Volume 4. Biological and nutrient chemistry data
 from principal participating ships,
first and second monitor cruises, April-July 1967

Love, C. M. (Ed.) (1970). Biological and nutrient chemistry data from principal participating ships, first and second monitor cruises, April-July 1967. EASTROPAC Atlas, vol. 4. Washington, D. C.: National Marine Fisheries Service.

Front cover
Inside front cover
Notice to recipients
Errata
Title page, cont.

PREFACE, cont. By Alan R. Longhurst

INTRODUCTION. By Cuthbert M. Love
EASTROPAC cruises
Program of observations
Preparation of Atlas charts
Organization of the Atlas, cont.
Acknowledgments

COLLECTION AND PROCESSING OF THE DATA
Temperature, salinity, and derived quantities. By Bruce A. Taft and Forrest R. Miller
Thickness of  the upper mixed layer. By Robert W. Owen, Jr.
Dissolved oxygen. By Robert W. Owen, Jr.
Meteorology. By Forrest R. Miller
Nutrient chemistry. By William H. Thomas
Phytoplankton standing stocks and production. By Robert W. Owen, Jr. and Bernt Zeitzschel
Zooplankton and fish larvae. By R. Michael Laurs
Micronekton. By Maurice Blackburn
Birds, fish schools, and marine mammals. By R. Michael Laurs

LITERATURE CITED

List of Figures iii, iv, v

Reference maps and track charts

FIGURE 10-TC-a. Locations of stations occupied by participating ships in the main portion of the EASTROPAC area during the first survey period, February-March 1967.
FIGURE 10-TC-b. Locations of stations occupied by participating ships in the southern coastal portion of the EASTROPAC area during the first survey period, February-March 1967.
FIGURE 20-TC. Locations of stations occupied by participating ships during the first monitor period, April-May 1967.
FIGURE 30-TC. Locations of stations occupied by participating ships during the second monitor period, June-July 1967.
FIGURE 40-TC-a. Locations of stations occupied by participating ships in the main portion of the EASTROPAC area during the second survey period, August-September 1967.
FIGURE 40-TC-b. Locations of stations occupied by participating ships in the southern coastal portion of the EASTROPAC area during the second survey period, August-September 1967.
FIGURE 50-TC. Locations of stations occupied by participating ships during the third monitor period, October-November 1967.
FIGURE 60-TC. Locations of stations occupied by participating ships during the fourth monitor period, December 1967 - January 1968.
FIGURE 70-TC-a. Locations of stations occupied by participating ships in the main portion of the EASTROPAC area during the third survey period, February-March 1968.
FIGURE 70-TC-b. Locations of stations occupied by participating ships in the southern coastal portion of the EASTROPAC area during the third survey period, February-March 1968.
FIGURE RM-a. Reference map of the main portion of the EASTROPAC area.
FIGURE RM-b. Reference map of the southern coastal portion of the EASTROPAC area.

Nutrient chemistry

FIGURE 20-P-10. Phosphate-phosphorus (µg-at/l) at 10 meters, April-May 1967.
FIGURE 20-Si-10. Silicate-silicon (µg-at/l) at 10 meters, April-May 1967.
FIGURE 20-NO₃-10. Nitrate-nitrogen (µg-at/l) at 10 meters, April-May 1967.
FIGURE 20-NO₂-10. Nitrite-nitrogen (µg-at/l) at 10 meters, April-May 1967.
FIGURE 20-NH₃-10. Ammonia-nitrogen (µg-at/l) at 10 meters, April-May 1967.
FIGURE 20-P-100. Phosphate-phosphorus (µg-at/l) at 100 meters, April-May 1967.
FIGURE 20-Si-100. Silicate-silicon (µg-at/l) at 100 meters, April-May 1967.
FIGURE 20-NO₃-100. Nitrate-nitrogen (µg-at/l) at 100 meters, April-May 1967.
FIGURE 20-NH₃-100. Ammonia-nitrogen (µg-at/l) at 100 meters, April-May 1967.

Phytoplankton

FIGURE 20-Ch-s. Chlorophyll-a (mg/m^₃) at the sea surface, April-May 1967.
FIGURE 20-Ch-ei. Chlorophyll-a (mg/m^₂) integrated over the euphotic layer, April-May 1967.
FIGURE 20-Ch-150i. Chlorophyll-a (mg/m^₂) integrated from the sea surface to 150 meters depth, April-May 1967.
FIGURE 20-Ph-150i. Phaeophytin (mg/m^₂) integrated from the sea surface to 150 meters depth, April-May 1967.
FIGURE 20-PP-s. Primary production (mgC/m^₃/day) at the sea surface, April-May 1967.
FIGURE 20-PP-ei. Primary production (mgC/m^₂/day) integrated over the euphotic layer, April-May 1967.
FIGURE 20-EL. Thickness of the euphotic layer in meters, April-May 1967.

Zooplankton and micronekton

FIGURE 20-FCp. Distribution of standing stock (ml/1000m^₃) of total fish and cephalopods taken in night micronekton hauls during April-May 1967.
FIGURE 20-Cr. Distribution of standing stock (ml/1000m^₃) of total crustaceans taken in night micronekton hauls during April-May 1967.
FIGURE 20-Nk. Distribution of standing stock (ml/1000m^₃) of total micronekton taken in night micronekton hauls during April-May 1967.
FIGURE 20-ZhN. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 50-cm net hauls at night, April-May 1967.
FIGURE 20-Z1N. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 1-m net hauls at night, April-May 1967.
FIGURE 20-ZhD. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 50-cm net hauls during the day, April-May 1967.
FIGURE 20-Z1D. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 1-m net hauls during the day, April-May 1967.

Fish larvae

FIGURE 20-FLN. Total fish larvae (number/haul) taken in 1-m oblique plankton hauls at night during April-May 1967.
FIGURE 20-FLD. Total fish larvae (number/haul) taken in 1-m oblique plankton hauls during the day, April-May 1967.
FIGURE 20-FE. Total fish eggs (number/haul) taken in 1-m oblique plankton hauls during April-May 1967.
FIGURE 20-FS. Total skipjack tuna, Katsuwonus pelamis, larvae (number/haul) taken in 1-m oblique plankton hauls during April-May 1967.
FIGURE 20-FA. Total frigate mackerel, Auxis, larvae (number/haul) taken in 1-m oblique plankton hauls during April-May 1967.
FIGURE 20-FC. Total dolphin (fish), Coryphaena, larvae (number/haul) taken in 1-m oblique plankton hauls during April-May 1967.
FIGURE 20-FMN. Total myctophid larvae (number/haul) taken in 1-m oblique plankton hauls at night during April-May 1967,
FIGURE 20-FMD. Total myctophid larvae (number/haul) taken in 1-m oblique plankton hauls during the day, April-May 1967.
FIGURE 20-FGN. Total gonostomatid and sternoptychid larvae (number/haul) taken in 1-m oblique plankton hauls at night during April-May 1967.
FIGURE 20-FGD. Total gonostomatid and sternoptychid larvae (number/haul) taken in 1-m oblique plankton hauls during the day, April-May 1967.

Nutrient chemistry

FIGURE 20-P-vl. Vertical distribution of phosphate-phorphorus (µg-at/l) along 119°20' W, April 13-21, 1967.
FIGURE 20-P-v2. Vertical distribution of phosphate-phosphorus (µg-at/l) along 112°20' W, April 23-29, 1967.
FIGURE 20-P-v3. Vertical distribution of phosphate-phosphorus (µg-at/l) along a section from 12° N, 112°20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-P-v4. Vertical distribution of phosphate-phosphorus (µg-at/l) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-P-v5. Vertical distribution of phosphate-phosphorus (µg-at/l) along 105°20' W, May 10-15, 1967.
FIGURE 20-P-v6. Vertical distribution of phosphate-phosphorus (µg-at/l) along 98°20' W, May 17-24, 1967.

FIGURE 20-Si-v1.  Vertical distribution of silicate-silicon (µg-at/l) along 119°20' W, April 13-21, 1967.
FIGURE 20-Si-v2. Vertical distribution of silicate-silicon (µg-at/l) along 112°20' W, April 23-29, 1967.
FIGURE 20-Si-v3. Vertical distribution of silicate-silicon (µg-at/l) along a section from 12° N, 112°20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-Si-v4. Vertical distribution of silicate-silicon (µg-at/l) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-Si-v5. Vertical distribution of silicate-silicon (µg-at/l) along 105°20' W, May 10-15,1967.
FIGURE 20-Si-v6. Vertical distribution of silicate-silicon (µg-at/l) along 98°20' W, May 17-24, 1967.

FIGURE 20-NO₃-v1. Vertical distribution of nitrate-nitrogen (µg-at/l) along 119°20' W, April 13-21, 1967.
FIGURE 20-NO₃-v2. Vertical distribution of nitrate-nitrogen (µg-at/l) along 112°20' W, April 23-29, 1967.
FIGURE 20-NO₃-v3. Vertical distribution of nitrate-nitrogen (µg-at/l) along a section from 12° N, 112°20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-NO₃-v4. Vertical distribution of nitrate-nitrogen (µg-at/l) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-NO₃-v5. Vertical distribution of nitrate-nitrogen (µg-at/l) along 105°20' W, May 10-15, 1967.
FIGURE 20-NO₃-v6. Vertical distribution of nitrate-nitrogen (µg-at/l) along 98°20' W, May 17-24, 1967.

FIGURE 20-NO₂-v1. Vertical distribution of nitrite-nitrogen (µg-at/l) along 119°20' W, April 13-21, 1967.
FIGURE 20-NO₂-v2. Vertical distribution of nitrite-nitrogen (µg-at/l) along 112°20' W, April 23-29, 1967.
FIGURE 20-NO₂-v3. Vertical distribution of nitrite-nitrogen (µg-at/l) along a section from 12° N,112°20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-NO₂-v4. Vertical distribution of nitrite-nitrogen (µg-at/l) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-NO₂-v5. Vertical distribution of nitrite-nitrogen (µg-at/l) along 105°20' W, May 10-15, 1967.
FIGURE 20-NO₂-v6. Vertical distribution of nitrite-nitrogen (µg-at/l) along 98°20' W, May 17-24, 1967.

Phytoplankton

FIGURE 20-Ch-vl. Vertical distribution of chlorophyll-a (mg/m^₃) along 119°20' W, April 13-21, 1967.
FIGURE 20-Ph-vl. Vertical distribution of phaeophytin (mg/m^₃) along 119°20' W, April 13-21, 1967.
FIGURE 20-PP-v1. Vertical distribution of primary production (mgC/m^₃/day) along 119°20' W, April 13-21, 1967.
FIGURE 20-Ch-v2. Vertical distribution of chlorophyll-a (mg/m^₃) along 112°20' W, April 23-29, 1967.
FIGURE 20-Ph-v2. Vertical distribution of phaeophytin (mg/m^₃) along 112°20' W, April 23-29, 1967.
FIGURE 20-PP-v2. Vertical distribution of primary production (mgC/m^₃/day) along 112°20' W, April 23-29, 1967.
FIGURE 20-Ch-v3. Vertical distribution of chlorophyll-a (mg/m^₃) along a section from 12° N, 112°20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-Ph-v3. Vertical distribution of phaeophytin (mg/m^₃) along a section from 12° N, 112°20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-PP-v3. Vertical distribution of primary production (mgC/m^₃/day) along a section from 12° N, 112° 20' W to Manzanillo, April 29-May 2, 1967.
FIGURE 20-Ch-v4. Vertical distribution of chlorophyll-a (mg/m^₃) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-Ph-v4. Vertical distribution of phaeophytin (mg/m^₃) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-PP-v4. Vertical distribution of primary production (mgC/m^₃/day) along a section from Acapulco to 12° N, 105°20' W, May 7-10, 1967.
FIGURE 20-Ch-v5. Vertical distribution of chlorophyll-a (mg/m^₃) along 105°20' W, May 10-15, 1967.
FIGURE 20-Ph-v5. Vertical distribution of phaeophytin (mg/m^₃) along 105°20' W, May 10-15, 1967.
FIGURE 20-PP-v5. Vertical distribution of primary production (mgC/m^₃/day) along 105°20' W, May 10-15, 1967.
FIGURE 20-Ch-v6. Vertical distribution of chlorophyll-a (mg/m^₃) along 98°20' W, May 17-24, 1967.
FIGURE 20-Ph-v6. Vertical distribution of phaeophytin (mg/m^₃) along 98°20' W, May 17-24, 1967.
FIGURE 20-PP-v6. Vertical distribution of primary production (mgC/m^₃/day) along 98°20' W, May 17-24, 1967.

Nutrient chemistry

FIGURE 30-P-10. Phosphate-phosphorus (µg-at/l) at 10 meters, June-July 1967.
FIGURE 30-Si-10. Silicate-silicon (µg-at/l) at 10 meters, June-July 1967.
FIGURE 30-NO₃-10. Nitrate-nitrogen (µg-at/l) at 10 meters, June-July 1967.
FIGURE 30-NO₂-10.  Nitrite-nitrogen (µg-at/l) at 10 meters, June-July 1967.
FIGURE 30-NH₃-10. Ammonia-nitrogen (µg-at/l) at 10 meters, June-July 1967.
FIGURE 30-P-100. Phosphate-phosphorus (µg-at/l) at 100 meters, June-July 1967.
FIGURE 30-Si-100. Silicate-silicon (µg-at/l) at 100 meters, June-July 1967.
FIGURE 30-NO₃-100. Nitrate-nitrogen (µg-at/l) at 100 meters, June-July 1967.
FIGURE 30-NH₃-100. Ammonia-nitrogen (µg-at/l) at 100 meters, June-July 1967.

Phytoplankton

FIGURE 30-Ch-s. Chlorophyll-a (mg/m^₃) at the sea surface, June-July 1967.
FIGURE 30-Ch-ei. Chlorophyll-a (mg/m^₂) integrated over the euphotic layer, June-July 1967.
FIGURE 30-Ch-150i. Chlorophyll-a (mg/m^₂) integrated from the sea surface to 150 meters depth, June-July 1967.
FIGURE 30-Ph-150i. Phaeophytin (mg/m^₂) integrated from the sea surface to 150 meters depth, June-July 1967.
FIGURE 30-PP-s. Primary production (mgC/m^₃/day) at the sea surface, June-July 1967.
FIGURE 30-PP-ei. Primary production (mgC/m^₂/day) integrated over the euphotic layer, June-July 1967.
FIGURE 30-EL. Thickness of the euphotic layer in meters, June-July 1967.

Zooplankton and micronekton

FIGURE 30-FCp. Distribution of standing stock (ml/1000m^₃) of total fish and cephalopods taken in night micronekton hauls during June-July 1967.
FIGURE 30-Cr. Distribution of standing stock (ml/1000m^₃) of total crustaceans taken in night micronekton hauls during June-July 1967.
FIGURE 30-Nk. Distribution of standing stock (ml/1000m^₃) of total micronekton taken in night micronekton hauls during June-July 1967.
FIGURE 30-ZhN. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 50-cm net hauls at night, June-July 1967.
FIGURE 30-Z1N. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 1-m net hauls at night, June-July 1967.
FIGURE 30-ZhD. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 50-cm net hauls during the day, June-July 1967.
FIGURE 30-Z1D. Distribution of standing stock (ml/1000m^₃) of zooplankton taken in 1-m net hauls during the day, June-July 1967.

Fish larvae

FIGURE 30-FLN. Total fish larvae (number/haul) taken in 1-m oblique plankton hauls at night during June-July 1967.
FIGURE 30-FLD. Total fish larvae (number/haul) taken in 1-m oblique plankton hauls during the day, June-July 1967.
FIGURE 30-FE. Total fish eggs (number/haul) taken in 1-m oblique plankton hauls during June-July 1967.
FIGURE 30-FS. Total skipjack tuna, Katsuwonus pelamis, larvae (number/haul) taken in 1-m oblique plankton hauls during June-July 1967.
FIGURE 30-FA. Total frigate mackerel, Auxis, larvae (number/haul) taken in 1-m oblique plankton hauls during June-July 1967.
FIGURE 30-FC. Total dolphin (fish), Coryphaena, larvae (number/haul) taken in 1-m oblique plankton hauls during June-July 1967.
FIGURE 30-FMN. Total myctophid larvae (number/haul) taken in 1-m oblique plankton hauls at night during June-July 1967.
FIGURE 30-FMD. Total myctophid larvae (number/haul) taken in 1-m oblique plankton hauls during the day, June-July 1967.
FIGURE 30-FGN. Total gonostomatid and sternoptychid larvae (number/haul) taken in 1-m oblique plankton hauls at night during June-July 1967.
FIGURE 30-FGD. Total gonostomatid and sternoptychid larvae (number/haul) taken in 1-m oblique plankton hauls during the day, June-July 1967.

Sightings of birds

FIGURE 30-BP. Relative abundance of plankton-feeding birds (birds/mile), June-July 1967.
FIGURE 30-BF. Relative abundance of fish and cephalopod-feeding birds (birds/mile), June-July 1967.

Nutrient chemistry

FIGURE 30-P-vl. Vertical distribution of phosphate-phosphorus (µg-at/l) along 118°30' W, June 17-26, 1967.
FIGURE 30-P-v2. Vertical distribution of phosphate-phosphorus (µg-at/l) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-P-v3. Vertical distribution of phosphate-phosphorus (µg-at/l) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-P-v4. Vertical distribution of phosphate-phosphorus (µg-at/l) along a section from Acapulco to 12° N, 104°30' W, July 10-13, 1967.
FIGURE 30-P-v5. Vertical distribution of phosphate-phosphorus (µg-at/l) along 104°30' W, July 13-18, 1967.
FIGURE 30-P-v6. Vertical distribution of phosphate-phosphorus (µg-at/l) along 97°30' W, July 20-27, 1967.
FIGURE 30-Si-vl. Vertical distribution of silicate-silicon (µg-at/l) along 118°30' W, June 17-26, 1967.
FIGURE 30-Si-v2. Vertical distribution of silicate-silicon (µg-at/l) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-Si-v3. Vertical distribution of silicate-silicon (µg-at/l) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-Si-v4. Vertical distribution of silicate-silicon (µg-at/l) along a section from Acapulco to 12° N, 104°30' W, July 10-13, 1967.
FIGURE 30-Si-v5. Vertical distribution of silicate-silicon (µg-at/l) along 104°30' W, July 13-18, 1967.
FIGURE 30-Si-v6. Vertical distribution of silicate-silicon (µg-at/l) along 97°30' W, July 20-27, 1967.
FIGURE 30-NO₃-vl. Vertical distribution of nitrate-nitrogen (µg-at/l) along 118°30' W, June 17-26,1967.
FIGURE 30-NO₃-v2. Vertical distribution of nitrate-nitrogen (µg-at/l) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-NO₃-v3. Vertical distribution of nitrate-nitrogen (µg-at/l) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-NO₃-v4. Vertical distribution of nitrate-nitrogen (µg-at/l) along a section from Acapulco to 12° N, 104°30'W, July 10-13, 1967.
FIGURE 30-NO₃-v5. Vertical distribution of nitrate-nitrogen (µg-at/l) along 104°30' W, July 13-18, 1967.
FIGURE 30-NO₃-v6. Vertical distribution of nitrate-nitrogen (µg-at/l) along 97°30' W, July 20-27, 1967.
FIGURE 30-NO₂-vl. Vertical distribution of nitrite-nitrogen (µg-at/l) along 118°30' W, June 17-26, 1967.
FIGURE 30-NO₂-v2. Vertical distribution of nitrite-nitrogen (µg-at/l) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-NO₂-v3. Vertical distribution of nitrite-nitrogen (µg-at/l) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-NO₂-v4. Vertical distribution of nitrite-nitrogen (µg-at/l) along a section from Acapulco to 12° N, 104°30' W, July 10-13,1967.
FIGURE 30-NO₂-v5. Vertical distribution of nitrite-nitrogen (µg-at/l) along 104°30' W, July 13-18,1967.
FIGURE 30-NO₂-v6. Vertical distribution of nitrite-nitrogen (µg-at/l) along 97°30' W, July 20-27, 1967.

Phytoplankton

FIGURE 30-Ch-vl. Vertical distribution of chlorophyll-a (mg/m^₃) along 118°30' W, June 17-26, 1967.
FIGURE 30-Ph-vl. Vertical distribution of phaeophytin (mg/m^₃) along 118°30' W, June 17-26, 1967.
FIGURE 30-PP-v1. Vertical distribution of primary production (mgC/m^₃/day) along 118°30' W, June 17-26, 1967.
FIGURE 30-Ch-v2. Vertical distribution of chlorophyll-a (mg/m^₃) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-Ph-v2. Vertical distribution of phaeophytin (mg/m^₃) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-PP-v2. Vertical distribution of primary production (mgC/m^₃/day) along 111°30' W, June 28-July 4, 1967.
FIGURE 30-Ch-v3. Vertical distribution of chlorophyll-a (mg/m^₃) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-Ph-v3. Vertical distribution of phaeophytin (mg/m^₃) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-PP-v3. Vertical distribution of primary production (mgC/m^₃/day) along a section from 12° N, 111°30' W to Manzanillo, July 4-7, 1967.
FIGURE 30-Ch-v4. Vertical distribution of chlorophyll-a (mg/m^₃) along a section from Acapulco to 12° N, 104°30' W July 10-13, 1967.
FIGURE 30-Ph-v4. Vertical distribution of phaeophytin (mg/m^₃) along a section from Acapulco to 12° N, 104°30' W, July 10-13, 1967.
FIGURE 30-PP-v4. Vertical distribution of primary production (mgC/m^₃/day) along a section from Acapulco to 12° N, 104°30' W, July 10-13,1967.
FIGURE 30-Ch-v5. Vertical distribution of chlorophyll-a (mg/m^₃) along 104°30' W, July 13-18, 1967.
FIGURE 30-Ph-v5. Vertical distribution of phaeophytin (mg/m^₃) along 104°30' W, July 13-18, 1967.
FIGURE 30-PP-v5. Vertical distribution of primary production (mgC/m^₃/day) along 104°30' W, July 13-18, 1967.
FIGURE 30-Ch-v6. Vertical distribution of chlorophyll-a (mg/m^₃) along 97°30' W, July 20-27, 1967.
FIGURE 30-Ph-v6. Vertical distribution of phaeophytin (mg/m^₃) along 97°30' W, July 20-27, 1967.
FIGURE 30-PP-v6. Vertical distribution of primary production (mgC/m^₃/day) along 97°30' W, July 20-27, 1967.