9. According to FAO statistics, in 1997 China was the
leading producer, importer and exporter of shark fins
in the world
According to FAO 1998, south-east Asian region is the
highest exporter, producer of shark fins.
Due to increase in new technologies like fish finding
techniques, finding PFZ ---------over-exploitaion of
resources occur.
10. Most of the world s fisheries are being fished at levels
above their maximum sustainable yield and many
regions are severely overfished.
In the late 1990s it was demonstrated that the mean
trophic level of fisheries is declining, i.e. that global
fisheries catches increasingly consist of smaller fish
and invertebrates lower in the food web
This process, now known as fishing down marine food
webs has become a major concern, as it means that
fish stocks especially of large bodied fish are being
overexploited and fisheries are not being sustainably
managed. This severely threatens marine biodiversity.
11. The Marine Trophic Index (MTI) ------ investigate the
impacts of fisheries on the world s marine ecosystems.
Fishing down effect has been demonstrated in various
parts of the world such as Thailand, Canada, Greece,
Iceland, etc.
14. Importance of top predators in a healthy ecosystems
As apex predators, sharks feed on the animals below
them in the food web, helping to regulate and
maintain the balance of marine ecosystems.
Apex predators not only affect population dynamics by
consuming prey, but they also can control the spatial
distribution of potential prey.
By preventing one species from monopolizing a
limited resource, predators increase the species
diversity of the ecosystem
15. Trawl fisheries are responsible for the largest by-catch
numbers in coastal areas, while longlines capture the
majority of sharks as by-catch on the high seas.
It is estimated that tens millions of sharks are caught
as by-catch each year, which is nearly half of the total
shark catch worldwide.
Additionally, they provide essential food sources for
scavengers and remove the sick and weak from
populations of prey species
27. References
Blévin, P., Carravieri, A., Jaeger, A., Chastel, O., Bustamante, P. & Cherel, Y.
2013, "Wide Range of Mercury Contamination in Chicks of Southern Ocean
Seabirds", PLoS One, vol. 8, no. 1.Daly, E.A., Benkwitt, C.E., Brodeur, R.D., Litz,
M.N.C. & Copeman, L.A. 2010, "Fatty acid profiles of juvenile salmon indicate
prey selection strategies in coastal marine waters", Marine Biology, vol. 157, no.
9, pp. 1975-1987.
Daly, E.A., Benkwitt, C.E., Brodeur, R.D., Litz, M.N.C. & Copeman, L.A. 2010,
"Fatty acid profiles of juvenile salmon indicate prey selection strategies in
coastal marine waters", Marine Biology, vol. 157, no. 9, pp. 1975-1987.
Deetae, S. & Wisespongpand, P. 2001, Sub-thermocline chlorophyll maximum in
the South China Sea, area 4: Vietnamese waters, SEAFDEC, Bangkok
(Thailand).
Fitzpatrick, R., Thums, M., Bell, I., Meekan, M.G., Stevens, J.D. & Barnett, A.
2012, "A Comparison of the Seasonal Movements of Tiger Sharks and Green
Turtles Provides Insight into Their Predator-Prey Relationship", PLoS One, vol.
7, no. 12.
Harkonen, T., Harding, K.C., Wilson, S., Baimukanov, M., Dmitrieva, L.,
Svensson, C.J. & Goodman, S.J. 2012, "Collapse of a Marine Mammal Species
Driven by Human Impacts", PLoS One, vol. 7, no. 9.
28. Jaaman, S.A., Lah-Anyi, Y. & Pierce, G.J. 2009, "The magnitude and
sustainability of marine mammal by-catch in fisheries in East
Malaysia", Marine Biological Association of the United
Kingdom.Journal of the Marine Biological Association of the United
Kingdom, vol. 89, no. 5, pp. 907-920.
Pauly, D., Christensen, V., Dalsgaard, J., Froese, R. & Torres, F. 1998,
"Fishing down marine food webs", Science, vol. 279, no. 5352, pp. 860-
863.
Pauly,Daniel,1979. Theory and management of tropical multispecies
stocks: A review with emphasis on the southeast Asian demersal
fisheries. ICLARM studies and reveiws No 1 . 35p. International Centre
of Laving Aquatic Resource Management, Manilla
Pelletier, L., Kato, A., Chiaradia, A. & Ropert-Coudert, Y. 2012, "Can
Thermoclines Be a Cue to Prey Distribution for Marine Top Predators?
A Case Study with Little Penguins", PLoS One, vol. 7, no. 4.
Todd, P.A., Ong, X. & Chou, L.M. 2010, "Impacts of pollution on marine
life in Southeast Asia", Biodiversity & Conservation,vol. 19, no. 4, pp.
1063-1082.
29. Worm, B., Sandow, M., Oschlies, A., Lotze, H.K. & Myers, R.A. 2005,
"Global Patterns of Predator Diversity in the Open
Oceans",Science, vol. 309, no. 5739, pp. 1365-9.
Yokota, K., Minami, H. & Kiyota, M. 2011, "Effectiveness of tori-lines for
further reduction of incidental catch of seabirds in pelagic longline
fisheries", Fisheries Science, vol. 77, no. 4, pp. 479-485.
www.fao.org
