These data include conductivity, temperature, pressure, pH, and DO measurements recorded by a Sea-Bird Scientific HydroCAT-EP V2. This dataset was collected as part of a coastal water quality study using sensors to measure salinity, conductivity, temperature, pressure, water flow direction and velocity, dissolved oxygen, pH, chlorophyll, and turbidity.  Sensors were all deployed in West Maui in coral reef systems that were within and adjacent to the burn zone of the Lahaina fires.  The temporal range of deployments in the project span from October of 2023 to October of 2024 with this dataset spanning from November of 2023 to February of 2024. The aim of these data is to understand the effects on coral reef health in response to the urban fires that occurred in August of 2023. Samples were collected by a collaborative effort of scientists Dr. Andrea K Kealoha, Dr. Craig Nelson, Dr. Eileen Nalley, and Dr. Nicholas Hawco.  

Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

Sensors were deployed within the benthic reef system at the listed sites.

 Sea-Bird Scientific HydroCAT-EP V2:

This instrument is factory calibrated prior to deployment. The sensors were configured using SEA-Bird's SeaCAT software to log at 20 minute intervals. 

Quality control processing was carried out in python.

Data was plotted to calculate delta (the rate of change between each pair of data points)

Regions of bad data to exclude using the following criteria:

1. Sensor is out of the water (identified visually by sudden drop in pressure)

2. Rapid changes in temperature (large deltas, indicates sensor out of water)

3. Drastic sensor drift (Example: negative values, or regions of data over long periods of time with a slope)

- Loaded data from "SBSHydrocat.csv.csv" into table "1001844_v1_lahina-hydrocat" as CSV with row 1 as header; empty strings and "nd" treated as missing values
- Filtered rows to remove last 21 rows containing no values (those filtered out rows only had "Kahelili,20.8825,-156.68848"); kept only rows where timestamps (HST) is not null as a proxy for which rows didn't contain measurements.
- Renamed columns: timestamps (HST) -> timestamps, pressure (Dbar) -> pressure, Temperature (C) -> Temperature, Chlorophyll (ug/L) -> Chlorophyll, Turbidity (NTU) -> Turbidity, Salinity (PSU) -> Salinity, Oxygen (mg/L) -> Oxygen, O2sat% (%) -> O2sat, site.name -> Site_Name, sensor.site -> Site_ID; names updated to be consistent with project site list and Lahaina sensor deployment table
- Converted timestamps column from HST timezone to UTC, creating new ISO_DateTime_UTC column in "%Y-%m-%dT%H:%M:%SZ" format as datetime type
- Timestamp in HST retained, but renamed "timestamps" -> "DateTime_HST"
- Set types for all key columns: DateTime_HST and ISO_DateTime_UTC as datetime, Chlorophyll/O2sat/Oxygen/Salinity/Temperature/Turbidity/pH/pressure/lat/long as number, Site_ID/Site_Name as string
- Resolved conflict with site name and id conflicting, data submitter consulted upon final review to ensure accuracy of change. Replaced Site_Name value "Kahelili" with "Baby Beach" for rows where Site_ID == 'SEN_4' since SEN_4 other metadata indicated SEN_4 corresponds to Baby Beach (lat 20.8825, lon approximately -156.68846). Lat lons in the data were at Baby Beach not Kahelili so that was additional evidence of the correct site name change in the dataset.
- Some Site_IDs were missing. "SEN_4" for all rows where Site_Name == 'Baby Beach', consistent with the Lahaina site list information.
- Replaced Site_Name value "KahomaOutflowReef" with "Kahoma outflow reef" for consistent syntax across project data
- Output saved to "1001844_v1_lahina-hydrocat.csv"

Supplemental files:
* Supplemental site and deployment tables formatted from listed information provided in the original dataset submission metadata section "Location." Added as lahaina_site_list.csv and lahaina_sensor_deployment.csv. These tables list all sites and deployments of the related datasets in the study.

Coverage: Lahaina, Maui, Hawaiʻi

NSF Award Abstract:
Maui’s coral reefs support subsistence, recreational, and commercial fishing, particularly for the large Native Hawaiian population. In August 2023, hurricane winds and low humidity combined with the recent drought to cause an unprecedented fire in Lahaina, an urban coastal town on the island of Maui. The fire quickly burned over 2170 acres and 2200 structures, releasing ash, particulate matter and potentially toxic materials into the adjacent coastal waters. This project provides novel information on the ecological impacts of wildfires to coral reefs to aid in climate change adaptation and emergency response planning. Cultural perspectives and traditional knowledge of Native Hawaiian community members are incorporated throughout the research process. The project directly supports four students, including a Native Hawaiian student, to participate in activities including field work, data collection, analyses and interpretation, and communication of research results.

A wildfire in an urban city located adjacent to a coral reef is unprecedented but may become more common as expanding shoreline development intersects with potentially increased fire risk with climate change. The overall objective of this study is to examine the direct effects of urban wildfires and associated potential stressors - such as reduced water quality, acidification, hypoxia, and heavy metals - on coral reef ecosystem function and the potential for regime shifts favoring benthic algae instead of corals. Using the 2023 Lahaina wildfire as a case study, the project employs a “before-after control-impact” design to compare three west Maui reefs both affected and unaffected by wildfire, with special attention to the anticipated remobilization of organic matter, toxic compounds (e.g., polycyclic aromatic hydrocarbons) and metals following rain events in autumn. Physical and chemical water parameters will constrain the reef-scale carbon cycle and coral metabolism before, during and after runoff events to document the ecological responses to urban fire impacts. This project will support three Early Career Researchers, contribute toward research training for multiple graduate and undergraduate students, and provide valuable information about contaminants and water quality to a community that relies heavily on coral reef resources.