DOI: 10.5061/dryad.4xgxd25jt
title: Coupling and de-coupling of the El Niño Southern Oscillation to the supply of larval fishes to benthic populations in the Hawaiian Islands

description: Several recent high intensity ENSO events have caused strong negative
 impacts on the adult phases of foundational species in coral reef
 ecosystems, but comparatively little is known about how climatic variables
 related to recent ENSOs are impacting the supply of larvae to benthic
 populations. In marine fishes and invertebrates, reproductive adults and
 planktonic larvae are generally more sensitive to environmental
 variability than older, non-reproductive adults. Further, the transport of
 larvae in ocean currents may also be strongly ENSO dependent. The
 interactions between the dynamics of larval survivorship and larval
 transport could lead to population bottlenecks as stronger ENSO events
 become more common. We tested the predictions of this hypothesis around
 the Main Hawaiian Islands (MHI) by constructing a correlation matrix of
 physical and biological time series variables that spanned 11 years (2007
 – 2017) and multiple ENSO events. Our correlation matrix included four
 types of variables: i. published ENSO indices, ii. satellite-derived sea
 surface temperature (SST) and chlorophyll variables, iii. abundance and
 diversity of larval fishes sampled during the late winter spawning season
 off Oahu, and iv. abundance and diversity of coral reef fish recruits
 sampled on the western shore of the Big Island of Hawaii. We found that
 the abundance and diversity of larval fishes was negatively correlated
 with the Multivariate El Niño Index (MEI), and that larval variables were
 positively correlated with measures of fall recruitment (September
 & November), but not correlated with spring-summer recruitment
 (May & July). In the MHI, SST variables were not correlated with
 the MEI, but two successive El Niño events of 2014-15 and 2015-2016 were
 characterized by SST maxima approaching 30 °C. Two large pulses of benthic
 recruitment occurred in the 2009 and 2014 recruitment seasons, with
 &gt; 8000 recruits observed by divers over the summer and fall months.
 Both events were characterized by either neutral or negative MEI indices
 measured during the preceding winter months. These patterns suggest that
 La Niña and the neutral phases of the ENSO cycle are generally favorable
 for adult reproduction and larval development in the spring and summer,
 while El Niño phases may limit recruitment in the late summer and fall. We
 hypothesize that episodic recruitment during non-El Niño phases is related
 to favorable survivorship and transport dynamics that are associated with
 the formation of pairs of anticyclonic and cyclonic eddies on the leeward
 sides (western shores) of the Main Hawaiian Islands.
description: See the published paper
description: # Coupling and de-coupling of the El Niño Southern Oscillation to the
 supply of larval fishes to benthic populations in the Hawaiian Islands
 [https://doi.org/10.5061/dryad.4xgxd25jt](https://doi.org/10.5061/dryad.4xgxd25jt) This readme file was generated on [2024-06-22] by Dave Carlon ### General information These data sets were either collected by the PI (larval fishes), the Department of Natural Resources, State of Hawaii (benthic recruitment data ), or downloaded from public websites (sea surface temperature, chlorophyll data, and ENSO indices) . The sources of downloaded data derived from satellite recordings are detailed in the Description section for each file.  **Author/Principal Investigator Information** Name: Dave Carlon ORCID: Institution: Bowdoin College  Address: Biology Department, 2 Polar Loop, Bowdoin College, Brunswick, Maine, 04011, USA Email: [dcarlon@bowdoin.edu](mailto:dcarlon@bowdoin.edu) Author/Associate or Co-investigator Information Name: Anuschka Faucci ORCID: Institution:  Leeward Community College Address: Division of Math and Sciences, Leeward Community College, Pearl City, Hawaii, 96782, USA Email: [anuschka@hawaii.edu](mailto:anuschka@hawaii.edu) **Date of data collection:** The data were collected between 2006/01/01 and 2017/11/01 **Geographic location of data collection**: Plankton tows were made from annual cruises near the city of Honolulu, Hawaii, USA (21°15'34", -157°51'00"). Benthic recruitment data were collected on the Kailua-Kona coast of the Big Island of Hawaii, Hawaii, USA. Satellite data were collected between these same years, and we specified a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W; and included all the Main Hawaiian Islands. ENSO indices are derived from physical data from the Central Pacific, see the paper for more details.  **Information about funding sources that supported the collection of the data:** Data collection was funded by the College of Natural Sciences, University of Hawaii, Manoa. Honolulu, HI 96822.  **SHARING/ACCESS INFORMATION** Licenses/restrictions placed on the data: None Links to publications that cite or use the data: this paper Recommended citation for this dataset: this paper **DATA & FILE OVERVIEW** File List: 1. correlation_matrix.csv - A csv file used to generate Figure 1 and Figure 2 in the paper and for all statistical tests. This file contains biological and physical variables organized by sampling years, from 2006 to 2017. Some of the variables were calculated from other sources, listed by variable in the DATA-SPECIFIC information.  2. temp_chla_timeseries.csv - A csv file used to generate Figure 3 in the paper. This file contains monthly summaries of sea surface temperature and chlorophyll a biomass from 2006 and 2017. These data were downloaded from  **METHODOLOGICAL INFORMATION** See the published paper for detailed methods. **DATA-SPECIFIC INFORMATION FOR:** correlation_matrix.csv Number of variables: 23 Number of cases/rows: 11 Variable List: 1. Year - Sampling year 2. Larval_abundance - Total counts of all fish larvae sampled each year divided by the total number of tows that year 3. \#_molecular_species - Total number of species of fish larvae sampled each year, identified by DNA barcoding 4. \#_molecular_families - Total number of famlies of fish larvae sampled each year, identified by DNA barcoding 5. \#_morph_species - Total number of species of fish larvae sampled each year, identified visually by an expert 6. \#_morph_families - Total number of famlies of fish larvae sampled each year, identified by visually by an expert 7. Myctophidae_larval_abundance - Total counts of all fish larvae in the family Myctophidae sampled each year divided by the total number of tows that year 8. Reef_fish_larval_abundance - Total counts of all fish larvae that were identifed to the following reef fish families: Anguiliformes Apogonidae Aulostomatidae Blenniidae Blenniidae-Salariinii Carangidae Congridae Gobiidae Kyphosidae Labridae Lutjanidae Pomacanthidae Pomacentridae Scaridae Scorpaenidae Tetraodontidae Tripterygiidae 9. May_recruitment - Total number of benthic reef fish recruits censused during the month of May on the Big Island from West Hawaii Aquarium Project surveys.  10. July_recruitment - Total number of benthic reef fish recruits censused during the month of July on the Big Island from West Hawaii Aquarium Project surveys.  11. September_recruitment - Total number of benthic reef fish recruits censused during the month of September on the Big Island from West Hawaii Aquarium Project surveys.  12. November_recruitment - Total number of benthic reef fish recruits censused during the month of November on the Big Island from West Hawaii Aquarium Project surveys.   13. Total_recruitment -  Total number of benthic reef fish recruits censused during May, July, November, and September on the Big Island from West Hawaii Aquarium Project surveys.  14. May_recruits_diversity -  Total number of species of benthic reef fish recruits censused during May on the Big Island from West Hawaii Aquarium Project surveys.  15. July_recruits_diversity - Total number of species of benthic reef fish recruits censused during June on the Big Island from West Hawaii Aquarium Project surveys.  16. Sept_recruits_diversity - Total number of species of benthic reef fish recruits censused during September on the Big Island  from West Hawaii Aquarium Project surveys.  17. Nov_recruits_diversity -  Total number of species of benthic reef fish recruits censused during November on the Big Island from West Hawaii Aquarium Project surveys.  18. MEI = Multivariate El Niño Index. The MEI is a multivariate score representing five different ENSO variables: sea level pressure, sea surface temperature, zonal and meridional components of the surface wind, and outgoing longwave radiation; over the tropical Pacific basin, from 30°S-30°N and 100°E-70°W. Values range between -2 (strong La Niña) to 2.0 (strong El Niño). Downloaded from: https://psl.noaa.gov/enso/mei/.  19. El_Nino_Index - The El Niño 3.4 index measures the sea surface temperature (SST) anomaly in the Central Pacific, from 5N-5S and 120-170W. Units are degrees celsius. Downloaded from: https://www.ncdc.noaa.gov/teleconnections/enso/sst. 20. SST_mean- Sea surface temperature averaged over the year from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Measured in degrees Celsius.** 21. SST_max - The maximum sea surface temperature recorded over the year from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Measured in degrees Celsius.** 22. SST_6 - Sea surface temperature averaged over the six months preceding the sampling dates for the sampling year (variable 1). Data are from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Units degrees Celsius.** 23. Chl_a_mean -  Chlorophyll a concentrations averaged over the year from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Units are mg chlorophyll a per square meter. ** 24. Chl_a_max Chl_a_6 - Chlorophyll a concentrations averaged over the six months preceding the sampling dates for the sampling year (variable 1). Data are from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Downloaded from X. Units are mg chlorophyll a per square meter. ** Missing data codes: none Specialized formats or other abbreviations used: none \** SST data is from NASA JPL Dataset ID: jplMURSST41. Chlorophyll a data is from Dataset ID: erdMH1chlamday. We used the R packages rerddap (v1.0.2; Chamberlain 2023, \\_rerddap: General Purpose Client for 'ERDDAP' Servers, https://CRAN.R-project.org/package=rerddap) and rerddapXtracto (v1.1.4, Mendelssohn 2022, \\_rerddapXtracto: Extracts Environmental Data from 'ERDDAP' Web Services, https://CRAN.R project.org/package=rerddapXtracto) for downloading and manipulating these satellite derived data sets. **DATA-SPECIFIC INFORMATION FOR:** temp_chla_timeseries.csv Number of variables: 10 Number of cases/rows: 139 Variable List: 1. year - The calendar year 2. year2 - A sequential number code for year 3. time - The last calendar date for averaging monthly values 4. month - A sequential number code for month. Values range from 1 -12, with 1 = January 5. month2 - A sequential number code for month that defines the ENSO cycle. Values range from 1-12, with 1 = June.  6. SST - The average sea surface temperature over the month defined by variable 3. Data are from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Units degrees Celsius.**  7. Chla - The average chlorophyll a concentrations averaged over the month defined by variable 3.  Data are from a grid bounded by the latitudes: 19°N - 22.5°N and longitudes: 154.5°W - 160°W. Units are mg chlorophyll a per square meter.** 8. MEI - MEI El_Nino_Index - Multivariate El Niño Index - See description for variable 18 above.  9. ENSO - The ENSO phase of the 12 month cycle delimited by variable 5 and measured by the MEI during the months 6-8. Data are text strings. MEI &gt; 0.5 = 'El Nino"; MEI &lt; -0.5 = "La Niña; -0.5 &gt; MEI &lt; 0.5 = "Neutral".  10. El Nino Intensity - Whether the months of variable 5 fell within the 2016/2017 "Godzilla" ENSO cycle or not. Data are text strings: "Godzilla", or "Other years". Missing data codes: none Specialized formats or other abbreviations used: none \** SST data is from NASA JPL Dataset ID: jplMURSST41. Chlorophyll a data is from Dataset ID: erdMH1chlamday. We used the R packages rerddap (v1.0.2; Chamberlain 2023, \\_rerddap: General Purpose Client for 'ERDDAP' Servers, https://CRAN.R-project.org/package=rerddap) and rerddapXtracto (v1.1.4, Mendelssohn 2022, \\_rerddapXtracto: Extracts Environmental Data from 'ERDDAP' Web Services, https://CRAN.R project.org/package=rerddapXtracto) for downloading and manipulating these satellite derived data sets. ## Code/Software See the paper for the R packages used to download and analyze these data. R-scripts are available from the PI by request: e-mail: dcarlon@bowdoin.edu