1 Genomics in the Discovery and Monitoring
17
ecological information could then be incorporated into models, as well as providing
new data for use in management and conservation.
Potential forensic applications of fish DNA barcoding include the monitoring
of fisheries quotas and by-catch, inspection of fisheries markets and products, the
control of trade in endangered species, and improvements in the traceability of fish
products (Ogden 2008). In Australian waters, for example, sharks are illegally captured, largely for their fins alone. Quality sharks’ fins can sell for $6,000–$8,000/kg
in Hong Kong, and it is estimated that globally more than 100 million sharks are
killed every year. Sharks are particularly susceptible to overexploitation due to slow
growth, their longevity and long gestation and low fecundity. Many species are morphologically very similar, and many are protected (R D Ward, pers comm.). A tool
enabling precise identification of shark species from fins, from the fisheries boat to
the soup in the restaurant, could be of great utility for law enforcement and conservation of endangered species (Chan et al. 2003). DNA barcoding could also be used for
detection of fraudulent species substitutions in fish markets and fish food products,
a practice that is generating concern among consumers (Wong and Hamer 2008). A
striking example comes from the Red Snapper (Lutjanus campechanus), which is
one of the most economically important fisheries in the Gulf of Mexico, and which
has been subject to stringent fishing restrictions due to stock depletion. Marko et al.
(2004) used sequences of the mtDNA gene cytochrome b, in an approach very similar to DNA barcoding, to show that up to 77% of the L. campechanus fillets were
mislabelled in USA markets. Such a level of mislabelling may adversely affect estimates of stock size and contribute to the false impression among consumers and
industry that the supply of fish is keeping up with demand.
Thus, DNA barcoding provides a standardised tool for describing and monitoring fish species diversity, not only in the wild, but also throughout the food supply
chain in relation to legal enforcement and consumer protection (see Chapter 7).
Moreover, a globally-accessible, standardised DNA barcoding data base means that
non-experts may utilise the information to examine species identity, but importantly also allows a coordinated and extensive effort to document biodiversity from
throughout species distributions.
1.2.5 Larvae in Marine Systems
The crucial influence of larval stages on population dynamics and on population connectivity, especially when adults are sessile, has long been acknowledged
(Underwood and Fairweather 1989). Recent investigations of larval dispersal patterns have challenged traditional models, where larvae are dispersed as passive
particles, by revealing the importance of larval behaviour and retention (Shanks and
Brink 2005, Kinlan et al. 2005, Marta-Almeida et al. 2006). Accurately estimating larval distribution and abundance and assessing larval dispersal and recruitment
patterns are all prerequisites for the sustainable management of marine resources
(e.g. Taylor et al. 2002, Fox et al. 2005, Kochzius et al. 2008) and the restoration of
17
ecological information could then be incorporated into models, as well as providing
new data for use in management and conservation.
Potential forensic applications of fish DNA barcoding include the monitoring
of fisheries quotas and by-catch, inspection of fisheries markets and products, the
control of trade in endangered species, and improvements in the traceability of fish
products (Ogden 2008). In Australian waters, for example, sharks are illegally captured, largely for their fins alone. Quality sharks’ fins can sell for $6,000–$8,000/kg
in Hong Kong, and it is estimated that globally more than 100 million sharks are
killed every year. Sharks are particularly susceptible to overexploitation due to slow
growth, their longevity and long gestation and low fecundity. Many species are morphologically very similar, and many are protected (R D Ward, pers comm.). A tool
enabling precise identification of shark species from fins, from the fisheries boat to
the soup in the restaurant, could be of great utility for law enforcement and conservation of endangered species (Chan et al. 2003). DNA barcoding could also be used for
detection of fraudulent species substitutions in fish markets and fish food products,
a practice that is generating concern among consumers (Wong and Hamer 2008). A
striking example comes from the Red Snapper (Lutjanus campechanus), which is
one of the most economically important fisheries in the Gulf of Mexico, and which
has been subject to stringent fishing restrictions due to stock depletion. Marko et al.
(2004) used sequences of the mtDNA gene cytochrome b, in an approach very similar to DNA barcoding, to show that up to 77% of the L. campechanus fillets were
mislabelled in USA markets. Such a level of mislabelling may adversely affect estimates of stock size and contribute to the false impression among consumers and
industry that the supply of fish is keeping up with demand.
Thus, DNA barcoding provides a standardised tool for describing and monitoring fish species diversity, not only in the wild, but also throughout the food supply
chain in relation to legal enforcement and consumer protection (see Chapter 7).
Moreover, a globally-accessible, standardised DNA barcoding data base means that
non-experts may utilise the information to examine species identity, but importantly also allows a coordinated and extensive effort to document biodiversity from
throughout species distributions.
1.2.5 Larvae in Marine Systems
The crucial influence of larval stages on population dynamics and on population connectivity, especially when adults are sessile, has long been acknowledged
(Underwood and Fairweather 1989). Recent investigations of larval dispersal patterns have challenged traditional models, where larvae are dispersed as passive
particles, by revealing the importance of larval behaviour and retention (Shanks and
Brink 2005, Kinlan et al. 2005, Marta-Almeida et al. 2006). Accurately estimating larval distribution and abundance and assessing larval dispersal and recruitment
patterns are all prerequisites for the sustainable management of marine resources
(e.g. Taylor et al. 2002, Fox et al. 2005, Kochzius et al. 2008) and the restoration of