Identification_Information: Citation: Citation_Information: Originator: Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Publication_Date: 20070916 Title: CRED Towed-Diver Benthic Characterization Surveys at Alamagan Island, Marianas Archipelago in 2005 Geospatial_Data_Presentation_Form: spreadsheet Online_Linkage: https://www.fisheries.noaa.gov/pacific-islands/ecosystems/coral-reefs-pacific Description: Abstract: To support NOAA Coral Reef Conservation Program (CRCP) long-term goals for sustainable management and conservation of coral reef ecosystems, towed-diver surveys (aka. towboard surveys) were conducted by the Coral Reef Ecosystem Division (CRED) of the NOAA Pacific Islands Fisheries Science Center (PIFSC) as part of biennial Pacific Reef Assessment and Monitoring Program (RAMP) Cruises. 6 towboard surveys (10.1482 km in length), were conducted at Alamagan Island during the Marianas Archipelago RAMP Cruise OES0511 from 3 September - 1 October 2005. Towboard surveys are a good method for obtaining a general description of large reef areas, assessing the status of low-density populations of large-bodied reef fish, large-scale disturbances (e.g., bleaching), general distribution and abundance patterns of macro-invertebrates (e.g., COT, giant clams), and for assessing trends in these populations and metrics. A pair of scuba divers (1 fish and 1 benthic diver) are towed 60 m behind a small survey launch at a speed of 1-2 knots and a depth of approximately 15m. Each survey is 50 min long, covers about 2 km of habitat, and is divided into ten 5-minute survey segments. The fish diver records, to the lowest possible taxon, all large-bodied reef fishes (>50cmTL) seen within 5m either side and 10m in front of the towboard. Length of each individual is estimated to the nearest cm. The fish towboard is also outfitted with a forward-facing digital video camera to record the survey swath. The benthic diver records percent cover of coral and macroalgae, estimates benthic habitat type and complexity, and censuses a suite of benthic macroinvertebrates including Crown of Thorns sea stars and sea urchins. The benthic towboard is equipped with a downward-facing digital still camera which images the benthos at 15 second intervals. These images are analyzed for percent cover of coral, algae, and other benthic components. Both towboards are equipped with SEABIRD SBE-39 temperature/depth sensors set to record at 5 second intervals. Latitude and longitude of each survey track is recorded at 15 second intervals using a Global Positioning System (GPS) receiver onboard the tow boat. A layback algorithm is applied to more accurately map the position of the divers with respect to the reef environment. This algorithm calculates the position of the divers based on the position of the tow boat taking into account the length of the tow rope, the depth of the divers, and the curvature of the survey track. This metadata applies to the benthic characterization observations. Purpose: Part of a long-term monitoring program at biennial intervals which documents the state of the reefs. Supplemental_Information: The benthic characterization observation data includes benthic composition, complexity estimations, observed macro-invertebrates, and observed man-made objects. Classification of habitat complexity was recorded in six categories: low (L), medium-low (ML), medium (M), medium-high (MH), high (H), and very high (VH). Benthic cover was estimated for four different types of substrate: hard substrate/pavement, sand, rubble, and live hard (scleractinian) coral. The time of the benthic digital photos were set to the GMT time. There were approximately 200 pictures of each 50-minute towed survey track. The resolution at "Draft" quality (the lowest) is 72 pixels/inch. The resolution at "Best" quality (the highest) is 266 pixels/inch. The naming convention of benthic photos is ***MMDDYY_X_###.JPG, where *** is 3 letters abbreviation of island/bank surveyed, MMDDYY is the local date of towboard survey, X is the Xth dive on the day of MMDDYY, and ### is the sequence number of the pictures taken at the Xth dive. For example, JAR032106_3_108.JPG means the picture was the 108th picture taken at 3rd dive on March 21, 2006 at Jarvis Island. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20050916 Ending_Date: 20050916 Currentness_Reference: Ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: asNeeded Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: 145.803113 East_Bounding_Coordinate: 145.863562 North_Bounding_Coordinate: 17.628686 South_Bounding_Coordinate: 17.571253 Keywords: Theme: Theme_Keyword_Thesaurus: NCEI Geoportal Filter Theme_Keyword: CoRIS_Metadata Theme: Theme_Keyword_Thesaurus: CRCP Project Theme_Keyword: Pacific Reef Assessment and Monitoring Program (Pacific RAMP): Biennial monitoring for the U.S. Pacific Islands and Atolls Theme_Keyword: 1221 Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Marine Ecosystem Theme_Keyword: Reef Assessment and Monitoring Program (RAMP) Theme_Keyword: Coral Reef Theme_Keyword: Towed Diver Surveys Theme_Keyword: Benthic Habitats Theme_Keyword: Marianas Archipelago Theme_Keyword: Alamagan Island Theme_Keyword: OES0511 Theme: Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus Theme_Keyword: EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs Theme_Keyword: EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral reef ecology Theme_Keyword: EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral reef ecology > Habitats Theme_Keyword: EARTH SCIENCE > Biosphere > Zoology > Corals > Reef monitoring and assessment Theme_Keyword: EARTH SCIENCE > Biosphere > Aquatic Habitat > Benthic Habitat Theme: Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus Theme_Keyword: Numeric Data Sets > Biology Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: biota Theme_Keyword: 002 Place: Place_Keyword_Thesaurus: None Place_Keyword: The United States Place_Keyword: Marianas Archipelago Place_Keyword: Alamagan Island Place: Place_Keyword_Thesaurus: CoRIS Region Place_Keyword: CNMI Place: Place_Keyword_Thesaurus: CoRIS Place Thesaurus Place_Keyword: OCEAN BASIN > Pacific Ocean > Western Pacific Ocean > Alamagan Island > Alamagan Island (17N145E0002) Place_Keyword: COUNTRY/TERRITORY > Northern Mariana Islands > Alamagan Island > Alamagan Island (17N145E0002) Access_Constraints: Data are available two years following data collection date. Use_Constraints: Please cite CRED when using the data. Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Contact_Address: Address_Type: mailing and physical address Address: NOAA IRC Address: NMFS/PIFSC/CRED Address: 1845 WASP Blvd., Building 176 City: Honolulu State_or_Province: HI Postal_Code: 96818 Country: USA Contact_Voice_Telephone: 808 725-5360 Contact_Facsimile_Telephone: 808 725-5429 Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov Contact_Instructions: e-mail preferred Data_Set_Credit: Molly Timmers and Elizabeth Keenan, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Sciences Center, National Marine Fisheries Service, NOAA Security_Information: Security_Classification_System: Not applicable Security_Classification: Unclassified Security_Handling_Description: Not applicable Native_Data_Set_Environment: Oracle Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Observations were made by the divers who are experts in coral reef ecologist. Surveying in this habitat will greatly depend on the current, wave conditions and field scheduling. The towed-diver survey is conducted one time per site per survey year; it is not replicated. Divers may change from year to year and by location. Logical_Consistency_Report: The same data collection protocols were used at each island/bank surveyed. Completeness_Report: The towed-diver surveys are completed in forereef, backreef, and lagoon habitats. Considering that the towed-divers are covering ~200 m during each 5-min time frame of a 50-minute survey, benthic coverage calculations are broad estimates. These data can be used to see large differences but can not be process to a fine scale. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Although resource grade GPS units were used and a layback model was applied to the survey tracks, the exact survey positions were rarely marked and little effort was made to revisit exact same tracks. Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: 1 Horizontal_Positional_Accuracy_Explanation: Instrument parameters Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Dive computer and SCUBA depth gauge Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 0.3 Vertical_Positional_Accuracy_Explanation: Instrument parameters Lineage: Process_Step: Process_Description: Benthic towed-diver surveys involve a SCUBA diver who maintains approximately 1 meter above the bottom and is towed 60 m behind a boat at a constant speed (~1.5 knots). The diver maneuvers a towboard equipped with a downward facing still camera that is programmed to take photographs of the benthos at every 15 seconds as well as a SBE39 depth/temperature recorder which records the temperature and depth every 5 seconds. The towboard survey is typically 50 min long and covers about 2 km of habitat, depending on the depth profile of the divers. The survey is divided into 5 min segments. During the survey, the benthic diver records benthic composition, complexity estimations, observed macro-invertebrates, and observed man-made objects. Process_Date: Unknown Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.0001 Longitude_Resolution: 0.0001 Geographic_Coordinate_Units: Decimal Degrees Geodetic_Model: Horizontal_Datum_Name: World Geodetic System 1984 (WGS84) Ellipsoid_Name: Geodetic Reference System 80 (GRS80) Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.2572236 Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Local surface Depth_Resolution: 1 Depth_Distance_Units: meters Depth_Encoding_Method: Explicit Depth Coordinate Included with Horizontal Coordinates Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Contact_Person: CRED data management team Contact_Address: Address_Type: mailing and physical address Address: NOAA IRC Address: NMFS/PIFSC/CRED Address: 1845 WASP Blvd., Building 176 City: Honolulu State_or_Province: HI Postal_Code: 96818 Country: USA Contact_Voice_Telephone: 808 725-5360 Contact_Facsimile_Telephone: 808 725-5429 Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov Contact_Instructions: e-mail preferred Resource_Description: Offline Data Distribution_Liability: While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: XLS (Microsoft Excel worksheet) Digital_Transfer_Option: Offline_Option: Offline_Media: CDROM, or email Recording_Format: ISO 9660 Fees: None if receiving the data online Custom_Order_Process: Contact CRED data management team for information Technical_Prerequisites: Contact CRED data management team for information Metadata_Reference_Information: Metadata_Date: 20190526 Metadata_Review_Date: 20100405 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA) Contact_Address: Address_Type: mailing and physical address Address: NOAA IRC Address: NMFS/PIFSC/CRED Address: 1845 WASP Blvd., Building 176 City: Honolulu State_or_Province: HI Postal_Code: 96818 Country: USA Contact_Voice_Telephone: 808 725-5360 Contact_Facsimile_Telephone: 808 725-5429 Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov Contact_Instructions: e-mail preferred Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 CoRIS: CoRIS_ID: 20100405070058 CoRIS_Children: None CoRIS_Beginning_Date: 20050916 CoRIS_Ending_Date: 20050916 CoRIS_Metadata_Link: https://www.coris.noaa.gov/metadata/records/html/cred_towboard_benthic_alamagan_island_2005.html CoRIS_Tracking_ID: 4702