Multiscale characterization of the sea temperature in an area of abalone banks (Haliotis spp.) at Bahia Asuncion, Baja California Sur, Mexico

Abstract

The Baja California abalone is one of the most important Mexican fisheries because of its high economic value. Despite strong management efforts, this fishery has faced dramatic fluctuations attributed mainly to overfishing and variability of the marine climate. In this report we analyze sea temperature variability off Bahía Asunción, Baja California Sur (Mexico), at temporal scales that may affect abalone biological processes, such as mortality, reproduction, recruitment, and individual growth rate. Since the analysis is based on different data sources, we conducted a series of correlation analyses to determine the coherence between them. We report the average daily cycle and its variations throughout the year and between years for the period 1997–2000, the seasonal cycle and interannual deviations for the period 1992–2000, the behavior of the decadal scale variability based on annual values for the period 1959–1997, and the long-term trends after analyzing the entire 20th century. Furthermore, we conducted a spectral density analysis to estimate the proportional contribution of each temporal scale to the entire variability signal. Results from the high-frequency variability (daily to interannual) suggest a relationship between temperature and the abalone reproductive cycles, a potential negative effect of the very strong ENSO events on the postlarvae, and a differential effect of temperature on juveniles of different species. Regarding the low-frequency variability (decadal to century), we show that recent years represent a much warmer period compared to previous decades, suggesting a different biological community structure between periods. The spectral density analysis indicates seasonal variability as the major contributor to the regional variability, followed by the interannual (related to ENSO). There is almost no information of the marine climate in this region, particularly in regard to fine and high-resolution observations. This contribution will provide new quantitative elements for studies dealing with the ecology of these coastal productive systems.

Effect of nutrient availability on understory algae during El Niño Southern Oscillation (ENSO) conditions in Central Pacific Baja California

“…The lowest temperatures in spring coincided with the upwelling phenomenon reported for the region, which results in nutrient enrichment of surface water (Walsh et al 1974,1977). A more detailed analysis of daily temperature carried out by Ponce-Díaz et al (2003) for the same site and using 2000 as reference year shows a positive deviation during the 1997-1998 ENSO year, which was followed by a period of lower temperature. The same authors pointed out that the differences in the amplitude of the daily cycle were lower during the ENSO 1997-1998 than in any other period.…”

“…Temperature was recorded using a Hobo (Onset) sensor during the studied year and was compared with historical temperature data (1994)(1995)(1996)(1997)(1998)(1999)) measured by thermometer. The correlation coefficient between the Hobo data and the data recorded daily within Bahía Asunción with thermometer was r=0.952 (n=704) (Ponce-Díaz et al 2003). Bottom and surface seawater nitrate concentrations were analyzed in control quadrats and experimental quadrats using the cadmium reduction technique (Strickland and Parson 1972).…”

“…The El Niño Southern Oscillation (ENSO) is associated to an anomalous increase of seawater temperature and a reduction of nutrient concentration (Hernández-Carmona et al 2001). The disappearance of all (1982)(1983) or part (1997)(1998) of the Macrocystis pyrifera populations in the Baja California Peninsula in the Pacific Coast of Mexico was caused by the presence of the ENSO events (Ponce-Díaz et al 2003). The effect of nutrient availability on M. pyrifera recruitment and survival of juvenile sporophytes was examined during the ENSO 1997-1998 off Baja California, Mexico, at the southern distribution limit of this species (Hernández-Carmona et al 2001).…”

Pathogenic Bacteria and their Effect on Plasma Components of Haliotis fulgens (Archaeogastropoda: Haliotidae) in Baja California Sur, Mexico

“…In Mexico, the catch of abalone Haliotis fulgens decreased considerably in 2012 [1]. Some researchers point out that the mortality of Haliotis on the coasts of the United States was associated with an infectious phenomenon [2].…”

The California lobster fishery and climate in the kelp bed ecosystem

“…The California Current, which transports water from the subarctic Pacific to the Equator and a counter current of tropical origin, penetrating the tropical north Pacific, near the coast; when mixed, produce a temperate-tropical transition zone (Guzmán del Proó et al 1991, Lluch-Belda 2000, Casas-Valdez 2003, Guzmán del Proó et al 2003, Ponce-Díaz et al 2003. The water of the California Current is characterized by low temperature (14-16°C), constant salinity (33.5 to 33.8), high values of dissolved oxygen, and a continuous supply of nutrients (Hemingway 1979, Durazo et al 2010, Gaxiola-Castro et al 2010.…”