More aquaculture to feed a silent world

Aug 13, 2022
Aquaculture, salmon farming, Norway
image: iStock

Sustainable aquaculture to boost fish supplies. Rich nations fund poor’s fossil fuel industries. Extinctions silence nature.

Fisheries, aquaculture, food security and the environment

The production of seafood (wild caught and aquaculture) is increasing at about 1% per year and in 2020 reached 178 million metric tons – the vast majority being produced in Asia. To put the 178 into context, it’s about half of the amount of meat produced on land annually (over 90% of which is poultry, pig and beef), and meat production is increasing at about 3% per year.

But all is not growing equally in ichthyic industries. Between 2018 and 2020, aquaculture production increased by 6%, while wild fish capture dropped by 4.4%. This is a continuation of long term trends of increasing inland and ocean aquaculture since 1970 and stagnating wild fish capture since the late 1980s.

No prizes for guessing the reason for the decline in wild fish capture: 35% of fish stocks are fished beyond their sustainable limit, 57% are fished at their limit, and only 7% are underfished – although the ‘underfished’ fish might quibble with that designation.

Seafood, both farmed and fished, has two practical advantages over land-based animal protein. First, it is a more efficient protein-producer: 1kg of beef requires about 5-10 times as much feed as 1kg of Atlantic salmon. Second, aquatic animals produce fewer greenhouse gases.

Although aquaculture is certain to continue expanding – to feed the world, help developing nations develop and generate profits – it has multiple environmental problems including pollution of the natural environment with uneaten feed, fish waste and antibiotics, weakening of wild gene pools by escaped fish, introduction of disease into wild stocks and, in the case of shrimp farming, destroying mangroves and salt marshes. And then, of course, there’s the ridiculous practice of catching wild fish to feed to farmed fish. Aquaculture must become environmentally sustainable if it is to expand.

The Food and Agriculture Organization aims to increase aquatic food production by 15% by 2030 through a strategy of ‘Blue Transformation’. This involves: sustainably expanding and intensifying global aquatic food systems to improve food security, nutrition and social well-being; promoting social equality; effectively managing all fisheries; reducing pollution; and protecting biodiversity. The FAO sees increasing sustainable aquaculture as the main source of increased production. However, improving yields from fisheries is also planned. This will be achieved through more effective governance and management to rebuild biologically sustainable fish stocks, growth in catches of underfished stocks, and reducing by-catch and fish waste.

Rich countries fund the poor’s fossil fuel projects

The wealthy countries of the G20 provide lots of finance to poorer nations to help them develop their energy systems. Fantastic – that’s just what they should be doing. Only problem is that most of that money is helping to develop fossil fuel facilities and supplies, not renewable energy sources. In recent years, the G20 have been providing an average of US$63 billion a year in international public finance for coal, oil and gas. The good news is that this is approximately half of the amount that they provided in 2016. The bad news is that it’s 2.5 times what they provided to clean sources of energy.

The major financers of international fossil fuel developments are Canada, Japan and Korea, each one providing more than US$10 billion per year, with China a little way behind on 7 billion. The asterisks in the chart below indicate that the data is possibly incomplete. Australian data, which doesn’t feature in this chart but has an asterisk against it elsewhere, indicates that in 2020 we provided US$130 million to oil and gas projects overseas and US$250,000 to clean energy.

Most of the G20 nations now have policies to end their overseas financing of coal and six signed a commitment at last year’s COP to end their support for oil and gas. But, as ever, it’s all too slow. The evidence is clear that to stand any chance at all of keeping warming under 2oC no new fossil fuel mines and fields can be opened up and to stay under 1.5oC 40% of the currently developed reserves need to be left in the ground as well.

In a somewhat positive development, in May the countries of the G7, which doesn’t include Korea and China, agreed to ‘end new direct public support for the international unabated fossil fuel energy sector by the end of 2022.’ Note the ‘unabated’ qualification though and only a month later some of the G7, with an eye on events in Ukraine, were further qualifying their promise because of concerns about ‘energy security’. In addition, Germany is planning to reopen closed coal-fired power stations at home.

Global electricity generation 2019-2021

I have constructed the table below from bp’s Statistical Review of World Energy reports for 2021 and 2022. I have compared 2019 and 2021 because electricity usage in 2020 was seriously affected by the economic downturn prompted by the first year of Covid but by 2021 trends had pretty much returned to normal (see the technicolour graph).

The principal points to note in the table are that the global consumption of electricity increased by roughly 2% over the two years and that this increase was provided by renewables (solar and wind) and hydro, with fossil fuel production of electricity remaining pretty constant. This confirms that renewables are supplementing rather than replacing fossil fuels in electricity generation. In 2021 solar, wind and hydro still accounted for only 13.5% of global electricity supply.

Between 2011 and 2021, greenhouse gas emissions from fossil fuel combustion rose at an average of 0.6% per year but, in fairness, this obscures the fact that emissions from this source peaked in 2018 and have been decreasing at an average of 0.26% per year since then. Nowhere near enough to keep the global warming wolf from the 1.5oC door but a decrease nonetheless.

Even that note of positivity is lost, however, if we examine the emissions from energy use plus gas flaring plus industry. Global emissions from these combined sources may have reached a plateau since 2018 but have still increased at an average of 0.7% per year since 2011. To keep warming below 1.5oC we need total emissions to fall at least 10% per year from right now.

The bottom line is that, despite the steady (but slow in absolute terms) increase in renewables, reducing the emissions of greenhouse gases from the use of fossil fuels and industrial processes still has a long way to go before we can have any hope that environmental and human catastrophes are not lurking around the rapidly approaching corner. To mangle Churchill, this is not the beginning of the end, nor even the end of the beginning, but we may be nearing the end of the beginning of the beginning.

USA’s disappearing birds, insects and amphibians

  • Over 300 North American bird species could lose half their ranges in the next 60 years due to the effects of climate change: rising temperatures, bushfires, warmer lakes and rivers, flooding of nests, loss of food due to the parallel loss of insects, etc.
  • Almost 3 billion North American birds have disappeared since 1970 as a result of not just climate change but also suburban sprawl, chemicals and plastics in the environment and the invasion of feral species that prey on them or outcompete them.
  • Amphibians face all the same assaults, plus the globally ubiquitous, highly toxic chytrid fungi which are threatening a third of amphibian species.

Rachel Carson famously wrote about the ‘Silent Spring’ but, 60 years later, faced with the possibility of a silent spring, summer, autumn and winter, researchers and naturalists are recording animal sounds, including the within-species variability, before they disappear for good. Even if you don’t read the text, the recordings of the chickadee, grasshopper, spadefoot toad and humpback whale are worth the price of entry on their own. But whatever you do, don’t miss the spooky-coyote-like call of the common loon. Even our own Regent Honeyeater gets a mention.

If you’d like to hear more disappearing sounds, have a listen to Cicadas and Spring Peepers.

I suspect that a couple of hundred years ago, maybe only a hundred, people were much more aware of the natural sounds around them – ‘the poetry of earth’ – than we are nowadays. Putting aside any lack of skills in versification, how many of us today could write so knowledgably about the sounds and habits of crickets and grasshoppers as Keats in 1816? A sonnet, incidentally, that was reputedly written in 15 minutes for a ‘competition’ with Leigh Hunt.


This ABC article is a trove of information about the history, distribution and appearance of the 800 or so species of eucalypts, plus some great photos and a quiz.

Here are two of the ten questions about eucalypts:

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