December, Copenhagen will host the 15th Conference of the Parties for the
United Nations Framework Convention on Climate Change (UNFCCC). This issue of Afishianado highlights some of the effects of
climate change that are most relevant to the seafood industry, including ocean
acidification, species migration and the proliferation of invasive species.
While the exact impacts of changing climate are not yet fully understood, what
we do know is that not every industry will be equally affected; the seafood
sector could be disproportionately impacted, compared to tourism and other
sectors that rely on the ocean. This industry is responsible for a relatively
small percentage of global greenhouse gas (GHG) emissions, yet its reliance on
marine resources means it is highly susceptible to the adverse effects of
temperature and acidity change.
climate issues may severely affect the seafood industry, it also has the power
to create disproportional positive change. By tapping into the sector's ability
to influence wider business practices and policies, seafood stakeholders have a
chance to catalyze much greater mitigation of climate change. Leveraging this
ripple effect is perhaps the industry's greatest opportunity-and, given that
time is of the essence, its greatest challenge. Tackling climate change and
ocean acidification allows members of this industry to take a proactive role in
protecting their businesses and way of life.
climate change is warming the atmosphere, it is also warming the ocean; in
fact, most of the extra heat in the atmospheric system is in the ocean. As with
the atmosphere, each area of the ocean will be impacted differently. One
repercussion of this warming is species migration. Many species have specific
temperature requirements and thus will be forced to abandon their natural
habitat as they seek more tolerable temperatures. Other species may have
greater tolerance for temperature change, but if their food sources either
migrate or become scarce as a result of such changes in temperature, these
species will migrate to find a new food supply.
species migration may not appear to be a serious issue, it will have
significant impacts not only on the ocean but also on the seafood industry.
Effects of species migration could include:
Dominance-Migration of species into different areas will alter food webs
in unpredictable ways and lead to changes in species dominance.
Depletion-Some regions, especially in the tropics, may no longer be able
to support the quantity and variety of species they currently support
because waters have warmed too much.
shifts-Fish will be found in different places from where they currently
live, meaning the corresponding fisheries will shift also, possibly out
of the territorial waters of the countries where they are now located.
some species will fail to adapt and become extinct; this is a
particular concern for cold-water species, as well as species that are
unable to adapt because of habitat or food supply constraints.
The warming of the oceans will
have many significant impacts on fish populations, species migration
included. Due to the complex nature of ecosystems, it's difficult to
predict exactly how an individual species will react to these habitat
changes and, inevitably, some species will fail to cope with the changes.
1. Turley, C, Findlay, HS,
Mangi, S, Ridgwell, A and Schmidt, DN. "Non-Native Species in Marine
Climate Change Ecosystem Linkages Report Card 2009." Online Science
Reveiws. 2009. http://www.mccip.org.uk/elr/non-natives/default.htm
2. Turley, C, Findlay, HS,
Mangi, S, Ridgwell, A and Schmidt, DN. "A View From Above in Marine Climate
Change Ecosystem Linkages Report Card 2009." Online Science Reveiws. 2009. http://www.mccip.org.uk/elr/view/default.htm
increased maritime activity, the introduction of non-native species has become
more common. The majority of species introductions happen accidentally, in
ballast water or as aquaculture escapees, to cite two examples. A non-native
species is considered invasive when it spreads rapidly, disrupts the natural
ecosystem, causes environmental or economic harm or presents a human health
hazard. Evidence is beginning to show that climate change is making
environments more suitable for non-native species, allowing them to establish
in these areas, increase in abundance and become invasive.
change offers non-native species several pathways to become invasive or
increase the potential for invasiveness. These include:
species to spread into new areas.
migration of species because of decreased sea ice.
species, which are already present, to increase in productivity where
they were previously limited by seasonally unfavorable conditions
An example of a non-native
species introduction likely due to climate change can be seen with the Mauve
Stinger, Pelagia nocticula. These jellyfish are increasingly common in British
waters, where a massive swarm killed approximately 100,000 salmon at a farm
in Northern Ireland in 2008.
There are also increasing numbers of jellies in the Sea of Japan,
causing fishermen countless troubles and it is thought that climate change
is at least partly to blame. As climate change intensifies, the
opportunities for invasive species to flourish will increase, causing irreparable
harm to the environment, maritime economy and health of coastal communities.
Turley, C, Findlay, HS, Mangi,
S, Ridgwell, A and Schmidt, DN. "Non-Native Species in Marine Climate Change
Ecosystem Linkages Report Card 2009." Online Science Reveiws. 2009. www.mccip.org.uk/elr/acidification
Photo credit: George Cathcart/Marine Photobank
acts as a regulator for carbon dioxide levels in the atmosphere, absorbing the
excess and thus moderating the effects of climate change. However, when CO2
dissolves in the ocean, it reacts with water to form carbonic acid, which then
separates into hydrogen ions and bicarbonate ions. This increase in hydrogen
ions causes the pH of the ocean to decrease, thus becoming more acidic.
A 2009 report from the UK's Marine Climate Change Impacts Partnership (MCCIP)
that acidification could reduce the growth and survival of marine life and
reduce marine animals ability to make shells and skeletons (calcification).
Some studies have forecast that ocean water will become corrosive to organisms
between 2050 and 2100. These impacts, particularly when combined with
climate-induced range shifts of commercial fish stocks, could affect commercial
fishing and aquaculture (particularly shellfish) productivity. The MCCIP report
estimates that ocean acidification will reduce shellfish growth rates 10 to 25
percent by 2050. This would result in a reduction of UK shellfish landings
equating to a financial loss of £24.4 to £61 million per year (based on 2006
Defra figures) and potentially 1,000 to 3,000 jobs lost. Implications such as
these could also similarly affect shellfish aquaculture.
European Project on Ocean Acidification. "What is Ocean Acidification?" Online. http://www.epoca-project.eu/index.php/What-is-ocean-acidification.html
Photo credit: Jessica King/Marine Photobank
Seafood Choices Alliance is an international program that provides leadership and creates opportunities for change across the seafood industry and ocean conservation community. We're about synergies and identifying creative solutions to long-held challenges. By building relationships and stimulating dialogue, Seafood Choices is encouraging and challenging all sectors of the seafood industry along the road toward sustainability.SeaWeb,
founded in 1996 to raise awareness of the growing threats to the ocean
and its living resources, utilizes social marketing techniques to
advance ocean conservation. By increasing public awareness, promoting
science-based solutions and mobilizing decision-makers around ocean
conservation, SeaWeb has brought together multiple, diverse and
powerful voices for a healthy ocean. www.seaweb.org.