1 / 52

The Story of a Swordfish Andrew Sammut

The Story of a Swordfish Andrew Sammut. “It is intended that this presentation…. gives an overview of the life of…. A SWORDFISH ….. from when it is born till it reaches adulthood and….later on finds itself on…. ……. Andrew’s plate for lunch”. Dad meets mum- Spawning

arella
Download Presentation

The Story of a Swordfish Andrew Sammut

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Story of a Swordfish Andrew Sammut

  2. “It is intended that this presentation…. gives an overview of the life of…. ASWORDFISH….. from when it is born till it reaches adulthood and….later on finds itself on…. ……. Andrew’s plate for lunch”

  3. Dad meets mum- Spawning • Best spawning grounds are found in the Mediterranean Sea • Adults spawn in all months except January and February • Spawning is most intensive from end of June to August • Mum swordfish lays 2 to 5 million eggs

  4. The Swordfish is Born… Eggs are fertilized externally and float at the sea surface due to the presence of a droplet of oil They hatch after 2.5 days Babies (fry) up to 5 kg have been recorded from October to December Large numbers of babies are found from November to March

  5. Characteristics of Swordfish Fry • Swordfish fry - recently hatched fish larvae - are different from adults • Upper & lower jaws are equally prolonged • Bodies are long, thin and snakelike • They are covered with rough, spiny scales and plates • Tails are rounded • Have just one long dorsal and anal fin

  6. Growth Rate • Swordfish grow extremely fast during their first year of life and may reach 90cm by one year of age • After two years of age, females tend to grow faster and to a larger size than males • Females are heavier than males at the same length • Maximum size: 4.5m in length and 540 kg in weight • Reaches reproductive maturity at about 5 to 6 years of age, when about 2m in length

  7. The Adult SwordfishMaximum life span of 9 years

  8. Characteristics of an Adult Swordfish (Xiphias gladius) • Known asPiscispat or Pixxi spad in Maltese • Lose all teeth and scales by adulthood

  9. The swordfish is named after its sharp bill which resembles a sword Sharp bill is used to injure prey Defensive against natural predators The Sharp Bill

  10. Cold blooded • Have special organs near eyes and brain which improves heating • This helps in their vision and catch their prey easily

  11. Not Schooling Fish Swim alone or…… ….. in loose aggregation having a swordfish 10 meters apart from the other

  12. Very powerful and vigorous when harpooned or hooked • Known to have run their bill like a sword through planking of small boats

  13. Known for their powerful jumping on surface called breaching

  14. Enjoys swimming at surface of water airing their dorsal fin

  15. TheFavorite Food for the Swordfish • Pelagic fish such as flying fish, barracuda and small tuna • Fish in Benthic zone • The squid

  16. Pelagic fish on which the swordfish feeds

  17. The Pelagic Zone • Open ocean zone • Part of water located in open water • Part of water not near coast • Different zones characterized by their depth

  18. Swordfish feeds on fish found in the Benthic Zone • Ecological region at lowest part of the water

  19. Enjoys eating Squid

  20. Enemies of the Swordfish • Very few natural predators in adulthood but highly vulnerable when young • Short fin mako shark is one of few sea creatures which are big and fast enough to kill a swordfish • Other enemies are sperm and killer whale

  21. Short fin mako shark

  22. Sperm Whale

  23. Killer Whale

  24. But the greatest threat to swordfish is HUMANS!!!!!

  25. Fisheries • Caught in gill nets with harpoon & on longlines (see slide further on re: local visit to Fort San Lucjan) • By Catch

  26. Consists of a main line, usually several miles long, which is supported in the water column by floats and from which baited hooks are suspended Long liners

  27. In addition, swordfish are often an incidental catch in the tuna fishery known as by catch This is used on all non-target fish whether retained and sold or discarded (Hall, 1996)

  28. Fishing nets

  29. TheSwordfish is caught !!!

  30. Swordfish ready to be cut….

  31. The swordfish is cleaned

  32. Swordfish is being sliced

  33. The swordfish is cut into pieces

  34. Swordfish & Mercury Intake • While swordfish sold on commercial markets is closely monitored to make sure that methyl mercury levels remain below the 1.0 ppm action level, most experts urge those concerned about chemical contaminants to take certain precautions

  35. Practical tips to avoid mercury consumption • Avoid eating excessive amounts of any single type of fish • Avoid eating the internal organs of the fish—they typically contain higher contaminant concentrations than the flesh • High-risk individuals — pregnant women, women of childbearing age, and children under age 15 — should limit their consumption of swordfish • Use cooking methods like baking or broiling to allow fats and juices to drain away

  36. The Swordfish in Andrew’s plate

  37. Andrew’s Visit to San Lucjan

  38. Fort San Lucjan - Malta Centre for fisheries

  39. Andrew and Mark (scientific officer at San Lucjan)

  40. A swordfish in a frame!

  41. A comparison in size between Tuna Fish (above) and Swordfish (below)

  42. The Flying Fish - the favorite food of the Swordfish

  43. Stuffed Fish including a Swordfish

  44. Preparing the long line

  45. A turtle caught by By Catch

  46. Additional Information • Ernest Hemmingway (1899-1961), one of America’s best writers and winner of Nobel Prize for Literature (1954) spent long years in Cuba. • One of his pleasures of life was fishing for swordfish. • This is reflected in his novel, The Old Man and the Sea, which was published in 1952. • Later the novel was adopted for a famous film, in which actor Spencer Tracey stared.

  47. Ernest Hemming in Cuba with his friend Mike Lerner and their swordfish catch (from Hemmingway in Cuba by H. Hemmingway and C. Brennan, Ruggedland, 2005) The Swordfish Catch

  48. World Record Swordfish • 382 kg • Caught in 1936 • In Chile

More Related