Medidas de Gestao das Pescarias Marinhas e Aquicultura 2019 The State of World Fisheries and Aquaculture 2018 | Page 163

THE STATE OF WORLD FISHERIES AND AQUACULTURE 2018
sur vival, and in battling epizootic diseases that
can cause mass mortalities. However, the
imprudent use of antibiotics in aquaculture has
led to issues concerning antimicrobial residues
and antimicrobial resistance.
Greenhouse gas emissions from aquaculture
remain relatively small, estimated to be 5 percent
those from agriculture ( Waite et al., 2014), but
have been growing because of increased use of
feeds. Reducing fishmeal and fish oil use and
feed conversion ratios (FCRs) can be important in
minimizing emissions (Hasan and Soto, 2017).
Too often, a long time elapses from the first
observation of mortality in the field to the
identification and reporting of the causative agent
and the application of appropriate control and risk
management measures. A paradigm shift is needed
in dealing with aquaculture biosecurity risks.
While discussions on aquaculture diets have
focused on fishmeal and fish oil resources, the
sustainabilit y of aquaculture sector growth also
remains closely linked to supplies of terrestrial
animal and plant proteins, oils and carbohydrates
(FAO, 2012d; Troell et al., 2014). Much research is
being directed into novel aquaculture feedstuffs,
including microbial seaweed and insect sources,
but it is likely to be some years before these
become widely available and affordable.
Addressing biosecurity requires significant
resources, strong political will and concerted
international action and cooperation. National
strategic planning for aquatic animal health and
biosecurity is vital; without it, a country can only
react in a piecemeal fashion to new developments
in international trade and serious transboundary
aquatic animal diseases, and its aquaculture and
fisheries sectors will remain vulnerable to new
and emerging diseases. FAO encourages Member
Countries to develop and formalize national
aquatic animal health strategies and health
management procedures (FAO, 2007) and to use
the Progressive Management Pathway (PMP), a
step-wise risk management framework based on
similar frameworks used to develop and monitor
national strategies for important livestock diseases
such as foot-and-mouth disease, African animal
trypanosomiasis, Peste des Petits Ruminants and
rabies (FAO, 2011c). The actions must be risk-
based, proactive and collaborative and should
adhere to international standards and regional
agreements (both obligatory and voluntary),
particularly for those countries sharing
transboundary waterways. Responsibilities must
be shared among key national, regional and
international stakeholders from government, the
production sector and academia as well as other
players in the value chain, building on each
other’s strengths towards a common goal.
Aquaculture biosecurity and aquatic animal
health management
The aquaculture sector is v ulnerable to exotic,
endemic and emerging disease epizootics. Acute
hepatopancreatic necrosis disease, Enterocytozoon
hepatopenaei and tilapia lake virus have emerged
during the past few years; the geographical
distribution of epizootic ulcerative syndrome and
infectious myonecrosis virus has recently
expanded; and white spot syndrome virus,
infectious salmon anaemia and other bacterial,
parasitic and fungal infectious diseases continue
to affect farmed aquatic species. Constraints in
dealing with aquaculture diseases include, among
others, limitations in diagnostic techniques; the
existence of cr yptic pathogens and benign
organisms that may become pathogenic when
introduced to new hosts and new environments;
limitations in control options for aquatic animal
diseases; the occurrence of multifactorial disease
syndromes and frequent subclinical infections;
the undomesticated status of most farmed aquatic
species; and the paucit y of information on the
health status of aquatic animals.
The basic principle of aquatic animal health
management remains a thorough consideration of
host, pathogen and environment interactions.
However, the application of findings from
emerging fields such as metagenomics (the study
of genetic materials recovered directly from
environmental samples) and the pathobiome
approach (looking at how the interaction of
The responsible use of veterinar y medicines,
including antimicrobials, has benefits in terms of
improved on-farm biosecurit y and husbandr y
(e.g. through the use of vaccines and
disinfectants). Such medicines are useful in
treating chronic diseases that cause reduced
growth, low food conversion rate and poor
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