It is not very often
everyone agrees on anything. Remarkably, the world’s top scientists and marine
researchers virtually all agree on the issues facing our oceans health, and the
demands being placed on what is arguably life’s greatest resource on the
planet. Here are 11 of the top issues facing the health of our oceans, and our
The oceans are among
our biggest resource for life on earth, and also our biggest dumping grounds.
That kind of paradox could give anyone an identity crisis. We seem to think we
can take all the goodies out and put all our garbage in, and then expect them
to keep happily ticking away indefinitely. However, while it's true the oceans
can provide us with some amazing eco-solutions like alternative energy, they're
are undergoing some serious stress factors. Here are the some of the biggest
problems facing the oceans. Making changes in our daily lives often starts with
awareness. Solutions are as simple as eating the right sort of seafood, to ensuring
garbage stays out of our waterways and Oceans.
Many marine scientists consider overfishing to be the worst impact humans are having
on the oceans. The Food and Agriculture Organization estimates that over 70% of the world’s fish species have been
entirely exploited or depleted. By capturing fish faster than they can
reproduce, we are harming entire ecosystems that interact with those species,
from the food they eat to the predators that eat them. These losses make the
ecosystems more vulnerable to other disturbances, such as pollution. A
complete overhaul of fishing policies, requiring global cooperation, is needed
to achieve a sustainable system. Overfishing is having
some serious impacts on our oceans. Not only does it work towards wiping out a species, but also
the other species of marine animals that are dependent upon those fish for
survival. It's been shown that overfishing can cause marine animals to starve, since we're
taking food from their mouths in too large of numbers for them to be able to get
their fill. It is also estimated that most seas already need long term fishing bans if certain species
are to recover at all.
There is much to be desired in the ways we fish. First,
we humans use some pretty destructive methods in how we pull catches, including
bottom trawling which destroys sea floor
habitat and scoops up many unwanted fish and animals that are tossed aside. We
also pull far too many fish to be sustainable, pushing many species to the point
of being listed as threatened and endangered.
overfishing are obvious in some ways, in that there are a lot of people who
like to eat a lot of fish. The more fish, the more money for the fishermen.
However there are other elements at work that promote overfishing that are less
obvious, such as promoting the health benefits of one fish over another, or the health of fish oils.
Knowledge of what
seafood can be sustainably eaten, whether that is the species of seafood or the
method by which it is caught, is a must in order to help keep the ocean's
fisheries healthy. It's our job as eaters to question restaurant servers, sushi chefs, and seafood purveyors about the sources of their fish,
and read labels when we buy from store shelves. There are helpful tools that
can assist us in buying and ordering seafood as well, from handouts to carry in our wallets to FishPhone. And of course there are our sustainable seafood slideshows that will show
you what you want to look for when you're choosing your next meal, and what to avoid.
2) Irresponsible Fish Farming
Fish farming, or aquaculture,
is the growing response to wild fish stocks rapidly depleting. While it sounds
like a good idea in theory, it unfortunately has many negative consequences due
to poorly managed operations. Nutrient and chemical pollution can occur easily
in open-ocean operations when fish feed, excrement, and medication is released
into the environment. Farmed fish accidentally released into wild populations
can also have destructive effects, such as loss of native stocks, disease
transmission, and damaging changes in habitat. Unfortunately, the biggest
hindrance to overcoming the challenges of an industry that supplies nearly 50% of the world’s fish food supply is that it currently
remains relatively unregulated.
3) Ghost Fishing
Ghost fishing is an
environmentally harmful issue caused when lost or discarded fishing gear
continues to catch fish and other marine life. Often times, the traps trigger a
chain-reaction problem when larger predators come to eat the smaller ones that
have been ensnared, only to get tangled in the mess themselves. The issue of
ghost fishing is most common with passive gear that has been abandoned, and
also poses a serious threat to other ocean vessels. Stray gear can be caught in
the propeller of a boat, damaging or even disabling it. Many solutions have
been offered, such as fishing gear made from biodegradable materials or
incentives like the Republic
of Korea’s buy-back
program, which rewards fisherman for turning in old gear.
The ocean absorbs as much as one third of the CO2 emitted worldwide, which keeps us cooler
but makes the ocean surface much more acidic. This has the effect of limiting
calcium carbonate needed by coral, plankton, and other marine life that use it to build the skeletal frames and shells that protect
them. Oceanic acidity has increased by 25%
since the industrial revolution, and will eventually destroy much marine life
if it increases at this rate.
is no small issue. The basic science behind acidification is that the ocean
absorbs CO2 through natural processes, but at the rate at which we're pumping
it into the atmosphere through burning fossil fuels, the ocean's pH balance is
dropping to the point where life within the ocean is having trouble coping.
"Ocean acidification is more
rapid than ever in the history of the earth and if you look at the pCO2
(partial pressure of carbon dioxide) levels we have reached now, you have to go
back 35 million years in time to find the equivalents" said Jelle Bijma,
chair of the EuroCLIMATE programme Scientific Committee and a biogeochemist at
the Alfred-Wegener-Institute Bremerhaven.
Freaky, right? At some point in
time, there is a
tipping point where the oceans become to acidic to support life that
can't quickly adjust. In other words, many species
are going to be wiped out, from shellfish to corals and the fish
that depend on them.
7) Mercury Pollution
Scientists report that our ocean’s mercury levels have risen over 30% the
last 20 years, and will increase another 50% in the next few decades. Emissions
from coal power plants are the primary
culprit, dispensing poisonous mercury that works its way up the food
chain, eventually coming to us through the fish we eat. This neurotoxin can alter brain development of fetuses and has been
linked with learning problems. Pollution is running rampant in the oceans but one of the scariest
pollutants is mercury because, well, it ends up on the dinner table. The worst
part is mercury levels in the oceans are predicted to
rise. So where does the mercury come from? You can probably guess.
Mainly coal plants.
In fact, according to the Environmental Protection Agency, coal-fired power
plants are the largest industrial source of mercury pollution in the country.
And, mercury has already contaminated water bodies in all 50 states, let alone
our oceans. The mercury is absorbed by organisms on the bottom of the food
chain and as bigger fish eat bigger fish, it works its way back up the food chain
right to us, most notably
in the form of tuna.
You can calculate how
much tuna you can safely eat, and while the though that calculating
your fish intake to avoid poisoning is really depressing, at least
we're aware of the dangers so that we can, hopefully, straighten up our act.
8) Offshore Drilling
Offshore drilling continues
to be a debate, but it’s clear that proceeding with oil production will only
exacerbate the dilemmas of our oceans. The use of fossil fuels is the reason
our oceans have been heating up and becoming more acidic, but offshore drilling
takes the risks even further. When oil is extracted from the ocean floor, other
chemicals like mercury, arsenic, and lead come up with it. Also, the seismic waves used to find oil harm
aquatic mammals and disorient whales. In 2008, 100 whales had beached themselves as a result of ExxonMobil
exploring for oil with these techniques. Furthermore, the infrastructure
projects to transport the oil often create worse problems, eroding the coastline. These realities are
9) Whaling and Shark Finning
The destruction of the
ocean’s most important predators has significant consequences that ripple down
the food chain. 50 to 100 million sharks are killed each year,
either as bycatch from fishing vessels or directly hunted for their dorsal
fins, used in an expensive soup popular across Asia. When finned, the sharks
are thrown back into the water, often still alive and left to bleed to death.
Unfortunately, sharks reproduce fairly slowly and don’t have a large amount of offspring, so these
actions have long-lasting effects on the delicate ecosystems they help regulate. Despite the 1986 moratorium on many types of
whaling, it still continues to be a problem, with some nations like Japan looking
for loopholes and lobbying for lax regulations. Overfishing is an issue that extends beyond familiar
species like bluefin tuna
and orange roughy.
It's also a serious issue with sharks. Sharks are killed in the
tens of millions each year, mainly for their fins. It is a common
practice to catch sharks, cut off their fins, and toss them back into the ocean
where they are left to die. The fins are sold as an ingredient for soup. And
the waste is extraordinary.
Sharks are top-of-the-food-chain
predators, which means their reproduction rate is slow. Their numbers don't
bounce back easily from overfishing. On top of that, their predator status also
helps regulate the numbers of other species. When a major predator is take out
of the loop, it's usually the case that species lower on the food chain start
to overpopulate their habitat, creating a destructive downward spiral of the ecosystem.
Shark finning is a practice
that needs to end if our oceans are to maintain some semblance of
balance. Luckily, a growing awareness around the unsustainability of the
practice is helping to lower the
popularity of shark fin soup.
10) Ocean Warming
The oceans are rising and getting warmer
faster than predicted. 71% of our planet is covered by oceans, yet we still neglect
them, harming the innumerable creatures that live in them, and polluting one of
our largest resources.
the fight for the environment, the health of our oceans should be a top
priority. Global warming is creating a climate time bomb by storing enormous
amounts of heat in the waters of the north Atlantic, UK
scientists have discovered.
Marine researchers at Southampton and Plymouth universities have found that the
upper 1,500 metres of the ocean from western Europe to the eastern US have
warmed by 0.015C in seven years. The capacity of the oceans to store heat means
that a water temperature rise of that size is enough to warm the atmosphere
above by almost 9C.
Neil Wells, a scientist on the project at the National
Oceanographic Centre in Southampton, said:
"People might think it doesn't sound like a big temperature rise but it's
very significant." The findings were announced in the journal Geophysical
Research Letters as James Lovelock, the UK scientist who developed the gaia
theory of life on Earth, warned that such ocean warming could stifle marine
life and accelerate climate change.
Professor Lovelock said that thermal mixing of water
and nutrients shuts down when the upper layer of ocean water reaches about 12C.
"That's why the tropical waters are clear blue and the water in the Arctic looks like soup," he said. Such a change
would affect marine life, which research suggests could help form clouds over
the oceans. Warmer waters would receive less protection from sunlight, which
would warm them further.
The Southampton and Plymouth study suggests heat stored in the
oceans could be released into the atmosphere in future, tempering efforts to
stabilize global temperatures with cuts in man made greenhouse gas emissions.
Other Negative Affects To Our Environment Our
Environment is affected by the changing magnetic north pole, according
to the CBC documentary "When North Goes South". Any change in our
environment affects our rivers, lakes and oceans of course. This
documentary is 45 minutes in length, suitable for age 10 and up. http://www.cbc.ca/documentaries/natureofthings/video.html?ID=1678474875
What is happening to our marine life? Globe and Mail reports: Fish farms cannot use water from our oceans! This is a wake up call we cannot afford to ignore.
National Geographic for Kids
Canada Department of
Fisheries and Oceans