DOI: 10.5061/dryad.j3tx95xnc
title: Physicochemical and acoustic conditions of habitats surrounding Kueishan Island, Yilan, Taiwan

description: In the past, research on hydrothermal vents has primarily focused on deep
 sea, but shallow-water ones have gained increasing attention in recent
 years. Shallow-water hydrothermal systems experience greater fluctuation
 due to various epipelagic factors such as insolation, tides, currents, and
 seasonality. While existing studies have explored geochemical and
 biological features of hydrothermal vents mostly through snapshot
 investigations, little is known about their spatio-temporal effects on the
 surrounding environments. In the present study, we monitored the
 physicochemical and audio conditions around Kueishan Island, Taiwan.
 Within a vertical distance of less than 4 km, Kueishan Island possesses
 both hydrothermal vents and coral ecosystems, making it an ideal platform
 to address these issues. Our results reveal that the impacts of
 hydrothermal vents on the ecological habitats surrounding Kueishan Island
 were not constant, which is attributed to the intermittent discharge of
 vent fluids. Additionally, we observed a potential connection between
 hydrothermal venting and earthquake activities, hinting at possible
 geophysical implications. Overall, our research provides insights into
 exploring these fascinating environments with a greater mastery of them.
 Prospectively, long-term, and continuous monitoring could broader our
 knowledge of hydrothermal vents, including interkingdom evolutionary
 processes, economic opportunities, and developing strategies for
 safeguarding these precious natural resources for future generations.
description: Seawater samples and audio data were collected and recorded by
 SCUBA diving at submarine areas surrounding Kueishan Island during the
 daytime from August 2020 to October 2022. Seawater
 samples were collected from six sampling sites surrounding Kueishan
 Island, including VN (near the vents), VF (about 30 m from the vents), C
 (CO<sub>2</sub> vents), S (south), N (north), and T (tail)
 sites of Kueishan Island. Physicochemical parameters were assessed,
 including temperature (Temp), pH value, dissolved oxygen (DO), sulfide
 (S<sup>2-</sup>), total alkalinity (TA), and dissolved
 inorganic carbon (DIC). The partial pressure of CO<sub>2
 </sub>(pCO<sub>2</sub>), bicarbonate
 (HCO<sub>3</sub><sup>-</sup>) and carbonate
 (CO<sub>3</sub><sup>2-</sup>) concentrations were
 calculated using a CO2SYS module within Microsoft Excel according to DIC,
 temperature, and pH level. Audio data were obtained
 using a SoundTrap recorder (ST300 STD, Ocean Instruments, New Zealand). To
 capture most underwater sounds from biological and environmental sources,
 the built-in hydrophone of recorder has a sensitivity of -175 dB re 1
 V/µPa and a working bandwidth of 20 Hz to 60 kHz (±3 dB). Based on the
 median spectrum, we calculated frequency band-specific sound pressure
 levels (SPLs) by integrating the power spectral densities from frequencies
 20-200 Hz, 200-2k Hz, and 2k-20k Hz.  For each survey, three 90-sec
 recording fragments were randomly selected from each site to ensure a
 consistent sampling effort with the physicochemical data.
description: # Physicochemical and acoustic conditions of habitats surrounding Kueishan
 Island, Yilan, Taiwan 
 Physicochemical parameters include pH, dissolved oxygen (DO), temperature
 (Temp), sulfide (S2-), dissolved inorganic carbon (DIC), total alkalinity
 (TA), pCO2, bicarbonate (HCO3-), and carbonate (CO32-). Temp (°C), pH, and
 DO (mg/L) were measured using a multi-parameter meter (Multiline® Multi
 3620 IDS, WTW, Weilheim, Germany) equipped with an IDS pH electrode
 (SenTix® 940, WTW) and an optical IDS dissolved oxygen sensor (FDO® 925,
 WTW). TA (μM) was determined following a published method (Sarazin et al.
 1999). Ref: Sarazin, G., G. Michard, and F. Prevot. 1999. A rapid and
 accurate spectroscopic method for alkalinity measurements in sea water
 samples. *Water Res* 33: 290-294. doi: 10.1016/S0043-1354(98)00168-7.
 Sulfide content (μM) was measured using a modified spectrophotometric
 method with a sulfide-sulfur specific reagent containing N,
 N-Dimethyl-p-phenylenediamine sulfate and ferric chloride in 50%
 hydrochloric acid (Cline 1969). Ref: Cline, J. D. 1969. Spectrophotometric
 Determination of Hydrogen Sulfide in Natural Waters. *Limnol Oceanogr* 14:
 454. doi: 10.4319/lo.1969.14.3.0454. DIC (μM) was analyzed using an
 analyzer (AS-C3, Apollo SciTech, Newark, DE, USA) with quantification via
 a non-dispersive infrared CO2/H2O analyzer (LI-7000, LI-COR, Lincoln, NE,
 USA). The pCO2 (μatm), HCO3- (μM) and CO32- (μM) were calculated using a
 CO2SYS module within Microsoft Excel according to DIC, temperature, and pH
 (Pierrot 2006). Ref: Pierrot, D., Lewis, E., and Wallace, D. W. R. 2006.
 MS Excel program developed for CO2 system calculations. ORNL/CDIAC-105a.
 Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory,
 U.S. Department of Energy. Acoustic parameters include sound pressure
 levels (SPLs) in dB re 1μPa at frequencies of &lt; 200 Hz, 200-2k Hz, and
 &gt; 2 kHz. Additionally, the earthquake data around Kueishan Island (龜山島)
 which possesses shallow-water hydrothermal vents are provided. Due to
 technical issues, which could be related to sampling equipment, detection
 tools, and weather conditions, some data were missing and are represented
 as "n/a." ## Description of the data and file structure
 ***Except for seismic data, the data processing sequence is Raw_data,
 Data_log, Data_matrix structure. Data_matrix structure is obtained by
 normalizing the values of Data_log. The details are as follows:*** In the
 log file, only the columns named with (log) were transformed to
 logarithmic scales, and CO32- and S2- were increased by one to avoid
 issues with zero values. The matrix structure file contains the matrix
 structure without rotation for principal component analysis (PCA). The
 physiochemical and acoustic parameters were normalized to a scale of zero
 to one according to the minimum and maximum values. There are 150
 observations and 12 variables with colunm head. PERMANOVA file contains
 the data with PC1 and PC2 components and the factor used for conducting
 PERMANOVA. Earthquake file contains the occurance date, latitude (lat),
 longitude (lon), local magnitude scale (ML), focal depth (km), and the
 distance (km) to the hydrothermal vents off Kueishan Island.
 "n/a" was filled in the column named "Vents lat" and
 "Vents lon" except for the second row which were used for the
 calculation of the distance to the vents.