CS3c
This presentation is the property of its rightful owner.
Sponsored Links
1 / 7

Male first sex-changing species PowerPoint PPT Presentation


  • 76 Views
  • Uploaded on
  • Presentation posted in: General

CS3c Red (=blackspot) seabream, Pagellus bogaraveo in the Bay of Biscay. Male first sex-changing species Distributed in the Mediterranean Sea, Straight of Gibraltar, Azores, Bay of Biscay and further North (ICES VII and VI) Longevity ~20 years. Landings in the BoB. ~5 000 t/y. ~10 000 t/y.

Download Presentation

Male first sex-changing species

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Male first sex changing species

CS3cRed (=blackspot) seabream, Pagellus bogaraveo in the Bay of Biscay

Male first sex-changing species

Distributed in the Mediterranean Sea, Straight of Gibraltar, Azores, Bay of Biscay and further North (ICES VII and VI)

Longevity ~20 years


Landings in the bob

Landings in the BoB

~5 000t/y

~10 000t/y

>15 000t/y

Effect of fish availabilty (?)

  • Significant catch by UK during the early XXth century may suggest the stock distribution extended further North (in ICES sub-area VII and even VI)

  • Reliabilty of French reported landings before the 1950s questionable


Male first sex changing species

Seasonal migration of the red seabream in the Bay of Biscay (From Sanchez, 1983)


Male first sex changing species

  • in addition to the geographical migration scheme a depth migration was understood since the 1920s

  • early juveniles are coastal in summer

  • larger fish occur on the shelf and migrate to the slope in winter

  • species known and exploited for long

  • - available also to recreational anglers and scuba divers

Spring: occurs pelagically

Late spring- Early summer: outer shelf

summer-autumn: all the shelf even coastal

January-February by depths > 400m)

From Olivier (1928) Poissons de chalut, la dorade (Pagellus centrodontus). Revue des Travaux de l'Office des PĂŞches Maritimes, I, 4, 5-32


Exploitation

Exploitation

  • The bulk of French landings was from the multi-species trawl fishery in the Bay fo Biscay and Celtic sea (fishing for hake, monkfish and demersal species)

  • Some catch in pelagic trawls

  • Subject of conflicts within the industry at the time of collapse

  • In the 2000s, landings reported mainly from a small handliners fishery (now banned from EU regulation)


Survey data

Survey data


Effects of the population collapse

Effects of the population collapse

4 euros/kg when landings were high (2005 euros)

1000 t -> 4 millions euros

  • Economy

  • Net economic loss

  • Fish community

  • Effect on other species (preys, predators, competitors) unknown.

  • Bay of Biscay fish community:

    • diverse

    • numerous piscivorous predator

    • RBS was not the dominant

  • Effect on taxonomic diversity metrix small and difficult to interpret


  • Login