With the growing awareness around fish and the environment
one question that comes up is whether or not eating fish
is environmentally friendly. So, is eating fish sustainable?
We often talk about the amazon rainforest being the lungs of the planet
and yet somewhere between 50 to 85%
of all the oxygen we breathe comes from marine phytoplankton,
tiny ocean plants that through the process of photosynthesis
produce oxygen. And so it's really our oceans that are our lungs.
The oceans also play a pivotal role in regulating temperature and overall climate,
which isn't really surprising
considering that around 70 percent of the earth's surface is water covered.
And yet, even though it is estimated that 50 to 80 percent of all life lives under the ocean's surface,
we have only explored less than 10% of the ocean.
It is no wonder then that there is an outcry when there are oil spills in the ocean
or when we see whaling vessels harpooning whales.
But what about the environmental cost of the fish that we eat?
When it comes to wild fish, the two main methods of catching fish are bottom trolling and long line fishing.
Bottom trolling is a method of fishing that involves dragging heavy weighted nets
across the sea floor in an effort to catch fish.
It is a popular method in commercial fishing because it can catch large quantities of fish in one go.
However, when dragging the large weighted nets across the seafloor everything that happens to be in the way
gets swept up in the nets too, leading to huge amounts of by-catch and also the damaging of the sea floor,
which creates harmful algae blooms and oxygen deficient dead zones.
Long line fishing is where fishing vessels trail huge lines of nets through the oceans
with hundreds or even thousands of baited hooks attached along the nets.
These nets can be as long as 50 to 100 kilometers.
Similar to bottom trolling, the lines are indiscriminate, meaning that by-catch is also a huge issue.
With every year, around 650 000 whales,
dolphins, seals, sea lions, and turtles are being killed because of the fishing industry,
which equals more than one every minute
and some estimates said it could be as many as double this number.
On top of that, it is estimated that 50 million sharks are unintentionally caught as by-catch each year
which is about half as many as are killed intentionally for their meat and fins.
Yet why is it then that we look in horror at those who eat shark fin soup
when our consumption of fish is also responsible
for the mass killing of tens of millions of sharks every single year?
Leading researchers have highlighted how it is the fishing industry
that has caused a 60% decline in shark numbers in Costa Rican waters.
But the problem of by-catch is even more significant than this
as it is estimated that somewhere between 10 to 40% of all fish caught are by-catch.
This has an impact on the biodiversity of the ocean
and also means that many species are being fished to the brink of extinction
simply as a consequence of commercial activities, not even as the target of them.
To make matters worse, one third of the fish that are caught are used to feed farmed animals
including farmed fish, but also pigs and chickens,
meaning our oceans are being destroyed to feed animals in an industry that is further contributing
to environmental degradation from greenhouse gas emissions, habitat destruction,
deforestation, water use, land use, and a whole host of other problems.
The number of overfished species has increased threefold in the past 40 years alone
with the United Nations FAO stating that 87%
of the world's fisheries are either over-exploited or fully exploited,
with nearly one-third of edible fish and seafood species having declined by 90 percent.
And a study from an international team of researchers published in the journal Science
even predicted that we could actually have fishless oceans by the year 2048.
Just imagine for a second the world's oceans devoid of life.
A once thriving and abundant variety of ecosystems full of wonder and intrigue
now decimated and dead.
Moreover, when it comes to plastic in the ocean,
it is reported that as much as 70 percent of macro plastics
found floating on the surface of the ocean are fishing related.
And a recent study of the Great Pacific Garbage Patch, an area of plastic accumulation in the North Pacific,
showed that 86% of the macro plastics in this area were fishing nets.
When it comes to farmed fish, which now provide around half of all the fish that are consumed globally,
this industry actually leads to even more fishing because many of the fish raised on these farms are carnivorous
meaning they need to eat smaller fish to live.
Billions of wild fish are therefore caught in order to feed these farmed species.
For example, it can take up to five pounds of ocean fish to produce just one pound of farmed salmon.
Overcrowding of fish and aquaculture also results in a high rate of disease and infestations,
leading to increased antibiotic use.
And it's estimated that in the US, farmed salmon are fed
more antibiotics per pound than any other farmed animal.
The diseases and infections from farmed fish can also spread to wild fish as well,
damaging natural ecosystems and spreading parasites to wild animals.
And on top of that, farming fish and crustaceans is responsible for the destruction of natural habitats.
With farmed shrimp being responsible for the destruction
of 45 percent of the mangroves in Bangladesh
and 50 to 65% of the mangroves in Thailand.
This is a significant problem because mangroves are highly effective at sequestering carbon.
So this destruction has resulted in huge amounts of carbon dioxide
being released back into the atmosphere.
Waste is also a significant issue.
The journal Science stated that a two acre salmon farm
produces as much waste as a town of ten thousand people.
And salmon farms in British Columbia were found to be producing as much waste
as a city of half a million people.
Fish waste also produces greenhouse gas emissions
and can negatively impact wild fish and the surrounding ecosystems.
In the end, our consumption of fish is destroying our planet
and decimating natural ecosystems and biodiversity.
Both wild-caught and farmed fish are wholly unsustainable,
and if we really want to protect our oceans and the life contained within them,
the best and most important thing that we can do
is stop eating fish.