Dataset: Species Sizes

Name: Lengths of organisms recorded during emergent and rapid emergent surveys conducted in the subtidal zone of northern California, Sonoma and Mendocino counties, from 1999 to 2023
Published: 2024-06-04
Keywords: kelp forest, abalone, Sea Urchin, size frequency distribution, subtidal survey, marine heatwaves, oceans

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Spatial Extent: N:39.428584 E:-123.071539 S:38.315361 W:-123.82905

Sub-tidal zone, North Coast of California, Sonoma and Mendocino counties

Temporal Extent: 1999-06-23 - 2023-09-18

Project:

Collaborative Research: The effects of marine heatwaves on reproduction, larval transport and recruitment in sea urchin metapopulations (Urchin metapopulations)

Principal Investigator:

Laura Rogers-Bennett (University of California-Davis, UC Davis-BML)

Contact:

Laura Rogers-Bennett (University of California-Davis, UC Davis-BML)

Data Manager:

Robert R. Klamt (University of California-Davis, UC Davis-BML)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2024-06-04

Restricted:

Validated:

Current State:

Data not available

Lengths of organisms recorded during emergent and rapid emergent surveys conducted in the subtidal zone of northern California, Sonoma and Mendocino counties, from 1999 to 2023

Abstract:

The Kelp Forest Monitoring data record span surveys across 28 years from 1971 through 2023 at 20 locations on the Sonoma-Mendocino Coast, Northern California. Years without data, inclusive: 1971-1998, 2002, 2020, 2021. These surveys are ongoing and are conducted by the California Department of Fish and Wildlife dive team with participation from dive program partners at UC Davis, UC Santa Cruz, Cal Poly Humboldt, Sonoma State and other dive programs and volunteers. Not all sites were surveyed in all years. Surveys prior to 2003 were not conducted by the same teams or with the same methods except that all surveys were done using Scuba along 30-meter x 2-meter transects randomly placed in the subtidal zone in rocky habitats dominated by bull kelp, Nereocystis luetkeana, forests. These randomly placed band transect surveys were stratified by depth (A=0-15, B=16-30, C=31-45, D=46-60 ft) as we know sea urchin and abalone populations differ by depth. Organisms along the transect were identified and measured on the longest axis to the nearest millimeter by the divers. Sea urchin and abalone species were identified and measured for every dive transect. However, data on associated species differed depending on resources, the year, and the focus of the studies in response to ecosystem conditions.

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Methods & Sampling

Data were collected during day-trips aboard California Department of Fish and Wildlife or NOAA patrol boats, generally 2-5 days at select survey locations in 1971, 1986, 1989-1992, 1999, 2000, 2001, 2003-2020, 2022, 2023.

All surveys were done using SCUBA along 30x2 meter (m) transects (60 square meters total area) randomly placed in the subtidal zone in rocky habitats dominated by bull kelp (Nereocystis luetkeana) forests. These randomly placed band transect surveys were stratified by depth (A=0-15, B=16-30, C=31-45, D=46-60 ft) as we know sea urchin and abalone populations differ by depth. Two divers (a dive team) work together to count and measure organisms.

Divers were deployed as teams to randomly-selected GPS waypoints within designated depth strata (A, B, C, D). As with other surveys, the patrol boats provide support to the small boats and logistical support to divers. Divers typically complete multiple transects within each of the four depth strata ranging from 0-60 feet at each site. Divers swim along transect tapes measuring 30 x 2m in area across the rocky reef. All transects are in habitat which is dominated (>70% rock) by rocky reef. Two divers (a dive team) work together to count and measure organisms.

Emergent Surveys:
Emergent sampling focused on emergent, exposed, or cryptic animals in rock crevices or under rock ledges but visible without turning rocks or the use of a flashlight. Organisms were identified and measured on the longest axis to the nearest millimeter by the divers as time allowed. Size data (and other physical and biological data) from each dive are recorded on waterproof datasheets which the divers fill out along the transect. Upon return to the boat, data sheets are checked by the lead diver to ensure accuracy and readability for the first quality control check.

Rapid Emergent Surveys:
In response to the extreme purple sea urchin population increase and abalone mortality event in 2016-18, divers conducted a rapid assessment sampling technique: Rapid Emergent Abalone Surveys (REAS). REAS are similar to standard emergent surveys but focus on purple sea urchin and red abalone counts, allowing divers to survey more area. Measurements of organisms are recorded as time allows. Divers conduct two to four rapid emergent transects per dive.

The data specific to this dataset are the lengths (mm) of red abalone, flat abalone, pinto abalone, red sea urchin, and purple sea urchin along each transect.

Problems/Issues

Surveys were not conducted in 1972-1985, 1987, 1988, 1993-1998, 2002, 2020, 2021. Not all locations were surveyed in every year.

Data Processing Description

Data were entered from the field data sheets into a Microsoft Access database, where they were sorted and exported to Excel files. Once data were proofed, they were given a version number and also saved in a file as comma-separated values (CSV).

BCO-DMO Processing

- Imported original files "NSF_OCE_2023664_KelpForestSurveys_Species_CODES_v2_20240119.csv" (species code list) and "NSF_OCE_2023664_KelpForestSurveys_LOCATIONS_v4_20240105.csv" (site code list) into the BCO-DMO system.
- Imported original file "NSF_OCE_2023664_KelpForestSurveys_Species_SIZES_v4_20240411.csv" (species size data) into the BCO-DMO system.
- Added the following columns from the site code list to the species size data: SiteName.
- Added the following columns from the species code list to the species size data: CommonName, ScientificName.
- Converted the SurveyDate column to YYYY-MM-DD format.
- Saved the final file as "929286_v1_kelp_forest_species_sizes.csv".

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-2023664

Deployments

None available yet

Instruments

calipers

Supplied Description:

Instrument Type

Generic Name: calipers

Generic Description:

A caliper (or "pair of calipers") is a device used to measure the distance between two opposite sides of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display.

Global Positioning System Receiver

Supplied Name: Handheld GPS (WGS84 datum)

Supplied Description:

Instrument Type

Generic Name: Global Positioning System Receiver

Acronym: GPS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/POS03/

Generic Description:

The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis. The U.S. Air Force develops, maintains, and operates the space and control segments of the NAVSTAR GPS transmitter system. Ships use a variety of receivers (e.g. Trimble and Ashtech) to interpret the GPS signal and determine accurate latitude and longitude.

Self-Contained Underwater Breathing Apparatus

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: Self-Contained Underwater Breathing Apparatus

Acronym: SCUBA

Generic Description:

The self-contained underwater breathing apparatus or scuba diving system is the result of technological developments and innovations that began almost 300 years ago. Scuba diving is the most extensively used system for breathing underwater by recreational divers throughout the world and in various forms is also widely used to perform underwater work for military, scientific, and commercial purposes.

Reference: https://oceanexplorer.noaa.gov/technology/technical/technical.html

Underwater Writing Slate

Supplied Name: dive slates, underwater data sheets, pencils, and erasers

Supplied Description:

Instrument Type

Generic Name: Underwater Writing Slate

Generic Description:

Underwater writing slates and pencils are used to transport pre-dive plans underwater, to record facts whilst underwater and to aid communication with other divers.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Survey_Num	The unique identifier used for each dive transect. For example, ALB18-A1-1 where ALB is the DFW_short_code for Albion Bay; 18 is the year (2018); A1-1 is the randomized transect. For those years with a letter preceding a number, the letter refers to a depth stratum in feet: A=0-15, B=16-30, C=31-45, D=46-60 ft.	unitless	transect
DFW_short_code	An alphanumeric code for the location	unitless	site
SiteName	The name of the location, e.g., Albion Bay	unitless	site
Lat	The latitude of the location	decimal degrees	lat
Lon	The longitude of the location; negative values = West	decimal degrees	lon
SurveyType	There are two survey types: Emergent surveys do not involve rolling over boulders or picking up rocks and do involve looking in rock crevices and under rocky overhangs. Transect-30m x 2 m (Emergent) - pre-2016. Transect-30m x 2 m (Rapid Emergent) - post-2017	unitless	sampling_method
SurveyDate	The date of the dive survey Format: %Y-%m-%d	unitless	date
Year	4-digit year of the dive survey	unitless	year
Month	Month of the dive survey	unitless	month
Day	Day of month of the dive survey	unitless	day
Timezone	Time zone; all surveys were conducted in the Pacific Standard Time Zone	unitless	time_zone
SpeciesID	The alphanumeric code for the species encountered and/or measured	unitless	taxon_code
ScientificName	The scientific name of the species per the World Register of Marine Species (WoRMS)	unitless	species
CommonName	The common name of the species used by the researchers	unitless	common_name
Size	Measurement of the longest axis of the observed species.	millimeters (mm)	diameter
Comments	The divers’ comments regarding conditions and other observations that may affect the data.	unitless	comment
ProtectionStatus	The special regulations for the location of the transect, e.g., no take MPA is a no take Marine Protected Area	unitless	site_descrip
AverageDepth	The average depth of the transect	feet	depth
MinimumDepth	The shallowest depth of the transect	feet	depth
MaximumDepth	The deepest part of the transect	feet	depth

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Dataset: Species Sizes