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Fat Content of Peruvian Anchovy (Engraulis ringens), After “El Niño” Phenomenon (1998––1999)
JOURNAL OF FOOD COMPOSITION AND ANALYSIS (2002) 15, 627–631 doi:10.1006/jfca.2002.1059 Available online at http://www.idealibrary.com on
ORIGINAL ARTICLE Fat Content of Peruvian Anchovy (Engraulis ringens), After ‘‘El Nin˜o’’ Phenomenon (1998--1999) Marı´ a Estela Ayala Galdos1, Miguel Albrecht-Ruiz, Alberto Salas Maldonado, and Jesu´s Paredes Minga Direccio´n de Investigacio´n del Instituto Tecnolo´gico Pesquero del Peru´, Carretera a Ventanilla, Km. 5,2. Callao. Lima, Peru´ Received August 16, 2001, and in revised form January 16, 2002
Variations in fat content of the Peruvian anchovy after ‘‘El Nin˜o’’ phenomenon (July 1998–August 1999) are presented confirming the correlation between fat content and spawning of fish as a consequence of this natural disruption. Results obtained show extremely low values (fat content of 0.91% in July 1998). A gradual recovery of the species to normal values of 11.20% was observed in June 1999. r 2002 Published by Elsevier Science Ltd.
Key Words: fat; anchovy; pelagic species; ‘‘El Nin˜o’’ phenomenon.
INTRODUCTION Peruvian anchovy, Engraulis ringens Jenyns, is a small pelagic and highly reproductive fish in the Engraulidae family, locally named ‘‘Peruvian anchovy’’, ‘‘black anchovy’’, and ‘‘peladilla’’ (Chirichigno and Nauen, 1982). It is distributed between 41 and 371SL. Two big stocks of anchovy are known, one at the central– northern part of Peru (between 4 and 161SL) and the other one at the southern part of the Pacific Coast (from 16 to 371 SL), south region of Peru and north of Chile (PECC, 1996). This species is of great economic importance for the fishmeal and oil industry in Peru and is highly utilized when it has the highest fat content. The Peruvian anchovy biological mass is one of the greatest in the world and its annual volume fluctuates between approximately 6 and 7 million tons (INE, 2001). Peruvian anchovy has spawn lasting between 8 and 9 months (July–March). The central–northern stock presents two periods, one in September or October of higher spawning intensity and a second, of less intensity, between January and February. The southern stock has one peak, around September and October. Fall of fat deposits after the spawning time is well known (Tsukayama, 1989). There is a good 1 To whom correspondence and reprint requests should be addressed: Tel./fax: +51-1-577-3130. E-mail: [email protected], [email protected]
0889-1575/02/060627 + 05 $35.00/0
r 2002 Published by Elsevier Science Ltd.
628
AYALA GALDOS ET AL.
correlation between fat content and spawning peaks. Besides biological variations, climatic and geographic conditions influence the species (Lam, 1968). Even though the dynamics of the Peruvian current and blooming favour anchovy abundance, the ‘‘El Nin˜o’’ phenomenon influences biomass and proximal composition, specifically moisture and fat content. ‘‘El Nin˜o’’ disrupts the ocean–atmosphere system in the Pacific, which has important consequences for weather around the globe like a rise in sea-surface temperature, stop of the upwelling and a drastic decline in primary productivity (McPhaden, 1993). In previous ‘‘El Nin˜o’’ phenomenon, unusual anchovy fat content values were 0.94% in October 1965, 2.6 and 2.7% in January and February 1983, respectively (Vicetti, 1988). During ‘‘El Nin˜o’’, Instituto del Mar del Pe´ru (IMARPE) conducted research to assess distribution and concentration of size structure of pelagic resources, but a lack of information about proximal composition, specifically the fat content of commercially important species, has been observed. This information is of great concern since these data are strongly related to processing and qualitative properties of the final fishery products. This paper is intended to present the variation of Peruvian anchovy fat content during the later period of ‘‘El Nin˜o’’ phenomenon (1998–1999). Moisture content correlation and some proximate composition values are also shown. MATERIALS AND METHODS Anchovies belonging to the central–northern stock were harvested by purse seiner (20 kg at least twice a month) from July 1998 to August 1999, between 10 and 131SL. After landing, all fish were transported in ice to the laboratories of the Instituto Tecnolo´gico Pesquero del Peru´ (ITP), accredited according to ISO 25. Samples were prepared according to the methodology recommended by AOAC (1990). Carefully homogenized dorsal muscle with skin of 15 fishes (with and without spawning) represented one sample. Determinations were performed on two replicates for each sample. Determinations were performed according to the methodology used by FAO (1986): moisture (air oven method), crude fat (Soxhlet extraction method), protein (semi-micro-Kjeldahl method) and total ash. Reproducibility of results was 0.5, 0.6, 0.7 and 0.5%, respectively, for each component. Moisture and fat analyses were determined in a total of 66 samples. Additionally, in eight of these samples, protein and ash were determined. RESULTS AND DISCUSSION Average length of the samples was 13.5170.78 cm, 78.06% were classified as extra large according to the distribution size by IMARPE: (small o10 cm, medium 10.1– 12.0 cm, large 12.1–14.0 cm and extra large 414.1 cm) (Lam, 1968). Table 1 and Figure 1 show the fluctuation of proximate components. The variation of anchovy proximate composition indicates that protein and ash contents remained almost constant with small fluctuations for all samples. Protein content varied from 18.07 to 20.79% and ash values varied from 1.38 to 2.19% while lower and upper limits for fat were 0.91–13.26% and 68.20–76.73% for moisture. Usually, water and oil contents in fish fillets are inversely related and their sum is approximately 80% (FAO, 1998). This inverse relationship can be observed in Figure 2 (original data are presented in Table 2).
629
FAT CONTENT OF PERUVIAN ANCHOVY TABLE 1 Variation of proximate composition (%) of Peruvian anchovy (1998–1999)
Jul-98 Aug-98 Nov-98 Feb-99 Mar-99 Apr-99 Jun-99 Aug-99 Lower and upper limits Protein 20.56 Ash 1.81 Moisture 76.73 Fat 0.91 77.64 M+F1 1
19.48 1.57 76.60 1.48 78.08
19.44 1.63 73.54 4.56 78.10
19.52 1.42 72.00 6.79 78.79
19.15 1.49 72.50 5.61 78.11
20.79 2.19 69.03 7.93 76.96
18.07 1.38 68.20 13.26 81.46
19.35 1.53 71.24 7.29 78.53
18.07–20.79 1.38–2.19 68.20–76.73 0.91–13.26
M+F=sum of moisture and fat.
FIGURE 1. Proximal composition of Peruvian anchovy July 1998–August 1999. ( ) moisture; ( ) fat; ( ) protein and ( ) ash. Each column represents the mean value of two replicates from composite sample of 15 fish. Protein and ash contents show minimal fluctuations while fat and moisture contents vary obviously.
The fat content data during the study period are shown in Table 2. From July to October, the spawning period, average values were 0.91, 1.48, 1.39 and 3.38%. These values were quite low compared to those reported in previous years. Former reports showed fat average contents of 8% in centre-north anchovy biomass and of 5–6% in the south anchovy biomass (Lam, 1968; ITP-IMARPE, 1996). Fat average content of July 1998 (0.91%) constitutes the lowest of those reported since 1964 and could only be compared to 0.94% in October 1965, other minimal content (2.6%) corresponded to January 1983 during ‘‘El Nin˜o’’ phenomenon (Tsukayama, 1989). Between November and December, some recovery of the species seemed to occur when comparing fat contents, with a maximum of 11.2% reached in June 1999. The obtained values suggest a tendency different from what has been previously reported for this species in common years (Lam, 1968; Tsukayama, 1989). It may be concluded that a definite recovery of the anchovy fat content belonging to the central–northern stock came around June 1999. Fat values in July and August 1998 are considerably depressed when compared to those of 1999. This seems to be related to the influence of ‘‘El Nin˜o’’ phenomenon
630
AYALA GALDOS ET AL. 80
16
12
8
Fat %
Moisture %
75
70 4
65
0
jul-98 aug
sep
oct
nov
dec
jan99
feb
mar
apr
may
jun
jul
aug
FIGURE 2. Moisture and fat contents in Peruvian anchovy July 1998–August 1999. ( ) Fat and ( ) moisture. Each point is the mean value of two replicates from composite sample of 15 fish. An inverse relationship (mirror image) between these components can be observed
TABLE 2 Moisture and fat contents of Peruvian anchovy (1998–1999)1 1998 Jul Moisture 76.732 76.75 76.70
x 76.73 s 0.03 Fat (%) 0.912 0.91 0.90
0.91 0.01
x s 1 2
Aug
Sept
1999
Oct
Nov
(%) 76.76 77.16 75.92 74.10 76.43 77.06 74.85 73.89 75.30 73.27 76.602 73.99 73.80 73.46 73.37 72.65 72.63 73.542 76.60 0.17
77.11 75.02 73.41 0.07 0.81 0.51
1.47 1.48 1.482
1.37 1.40
3.20 2.90 3.31 4.11
4.53 3.68 4.58 4.53 5.21 5.37 5.83 5.81 4.562
1.48 0.01
1.39 0.02
3.38 0.52
4.90 0.71
Dec 74.11 74.13 72.65 72.70 73.38 74.54 73.41 73.49 71.83 71.81 73.21 0.94 4.77 4.60 6.46 7.56 5.51 5.53 6.20 6.15 7.99 7.98 6.28 1.24
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
72.13 71.80 73.00 72.002 72.65 71.63 71.90
68.98 71.63 70.58 70.27 71.26 73.31 69.07 71.61 70.56 70.28 71.22 73.42 71.69 69.032 68.21 70.56 71.58 68.19 70.53 70.06 72.49 68.202 72.51 69.85 72.43 71.241 72.52 72.502
72.59 71.83 0.44 0.16
71.53 1.47
70.76 1.50
70.57 69.03 0.01 1.14
6.41 5.89 6.22
6.81 6.792 6.43 6.80
7.90 7.95 7.56 7.75 5.56 5.66 5.78 5.77 5.612
6.43 6.09 7.932
8.29 8.17
6.17 0.26
6.71 0.19
6.62 1.12
6.82 0.98
8.23 11.20 0.08 2.82
Each value was obtained from two replicates of a 15 fishes composite sample. Protein and ash determinations were additionally performed for these samples.
7.93 8.30 13.11 13.40 13.262
71.24 71.28 0.03 1.49 7.23 7.35
3.97 4.07 8.42 8.42 9.87 9.95 7.292
7.29 0.08
7.43 2.50
FAT CONTENT OF PERUVIAN ANCHOVY
631
and the warming of the sea water begun in December 1997 and continued during 1998. In 1999, increased anchovy fat values could be associated with cooler sea-water temperature and supply of nutrients. It is important to remark that anchovy sampling was not possible for the first semester of 1998 due to the critical depression of the biomass. REFERENCES AOAC. (1990). Fish and marine products (T. Hollingsworth and M. M. Wekell, Chapter Eds.) In Official Methods of Analysis of the Association of Official Analytical Chemists (Kenneth Helrich, Ed), 15th Edn, p. 864. Association of Official Analytical Chemists, Inc. Arlington, Virginia, U.S.A. Chirichigno, N. F. and Nauen, C. E. (Comps.) (1982). Refered: Catalogo de Especies Marinas de Intere´s Economico Actual o Potencial para America Latina IIFPacı´fico Centro y Sur Oriental. FAO/PNUD, SIC/82/2, Rome. ITPFMARPE. Instituto Tecnolo´gico Pesquero del Peru´-Instituo del Mar del Peru (1996). Compendio Biolo´gico de las Principales Especies Hidrobiolo´gicas Comerciales del Peru´. INE. Instituto Nacional de Estadı´ stica. (2001). Compendio Estadı´ stico Econo´mico Financiero 2000. Peru´. Ed. Gra´fica Monterrico S.A. FAO. (1986). Food analysis: general techniques, additives, contaminants, and composition. Food and Nutrition Papers 14/7. Manuals of Food Quality Control, Vol. 7, p. 205. Prepared by FAO with the support of the Swedish International Development Authority (SIDA). Food and Agriculture Organization of the United Nations, Rome. FAO. (1998). Chapter 4; Quality and quality changes in fresh fish. (Huss, H. H., Ed.), FAO Fisheries Technical Paper 348. Technological Laboratory, Ministry of Agriculture and Fisheries, Government of Denmark. Lam, R. (1968). Estudio sobre la variacio´n del contenido de Grasa en la anchoveta Peruana (Engraulis ringens J.). Informe No. 24. Instituto del Mar del Peru´ (IMARPE), Callao, Peru´. McPhaden, M. J. (1993). TOGA–TAO and the 1991–93 El Nin˜o-Southern Oscillation Event. Oceanography, 6, 36–44. IMARPE. (1996). Peruvian fisheries: ‘‘Peru’s contribution to the utilization of underexploited and potential fishery resources’’. Proceedings of the PECC Fisheries Task Force Symposium, November 1996. Wellington, New Zealand. Tsukayama, I. (1989). Dynamics of the fat content of Peruvian anchovy (Engraulis ringens). In The Peruvian Upwelling Ecosystem: Dynamics and Interactions. ICLARM Conference Proceedings (D. Pauly, P. Muck, J. Mendo and I. Tsukayama, Eds.) Vol. 18, 438 p, pp. 125–131. Instituto del Mar del Peru´ (IMARPE), Callao, Peru´; Deutsche Gesellschaft fu¨r Technische Zusammenarbeit (GTZ) GmbH, Eschborn, Federal Republic of Germany and International Center for Living Aquatic Resources Management (ICLARM), Manila, Philippines. Vicetti, S. R. (1988). Country Report on Marine Food Processing and its Problems in Peru. Group Training Course in Marine Food Processing and Technology, ITP.
.
ORIGINAL ARTICLE Fat Content of Peruvian Anchovy (Engraulis ringens), After ‘‘El Nin˜o’’ Phenomenon (1998--1999) Marı´ a Estela Ayala Galdos1, Miguel Albrecht-Ruiz, Alberto Salas Maldonado, and Jesu´s Paredes Minga Direccio´n de Investigacio´n del Instituto Tecnolo´gico Pesquero del Peru´, Carretera a Ventanilla, Km. 5,2. Callao. Lima, Peru´ Received August 16, 2001, and in revised form January 16, 2002
Variations in fat content of the Peruvian anchovy after ‘‘El Nin˜o’’ phenomenon (July 1998–August 1999) are presented confirming the correlation between fat content and spawning of fish as a consequence of this natural disruption. Results obtained show extremely low values (fat content of 0.91% in July 1998). A gradual recovery of the species to normal values of 11.20% was observed in June 1999. r 2002 Published by Elsevier Science Ltd.
Key Words: fat; anchovy; pelagic species; ‘‘El Nin˜o’’ phenomenon.
INTRODUCTION Peruvian anchovy, Engraulis ringens Jenyns, is a small pelagic and highly reproductive fish in the Engraulidae family, locally named ‘‘Peruvian anchovy’’, ‘‘black anchovy’’, and ‘‘peladilla’’ (Chirichigno and Nauen, 1982). It is distributed between 41 and 371SL. Two big stocks of anchovy are known, one at the central– northern part of Peru (between 4 and 161SL) and the other one at the southern part of the Pacific Coast (from 16 to 371 SL), south region of Peru and north of Chile (PECC, 1996). This species is of great economic importance for the fishmeal and oil industry in Peru and is highly utilized when it has the highest fat content. The Peruvian anchovy biological mass is one of the greatest in the world and its annual volume fluctuates between approximately 6 and 7 million tons (INE, 2001). Peruvian anchovy has spawn lasting between 8 and 9 months (July–March). The central–northern stock presents two periods, one in September or October of higher spawning intensity and a second, of less intensity, between January and February. The southern stock has one peak, around September and October. Fall of fat deposits after the spawning time is well known (Tsukayama, 1989). There is a good 1 To whom correspondence and reprint requests should be addressed: Tel./fax: +51-1-577-3130. E-mail: [email protected], [email protected]
0889-1575/02/060627 + 05 $35.00/0
r 2002 Published by Elsevier Science Ltd.
628
AYALA GALDOS ET AL.
correlation between fat content and spawning peaks. Besides biological variations, climatic and geographic conditions influence the species (Lam, 1968). Even though the dynamics of the Peruvian current and blooming favour anchovy abundance, the ‘‘El Nin˜o’’ phenomenon influences biomass and proximal composition, specifically moisture and fat content. ‘‘El Nin˜o’’ disrupts the ocean–atmosphere system in the Pacific, which has important consequences for weather around the globe like a rise in sea-surface temperature, stop of the upwelling and a drastic decline in primary productivity (McPhaden, 1993). In previous ‘‘El Nin˜o’’ phenomenon, unusual anchovy fat content values were 0.94% in October 1965, 2.6 and 2.7% in January and February 1983, respectively (Vicetti, 1988). During ‘‘El Nin˜o’’, Instituto del Mar del Pe´ru (IMARPE) conducted research to assess distribution and concentration of size structure of pelagic resources, but a lack of information about proximal composition, specifically the fat content of commercially important species, has been observed. This information is of great concern since these data are strongly related to processing and qualitative properties of the final fishery products. This paper is intended to present the variation of Peruvian anchovy fat content during the later period of ‘‘El Nin˜o’’ phenomenon (1998–1999). Moisture content correlation and some proximate composition values are also shown. MATERIALS AND METHODS Anchovies belonging to the central–northern stock were harvested by purse seiner (20 kg at least twice a month) from July 1998 to August 1999, between 10 and 131SL. After landing, all fish were transported in ice to the laboratories of the Instituto Tecnolo´gico Pesquero del Peru´ (ITP), accredited according to ISO 25. Samples were prepared according to the methodology recommended by AOAC (1990). Carefully homogenized dorsal muscle with skin of 15 fishes (with and without spawning) represented one sample. Determinations were performed on two replicates for each sample. Determinations were performed according to the methodology used by FAO (1986): moisture (air oven method), crude fat (Soxhlet extraction method), protein (semi-micro-Kjeldahl method) and total ash. Reproducibility of results was 0.5, 0.6, 0.7 and 0.5%, respectively, for each component. Moisture and fat analyses were determined in a total of 66 samples. Additionally, in eight of these samples, protein and ash were determined. RESULTS AND DISCUSSION Average length of the samples was 13.5170.78 cm, 78.06% were classified as extra large according to the distribution size by IMARPE: (small o10 cm, medium 10.1– 12.0 cm, large 12.1–14.0 cm and extra large 414.1 cm) (Lam, 1968). Table 1 and Figure 1 show the fluctuation of proximate components. The variation of anchovy proximate composition indicates that protein and ash contents remained almost constant with small fluctuations for all samples. Protein content varied from 18.07 to 20.79% and ash values varied from 1.38 to 2.19% while lower and upper limits for fat were 0.91–13.26% and 68.20–76.73% for moisture. Usually, water and oil contents in fish fillets are inversely related and their sum is approximately 80% (FAO, 1998). This inverse relationship can be observed in Figure 2 (original data are presented in Table 2).
629
FAT CONTENT OF PERUVIAN ANCHOVY TABLE 1 Variation of proximate composition (%) of Peruvian anchovy (1998–1999)
Jul-98 Aug-98 Nov-98 Feb-99 Mar-99 Apr-99 Jun-99 Aug-99 Lower and upper limits Protein 20.56 Ash 1.81 Moisture 76.73 Fat 0.91 77.64 M+F1 1
19.48 1.57 76.60 1.48 78.08
19.44 1.63 73.54 4.56 78.10
19.52 1.42 72.00 6.79 78.79
19.15 1.49 72.50 5.61 78.11
20.79 2.19 69.03 7.93 76.96
18.07 1.38 68.20 13.26 81.46
19.35 1.53 71.24 7.29 78.53
18.07–20.79 1.38–2.19 68.20–76.73 0.91–13.26
M+F=sum of moisture and fat.
FIGURE 1. Proximal composition of Peruvian anchovy July 1998–August 1999. ( ) moisture; ( ) fat; ( ) protein and ( ) ash. Each column represents the mean value of two replicates from composite sample of 15 fish. Protein and ash contents show minimal fluctuations while fat and moisture contents vary obviously.
The fat content data during the study period are shown in Table 2. From July to October, the spawning period, average values were 0.91, 1.48, 1.39 and 3.38%. These values were quite low compared to those reported in previous years. Former reports showed fat average contents of 8% in centre-north anchovy biomass and of 5–6% in the south anchovy biomass (Lam, 1968; ITP-IMARPE, 1996). Fat average content of July 1998 (0.91%) constitutes the lowest of those reported since 1964 and could only be compared to 0.94% in October 1965, other minimal content (2.6%) corresponded to January 1983 during ‘‘El Nin˜o’’ phenomenon (Tsukayama, 1989). Between November and December, some recovery of the species seemed to occur when comparing fat contents, with a maximum of 11.2% reached in June 1999. The obtained values suggest a tendency different from what has been previously reported for this species in common years (Lam, 1968; Tsukayama, 1989). It may be concluded that a definite recovery of the anchovy fat content belonging to the central–northern stock came around June 1999. Fat values in July and August 1998 are considerably depressed when compared to those of 1999. This seems to be related to the influence of ‘‘El Nin˜o’’ phenomenon
630
AYALA GALDOS ET AL. 80
16
12
8
Fat %
Moisture %
75
70 4
65
0
jul-98 aug
sep
oct
nov
dec
jan99
feb
mar
apr
may
jun
jul
aug
FIGURE 2. Moisture and fat contents in Peruvian anchovy July 1998–August 1999. ( ) Fat and ( ) moisture. Each point is the mean value of two replicates from composite sample of 15 fish. An inverse relationship (mirror image) between these components can be observed
TABLE 2 Moisture and fat contents of Peruvian anchovy (1998–1999)1 1998 Jul Moisture 76.732 76.75 76.70
x 76.73 s 0.03 Fat (%) 0.912 0.91 0.90
0.91 0.01
x s 1 2
Aug
Sept
1999
Oct
Nov
(%) 76.76 77.16 75.92 74.10 76.43 77.06 74.85 73.89 75.30 73.27 76.602 73.99 73.80 73.46 73.37 72.65 72.63 73.542 76.60 0.17
77.11 75.02 73.41 0.07 0.81 0.51
1.47 1.48 1.482
1.37 1.40
3.20 2.90 3.31 4.11
4.53 3.68 4.58 4.53 5.21 5.37 5.83 5.81 4.562
1.48 0.01
1.39 0.02
3.38 0.52
4.90 0.71
Dec 74.11 74.13 72.65 72.70 73.38 74.54 73.41 73.49 71.83 71.81 73.21 0.94 4.77 4.60 6.46 7.56 5.51 5.53 6.20 6.15 7.99 7.98 6.28 1.24
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
72.13 71.80 73.00 72.002 72.65 71.63 71.90
68.98 71.63 70.58 70.27 71.26 73.31 69.07 71.61 70.56 70.28 71.22 73.42 71.69 69.032 68.21 70.56 71.58 68.19 70.53 70.06 72.49 68.202 72.51 69.85 72.43 71.241 72.52 72.502
72.59 71.83 0.44 0.16
71.53 1.47
70.76 1.50
70.57 69.03 0.01 1.14
6.41 5.89 6.22
6.81 6.792 6.43 6.80
7.90 7.95 7.56 7.75 5.56 5.66 5.78 5.77 5.612
6.43 6.09 7.932
8.29 8.17
6.17 0.26
6.71 0.19
6.62 1.12
6.82 0.98
8.23 11.20 0.08 2.82
Each value was obtained from two replicates of a 15 fishes composite sample. Protein and ash determinations were additionally performed for these samples.
7.93 8.30 13.11 13.40 13.262
71.24 71.28 0.03 1.49 7.23 7.35
3.97 4.07 8.42 8.42 9.87 9.95 7.292
7.29 0.08
7.43 2.50
FAT CONTENT OF PERUVIAN ANCHOVY
631
and the warming of the sea water begun in December 1997 and continued during 1998. In 1999, increased anchovy fat values could be associated with cooler sea-water temperature and supply of nutrients. It is important to remark that anchovy sampling was not possible for the first semester of 1998 due to the critical depression of the biomass. REFERENCES AOAC. (1990). Fish and marine products (T. Hollingsworth and M. M. Wekell, Chapter Eds.) In Official Methods of Analysis of the Association of Official Analytical Chemists (Kenneth Helrich, Ed), 15th Edn, p. 864. Association of Official Analytical Chemists, Inc. Arlington, Virginia, U.S.A. Chirichigno, N. F. and Nauen, C. E. (Comps.) (1982). Refered: Catalogo de Especies Marinas de Intere´s Economico Actual o Potencial para America Latina IIFPacı´fico Centro y Sur Oriental. FAO/PNUD, SIC/82/2, Rome. ITPFMARPE. Instituto Tecnolo´gico Pesquero del Peru´-Instituo del Mar del Peru (1996). Compendio Biolo´gico de las Principales Especies Hidrobiolo´gicas Comerciales del Peru´. INE. Instituto Nacional de Estadı´ stica. (2001). Compendio Estadı´ stico Econo´mico Financiero 2000. Peru´. Ed. Gra´fica Monterrico S.A. FAO. (1986). Food analysis: general techniques, additives, contaminants, and composition. Food and Nutrition Papers 14/7. Manuals of Food Quality Control, Vol. 7, p. 205. Prepared by FAO with the support of the Swedish International Development Authority (SIDA). Food and Agriculture Organization of the United Nations, Rome. FAO. (1998). Chapter 4; Quality and quality changes in fresh fish. (Huss, H. H., Ed.), FAO Fisheries Technical Paper 348. Technological Laboratory, Ministry of Agriculture and Fisheries, Government of Denmark. Lam, R. (1968). Estudio sobre la variacio´n del contenido de Grasa en la anchoveta Peruana (Engraulis ringens J.). Informe No. 24. Instituto del Mar del Peru´ (IMARPE), Callao, Peru´. McPhaden, M. J. (1993). TOGA–TAO and the 1991–93 El Nin˜o-Southern Oscillation Event. Oceanography, 6, 36–44. IMARPE. (1996). Peruvian fisheries: ‘‘Peru’s contribution to the utilization of underexploited and potential fishery resources’’. Proceedings of the PECC Fisheries Task Force Symposium, November 1996. Wellington, New Zealand. Tsukayama, I. (1989). Dynamics of the fat content of Peruvian anchovy (Engraulis ringens). In The Peruvian Upwelling Ecosystem: Dynamics and Interactions. ICLARM Conference Proceedings (D. Pauly, P. Muck, J. Mendo and I. Tsukayama, Eds.) Vol. 18, 438 p, pp. 125–131. Instituto del Mar del Peru´ (IMARPE), Callao, Peru´; Deutsche Gesellschaft fu¨r Technische Zusammenarbeit (GTZ) GmbH, Eschborn, Federal Republic of Germany and International Center for Living Aquatic Resources Management (ICLARM), Manila, Philippines. Vicetti, S. R. (1988). Country Report on Marine Food Processing and its Problems in Peru. Group Training Course in Marine Food Processing and Technology, ITP.
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