Environment
How a Filipino
Scientist
is Making
Headlines in
Culturing Marine
Herbivores
By Jonah van Beijnen (VB Consultancy
Head) and Gregg Yan (Best Alternatives
Head)
Dr. Westly Rosario
/ BFAR
G
Credit: Dr. Westly Rosario / BFAR
lobally, the culture of carnivorous marine finfish
and crustaceans receives the most interest from
constitutional investors, with species groups
like sea bass, salmon and shrimp showing
double-digit growth rates. These species are
enjoying high demand from western and Chinese
customers and fetch relatively high prices. Their
culture however comes with high environmental
impacts. Large amounts of fishmeal are typically
required as feeds, and it is estimated that at
present, a quarter of all fish landed globally – a
whopping 21 million tons annually – are caught for the fishmeal industry.
With the planet facing a global environmental crisis, improving the
sustainability of our farming methods is critical. Together with more
efficient ways of farming fish, a serious part of the solution is to critically
consider just which species we should be farming.
Though it is definitely an option to develop vegetarian and lower-impact
diets for farmed carnivorous species, shifting away from top predators
like salmon and sea bass to herbivorous fish and shellfish would maybe
constitute a far more logical solution? Bivalves for example, require no
external inputs to be farmed. Due to their massive filtration capacities,
their culture actually has a positive effect on the water quality around
farms. Similarly, the culture of marine herbivores has a significantly lower
impact on the environment surrounding fish farms. When stocked at low
densities, there is also the potential to culture herbivore finfish without
external inputs. This has been common practice for the culture of carp
in freshwater habitats and Milkfish in backwater fishponds for centuries
across Southeast Asia.
Aside from lower environmental footprints, culturing marine herbivores
is crucial for ensuring food security in developing countries surrounded by
vast amounts of seawater like Indonesia, Bangladesh and the Philippines.
In the Philippines, an island-nation of over 7000 islands, finfish play an
important role in the daily diet of people living in rural communities. With
a population exceeding 100 million people, large amounts of fish must
be produced. Since the Philippines has limited freshwater resources but
nigh-endless coastal marine areas, the country’s Bureau of Fisheries and
Aquatic Resources (BFAR) has for years been wisely focusing on promoting
the culture of marine herbivores. Their main focal point has been the
culture of Milkfish, with the Philippines now producing around 400.000
tons annually, making it the country’s top aquaculture species in terms of
volume.
Dr. Westly Rosario, lead scientist for BFAR’s aquaculture research station
While the private sector is focusing on the culture of highly-prized carnivorous species,
Filipino scientist Doctor Westly Rivera Rosario and his team have been busy developing
new culture methods for herbivorous marine finfish. After perfecting the culture of
Milkfish (Chanos chanos) and creating marine-tolerant strains of Tilapia (Oreochromis
spp.), he and his team have now succeeded in developing a hybrid Rabbitfish (Siganus
spp.) with a higher growth rate and improved disease resistance.
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