australian government against criticism over its climate policy from island countries, for which the climate change issue is major, Morrison has announced Australia is redirecting $500 million of the aid budget over five years to go to “investing for the Pacific’s renewable energy and its climate change and disaster resilience”.

But Tuvalu’s Prime Minister Enele Sopoaga quickly said the money should not be a substitute for action.

“No matter how much money you put on the table, it doesn’t give you the excuse not to do the right thing,” he said on Tuesday.

“Cutting down your emissions, including not opening your coal mines, that is the thing we want to see,” he said.

Fiji’s Prime Minister Frank Bainimarama said this week: “I appeal to Australia to do everything possible to achieve a rapid transition from coal to energy sources that do not contribute to climate change”.

Morrison said on Tuesday: “Australia’s going to meet its 2030 Paris commitments. Australia’s going to smash its 2020 commitments when it comes to meeting our emissions reduction targets. So Australia meets its commitments, and we will always meet our commitments. And that is a point that I’ll be making again when I meet with Pacific leaders.”

Morrison confirmed before the election that Australia would use credits from overachieving on its Kyoto 2020 targets to meet its 2030 emissions reduction target.

The Australian Institute said: “If Australia uses this loophole, it would be the equivalent of about eight times larger than the annual fossil fuel emissions of its Pacific neighbours.”

Australia intends to use 367 Mt of carbon credits to avoid the majority of emission reductions pledged under its Paris Agreement target. Meanwhile the entire annual emissions from the Pacific Islands Forum members, excluding Australia, is only about 45 Mt.

The institute’s director for climate change and energy, Richie Merzian, said the government’s plan to use Kyoto credits was an insult to Pacific islanders.

“You can’t ‘step up’ in the Pacific while stepping back on climate action,” he said.The Conversation

Michelle Grattan, Professorial Fellow, University of Canberra

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

Sharks: one in four habitats in remote open ocean threatened by longline fishing



Though they’re protected worldwide, great white sharks encounter longline fishing vessels in half of their range.
Wildestanimal/Shutterstock

David Sims, University of Southampton

Unlike the many species which stalk the shallow, coastal waters that fisheries exploit all year round, pelagic sharks roam the vast open oceans. These are the long-distance travellers of the submarine world and include the world’s largest fish, the whale shark, and also one of the fastest fish in the sea, the shortfin mako shark, capable of swimming at 40mph.

Because these species range far from shore, you might expect them to escape most of the lines and nets that fishing vessels cast. But over the last 50 years, industrial scale fisheries have extended their reach across the world’s oceans and tens of millions of pelagic sharks are now caught every year for their valuable fins and meat.

On average, large pelagic sharks account for over half of all shark species identified in catches worldwide. The toll this has taken on species such as the shortfin mako has prompted calls to introduce catch limits in the high seas – areas of the ocean beyond national jurisdiction where there is little or no management for the majority of shark species.

We wanted to know where the ocean’s shark hotspots are – the places where lots of different species gather – and how much these places are worked by fishing boats. We took up the challenge of finding out where pelagic sharks hang out by satellite tracking their movements with electronic tags. This approach by our international team of over 150 scientists from 26 countries has an important advantage over fishery catch records. Rather than showing where a fishing boat found them, it can precisely map all of the places sharks visit.

Nowhere to hide

For a new study published in Nature we tracked nearly 2,000 sharks from 23 different species, including great whites, blue sharks, shortfin mako and tiger sharks. We were able to map their positions in unprecedented detail and discern the most visited hotspots where sharks feed, breed and rest.

Hotspots were often located in frontal zones – boundaries in the sea between different water masses that can have the best conditions of temperature and nutrients for phytoplankton to bloom, which attracts masses of zooplankton, as well as the fish and squid that sharks eat.

Then we calculated how much these hotspots overlapped with global fleets of large, longline fishing vessels, which we also tracked by satellite. This type of fishing gear is used very widely on the high seas and catches more pelagic sharks than trawls and other gear. Each longline vessel is capable of deploying a 100km long line bearing over 1,000 baited hooks.

We found that even the most remote parts of the ocean that are many miles from land offer pelagic sharks little refuge from industrial-scale fishing fleets. One in four of the places sharks visited each month overlapped with the areas longline fishing vessels operated in.

Sharks such as the North Atlantic blue and the shortfin mako – which fishers also target for their fins and meat – were much more likely to encounter these vessels, with as much as 76% of the places these species visited most in each month overlapping with where longline vessels were fishing. Even internationally protected species such as great whites and porbeagle sharks encountered longline vessels in half of their tracked range.

It’s now clear that much of the world’s fishing activity on the high seas is centred on shark hotspots, which longlines rake for much of the year. Many large sharks, which are already endangered, face a future without refuge from industrial fishing in the places they gather.

High seas marine protected areas

The maps of shark hotspots and longline fishing activity that we created can at least provide a blueprint for where large-scale marine protected areas aimed at conserving sharks could be set. Outside of these, strict quotas could reduce catches.

The United Nations is creating a high seas treaty for protecting ocean biodiversity – negotiations are due to continue in August 2019 in New York. They’ll consider large-scale marine protected areas for the high seas and we’ll suggest where these could be located to best protect pelagic sharks.

Satellite monitoring could give real-time signals of where sharks and other threatened creatures such as turtles and whales are gathering. Tracking where these species roam and where fishers interact with them will help patrol vessels monitor these high-risk zones more efficiently.

Such management action is overdue for many shark populations in the high seas. Take North Atlantic shortfin makos – not only are they overfished
and endangered, but now we know they have no respite from longline fishing during many months of the year in the places they gather most often. Some of these shark hotspots may not exist in the near future if action isn’t taken now to conserve these species and the habitats they depend on.The Conversation

David Sims, Professor of Marine Ecology, University of Southampton

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

Study identifies nine research priorities to better understand NZ’s vast marine area



New Zealand’s coastline spans a distance greater than from the south pole to the north pole.
from http://www.shutterstock.com, CC BY-ND

Rebecca Jarvis, Auckland University of Technology and Tim Young, Auckland University of Technology

The islands of New Zealand are only the visible part of a much larger submerged continent, known as Te Riu a Māui or Zealandia. Most of New Zealand’s sovereign territory, around 96%, is under water – and this means that the health of the ocean is of paramount importance.

Most of the Zealandia continent is under water.
CC BY-SA

New Zealand’s marine and coastal environments have significant ecological, economic, cultural and social value, but they face many threats. Disjointed legislation and considerable knowledge gaps limit our ability to effectively manage marine resources.

With the UN decade of ocean science starting in 2021, it is essential that we meet the challenges ahead. To do so, we have asked the New Zealand marine science community to collectively identify the areas of research we should focus on.

Ten important science questions were identified within nine research areas. The full list of 90 questions can be found in the paper and policy brief, but these are the nine priority areas:




Read more:
No-take marine areas help fishers (and fish) far more than we thought



CC BY-ND

1. Food from the ocean

Fisheries and aquaculture are vital sources of food, income and livelihoods, and it is crucial that we ensure these industries are sustainable. Our study has identified the need for new methods to minimise bycatch, mitigate environmental impacts and better understand the influence of commercial interests in fishers’ ability to adequately conserve and manage marine environments.

2. Biosecurity

The number of marine pests has increased by 10% since 2009, and questions remain around how we can best protect our natural and cultural marine heritage. Future directions include the development of new techniques to improve the early detection of invasive species, and new tools to identify where they came from, and when they arrived in New Zealand waters.

3. Climate change

Climate change already has wide ranging impacts on our coasts and oceans. We need research to better understand how climate change will affect different marine species, how food webs might respond to future change, and how ocean currents around New Zealand might be affected.

Climate change already affects marine species and food webs.
CC BY-ND

4. Marine reserves and protected areas

Marine protected areas are widely recognised as important tools for marine conservation and fisheries management. But less than 1% of New Zealand’s waters is protected to date. Future directions include research to identify where and how we should be implementing more protected areas, whether different models (including protection of customary fisheries and temporary fishing closures) could be as effective, and how we might integrate New Zealand’s marine protection into a wider Pacific network.




Read more:
Squid team finds high species diversity off Kermadec Islands, part of stalled marine reserve proposal


5. Ecosystems and biodiversity

While we know about 15,000 marine species, there may be as many as 65,000 in New Zealand. On average, seven new species are identified every two weeks, and there is much we do not know about our oceans. We need research to understand how we can best identify the current baseline of biodiversity across New Zealand’s different marine habitats, predict marine tipping points and restore degraded ocean floor habitats.

6. Policy and decision making

New Zealand’s policy landscape is complicated, at times contradictory, and we need an approach to marine management that better connects science, decision making and action. We also need to understand how to navigate power in decision making across diverse interests to advance an integrated ocean policy.

7. Marine guardianship

Marine guardianship, or kaitiakitanga, means individual and collective stewardship to protect the environment, while safeguarding marine resources for future generations. Our research found that citizen science can help maximise observations of change and connect New Zealanders with their marine heritage. It can also improve our understanding of how we can achieve a partnership between Western and indigenous science, mātauranga Māori.

8. Coastal and ocean processes

New Zealand’s coasts span a distance greater than from the south pole to the north pole. Erosion and deposition of land-based sediments into our seas has many impacts and affects ocean productivity, habitat structure, nutrient cycling and the composition of the seabed.

Future research should focus on how increased sedimentation affects the behaviour and survival of species at offshore sites and on better methods to measure physical, chemical and biological processes with higher accuracy to understand how long-term changes in the ocean might influence New Zealand’s marine ecosystems.

9. Other anthropogenic factors

Our study identified a range of other human threats that need more focused investigation, including agriculture, forestry mining and urban development.
We need more research into the relative effects of different land-use types on coastal water quality to establishing the combined effects of multiple contaminants (pesticides, pharmaceuticals, etc) on marine organisms and ecosystems. Pollution with microplastics and other marine debris is another major issue.

We hope this horizon scan will drive the development of new research areas, complement ongoing science initiatives, encourage collaboration and guide interdisciplinary teams. The questions the New Zealand marine science community identified as most important will help us fill existing knowledge gaps and make greater contributions to marine science, conservation, sustainable use, policy and management.The Conversation

Rebecca Jarvis, Research Fellow, Auckland University of Technology and Tim Young, Marine Scientist, Auckland University of Technology

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

Daylight robbery: how human-built structures leave coastal ecosystems in the shadows



Human-built structures are home to a wide variety of creatures.

Martino Malerba, Monash University; Craig White, Monash University; Dustin Marshall, Monash University, and Liz Morris, Monash University

About half of the coastline of Europe, the United States and Australasia is modified by artificial structures. In newly published research, we identified a new effect of marine urbanisation that has so far gone unrecognised.

When we build marinas, ports, jetties and coastal defences, we introduce hard structures that weren’t there before and which reduce the amount of sunlight hitting the water. This means energy producers such as seaweed and algae, which use light energy to transform carbon dioxide into sugars, are replaced by energy consumers such as filter-feeding invertebrates. These latter species are often not native to the area, and can profoundly alter marine habitats by displacing local species, reducing biodiversity, and decreasing the overall productivity of ecosystems.

Incorporating simple designs in our marine infrastructure to allow more light penetration, improve water flow, and maintain water quality, will go a long way towards curbing these negative consequences.

Pier life

We are used to thinking about the effects of urbanisation in our cities – but it is time to pay more attention to urban sprawl in the sea. We need to better understand the effects on the food web in a local context.




Read more:
Concrete coastlines: it’s time to tackle our marine ‘urban sprawl’


Most animals that establish themselves on these shaded hard structures are “sessile” invertebrates, which can’t move around. They come in a variety of forms, from encrusting species such as barnacles, to tree-shaped or vase-like forms such as bryozoans or sponges. But what they all have in common is that they can filter out algae from the water.

In Australian waters, we commonly see animals from a range of different groups including sea squirts, sponges, bryozoans, mussels and worms. They can grow in dense communities and often reproduce and grow quickly in new environments.

The sheltered and shaded nature of marine urbanisation disproportionately favours the development of dense invertebrate communities, as shown here in Port Phillip Bay.

How much energy do they use?

In our new research, published in the journal Frontiers in Ecology and the Environment, we analysed the total energy usage of invertebrate communities on artificial structures in two Australian bays: Moreton Bay, Queensland, and Port Phillip Bay, Victoria. We did so by combining data from field surveys, laboratory studies, and satellite data.

We also compiled data from other studies and assessed how much algae is required to support the energy demands of the filter-feeding species in commercial ports worldwide.

In Port Phillip Bay, 0.003% of the total area is taken up by artificial structures. While this doesn’t sound like much, it is equivalent to almost 50 soccer fields of human-built structures.

We found that the invertebrate community living on a single square metre of artificial structure consumes the algal biomass produced by 16 square metres of ocean. Hence, the total invertebrate community living on these structures in the bay consumes the algal biomass produced by 800 football pitches of ocean!

Similarly, Moreton Bay has 0.005% of its total area occupied by artificial structures, but each square metre of artificial structure requires around 5 square metres of algal production – a total of 115 football pitches. Our models account for various biological and physical variables such as temperature, light, and species composition, all of which contribute to generate differences among regions.

Overall, the invertebrates growing on artificial structures in these two Australian bays weigh as much as 3,200 three-tonne African elephants. This biomass would not exist were it not for marine urbanisation.

Colonies of mussels and polychaetes near Melbourne.

How does Australia compare to the rest of the world?

We found stark differences among ports in different parts of the world. For example, one square metre of artificial structure in cold, highly productive regions (such as St Petersburg, Russia) can require as little as 0.9 square metres of sea surface area to provide enough algal food to sustain the invertebrate populations. Cold regions can require less area because they are often richer in nutrients and better mixed than warmer waters.

In contrast, a square metre of structure in the nutrient-poor tropical waters of Hawaii can deplete all the algae produced in the surrounding 120 square metres.

All major commercial ports worldwide with associated area of the underwater artificial structures (size of grey dots) and trophic footprint (size of red borders). Trophic footprints indicate how much ocean surface is required to supply the energy demand of the sessile invertebrate community growing on all artificial structures of the port, averaged over the year. This depends on local conditions of ocean primary productivity and temperature. Ports located in cold, nutrient-rich waters (dark blue) have a lower footprint than ports in warmer waters (light blue).

Does it matter?

Should we be worried about all of this? To some extent, it depends on context.

These dense filter-feeding communities are removing algae that normally enters food webs and supports coastal fisheries. As human populations in coastal areas continue to increase, so will demand on these fisheries, which are already under pressure from climate change. These effects will be greatest in warmer, nutrient-poor waters.

But there is a flip side. Ports and urban coastlines are often polluted with increased nutrient inputs, such as sewage effluents or agricultural fertilisers. The dense populations of filter-feeders on the structures near these areas may help prevent this nutrient runoff from triggering problematic algal blooms, which can cause fish kills and impact human health. But we still need to know what types of algae these filter-feeding communities are predominantly consuming.




Read more:
Explainer: what causes algal blooms, and how we can stop them


Our analysis provides an important first step in understanding how these communities might affect coastal production and food webs.

In places like Southeast Asia, marine managers should consider how artificial structures might affect essential coastal fisheries. Meanwhile, in places like Port Phillip Bay, we need to know whether and how these communities might affect the chances of harmful algal blooms.The Conversation

Mussels in the port of Hobart.

Martino Malerba, Postdoctoral Fellow, Monash University; Craig White, Head, Evolutionary Physiology Research Group, Monash University; Dustin Marshall, Professor, Marine Evolutionary Ecology, Monash University, and Liz Morris, Administration Manager, Monash University

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