Dataset: Abalone recruitment data from Baja California and Baja California Sur, Mexico in 2019

ValidatedFinal no updates expectedDOI: 10.26008/1912/bco-dmo.907383.1Version 1 (2023-10-18)Dataset Type:Other Field Results

Principal Investigator: Fiorenza Micheli (Stanford University)

Scientist: Arturo Hernández-Velasco (Comunidad y Biodiversidad, A.C.)

Scientist: Laura Rogers-Bennett (University of California-Davis)

Scientist: Alexandra Smith (Stanford University)

Technician: Arquimedes Aguilar (Sociedad Cooperativa de Producción Pesquera Buzos y Pescadores de la Baja California)

Technician: Miguel Bracamontes (Cooperativa Ensenada)

Technician: Ramon Martinez (Sociedad Cooperativa de Producción Pesquera Buzos y Pescadores de la Baja California)

Technician: Alfonso Romero (Comunidad y Biodiversidad, A.C.)

Data Manager: Carolina Olguín Jacobson (Stanford University)

BCO-DMO Data Manager: Amber D. York (Woods Hole Oceanographic Institution)


Project: Collaborative Research: Evaluating how abalone populations in the California Current are structured by the interplay of large-scale oceanographic forcing and nearshore variability (Abalone Safe Places)


Abstract

Abalone support commercial and recreational fishery, however their population have decline dramatically since 1950's. To understand the recruitment of abalone populations, standarized abalone recruitment modules made of half cinder blocks inside cages were deployed in Baja California and Baja California Sur, Mexico. 12 cages were deployed at three sites (i.e., El Rosario, Isla Natividad and La Bocana) in Mexico. The abundances of abalone and invertebrates found in the cages were checked after 12...

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LOCATION:
Baja California, Mexico. El Rosario
Baja California Sur, Mexico. Isla Natividad and La Bocana

DEPLOYMENT OF CAGES
Twelve cages per site were deployed between 5-40ft, at the three locations (El Rosario, Isla Natividad and La Bocana) and left for 12 months before surveys.

SURVEY OF CAGES
1. Diver 1 opens cage and holds the blocks 1 at a time while Diver 2 fills in the data sheet
2. Diver 2 fills in the datasheet and sets the blocks in a pile off to the side

Part 1 – count and measure focal species
▪ Stop measuring after 30 measurements
▪ Stop counting after 100 counts
▪ Organisms outside or on the cage should not sampled.

Part 2 – identify and qualitatively measure the dominant cover on each block
▪ For each block identify what the most common cover is (CCA, red algae, other)
▪ Determine whether it covers 25, 50, 75 or 100% of the block
▪ But a tally point in the corresponding cell
▪ Each block should only have 1 tally

Part 3 – note presence/absence of Macrocystis/Eisenia algae or sessile invertebrates for each block

3. Once the cage is empty divers inspect the cage and lines, making any minor repairs that are
possible

4. Diver 1 puts the blocks back into the cage 1 at a time while diver 2 keeps track (comments section) of the number of blocks and broken pieces.

5. Close the cage with line and cable ties, ascend for surface interval

INSTRUMENTS:
SCUBA diving equipment
Calipers (150mm)
Ruler
Mesh bag
Transect tape
Slate
Datasheet
Pencils
Snipes/knife
Cable ties
Extra line
GoPro camera


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Related Publications

Results

Provost, M.M., G. de Leo, B. Woodson, F. Micheli (n.d.). Finding the ‘safe spaces’ for abalone on the Pacific coast of Baja California, Mexico. In Prep.
Results

Rogers-Bennett, L., Allen, B. L, & Davis, G. E. (2004). Measuring abalone (Haliotis Spp.) recruitment in California to examine recruitment overfishing and recovery criteria. SHERIDAN PRESS. Journal of Shellfish Research, 23(4), 1201-1207. Retrieved from https://escholarship.org/uc/item/3kc705w1