South Antarctic Krill (Euphausia superba, Dana)

Transcription

1 Biological and Chemical Impact of Fishing Seasonality Impact in Krill Lipids (& Other Compounds) Period 80 s to 2000 s South Antarctic Krill (Euphausia superba, Dana) Summarized Tharos Information At-Sea and On-Shore (80 s~2000 s) Edited June 2014 Lipid Information Page Nbr 1 of 12

2 (AA) Maturity versus Lipid Content Research confirms that males prevail in maturity towards the end of each season (Q3 each year) containing less lipid content, affecting oil extraction. In July, the female is in her 2 nd stage of maturity while most males are in their third stage. Maturity Stage of Krill (July 2008) Maturity stage () Sex Grand Total Females Males Grand Total In August, the female is on her a 2 nd stage of maturity, while the majority of males (42.7) are in their third stage of maturity Maturity Stage of Krill (August 2008) Maturity stage Sex Grand Total Females Males Grand Total Maturity stage of male krill in the July-August 2008 Lipid Information Page Nbr 2 of 12

3 July-August (BB) Catch Region & Capture Efficiency Approaching the end of each season (August), fishing becomes scattered, difficult and erratic. It has a direct relationship with krill s biology and environmental factors. (Yellow spots = capture trawls) Dynamics of Water and Place of Hauls (first half August 2008) Lipid Information Page Nbr 3 of 12

4 Dynamics of Water and Place of Hauls (last half August 2008) Lipid Information Page Nbr 4 of 12

5 Remarks of data collection 1. Performed onboard F/T RTMK-S Maxim Starostin 2. Period July/25/2008 ~ August/31/2008 (Subarea 48.3) 3. Hauls = 36 (traditional method = 25, pumping = 11) 4. Observations of hydrometeorological conditions = Measurements for weight, sex, color = 8,848 units 6. Determination of maturity = 800 units 7. Prevailing wind speed (Beaufort scale) = 2.1 (July) ~ 3 (August) 8. Prevailing wind direction (July) North-West (41.9). First half of August (from 1 to 15) most frequently winds North-West (36.9) 9. Barometer (July) 740 ~ 765 mm. Prevailing values 763 ~ 764 mm. For August (first half) 731 ~ 757 mm. Prevailing values 740 ~ 745 mm. 10. Air temperature during the entire period of work +4 ~ -3ºC. Most frequently observed (July) -1ºC, (August) -2ºC. 11. Constantly observed icebergs (big and small), not interfering with fishing. 12. Trawl system DANA 400m/2000, Beam trawl , Maritime Krill. 13. Coordinates (July) within 53 40'S 35 60' W. In August, in connection with the deterioration of fishing conditions, coordinates within 53 40'S 38 55'W. Mid-End August within 53 40'S 35 47'W. 14. Spots consisted of numerous shoals length 100 ~ 500m. During the day, krill held over depth of 200 meters, average depths m with a vertical development of 30m. 15. At night, scattered with vertical development of up to 100 m at depths of m. Lipid Information Page Nbr 5 of 12

6 Accumulations of Krill on the Sonar "dark" (A) and "bright" (B) = time of day Lipid Information Page Nbr 6 of 12

7 (CC) Sizing Distribution of length a) Males 22 ~ 60 mm, mode 45mm b) Females 22 ~ 55 mm, mode 42mm c) Average length for male (July and August) ~ 44.7mm females ~ 42.4mm. Average weight (July) ~ 0.549g, (August) ~ 0.565g. Ratio males:females 1:0,70 (July) and 1:1,01 (August). In July krill does not fed on algae = 100 have a pale pink color. In August, the number of eating krill increases getting a light greener color ~ 5,5. Size Composition (July-August 2008) = females in July = females in August = males in July = males in August Lipid Information Page Nbr 7 of 12

8 As a reference, how it looks the March/April Krill a) Length of males 31 ~ 59mm, mode 51mm b) Females 25 ~ 59 mm, mode 50mm c) Juveniles 21 ~ 26 mm, 0.1 of total d) Average weight females ~ 0.81g, for males ~ 1.0g e) Ratio of males and females 1:2,35. How about the May Krill a) Male length 20 ~ 60 mm, mode 52mm b) Females 20 ~ 58mm, mode 50mm c) Average weight Females ~ 0.72g, for males ~0.95g d) Ratio males to females 1:2,48. Size structure of krill in May 2009 Lipid Information Page Nbr 8 of 12

9 Size structure of krill in March 2009 Lipid Information Page Nbr 9 of 12

10 (DD) Summarized Lipid Content Russia s VNIRO s late 80s research is compiled bellow. It summarizes krill lipid content by period and aminoacids content. Date of COMPONENT catch Moisture Fat Total N No-Protein N Residual N Ash Chitin January February March April May June August September October November December July not available Amino acid SCORE December January February April May June August Tryptophan Lysine Threonine Valine Methionine Isoleucine Leucine Tyrosine + Phenylalanine Lipid Information Page Nbr 10 of 12

11 The Amino acid score-indicator is the biological value of the protein. Amino acid Amino Acid Composition (mg/g Protein) (data when available) PERIOD December January February April May June August Tryptophan Lysine Histidine Ammonia Arginine Cysteine acid Aspartic acid Threonine Serine Glutamic Proline Glycine Adanin Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine (-) no data Lipid Information Page Nbr 11 of 12

12 Regarding enzymatic activity, krill caught December ~ February shows a high activity, explained mostly by the significantly high Southern Hemisphere springsummer phytoplankton outbreak, when krill actively feds. This enzymatic activity can severely affect the krill oil extraction process (yield and quality) when extracted from krill meals and frozen krill. The extraction efficiency depends on the raw material handling at sea and how resulting dried meal and frozen krill were re-processed onshore. In the Southern Hemisphere autumn-winter period (March ~ September), krill proteinase is less active. Lipid Information Page Nbr 12 of 12