CRUISE REPORT S211

Scientific data collected aboard SSV Robert C. Seamans

Honolulu, Hawai’i – Kirimati (Christmas) Island, Kiribati – Teraina (Washington) Island, Kiribati – Palmyra Atoll, U.S.A. – Kingman Reef, U.S.A. – Honolulu, Hawai’i

09 May – 13 June, 2007

Palmyra Atoll, U.S.A.

Sea Education Association Woods Hole, Massachusetts & Stanford University Palo Alto, California

This document should be cited as: Schell, J., Block, B., Dunbar, R.,Worm, B. 2007. Final report for S.E.A. cruise S211. Sea Education Association, Woods Hole, MA 02540. www.sea.edu.

To obtain unpublished data, contact the Chief Scientist or SEA data archivist: Data Archivist Sea Education Association P.O. Box 6 Woods Hole, MA. 02543 Phone: 508.540.3954 Fax: 508.457.4673 E-mail: [email protected] Web: www.sea.edu

Table of Contents

Table 1 Ship’s Company 3

Data Description 4-5

Figure 1 Cruise track 6

Figure 2a-d Station locations and remote sensing images of 7-8 key oceanographic features Table 2 Summary of oceanographic sampling stations 9-10

Table 3 Surface station data 11-12

Figure 3 Surface plots of temperature, salinity and 13 chlorophyll-a fluorescence Table 4 CTD station data 14

Table 5 Hydrocast station data 15-19

Figure 4 Surface plots of temperature, salinity, 20 chlorophyll-a and CDOM fluorescence for entire cruise track Figure 5a-d Temperature, salinity, and chlorophyll-a and 21-24 CDOM fluorescence for transects across key oceanic features Figure 6 Surface and cross-section plots for current 25 direction (east-west component) and magnitude for entire cruise track Table 6 Neuston tow station data 26

Table 7 Meter net station data 27

Table 8 Tucker trawl station data 28

Table 9 Bongo net station data 29

Table 10 Gelatinous composition from net 30 tows Table 11 Micronekton composition from net tows 31-32

Table 12 net station data 33

Table 13 Phytoplankton composition from net tows 34

1 Table 14 Shipek grab station data 35

Table 15 Secchi disc station data 35

Table 12 Student projects 36

Student Abstracts 37-43

2 Table 1. S211 Ship’s crew and student participants

Nautical Staff Title Phil Sacks Captain Jason Quillter Chief Mate Carter Castle 2nd Mate Colleen Allard 3rd Mate Dusty Smith Engineer Michael McVeigh Assistant Engineer Maggie McCullough Steward Dorine Remillaud Assistant Steward

Scientific Staff Title Dr. Jeff Schell Chief Scientist – Sea Education Association Dr. Barbara Block Chief Scientist – Stanford University Dr. Rob Dunbar Chief Scientist – Stanford University Adam Baske 1st Scientist Skye Moret 2nd Scientist Cara Fritz 3rd Scientist

Visiting Scholars Title Dr. Boris Worm Professor – Dalhousie University

Kathryn Price Media Consultant

Stanford University Students

Johnny Bartz Maija Leff Juliann Schamel Amy Briggs Larisa Lehmer Anne Scofield Meredith Carpenter Karen Lone John Stoecker Gen Del Raye Scott McCracken Mindi Summers Chris Hanson Jessica McNally Kaori Tsukada Kathryn Hoffman Delamon Rego Samuel Urmy Melissa Kunz Sarah Rizk Visrin Vichit-Vadakan

3 Data Description

This cruise report provides a record of data collected during S211 aboard the SSV Robert C. Seamans. The cruise track for S-211 (Figure 1) departed from Honolulu, Hawai’i, sailed south through the Line Islands and returned, 5 weeks later, to Honolulu. During the transit south the physical, chemical and biological characteristics of several distinct oceanographic features were compared: a) A cyclonic and anti-cyclonic pair of eddies that formed in the lee of Hawai’i b) The oligotrophic, North Pacific Central Water (NPCW) mass c) The productive, North Pacific Equatorial Water (NPEW) mass d) The dynamic, north equatorial front between the NPCW and the NPEW e) The ephemeral sea surface conditions associated with the shifting position of the Inter-tropical Convergence Zone (ITCZ)

We also visited five island/atoll systems: Kaleakakua Bay, Hawai’i, Kirimati (Christmas) Island, Kiribati, Teraina (Washington) Island, Kiribati, Palmyra Atoll, U.S.A. and Kingman Reef, U.S.A. The physical (temperature, salinity) characteristics and biological assemblages of these reef and island systems were surveyed. Biological surveys included: a) line and point transects to measure coral species and live-dead coral cover, macroalgal species and macroalgal cover, and herbivorous and predaceous fish species; b) specimen collections to determine toxic associations with macroalgae, and the susceptibility of sea urchin development and toxin transporter activity to changing pH conditions; c) settlement tiles to measure diversity of growth forms and abundance of macroalgal propagules; d) hydroacoustic listening stations to estimate fish and invertebrate abundance and diversity; and e) GPS tagging of red-footed boobies to determine marine foraging locations which were later sampled for oceanographic conditions.

This report summarizes physical, chemical and biological characteristics along our cruise track and around surveyed island and atoll reef systems.

Oceanographic sampling across these regions included continuous sea surface temperature, salinity, and in vivo fluorescence (chlorophyll-a) values, along with current magnitude and direction to 600m. Every hour seabird species, number and marine life associates (i.e. marine mammals, schooling fish, etc) were recorded along with barometric pressure, wind magnitude and direction and water depth. From discrete locations surface chlorophyll-a, and phosphate concentrations were measured (57 stations). Water column stratification was routinely measured with an instrumented CTD for temperature, salinity and density (26 stations), along with dissolved oxygen and chlorophyll-a, fluorescence (24 stations), and chromic dissolved organic matter – CDOM fluorescence (18 stations). Chemical analyses of discrete water samples taken to depths of 400m were made concurrent with the physical measurements; including nutrients (phosphate and nitrate – 9 stations), extracted chlorophyll-a (9 stations) and pH (measured) and alkalinity (calculated) from 8 stations. Zooplankton assemblages (mesh size 333mm to 500mm) were sampled using a variety of methods from a variety of depths: a neuston net was towed at the surface (6 stations), a 2m diameter, conical net was towed at various depths from 10 to 150m (8 stations), a multiple net Tucker trawl was towed at depths from 0m to 425m (3 stations), and a Bongo net was towed consistently around 50m depth (10 stations). On occasion, live zooplankton specimens were collected to measure oxygen consumption and determine respiration rates. Phytoplankton assemblages (mesh 63mm) were sampled using a 0.5m diameter, conical net by making vertical hauls between 0m and 125m. In

4 addition, sediment samples were collected from the southern continental slope off Palmyra atoll (2 stations). Routinely water column clarity was estimated using a secchi disc (8 stations). The information in this report is not intended to represent final interpretation of the data and should not be excerpted or cited without written permission from SEA. Results, not reported here, are available upon request through SEA. As part of SEA’s educational program, undergraduates conducted independent oceanographic research during the cruise. Project explored regionally, relevant topics in the disciplines of physical, chemical, biological and geological oceanography. Student research efforts culminated in a written report and public presentation to the ship’s company. These papers are available on request from SEA.

Jeff Schell Chief Scientist S211

5 Figure 1. Final cruise track for S211 based on hourly (local time) positions. Oceanic biomes and atmospheric features recognized during S211 include an eddy field in the southwest lee of the Hawaiian islands (anticyclonic eddy – EddyAC, cyclonic eddy - EddyC), North Pacific Central Water (NPCW), North Pacific Equatorial Water (NPEW), the dynamic, north equatorial front with a north-entrained filament (NEF and NEFFil), the Inter-Tropical Convergence Zone (ITCZ) and Line Island coastal areas.

Kaleakakua Honolulu, HI Bay, HI

EddyAC

EddyC

NEFfil NPCW

NEF

Kingman Reef ITCZ NPEW Palmyra Atoll Line Islands

Washington Is.

Christmas Is.

6 Figure 2a-d. Remote sensing images along cruise track. Sea surface height anomaly from Colorado Center for Astrodynamics Research, Real-time Altimetry Project, University of Colorado, Boulder (http://argo.colorado.edu/~realtime/gsfc_global-real-time_ssh/). Sea surface temperature (8-day composite blended from multiple data sources, 0.1o resolution) and chlorophyll-a (8-day composite from MODIS on Aqua, 2.5km resolution) data accessed from Pacific Fisheries Environmental Laboratory, (http://las.pfeg.noaa.gov/oceanWatch/oceanwatch_safari.php), OceanWatch project, Live Access Server.

2a-b Window dimensions are: 159oW by 154oW and 20oN by 15oN on 13 May 2007 and 15oN by 10oN on 16 May 2007. From left to right, S211 cruise track based on hourly positions, sea surface height anomaly (cm), sea surface temperature (oC) and chlorophyll-a concentration (log mg/m3). Abbreviations for oceanic biomes and atmospheric feature as in Figure 1. a.

001 Eddy AC

002 Eddy C 003 004

005 NPCW

b.

006 NEFFil

007

008, 009 NPCW

010 NEF 011

7 Figure 2a-d. cont.

2c-d. Window dimensions are: 159oW by 154oW and 10oN by 05oN on 19 May 2007, and 05oN by 0oN on 16 May 2007. From left to right, S211 cruise track based on hourly positions, sea surface height anomaly (cm), sea surface temperature (oC) and chlorophyll-a concentration (log mg/m3). Abbreviations for oceanic biomes and atmospheric feature as in Figure 1. c.

012

NPEW 013

014. 015 016

017 ITCZ

d.

018

NPEW 019

8 Table 2. Station summary of oceanographic sampling for S211.

Station # Date Time Log (nm) Lat (dec Lon (dec Location Station (S211-) (2007) (local +10 Deg N) Deg W) Type GMT) 001 13-May 0722 225 18.86 -156.32 NPCW - anticyclonic eddy CTD 001 13-May 0722 225 18.86 -156.32 NPCW - anticyclonic eddy HC 001 13-May 0722 225 18.86 -156.32 NPCW - anticyclonic eddy SD 001 13-May 0819 226 18.84 -156.34 NPCW - anticyclonic eddy PN 001 13-May 0940 227 18.82 -156.37 NPCW - anticyclonic eddy TT 001 13-May 1015 229 18.80 -156.38 NPCW - anticyclonic eddy TT 001 13-May 1050 230 18.78 -156.39 NPCW - anticyclonic eddy TT 001 13-May 1150 232 18.74 -156.41 NPCW - anticyclonic eddy MN 001 13-May 1208 232 18.73 -156.42 NPCW - anticyclonic eddy NT 002a 14-May 0029 304 17.54 -156.58 NPCW - anticyclonic eddy BN 002b 14-May 0119 307 17.50 -156.59 NPCW - anticyclonic eddy BN 003 14-May 0757 340 17.04 -156.50 NPCW - cyclonic eddy CTD 004 14-May 1156 356 16.92 -156.34 NPCW - cyclonic eddy CTD 004 14-May 1156 356 16.92 -156.34 NPCW - cyclonic eddy HC 004 14-May 1156 356 16.92 -156.34 NPCW - cyclonic eddy SD 004 14-May 1300 356 16.90 -156.37 NPCW - cyclonic eddy PN 004 14-May 1358 357 16.87 -156.39 NPCW - cyclonic eddy TT 004 14-May 1430 358 16.86 -156.40 NPCW - cyclonic eddy TT 004 14-May 1500 359 16.84 -156.41 NPCW - cyclonic eddy TT 004 14-May 1614 362 16.79 -156.43 NPCW - cyclonic eddy MN 004 14-May 1619 363 16.78 -156.43 NPCW - cyclonic eddy NT 004 14-May 1720 365 16.75 -156.45 NPCW - cyclonic eddy BN 005 15-May 0847 462 15.36 -156.45 NPCW CTD 005 15-May 0847 462 15.36 -156.36 NPCW HC 005 15-May 0847 462 15.36 -156.45 NPCW TT 005 15-May 0847 462 15.36 -156.45 NPCW SD 005 15-May 0919 463 15.35 -156.45 NPCW TT 005 15-May 0950 465 15.33 -156.45 NPCW TT 005 15-May 1048 465 15.31 -156.45 NPCW PN 006 15-May 2121 529 14.52 -156.50 NEF - Filament CTD 006 15-May 2215 530 14.51 -156.51 NEF - Filament MN 006 15-May 2221 530 14.50 -156.51 NEF - Filament NT 006 15-May 2332 538 14.47 -156.51 NEF - Filament BN 007 16-May 1119 609 13.37 -156.51 NPCW CTD 007 16-May 1119 609 13.37 -156.51 NPCW HC 007 16-May 1119 609 13.37 -156.51 NPCW SD 007 16-May 1219 610 13.35 -156.53 NPCW PN 008 16-May 2105 676 12.40 -156.59 NPCW CTD 009 17-May 0420 703 12.32 -156.55 NPCW MN 009 17-May 0428 703 12.32 -156.55 NPCW NT 009 17-May 0518 705 12.29 -156.56 NPCW BN 010 17-May 1142 750 11.67 -156.60 NPCW HC 010 17-May 1142 750 11.67 -156.60 NPCW SD 010 17-May 1142 750 11.67 -156.60 NPCW CTD 010 17-May 1238 750 11.68 -156.62 NPCW PN 011 17-May 2208 815 10.80 -156.59 NEF CTD 011 17-May 2312 816 10.78 -156.59 NEF MN 011 17-May 2335 817 10.77 -156.60 NEF NT

9 Station # Date Time Log (nm) Lat (dec Lon (dec Location Station (S211-) (2007) (local +10 Deg N) Deg W) Type GMT) 012 18-May 1148 908 9.53 -156.53 NPEW SD 012 18-May 1148 908 9.53 -156.53 NPEW CTD 012 18-May 1236 909 9.52 -156.54 NPEW PN 013 18-May 2208 992 8.34 -156.45 NPEW CTD 013 18-May 2310 994 8.31 -156.47 NPEW MN 013 18-May 2319 994 8.31 -156.47 NPEW NT 014a 19-May 1138 1075 7.15 -156.49 NPEW at ITCZ CTD 014b 19-May 1241 1075 7.15 -156.49 NPEW at ITCZ CTD 014 19-May 1323 1075 7.15 -156.49 NPEW at ITCZ PN 015 19-May 1436 1080 7.08 -156.49 NPEW at ITCZ CTD 015 19-May 1436 1080 7.08 -156.49 NPEW at ITCZ HC 016 19-May 2330 1121 6.47 -156.46 NPEW at ITCZ BN 017 20-May 1100 1179 5.78 -156.39 NPEW at ITCZ CTD 017 20-May 1100 1179 5.78 -156.39 NPEW at ITCZ HC 017 20-May 1100 1179 5.78 -156.39 NPEW at ITCZ SD 017 20-May 1147 1179 5.78 -156.40 NPEW at ITCZ PN 018 20-May 2352 1233 4.98 -156.49 NPEW BN 019 21-May 1141 1341 3.50 -156.89 NPEW CTD 019 21-May 1141 1341 3.50 -156.89 NPEW HC 019 21-May 0000 1341 3.50 -156.89 NPEW SD 019 21-May 0000 1341 3.50 -156.90 NPEW PN 020 25-May 2332 1714 4.08 -159.68 Line Islands BN 021a 27-May 1107 1919 5.86 -162.07 Line Islands SG 021b 27-May 1143 1919 5.86 -162.08 Line Islands SG 021 26-May 1146 1780 4.67 -160.39 Line Islands CTD 022a 29-May 1520 1943 5.80 -162.10 Line Islands MN 022b 29-May 1608 1944 5.78 -162.10 Line Islands MN 023 02-Jun 1133 2137 7.98 -162.17 NPEW CTD 024a 03-Jun 1139 2261 9.83 -162.11 NPEW CTD 024b 03-Jun 1207 2261 9.82 -162.12 NPEW CTD 025 03-Jun 2158 2309 10.61 -162.23 NPEW BN 026 04-Jun 2210 2444 12.84 -162.04 NPCW BN 027 05-Jun 1033 2509 13.91 -162.12 NPCW CTD 028 05-Jun 1403 2525 14.14 -162.09 NPCW CTD 029 06-Jun 1117 2637 15.95 -162.17 NPCW CTD 030 07-Jun 1110 2750 17.88 -162.10 NPCW CTD 031 08-Jun 1131 2867 18.71 -160.38 NPCW CTD 032 09-Jun 2019 3010 20.15 -158.69 NPCW CTD

Duplicate station numbers refer to different oceanographic equipment that was either deployed concurrently in the same location or was deployed sequentially in the same general location once the vessel was hove to. Replicate equipment deployments at the same location are designated with appended letters. The General Location for stations has been categorized by major water masses: North Pacific Central Water (NPCW) and North Pacific Equatorial Water (NPEW); and mesoscale atmospheric/oceanographic features located within each major water mass: cyclonic and anticyclonic eddies, the North Equatorial Front (NEF) and north-entrained filament, the Inter-Tropical Convergence Zone and the Line Island coastal region. Abbreviations for oceanographic equipment: BN – Bongo Net, CTD – conductivity, HC – hydrocast with 12 Niskin bottles, MN – meter net (either 1 or 2 m diameter), NT – neuston tow, PN – phytoplankton net, , temperature and depth profiler, SD – secchi disk, SG – shipek grab, and TT – Tucker trawl.

10 Table 3. Surface Station data for S211. Surface stations collected as part of a hydrocast are indicated by HC -bottle #13, however, samples are collected and processed in a consistent manner.

Station Date Time Log Temp Salinity PO4 Chl-a Flourescence Lat (dec Lon (dec (deg C) (psu) (uM) (ug/l) Deg N) Deg W) SS001 10-May 1323 0 25.5 34.9 0.173 0.137 3.1 21.26 -157.88 SS002 10-May 1612 13 25.3 34.8 0.222 0.073 3.1 21.00 -157.82 SS003 11-May 0717 115 25.4 34.8 0.137 0.076 3.0 19.78 -156.94 SS004 11-May 1005 134 25.5 34.6 0.146 0.068 2.8 19.54 -156.64 SS005 11-May 1306 153 25.8 34.6 0.191 0.053 2.7 19.49 -156.26 SS006 11-May 1602 166 26.2 34.6 0.088 0.050 2.7 19.48 -156.01 HC-001 #13 13-May 0722 225 25.4 34.4 0.160 0.095 18.86 -156.32 SS007 13-May 1000 228 25.4 34.3 0.236 0.061 3.2 18.81 -156.37 SS008 14-May 0700 337 25.0 34.2 0.290 0.066 3.1 17.07 -156.48 SS009 14-May 1000 344 24.9 34.3 0.272 0.070 3.0 16.99 -156.49 SS010 14-May 1300 356 24.8 34.3 0.254 0.056 3.0 16.90 -156.37 SS011 14-May 1600 362 24.8 34.3 0.119 0.046 3.8 16.79 -156.43 SS012 15-May 0700 452 25.6 34.3 0.339 0.030 2.9 15.48 -156.43 SS013 15-May 1000 465 25.7 34.4 0.164 0.032 2.9 15.33 -156.45 SS014 15-May 1300 471 25.8 34.4 0.231 0.026 2.8 15.24 -156.47 SS015 15-May 1700 497 26.6 34.5 0.285 0.079 3.2 14.90 -156.53 SS016 15-May 2336 538 26.5 34.4 0.303 0.071 3.9 14.47 -156.51 SS017 16-May 0700 579 26.0 34.2 0.245 0.089 3.2 13.81 -156.49 SS018 16-May 1000 601 26.1 34.3 0.290 0.086 3.0 13.45 -156.48 HC-007 #13 16-May 1300 611 26.1 34.3 0.335 0.067 2.9 13.33 -156.54 SS019 16-May 1600 632 26.2 34.3 0.155 0.089 3.0 13.03 -156.56 SS020 17-May 0700 716 26.1 34.3 0.110 0.062 2.9 12.14 -156.57 SS021 17-May 1000 738 26.4 34.3 0.218 0.039 2.8 11.83 -156.58 SS022 17-May 1300 750 26.7 34.5 0.182 0.057 2.7 11.67 -156.62 SS023 17-May 1600 768 26.8 34.7 0.222 2.9 11.43 -156.63 SS024 18-May 0700 870 27.4 34.9 0.258 0.111 3.7 10.05 -156.57 SS025 18-May 1000 895 27.4 34.9 0.162 4.1 9.70 -156.53 HC-012 #13 18-May 1148 908 27.6 34.9 0.276 0.174 9.53 -156.53 SS026 18-May 1700 945 27.6 34.9 0.272 0.199 5.3 9.01 -156.51 SS027 19-May 0726 1045 27.6 34.5 0.303 0.138 5.0 7.58 -156.50 SS028 19-May 1000 1064 27.5 33.9 0.285 0.163 5.3 7.29 -156.49 HC-014 #13 19-May 1300 1072 27.6 34.3 0.317 0.182 6.9 7.15 -156.49 SS029 19-May 1600 1088 27.8 34.4 0.173 0.174 5.6 6.99 -156.49

11 Station Date Time Log Temp Salinity PO4 Chl-a Flourescence Lat (dec Lon (dec (deg C) (psu) (uM) (ug/l) Deg N) Deg W) SS030 20-May 0719 1164 27.9 34.5 0.182 0.179 6.5 5.95 -156.37 SS031 20-May 1300 1182 28.4 34.4 0.734 0.192 4.4 5.74 -156.41 SS032 20-May 1800 1210 28.4 34.5 0.545 0.198 6.5 5.31 -156.43 SS033 21-May 0700 1297 28.2 34.8 0.236 0.204 7.8 4.07 -156.68 SS034 21-May 0958 1327 28.2 34.9 0.348 0.185 6.3 3.69 -156.82 HC-019 #13 21-May 1141 1341 28.3 34.9 0.158 6.1 3.50 -156.89 SS035 21-May 1600 1361 28.4 35.0 0.492 0.124 6.5 3.25 -156.98 SS036 25-May 1310 1642 28.8 34.8 0.052 3.6 3.50 -158.92 SS037 25-May 1600 1666 28.8 34.8 0.137 3.9 3.69 -159.17 SS039 26-May 1000 1779 28.5 34.6 0.169 5.1 4.67 -160.39 SS040 26-May 1300 1780 28.6 34.6 0.144 4.6 4.67 -160.40 SS041 26-May 1700 1790 28.9 34.6 0.112 5.2 4.74 -160.52 SS042 27-May 0700 1888 28.5 34.7 0.171 6.9 5.59 -161.71 SS043 27-May 1000 1913 28.5 34.7 0.169 6.0 5.81 -161.99 SS044 27-May 1300 1922 28.6 34.7 0.140 5.3 5.86 -162.12 SS045 31-May 1000 1976 28.5 34.7 0.232 4.5 6.06 -162.25 SS046 31-May 1302 1999 28.6 34.7 0.316 4.2 6.39 -162.47 SS047 31-May 1721 2008 28.6 34.7 0.276 6.6 6.39 -162.35 SS048 01-Jun 0760 2019 28.3 34.7 0.168 5.8 6.40 -162.35 SS049 01-Jun 1020 2012 28.4 34.7 0.206 6.4 6.40 -162.35 SS050 01-Jun 1300 2024 28.3 34.7 0.222 7.1 6.40 -162.36 SS051 01-Jun 1600 2035 28.3 34.7 0.214 5.9 6.42 -162.52

12 Figure 3. Surface plots of temperature, salinity, and fluorescence or S211. Abbreviations for oceanic biomes and atmospheric feature as in Figure 1. Labels are placed with the ocean parameter that was most distinguishing. Data interpolation by VG Gridding in ODV, 20 x-scale and 20 y-scale.

EddyAC

Eddy

C NPCW

NEFfil

NEF NPEW

ITCZ

13 Table 4. CTD station data for S211.

Station # Date Local Time Cast Locale Sensors (S211) (2007) (+10 GMT) Depth (m) 001 13-May 0722 507 NPCW - anticyclonic eddy DO, CDOM, Fluor 003 14-May 0757 476 NPCW - cyclonic eddy DO, CDOM, Fluor 004 14-May 1156 487 NPCW - cyclonic eddy DO, CDOM, Fluor 005 15-May 0847 521 NPCW DO, CDOM, Fluor 006 15-May 2121 488 NEF - Filament DO, CDOM, Fluor 007 16-May 1119 464 NPCW DO, CDOM, Fluor 008 16-May 2105 423 NPCW DO, CDOM, Fluor 010 17-May 1142 506 NPCW DO, CDOM, Fluor 011 17-May 2208 470 NEF DO, CDOM, Fluor 012 18-May 1148 516 NPEW DO, CDOM, Fluor 013 18-May 2208 480 NPEW DO, CDOM, Fluor 014a 19-May 1138 501 NPEW at ITCZ DO, CDOM, Fluor 014b 19-May 1241 500 NPEW at ITCZ DO, CDOM, Fluor 015 19-May 1436 450 NPEW at ITCZ DO, CDOM, Fluor 017 20-May 1100 539 NPEW at ITCZ DO, CDOM, Fluor 019 21-May 1141 531 NPEW DO, CDOM, Fluor 021 26-May 1146 225 Line Islands 023 02-Jun 1133 ND NPEW DO, Fluor 024a 03-Jun 1139 48 NPEW DO, Fluor, PAR 024b 03-Jun 1207 ND NPEW DO, Fluor, PAR 027 05-Jun 1033 49 NPCW DO, CDOM, Fluor 028 05-Jun 1403 978 NPCW DO, Fluor 029 06-Jun 1117 962 NPCW DO, Fluor 030 07-Jun 1110 929 NPCW DO, Fluor 031 08-Jun 1131 988 NPCW DO, Fluor 032 09-Jun 2019 2743 NPCW

14 Table 5. Hydrocast station data for S211.

Station Bottle # Depth Temp Salinity Density O2 PO4 NO3 pH Total Chl-a Locale # (m) (oC) (ppt) (kg/m3) (ml/l) (µM) (µM) Alk (µg/l) (S211-) (mmol/ kg) 001 1 397 8.8 34.18 26.52 2.53 1.69 18.64 0.002 NPCW - anticyclonic eddy 001 2 348 9.9 34.21 26.36 2.99 1.59 NPCW - anticyclonic eddy 001 3 298 12.2 34.23 25.95 3.62 1.14 9.00 0.003 NPCW - anticyclonic eddy 001 4 269 14.1 34.36 25.68 3.86 0.98 NPCW - anticyclonic eddy 001 5 239 16.2 34.57 25.39 4.07 0.63 0.008 NPCW - anticyclonic eddy 001 6 209 18.3 34.84 25.10 4.09 0.44 NPCW - anticyclonic eddy 001 7 179 20.1 34.90 24.66 4.18 0.16 0.047 NPCW - anticyclonic eddy 001 8 149 22.3 34.97 24.13 4.57 0.09 NPCW - anticyclonic eddy 001 9 119 23.9 34.97 23.66 4.74 0.12 0.03 0.204 NPCW - anticyclonic eddy 001 10 89 24.7 34.85 23.31 4.75 0.16 NPCW - anticyclonic eddy 001 11 60 25.1 34.79 23.16 4.68 0.11 0.14 0.063 NPCW - anticyclonic eddy 001 12 30 25.1 34.78 23.15 4.67 0.06 NPCW - anticyclonic eddy 001 13 0 25.4 34.40 23.16 0.16 0.05 0.095 NPCW - anticyclonic eddy 004 1 398 7.4 34.12 26.68 2.16 1.92 34.92 NPCW - cyclonic eddy 004 2 348 8.5 34.14 26.52 2.80 1.74 7.63 2210 NPCW - cyclonic eddy 004 3 298 10.4 34.22 26.27 3.19 1.49 14.04 0.001 NPCW - cyclonic eddy 004 4 269 11.0 34.19 26.15 4.12 1.40 7.82 2210 NPCW - cyclonic eddy

15 Station Bottle # Depth Temp Salinity Density O2 PO4 NO3 pH Total Chl-a Locale # (m) (oC) (ppt) (kg/m3) (ml/l) (µM) (µM) Alk (µg/l) (S211-) (mmol/ kg) 004 5 239 11.9 34.19 25.98 4.03 1.06 0.002 NPCW - cyclonic eddy 004 6 210 13.7 34.28 25.71 4.00 0.90 7.89 2250 NPCW - cyclonic eddy 004 7 179 15.1 34.41 25.50 4.04 0.51 0.017 NPCW - cyclonic eddy 004 8 150 18.2 34.76 25.06 4.13 0.25 8.00 2289 NPCW - cyclonic eddy 004 9 120 20.0 34.73 24.57 4.22 0.25 2.63 0.269 NPCW - cyclonic eddy 004 10 90 23.4 34.85 23.72 4.80 0.07 8.13 2331 NPCW - cyclonic eddy 004 11 60 24.2 34.82 23.44 4.73 0.16 0.13 0.071 NPCW - cyclonic eddy 004 12 29 24.3 34.82 23.42 4.72 0.27 8.15 2293 NPCW - cyclonic eddy 004 13 0 24.8 34.33 23.26 0.20 0.10 8.11 2287 0.049 NPCW - cyclonic eddy 005 1 398 8.6 34.40 26.72 0.87 2.45 41.71 NPCW 005 2 347 9.3 34.35 26.57 1.46 2.31 7.43 2268 NPCW 005 3 298 10.2 34.27 26.35 2.60 1.57 17.41 0.004 NPCW 005 4 268 11.2 34.20 26.13 4.19 1.06 7.66 2233 NPCW 005 5 239 12.7 34.25 25.87 4.15 0.82 0.004 NPCW 005 6 209 15.8 34.50 25.41 3.95 0.48 7.82 2259 NPCW 005 7 179 19.7 35.02 24.86 4.28 0.23 0.113 NPCW 005 8 149 21.9 35.21 24.42 4.63 0.17 8.00 2308 NPCW 005 9 120 23.2 35.03 23.89 4.80 0.14 0.08 0.155 NPCW 005 10 89 24.4 34.79 23.36 4.74 0.19 8.04 2281 NPCW 005 11 60 24.5 34.74 23.29 4.71 0.17 0.05 0.069 NPCW 005 12 30 25.3 34.57 22.91 4.62 0.17 8.05 2269 NPCW 005 13 0 25.6 34.31 22.89 0.24 0.10 8.06 2270 0.037 NPCW 007 1 397 8.4 34.50 26.82 0.55 2.41 36.13 NPCW 007 2 348 9.1 34.52 26.73 0.53 2.37 7.38 2297 NPCW 007 3 297 9.6 34.44 26.59 1.08 2.24 24.07 0.002 NPCW 007 4 268 10.1 34.38 26.45 1.50 2.25 7.49 2278 0.003 NPCW

16 Station Bottle # Depth Temp Salinity Density O2 PO4 NO3 pH Total Chl-a Locale # (m) (oC) (ppt) (kg/m3) (ml/l) (µM) (µM) Alk (µg/l) (S211-) (mmol/ kg) 007 5 240 10.9 34.27 26.22 2.38 1.41 0.030 NPCW 007 6 208 12.7 34.26 25.88 2.98 1.54 7.67 2264 0.025 NPCW 007 7 179 16.1 34.42 25.29 3.22 0.87 0.054 NPCW 007 8 149 22.1 34.66 23.95 4.52 0.35 7.98 2290 0.215 NPCW 007 9 120 25.7 34.45 22.73 4.54 0.26 0.11 0.168 NPCW 007 10 89 25.7 34.47 22.72 4.55 0.31 8.08 2265 0.080 NPCW 007 11 59 25.7 34.47 22.72 4.54 0.38 0.09 0.082 NPCW 007 12 29 25.7 34.47 22.72 4.55 0.29 8.08 2271 0.069 NPCW 007 13 0 26.1 34.28 22.70 0.33 0.08 8.06 2286 0.067 NPCW 010 1 398 9.4 34.65 26.79 0.34 2.94 28.30 0.007 NPCW 010 2 347 9.8 34.67 26.73 0.38 2.42 7.40 2291 NPCW 010 3 298 10.4 34.69 26.65 0.31 1.96 22.47 0.009 NPCW 010 4 268 10.7 34.71 26.60 0.29 2.11 7.42 2288 0.007 NPCW 010 5 239 11.0 34.70 26.55 0.21 2.31 0.009 NPCW 010 6 207 11.6 34.71 26.44 0.11 2.12 7.41 2305 0.013 NPCW 010 7 179 12.2 34.59 26.23 0.35 1.92 0.035 NPCW 010 8 147 16.0 34.53 25.38 3.17 0.75 7.78 2270 0.106 NPCW 010 9 118 21.5 34.77 24.18 4.33 0.46 1.23 0.213 NPCW 010 10 88 25.0 34.65 23.09 4.70 0.07 8.08 2283 0.109 NPCW 010 11 60 25.9 34.48 22.67 4.54 0.18 0.09 0.056 NPCW 010 12 28 26.0 34.49 22.66 4.55 0.10 8.08 2263 0.043 NPCW 010 13 0 26.5 34.34 22.64 0.24 0.10 8.08 2266 0.035 NPCW 012 1 396 9.4 34.66 26.79 0.37 2.74 NPEW 012 2 347 9.8 34.68 26.74 0.33 2.10 33.69 7.38 2362 NPEW 012 3 298 10.2 34.70 26.68 0.29 1.88 0.007 NPEW 012 4 268 10.5 34.70 26.64 0.28 2.49 25.50 7.36 2332 0.007 NPEW 012 5 238 10.8 34.71 26.58 0.29 2.60 0.006 NPEW 012 6 210 11.3 34.71 26.50 0.32 2.06 7.42 2354 0.005 NPEW 012 7 179 11.9 34.59 26.30 0.59 NPEW 012 8 149 13.6 34.38 25.80 2.09 1.22 7.59 2265 0.050 NPEW 012 9 119 18.5 34.75 24.95 3.81 0.41 0.083 NPEW 012 10 89 27.0 34.91 22.65 4.38 0.22 0.83 8.07 2300 0.219 NPEW 012 11 59 27.0 34.91 22.65 4.44 0.27 0.195 NPEW 012 12 30 27.0 34.91 22.64 4.46 0.30 0.96 8.06 2322 0.184 NPEW

17 Station Bottle # Depth Temp Salinity Density O2 PO4 NO3 pH Total Chl-a Locale # (m) (oC) (ppt) (kg/m3) (ml/l) (µM) (µM) Alk (µg/l) (S211-) (mmol/ kg) 012 13 0 27.6 34.92 22.62 0.28 0.77 8.07 2322 0.152 NPEW 015 1 398 9.2 34.66 26.83 0.21 2.93 32.56 NPEW at ITCZ 015 2 348 9.7 34.69 26.77 0.39 2.67 7.41 2301 NPEW at ITCZ 015 3 298 10.0 34.70 26.72 0.50 2.65 0.006 NPEW at ITCZ 015 4 268 10.3 34.71 26.68 0.53 2.55 7.43 2296 0.010 NPEW at ITCZ 015 5 239 10.5 34.72 26.64 0.35 2.74 21.51 0.007 NPEW at ITCZ 015 6 209 10.9 34.73 26.59 0.29 2.58 7.39 2283 0.008 NPEW at ITCZ 015 7 179 11.3 34.72 26.51 0.32 2.63 0.007 NPEW at ITCZ 015 8 149 11.7 34.67 26.39 0.53 2.34 7.46 2310 0.017 NPEW at ITCZ 015 9 119 14.4 34.50 25.73 1.34 2.25 19.12 0.055 NPEW at ITCZ 015 10 90 27.0 34.98 22.71 4.20 0.53 8.05 2336 0.112 NPEW at ITCZ 015 11 59 27.4 34.81 22.47 4.37 0.47 1.43 0.232 NPEW at ITCZ 015 12 29 27.4 34.74 22.39 4.43 0.42 8.07 2283 0.187 NPEW at ITCZ 015 13 0 27.7 34.48 1.28 8.07 2273 0.200 NPEW at ITCZ 017 1 397 8.4 34.63 26.93 1.14 2.65 NPEW at ITCZ 017 2 349 8.8 34.64 26.88 1.39 2.50 26.34 7.49 2299 NPEW at ITCZ 017 3 299 9.2 34.66 26.83 1.47 2.58 0.002 NPEW at ITCZ 017 4 269 9.3 34.67 26.81 1.47 2.49 18.95 7.50 2291 0.002 NPEW at ITCZ 017 5 239 9.7 34.68 26.76 1.45 2.51 0.004 NPEW at ITCZ 017 6 209 9.8 34.68 26.73 1.34 7.48 2301 0.005 NPEW at ITCZ 017 7 178 10.4 34.67 26.63 1.30 2.45 0.004 NPEW at ITCZ 017 8 148 11.6 34.67 26.42 0.93 2.47 27.73 7.46 2288 0.004 NPEW at ITCZ 017 9 119 13.9 34.66 25.95 1.51 1.86 0.029 NPEW at ITCZ 017 10 89 22.5 34.81 23.93 3.31 0.70 4.35 7.93 2285 0.105 NPEW at ITCZ 017 11 60 27.4 34.85 22.49 4.26 0.50 0.152 NPEW at ITCZ 017 12 30 27.6 34.54 22.19 4.45 0.42 8.08 2271 0.240 NPEW at ITCZ 017 13 0 28.2 34.46 22.07 0.22 0.84 8.08 2259 0.172 NPEW at ITCZ 019 1 397 8.6 34.64 26.91 1.22 2.56 NPEW 019 2 348 9.0 34.66 26.86 1.66 2.51 27.40 7.51 2307 NPEW 019 3 299 9.5 34.68 26.78 1.55 2.31 0.002 NPEW 019 4 269 9.8 34.69 26.75 1.69 2.32 23.36 7.51 2291 0.003 NPEW 019 5 239 10.1 34.71 26.71 1.76 NPEW 019 6 209 10.3 34.70 26.67 1.94 2.11 7.55 2311 0.003 NPEW 019 7 180 10.7 34.67 26.57 2.07 2.07 0.002 NPEW

18 Station Bottle # Depth Temp Salinity Density O2 PO4 NO3 pH Total Chl-a Locale # (m) (oC) (ppt) (kg/m3) (ml/l) (µM) (µM) Alk (µg/l) (S211-) (mmol/ kg) 019 8 149 11.8 34.67 26.37 1.88 2.06 7.57 2307 NPEW 019 9 120 15.7 34.70 25.59 2.62 1.36 0.015 NPEW 019 10 90 21.1 34.80 24.32 3.13 7.86 2278 0.105 NPEW 019 11 60 27.4 34.91 22.52 4.20 0.54 0.111 NPEW 019 12 30 27.7 34.87 22.39 4.41 0.41 1.96 8.05 2314 0.195 NPEW 019 13 0 28.3 34.90 22.34 0.43 2.57 8.04 2279 0.158 NPEW

Water samples were collected in 2.5 liter Niskin bottles deployed on a self-contained carousel system with a SBE-019Plus CTD sensor (Seabird Instruments, Inc.). Dissolved oxygen (O2) concentrations were determined using a SeaBird dissolved oxygen sensor, pH were determined using an Oaktron pH meter and total alkalinity was determined by calculation using CO2sys.xls (version1) Lewis and Wallace 1998. Phosphate (PO4), and, nitrate (NO3) levels were measured by colorimetric analysis with an Ocean Optics Chem2000 digital spectrophotometer and chlorophyll-a (Chl-a) concentrations were determined with a Turner Designs Model 10-AU Fluorometer following methods outlined in Parsons, Maita and Lalli (1984; A Manual of Chemical and Biological Methods for Seawater Analysis, Pergamon Press). Chlorophyll-a samples were filtered through 0.45 µm glass fiber filters. A blank space indicates that no sample was collected for that analysis. Sample concentrations below detectable limits are indicated as “BD”.

19 Figure 4. Cross-section plots of temperature, salinity, chlorophyll-a and CDOM fluorescence, and dissolved oxygen for the eastern, meridional transect, S211. Abbreviations for oceanic biomes and atmospheric feature as in Figure 1, with the addition of North Pacific Intermediate Water (NPIW). Features to note: surface chlorophyll-a fluorescence associated with NEF and NPEW, upwelling NPIW and oxygen minimum zone, and influence of the equatorial counter-current (see Figure 6 ahead) on the oxygen minimum zone south of 5oN. Labels are placed with the ocean parameter that is most distinguishing. Data interpolation by VG Gridding in ODV, 80 x-scale and 10 y-scale. fil AC C NEF NEF Eddy Eddy

NPCW NPEW ITCZ

NPIW

20

Figure 5a. Vertical profiles of temperature, salinity, and chlorophyll-a and CDOM fluorescence, S211. Comparison of eddy features with prevailing NPCW. Abbreviations for oceanic biomes and atmospheric feature as in Figure 1. Features to note: shallowing of thermocline in cyclonic eddy, increased chlorophyll-a fluorescence and shallower depth of deep-chlorophyll-a maximum layer (DCM).

EddyC

001 - EddyAC EddyAC 002, 003 NPCW - EddyC

005 - NPCW

21 Figure 5b. Vertical profiles of temperature, salinity, and chlorophyll-a and CDOM fluorescence, S211. Transition of NPCW moving from north to south. Features to note: shallowing of thermocline, shallowing and narrowing of salinity minimum (NPIW), freshening of the salinity maximum layer (winter subduction of NPCW). Abbreviations for oceanic biomes and atmospheric feature as in Figure 1, including North Pacific Intermediate Water (NPIW).

001 - EddyAC Moving south 001 to 010

005 - NPCW

007 - NPCW 008 - NPCW 010 - NPCW

Moving south 001 to 010

22 Figure 5c. Vertical profiles of temperature, salinity, and chlorophyll-a and CDOM fluorescence, S211. Comparison of NPCW and NEF features. Features to note: DCM at or near the surface for NEF, and NEFFIL temperature and salinity characteristics mirror NPCW stations below 100m, and NPEW stations above; revealing the vertical extent of this feature. Abbreviations for oceanic biomes and atmospheric feature as in Figure 1.

NPCW

NEF and NPEW

NEFFIL

006 - NEFFIL

007 - NPCW 008 - NPCW 010 - NPCW 011 - NEF 012 - NPEW

23 Figure 5d. Vertical profiles of temperature, salinity, and chlorophyll-a and CDOM fluorescence, S211. Demonstrating the influence of the ITCZ on surface waters of NPEW. Features to note: freshening of the upper 50m in location of ITCZ and formation of a barrier layer, and the influence of this barrier layer on the DCM position in the water column. Abbreviations for oceanic biomes and atmospheric feature as in Figure 1.

ITCZ

019 - NEF and NPEW NPEW

011 - NEF 012 - NPEW 013 - NPEW 015 - ITCZ

017 - ITCZ

019 - NPEW

24 Figure 6. Current direction and magnitude, E-W component cross-section plots, S211. Abbreviations for currents: north equatorial current (NEC), filament of north equatorial front (NEFFIL), south equatorial current (SEC), equatorial under current (EUC), north sub-surface counter current (NSCC). .A – 17 May, B – 04 June. Data interpolation by VG Gridding in ODV, 20 x-scale and 20 y-scale (surface plot), and 10 x-scale and 10 y-scale (section plots).

Eddy NEF Weak FIL NEC EUC and features NECC SEC NSCC

Eddy features

NEFFIL

Weak A NEC Eddy NEF FIL EUC and features NEC NECC SEC NSCC B

Weak NECC SEC

EUC

25 Table 6. Neuston station data for S211.

Net opening was 1.0 m wide by 0.5 m tall with a net mesh of 333 µm. Tow distance (m) was estimated using successive GPS positions (every minute) and calculating distance between positions. Samples were processed in the following manner: plastic pieces and pellets were sorted from net contents, counted and recorded as numbers collected per tow, tar clumps were sorted from the nets contents and recorded as present or absent, macrophyte material was rinsed and discarded, micronekton (>2cm in length), and gelatinous organisms (>2cm length) were removed using a 1cm sieve and other manual techniques (see Table ?? for details). The remaining zooplankton biomass was measured by volume displacement and used to calculate density. A small fraction of zooplankton biomass was set aside in a Petri dish for compositional analysis using a dissecting microscope; Shannon-Wiener diversity index was determined based on a random 100 count of organisms.

Station # Date Local Time Tow Temp Salinity Moon Zoop Zoop Plastic Tar Locale (S211-) (2007) (+10 GMT) Area (°C) (ppt) Phase Den Div (#) (yes/ (m²) (%) (ml/m²) (H') no)

001 13-May 1208 2389 25.2 34.20 16% 0.001 0.21 14 no NPCW - anticyclonic eddy 004 14-May 1619 1811 24.8 34.30 8% 0.005 0.19 9 no NPCW - cyclonic eddy 006 15-May 2221 1852 26.6 34.40 3% 0.010 0.30 0 no NEF - Filament 009 17-May 0428 2162 26.1 34.30 1% 0.001 0.27 0 no NPCW 011 17-May 2335 1819 27.2 34.90 3% 0.027 0.50 0 no NEF 013 18-May 2319 1160 27.6 35.00 4% 0.034 0.58 0 no NPEW

26 Table 7. Meter net station data for S211.

Duplicate station numbers indicate multiple net deployments on the hydrowire for a given location. Net size based on net diameters 1MN = 1 meter dia meter, 2MN = 2 meter diameter. Tow distance (m) was estimated using successive GPS positions (every minute) and calculating distance between positions. Net mesh was 333µm for 1MN and 500µm for 2MN. Nets were towed at different depths based on study specifications. Samples were processed in the following manner: macrophyte material was rinsed and discarded, micronekton (>2cm in length), and gelatinous organis ms (>2cm length) were removed using a 1cm sieve and other manual techniques (see Table ?? for details). The remaining zooplankton biomass was measured by volume displacement and used to calculate density. A small fraction of zooplankton biomass was set aside in a Petri dish for compositional analysis using a dissecting microscope; Shannon-Wiener diversity index was determined based on a random 100 count of organisms.

Station # Date Local Time Target Tow Net Tow Zoop Den Zoop Div Descriptive Significance (S211-) (2007) (+10 GMT) Depth Diameter Volume (ml/m3) (H') (m) (m) (m3) 001 13-May 1150 150 2 6037 0.008 0.80 Shark foraging study - thermocline 004 14-May 1614 89 2 5032 0.016 0.59 Shark foraging study - thermocline 006 15-May 2215 44 2 4459 0.076 0.39 Turtle foraging study - presumed turtle dive depths

009 17-May 0420 55 2 4545 0.023 0.49 Turtle foraging study - presumed turtle dive depths

011 17-May 2312 37 2 3815 0.064 0.44 Turtle foraging study - presumed turtle dive depths

013 18-May 2310 41 2 5532 0.056 0.43 Turtle foraging study - presumed turtle dive depths

022a 29-May 1520 50 2 3095 0.017 0.62 Booby foraging study - presumed booby dive depths

022b 29-May 1608 10 2 1617 0.024 0.74 Booby foraging study - presumed booby dive depths

27 Table 8. Tucker trawl station data for S211.

Duplicate station numbers indicate multiple net deployments occurring in sequence during the tow. Net1 was open from the surface down to the deepest target dept listed for Net 2 and represents an oblique tow. A trigger weight closed Net 1, opening Net 2; the latter was towed for 30’ at the listed target depth based on study specifications. Another trigger weight closed Net 2 and opened the final net. Net 3 was also an oblique tow from depth to the surface. Net frame was 1 m2 and nets were 333 um mesh. Tow distance (m) was estimated using successive GPS positions (every minute) and calculating distance between positions. Samples were processed in the following manner: macrophyte material was rinsed and discarded, micronekton (>2cm in length), and gelatinous organisms (>2cm length) were removed using a 1cm sieve and other manual techniques (see Table ?? for details). The remaining zooplankton biomass was measured by volume displacement and used to calculate density. A small fraction of zooplankton biomass was set aside in a Petri dish for compositional analysis using a dissecting microscope; Shannon-Wiener diversity index was determined based on a random 100 count of organisms.

Station # Date Local Time Target Tow Net Tow Zoop Zoop Div Descriptive Significance (S211-) (2007) (+10 GMT) Depth Number Volume Den(ml/m (H') (m) (m3) 3) 001 13-May 0940 0-425 1 2702 0.008 0.39 Shark foraging study - DSL 001 13-May 1015 425 2 2539 0.008 0.35 Shark foraging study - DSL 001 13-May 1050 425-0 3 2378 0.019 0.38 Shark foraging study - DSL 004 14-May 1358 0-430 1 5529 0.003 0.38 Shark foraging study - DSL 004 14-May 1430 430 2 2053 0.025 0.16 Shark foraging study - DSL 004 14-May 1500 430-0 3 2464 0.018 0.36 Shark foraging study - DSL 005 15-May 0847 0-425 1 1492 0.006 0.39 Shark foraging study - DSL 005 15-May 0919 425 2 1576 0.008 0.25 Shark foraging study - DSL 005 15-May 0950 425-0 3 1482 0.013 0.35 Shark foraging study - DSL

28 Table 9. Bongo net station data for S211.

The Bongo net array consisted of two 0.5m diameter, 500um mesh nets towed in parallel. Contents of nets were combined and not treated as replicates. Duplicate station numbers indicate multiple net deployments occurring in sequence of different tow durations (30’ vs 15’); tow duration remained at 30’ for remaining tows. Tow distance (m) was estimated using successive GPS positions (every minute) and calculating distance between positions. Samples were processed in the following manner: macrophyte material was rinsed and discarded, micronekton (>2cm in length), and gelatinous organisms (>2cm length) were removed using a 1cm sieve and other manual techniques (see Table ?? for details). The remaining zooplankton biomass was measured by volume displacement and used to calculate density. A small fraction of zooplankton biomass was set aside in a Petri dish for compositional analysis using a dissecting microscope; Shannon-Wiener diversity index was determined based on a random 100 count of organisms.

Station # Date Local Time Target Tow Tow Zoop Zoop Div Descriptive Significance (S211-) (2007) (+10 GMT) Depth Volume Den (H') (m) (m3) (ml/m3)

002a 14-May 0029 50 719 0.042 Paralarval, squid distribution study

002b 14-May 0119 50 351 0.054 0.43 Paralarval, squid distribution study

004 14-May 1720 50 963 0.027 0.76 Paralarval, squid distribution study

006 15-May 2332 58 948 0.070 0.41 Paralarval, squid distribution study

009 17-May 0518 44 667 0.024 0.57 Paralarval, squid distribution study

016 19-May 2330 50 570 0.106 0.66 Paralarval, squid distribution study

018 20-May 2352 79 516 0.085 0.64 Paralarval, squid distribution study

020 25-May 2332 70 623 0.106 0.70 Paralarval, squid distribution study

025 03-Jun 2158 54 606 0.203 0.70 Paralarval, squid distribution study

026 04-Jun 2210 50 580 0.046 0.53 Paralarval, squid distribution study

29 Table 10. net collections for S211: Gelatinous organisms Gelatinous organisms were separated from all net tows using a 1 cm sieve and other manual techniques and enumerated into 7 general categories. Total biomass was determined via volume displacement. Station Net Ctenophore Cnidarian Physalia Siphonophores Salps Pyrosome Urochordate Biomass (#) (#) (#) (#) (#) (#) (#) (ml) 001 NT 0 0 8 0 0 0 0 2 004 NT 0 0 8 0 0 0 0 2 006 NT 0 1 13 0 26 0 0 15 009 NT 14 0 0 0 0 0 0 1 011 NT 0 3 1 9 12 0 0 9 013 NT 0 0 0 0 0 0 0 3 002b BN 1 0 0 0 5 0 0 3 004 BN 0 0 0 0 0 0 0 0 006 BN 0 0 0 0 0 0 0 0 009 BN 0 0 0 0 0 1 0 27 016 BN 11 0 0 21 18 3 0 11 018 BN 3 0 0 3 16 8 0 110 020 BN 5 34 0 27 10 46 0 42 025 BN 0 0 0 124 10 10 0 288 026 BN 0 21 0 6 29 0 0 12 001 2MN 0 0 0 1 8 0 1 4 004 2MN 0 0 0 0 0 0 0 5 006 2MN 2 0 0 12 70 7 0 91 009 2MN 28 0 0 0 8 1 0 50 011 2MN 0 4 0 226 19 1 0 200 013 2MN 6 0 0 117 16 18 0 501 022a 2MN 3 0 0 0 1 0 0 4 022b 2MN 0 0 0 6 4 0 0 11 001 (net 1) TT 1 6 0 0 0 0 0 2 001 (net 2) TT 0 0 0 0 0 0 0 0 001 (net 3) TT 0 0 0 0 2 0 0 3 004 (net 1) TT 0 4 0 0 0 0 0 1 004 (net 2) TT 0 0 0 2 0 0 0 1 004 (net 3) TT 0 5 0 1 0 0 0 4 005 (net 1) TT 0 1 0 0 2 0 0 2 005 (net 2) TT 4 0 0 0 2 0 0 3 005 (net 3) TT 1 1 0 3 0 1 0 55

30 Table 11. Plankton net collections for S211: Micronekton organisms Micronekton organisms were separated from all net tows using a 1 cm sieve and other manual techniques and enumerated into 14 general categories. Total biomass was determined via volume displacement. Abbreviatoins: Nudi – nudibranch, Hete – heteropod, Jan – janthinid gastropods, Euph – euphausids, Shr – pelagic shrimp, Amph – amphipods, Stom – stomatopod larvae, Poly – pelagic polychaetes, Squ – squid larvae, Halo – halobates insects, Myct – myctophid fish, Lept – leptocephali (eel larvae), phyll – phyllosoma (spiny lobster larvae), and other fish. Total biomass of micronekton was determined using volume displacement.

Station Net Nudi Hete Jan Euph Shr Amph Stom Poly Squ Halo Myct Lept Phyll Fish Biomass (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (#) (ml) 001 NT 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1.0 004 NT 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0.0 006 NT 0 0 5 0 0 0 0 0 0 7 2 0 0 1 6.4 009 NT 0 4 0 3 0 0 0 0 0 1 0 0 0 0 0.2 011 NT 0 0 0 4 0 1 0 2 0 0 1 0 0 0 1.0 013 NT 0 0 0 1 0 0 0 0 0 3 1 0 0 1 3.0 002b BN 0 3 0 1 1 0 0 0 2 0 6 1 0 1 1.2 004 BN 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0 006 BN 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0 009 BN 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0 016 BN 0 0 0 0 78 5 0 1 0 0 2 0 0 0 11.4 018 BN 0 1 0 0 19 0 0 1 0 0 4 0 0 9 6.5 020 BN 0 0 0 0 6 0 0 0 0 0 2 0 0 0 3.0 025 BN 0 2 0 8 0 7 0 3 0 0 0 0 0 0 2.1 026 BN 0 0 0 6 2 1 0 0 4 0 0 0 0 0 3.2 001 2MN 0 4 0 0 0 0 1 0 0 0 0 0 4 3 2.8 004 2MN 0 0 0 0 1 0 0 0 1 0 0 0 0 4 1.6 006 2MN 0 0 0 0 27 11 0 0 0 0 0 1 0 0 17.0 009 2MN 0 0 0 0 0 1 0 1 0 0 1 0 0 1 0.8 011 2MN 0 1 0 82 0 8 0 1 2 0 3 0 0 0 11.5 013 2MN 0 0 0 0 62 4 0 0 1 0 3 2 0 0 7.0 022a 2MN 0 3 0 0 0 13 0 0 0 0 0 0 0 0 0.9 022b 2MN 0 8 0 0 0 0 0 0 0 0 0 0 0 0 0.0 001 TT 0 0 0 1 0 2 0 0 0 0 0 1 0 0 0.5 (net 1) 001 TT 0 0 0 0 1 2 0 0 0 0 0 0 0 0 0.6 (net 2) 001 TT 0 1 0 0 0 0 2 0 0 0 0 0 0 3 2.0 (net 3) 004 TT 0 1 0 1 0 1 0 0 0 0 0 0 0 7 1.2

31 (net 1) 004 TT 0 0 0 0 0 0 0 0 0 0 1 0 0 14 0.9 (net 2) 004 TT 0 0 0 0 4 0 0 0 0 0 2 0 0 3 2.0 (net 3) 005 TT 0 0 0 0 5 3 0 0 0 0 0 0 0 1 1.4 (net 1) 005 TT 0 0 0 5 12 0 0 0 0 0 0 0 0 79 5.5 (net 2) 005 TT 0 3 0 4 1 1 0 0 0 0 1 0 0 13 3.5 (net 3)

32

Table 12. Phytoplankton net station data for S211. Oblique tows to 125m were made with a 0.3m diameter, conical net with 63 µm mesh. Samples were passed through a 333 µm sieve and collected on a 63 µm sieve. Collected contents were diluted in a known volume of seawater. Cell counts were conducted on a 1ml sub-sample in a Sedgewick-Rafter counting chamber from which 30 randomly placed, digital images were taken and used for taxa identification (see Table 13 for details). Abbreviations as in Table 1.

Station # Date Local Time Oblique Tow Tow Sub-Sample Percent Dinoflagellate Descriptive (S211-) (2007) (+10 GMT) Depth Volume Proportion Slide Density Density Significance (m) (m3) (ml) Counted (#/m3) (#/m3) 001 13-May 0819 0-125m 49.1 NPCW - anticyclonic eddy 004 14-May 1300 0-125m 49.1 1:118 4.40% 15003 1259 NPCW - cyclonic eddy 005 15-May 1048 0-125m 49.1 1:45 4.40% 2965 794 NPCW 007 16-May 1219 0-125m 49.1 1:71 4.40% 4547 1647 NPCW 010 17-May 1238 0-125m 49.1 1:105 4.40% 2193 2095 NPCW 012 18-May 1236 0-125m 49.1 1:109 4.40% 28982 2124 NPEW 014 19-May 1323 0-125m 49.1 1:134 4.40% 25805 1492 NPEW at ITCZ 017 20-May 1147 0-125m 49.1 NPEW at ITCZ 019 21-May 0000 0-125m 49.1 1:73 4.40% 8265 203 NPEW

33 Table 13. Phytoplankton net collections for S211: and Oblique tows to 125m were made with a 0.3m diameter, conical net with 63 µm mesh. Taxa density in #/m3. Abbreviations as in Table 1.

Station --> 004 005 007 010 012 014 019 Family Genera NPCW - NPCW NPCW NPCW NPEW NPEW at NPEW cyclonic eddy ITCZ

Thalassiosiraceae Planktoniella 164 0 231 49 17602 5472 2066 Hemidiscaceae Gen. 0 0 0 0 0 62 34 Asterolampraceae Asterolampra 55 167 33 146 152 0 0 Asteromphalus 274 125 231 195 0 0 0 Rhizosoleniaceae Gen.(pointy) 2957 1817 2800 877 4097 14799 3083 Rod-shaped 9090 376 0 0 51 373 0 Guinardia 219 0 0 0 0 684 34 Hemiaulaceae Climacodium 548 84 0 0 0 0 0 Hemialus 110 21 0 0 51 187 102 Chaetocerotaceae 110 42 33 97 51 249 542 Fragilariaceae Gen. 55 0 33 0 0 0 0 Naviculaceae Gen. 110 0 0 0 0 0 68 Thalassionemataceae Gen. 1259 292 1087 536 6929 3980 2337 Bacillariaceae Gen. 55 42 99 292 51 0 0 Oxytoxaceae Centrodinium 55 42 0 0 0 0 0 Dinophysiaceae Ornithocercus 55 42 165 97 51 0 0 Goniodomataceae Gen. 55 21 0 0 0 0 0 Prorocentraceae Prorocentrum 0 0 33 0 0 0 0 Ceratiaceae Ceratium 986 564 1153 1559 1871 1244 203 Amphisoleniaceae Amphisolenia 55 63 297 341 51 62 0 Pyrocystaceae Pyrocystis lunula 55 63 0 97 152 187 0

Total 16263 3759 6194 4288 31107 27297 8469

34 Table 14. Shipek grab station data for S211.

Station # Date Time Sample Locale (S211-) (2007) (local +10 Depth GMT) (m) 021a 27-May 1107 520 Off Palmyra Atoll - southern slope 021b 27-May 1143 940 Off Palmyra Atoll - southern slope

Table 15. Secchi disc station data for S211.

Station # Date Time Secchi Location (S211-) (2007) (local Depth +10 (m) GMT) 001 13-May 0722 30 NPCW - anticyclonic eddy 004 14-May 1156 35 NPCW - cyclonic eddy 005 15-May 0847 37 NPCW 007 16-May 1119 31 NPCW 010 17-May 1142 37 NPCW 012 18-May 1148 20 NPEW 017 20-May 1100 24 NPEW at ITCZ 019 21-May 0000 21 NPEW

35 Table 16. Student research topics for S211.

Transit Projects Annie Scofield The Inorganic Carbon System and Nutrient Cycling in the Equatorial North Pacific: A study of the interactions between oceanographic features and seawater chemistry Kathryn (Kat) Hoffman Planktonic Communities and Trophic Interactions in the North Equatorial Pacific Ocean Juliann Schamel The Distribution of Central Pacific Seabirds: Relationships with Productivity, Distance from Land, and Island Nutrient Systems Larisa Lehmer & Scott The distribution of gelatinous plankton and zooplankton in McCracken the region of the North Equatorial Front (NEF) and its implications for the trans-oceanic migration of western- Pacific leatherback sea turtles (Dermochelys coriacea)

Meredith Carpenter Biogeographical Distribution and Systematic Differentiation of Cephalopoda Associated with Oceanic Circulation Patterns in the Central Pacific Gen Del Raye A Characterization of the Habitat of Charcharodon carcharias Between Hawaii and the Line Islands: To What Extent is Productivity a Determining Factor in Habitat Choice? Experimental Projects Mindi Summers Marine Respiration: The Effects of Temperature, Light, and Body Size on Pacific Zooplankton and Reef Goby Collected 2-10ºN Latitude Sarah Rizk Low pH effects on early development and toxin transporter activity in sea urchins (Strongylocentrotus Purpuratus, Tripneustes gratilla, Echinometra mathaei) Island Projects Amy Briggs & Maija Leff A comparison of toxic dinoflagellate densities along a gradient of human disturbance in the North Line Islands Delamon Rego & Analysis of Large Predator Populations in the Line Islands Christopher Hanson Jessica McNally, Samuel Urmy, Does lagoon water eflux affect coral health? & John Bartz An investigation of physical properties of lagoon circulation on coral health at Christmas Island and Palmyra Atoll John Stoecker Using Underwater Sound to Measure Biodiversity and Productivity in the Line Islands Melissa Kunz & Karen Lone Using GPS tracking to determine flight patterns of red- footed boobies (Sula sula) near Palmyra Atoll Visrin Vichit-Vadakan & Kaori Factors influencing macroalgal cover in reef systems across Tsukada the Line Islands

36 The Inorganic Carbon System and Nutrient Cycling in the Equatorial North Pacific: A study of the interactions between oceanographic features and seawater chemistry Annie Scofield

The world’s oceans are an extremely important component of the global carbon cycle. As anthropogenic greenhouse gas emissions become a growing concern, increasing our understanding of the oceanic carbon system will be a key factor in projecting the affects of global climate change and the ability of the oceans to regulate increases in atmospheric CO2. Extensive progress in this area has been made over the past 20 years, but significant gaps still exist. This study examines the carbon system and nutrient cycling processes occurring the north equatorial Pacific along a transect from Kealakekua Bay, Hawaii to Christmas Island, Kiribati. Total dissolved inorganic carbon (DIC) and in situ pCO2 were calculated from the total alkalinity and pH measured at several depths down to 350 meters at eight stations along the transect. It was found that both pCO2 and DIC were regulated by biological and oceanographic factors and that water mass characteristics played an important role in determining parameters of the carbon system. In addition, nutrient data was used to determine which areas along the transect show ratios similar to those projected by the Redfield Ratio. It was found that although slight variations occurred along the transect, the area as a whole demonstrated nutrient ratios which adhered very closely to the Redfield Ratio. While this study provides a baseline for the carbon system parameters in the equatorial north Pacific, further research will be needed to fully define the system and mechanisms taking place in the region.

Planktonic Communities and Trophic Interactions in the North Equatorial Pacific Ocean Kathryn (Kat) Hoffman

The complex relationships between marine planktonic trophic levels are not yet well understood, despite the importance of the plankton community in the global carbon cycle and its role as a food source for commercial fisheries. In this study, phytoplankton and zooplankton community samples were collected and identified along a transect from a Hawaiian cyclonic eddy, through the oligotrophic North Pacific gyre, to the high-nutrient equatorial ocean. Within the phytoplankton community, siliceous diatoms and dinoflagellates were found to respond differently to environmental fluctuations, with more significant correlations between nutrient availability and diatoms than dinoflagellates. Differential responses by different trophic communities were also found; with bottom-up forcings more important for phytoplankton communities and top-down influences primarily controlling zooplankton. Using the different productivities along this transect, planktonic biodiversity was correlated with resource availability. Phytoplankton, due to competitive exclusion, have higher diversity at lower productivities. Zooplankton, due to predation influences, have higher diversity at higher productivities. By tracking changes in planktonic biodiversity over time, both top-down effects from anthropogenic influences like over fishing and bottom-up forcings from nutrient runoff and may be revealed.

37 The Distribution of Central Pacific Seabirds: Relationships with Productivity, Distance from Land, and Island Nutrient Systems Juliann Schamel

Seabirds are a major top marine predator and in large numbers, can play a large role in nutrient cycling between land and sea. Understanding the relationship between seabird distribution across the ocean and factors such as productivity and distance from land can help us to understand the area of this nutrient flow, and to predict where seabirds may influence marine systems. This project strove to understand the effect of productivity on population size and distance traveled from land in two central Pacific seabird communities. One hundred and eighty- two 10-minute observations, recording the number and type of seabirds seen, were carried out on a cruise track between 19 degrees north and 2 degrees north. This cruise track passed from the Hawaiian Islands to the Line Islands. Forty-eight sea surface water samples were also analyzed for chlorophyll-a concentration. Results show that the Line Islands are surrounded by much more productive waters than the Hawaiian Islands, and as such support a much larger and more diverse seabird community. In addition, the Line Islands seabirds travel less far from land, on average, to forage. This suggests that there is a relationship between productivity and foraging distance. The Line Islands supported a seabird community dominated by terns and boobies, whereas the Hawaiian Islands community was dominated by shearwaters and petrels, a group with much lower cost of traveling. These results suggest that the more productive Line Islands system is receiving more nutrients from seabirds, but from a much smaller ocean area than the Hawaiian Islands.

The distribution of gelatinous plankton and zooplankton in the region of the North Equatorial Front (NEF) and its implications for the trans-oceanic migration of western- Pacific leatherback sea turtles (Dermochelys coriacea) Larisa Lehmer and Scott McCracken

Given the concern over the endangered status of the Pacific Leatherback Sea Turtle (Dermochelys coriacea), attention has been brought to the threats they face during nesting periods on shore, but less effort has been made to reduce the risks leatherbacks face during their pelagic migrations – namely by-catch by long-line fisheries. Satellite images of turtles tagged in Monterey, CA have revealed that they repeatedly travel along the North Equatorial Front (NEF)— the boundary between the North Pacific Central Water (NPCW) and North Pacific Equatorial Water (NPEW) masses— during their trans-Pacific migrations. We hypothesize that leatherback turtles are attracted back to this region in order to feed on the gelatinous plankton that aggregates along frontal boundaries. To test this hypothesis, neuston and meter tows were performed along a portion of the North Pacific Equatorial Front along which a tagged leatherback was migrating. The tows revealed that the density of gelatinous organisms was much higher at the front than in the colder, oligotrophic waters to the north. It was concluded that the leatherback was using this frontal boundary during its migration to balance its need to feed on gelatinous plankton with its metabolic need to stay in cooler waters. Because leatherback turtles exhibit such high fidelity for this stretch of the pelagic Pacific, we recommend the establishment of a “corridor” of protection for these animals.

38 Biogeographical Distribution and Systematic Differentiation of Cephalopoda Associated with Oceanic Circulation Patterns in the Central Pacific Meredith Carpenter

Observation of cephalopod paralarvae in the Central Pacific along the SSV Robert C Seamans cruise track, 2007. Geared towards an increased understanding of the morphology and distribution of cephalopod paralarvae, the main questions explored were (1) if and how can paralarvae be visually identified to the family or species level and (2) knowing these species classifications, what are the distributional ranges as they correlate with oceanic characteristics. A total of 57 paralarvae were obtained through a combination of bongo net, meter net and neuston tows at 10 stations from approximately 19ºN north to 4ºS south along the cruise track. Using 10 key morphological feature measurements and photographs the specimen were classified into six functional groups: Ommastrephidae, Eucleoteuthis, Enoploteuthidae, Octopodae, Cranchiidae and Onychoteuthidae. Corresponding to tows, sea surface temperature, salinity and fluorescence were measured by a thermosalinograph and dissolved oxygen was recorded at five stations that corresponded with CTD deployments. Multivariable analysis of morphological features resulted in clustered scatter plots suggesting species-specific ratios of morphological characteristics. Distributional trends depicted functional group related peaks that explained the bimodal appearance of the overall tow data. While morphological feature analysis at this point is not precise enough to support significant species accuracy, the functional groups indicated the species related distribution trends with Ommastrephidae and Eucleoteuthis inhabiting higher latitudes with lower temperatures, lower salinity, lower fluorescence and higher oxygen saturation levels, and Enoploteuthidae inhabiting lower latitudes with higher temperatures, higher salinity, higher fluorescence and lower oxygen saturation levels. This research helps to explain the who and the where of cephalopod distribution in the Central Pacific.

A Characterization of the Habitat of Charcharodon carcharias Between Hawaii and the Line Islands: To What Extent is Productivity a Determining Factor in Habitat Choice? Gen Del Raye

This study attempted to describe the distribution patterns of great white sharks, C. carcharias, in the geostrophic eddy field between Hawaii and the Line Islands in relation to primary and secondary productivity in the water column. To do so, in situ chl-a fluorescence measurements as well as zooplankton net tows were taken along a cruise track between Hawaii the Line Islands. This data was analyzed together with an equivalent dataset collected in 2005 by Markman and Schwartz. Also, Pop Up Satellite Archival Tag (PSAT) data for white shark movements in the vicinity of Hawaii was used to determine the degree of correlation between white shark distribution and eddy locations. The results of this study tentatively suggest that firstly, geostrophic currents seem to boost primary and secondary productivity in a largely predictable manner, and secondly, that white sharks may take advantage of this by focusing on these relatively productive eddies during their aggregation period offshore of Hawaii.

39 Marine Respiration: The Effects of Temperature, Light, and Body Size on Pacific Zooplankton and Reef Goby Collected 2-10ºN Latitude Mindi Summers

Methodology for conducting respiration studies on marine zooplankton and a small goby fish were established and implemented using a Unisef microrespirometer on the open ocean. Specimens were collected from 2-10ºN latitude. Oxygen consumption for all animals at ambient temperatures ranging from 26-28ºC in both light and dark conditions were measured. Although the amount of testing depended on the availability of animals and their survival, temperature change was stimulated on a goby and hyperiid amphipod. Euphausiids and phronemids collected from 26-28ºC were also measured. Rates of oxygen consumption were calculated using Excel and analyzed with Anova statical programming. An increase in temperature, both through stimulation on an individual level and with increasing ambient temperature resulted in an increasing rate of oxygen consumption. Light conditions significantly increased euphausiid respiration. These two factors provide insight into the metabolic effects of diel migration and changing ocean temperatures. Additionally, the zooplankton follows the trend of larger size having a lower metabolic rate. Using the methodology introduced and tested in this experiment, future studies will be able to replicate and expand the implications of this study to better understand the physiology of marine animals, diel migration, community respiration, and the impact of the ocean on the global carbon cycle.

Low pH effects on early development and toxin transporter activity in sea urchins (Strongylocentrotus Purpuratus, Tripneustes gratilla, Echinometra mathaei) Sarah Rizk

This study explores both the direct effects of ocean acidification on early embryology and the indirect effects of a low pH environment on the embryos ability to expel toxins through membrane-bound transporters. This work was done on three different species of sea urchins, Strongylocentrotus Purpuratus, Tripneustes gratilla, and Echinometra mathaei, each collected at a different location (Monterey, CA, Hawaii, and Washington Island, respectively). Cell counts in individuals were performed to assess impact on early development. Surface membrane toxin transporters (mrp, pgp) were blocked, and accumulation of a toxin proxy, calcein-am, was noted by measuring the fluorescent levels as calcein-am hydrolyzed into fluorescent calcein in the embryo. The results indicate negative effects of low pH on early development of Echinometra, while the toxin transporters in all three species appear to work more effectively at low pH. There is some evidence that specific types of transporters may work more effectively until a threshold pH, below where the transporter no longer functions as well. In general, Echinometra had less transporter activity than Tripneustes.

40 A comparison of toxic dinoflagellate densities along a gradient of human disturbance in the North Line Islands Amy Briggs and Maija Leff

Understanding the ecology influencing the toxic dinoflagellate populations implicated in ciguatera or ciguatera-like sea-food poisoning in humans is a problem of great importance to small-scale fisheries and island communities in the tropical Pacific and Caribbean waters. This study attempted to ascertain the effects of long term human disturbance on the densities of toxic dinoflagellates of the genera Gambierdiscus, Ostreopsis, and Prorocentrum and the corresponding percent algal coverage in reef environments in theNorth Line Islands. Toxic dinoflagellate densities measured in cells/g macroalgae and the total percent algal cover were recorded at three sites of varying levels of human impact. The most heavily impacted site was a lagoonal area near the town London at Christmas Island, and this site was found to have both the highest densities of toxic dinoflagellates as well as the highest macroalgal cover. The second most impacted site was located at Cook Island, a protected area on Christmas Island. The least impacted site was located on the back reef at Palmyra Atoll, a National Wildlife Preserve, and was found to have the lowest densities of toxic dinoflagellates. Statistically significant dinoflagellate preference for areas of higher human disturbance was found for Ostreopsis between the first and second sites (p= 0.007) and for Prorocentrum between the second and third sites (p= 0.003).

Analysis of Large Predator Populations in the Line Islands Delamon Rego and Christopher Hanson

Human disturbance and reef health are inextricably linked. Specifically, the biomass of predators in a marine ecosystem has been identified as an indicator of overall reef health. Less affected reefs have been shown to have a significantly high percentage of predator biomass relative to the biomass of other fish. Our research examines this trend, observing individual species of predators and accounting for their biomass, species diversity, and functional diversity. All research was conducted in the Pacific Line Islands along a gradient of human disturbance throughout the islands. By using both a line transect and a point count we were able to compile two independent data sets. Both data sets were comparable and indicated that more heavily impacted reefs have lower predator biomass, less predator species diversity, and fewer functional groups represented. With this data we are better able to determine which functional groups are threatened the most and therefore deduce which species face the highest risk of extinction in the respective regions. Furthermore, previous biomass research is reinforced by our findings.

41 Does lagoon water eflux affect coral health? An investigation of physical properties of lagoon circulation on coral health at Christmas Island and Palmyra Atoll Jessica McNally, Samuel Urmy, and John Bartz

At Christmas Island and Palmyra Atoll, two coral atolls in the Northern Line Group, we surveyed coral communities and gathered data on physical properties and flow patterns of the lagoon water to assess the effects of lagoon water efflux on their health and genus richness. Physical data and flow pattern information was gathered by using HOBO loggers to record light intensity and water temperature over time (May 22-24 and 28-30, 2007, at Christmas and Palmyra, respectively), using a towable CTD and doing transects near the channel openings at each island using the Acoustic Doppler Current Profiler. At Christmas Island, we hypothesized that effects of lagoon water would be indiscernible due to other anthropogenic forcings such as overfishing and sediment runoff; however, we found that areas of low live cover and genus richness seemed to be correlated to areas of higher lagoon water efflux, and that areas with the highest live cover seemed to be protected from the efflux of warm lagoon water. At Palmyra Atoll, we hypothesized that the lagoon water was flowing westward across the atoll and out the channel opening. Furthermore, that this warmer, more turbid water mass was negatively impacting the corals near the channel opening. Our findings support this hypothesis: we found evidence both for the westward flow of the lagoon water and lower live cover near the channel opening on the west side, which correlated to higher maximum temperatures at these sites.

Using Underwater Sound to Measure Biodiversity and Productivity in the Line Islands John Stoecker

In order to create a more complete description of coral reef habitats for use in conservation, this study aims to develop acoustic indices for biodiversity and productivity. Qualitative analysis, sound pressure levels, biological sound signal detection, and spectral variability in recorded underwater sound combine to give detail on coral reefs in Washington Island, Kiritimati Island, and Palmyra Atoll. Qualitative analysis and sound pressure level correlate strongly with biomass and biodiversity in the island reefs, and sound pressure and spectral variabilities give insight into the type and number of marine animals in each habitat. These measurements show evidence of a fishing gradient along the Pacific Line Islands and help create an aesthetic definition of coral reef health and biodiversity.

42 Using GPS tracking to determine flight patterns of red-footed boobies (Sula sula) near Palmyra Atoll Melissa Kunz and Karen Lone

Efforts to understand Palmyra Atoll’s natural systems have concentrated mostly on marine communities, but recent work has been undertaken to investigate its terrestrial communities. Red-footed boobies represent one of many bird populations inhabiting Palmyra. We investigated the flight and foraging movements of red-footed boobies nesting on the north-western side of the atoll using GPS data logging tags. The birds flew in a westerly direction from their nest sites towards an area of patchy ocean primary productivity, suggesting that wind direction and nest location may be stronger factors than primary productivity in determining flight direction. In seagoing flights, the birds demonstrated two modes of behavior, “directed movement” and “meandering”, which differed significantly in speed and linearity of flight. These two modes of movement at sea suggest a foraging strategy that emphasizes searching for food over large areas and catching prey in small patches.

Factors influencing macroalgal cover in reef systems across the Line Islands Visrin Vichit-Vadakan and Kaori Tsukada

Our study focused on what factors affect macroalgal cover in the Line Islands, specifically Christmas Island, Washington Island, Palmyra Atoll, and Kingman Reef. Macroalgal cover can be influenced in three ways: from the top-down by herbivory, from the bottom-up by nutrients, and by the amount of available spores. Using ceramic settlement tiles, we estimated algae spore recruitment. We estimated herbivore biomass and algae cover using snorkeling line transects, and we used ceramic settlement tiles to estimate algae spore recruitment. We found that the human population gradient across the four islands reduced herbivore biomass in accord with the varying degrees in fishing pressure. Christmas Island had an estimated herbivore biomass of 233.84 g/m2, Palmyra Atoll, Washington Island, and Kingman reef with a biomass of 11.9%, 82.4%, and 85.1% less than Christmas respectively. In addition, we found ample spore supply at each island we tested. However, our results found no overarching relationship between herbivory and algal cover, nor did it find a solid correlation between the amount of available spores and algal cover. Therefore, we speculate that human impact on algal cover takes the form of adding nutrients to the water rather than in the form of localized fishing pressure causing a trophic cascade. Further research on nutrient levels is necessary to test this hypothesis

43