Spatial and temporal variation of satellite-derived phytoplankton biomass and production in the California Current System off Punta Eugenia, during 1997-2012

The great biodiversity of the California Current System area off Punta Eugenia is supported by high phytoplankton production (PP) caused by coastal upwelling. Satellite imagery was used to characterize the sea surface temperature (SST), phytoplankton biomass (Chlsat), and PP variation in this area during 1997-2012, and to generate a first approximation to its climatology, or an average year. Chlsat and PP had higher values inshore (0-120 km from shore) than offshore. SST had minima inshore and maxima offshore from January through October, with a gradient reversal at the end of autumn. SST often presented spatial distributions with minima and maxima suggesting mesoscale phenomena, such as meanders and eddies. These affected Chlsat and PP inshore. In general, inshore Chlsat and PP were high in March-August (up to >5 mg m-3, and >3.5 g C m-2 d-1), and low in September-February (up to ~1.2 mg m-3, and ~1.2 g C m-2 d-1). Offshore (120-240 km), Chlsat and PP presented similar and relatively low values throughout the whole year, ~0.3 mg m-3 and ~0.5 g C m-2 d-1. Most Chlsat and PP variation was in the annual and interannual periods. Chlsat data from 1998 (El Niño year) and those of 2000 presented significant differences for the inshore region. But, when comparing other El Niño years, there were no significant differences, suggesting that the local impact of ENSO events depend on the type of El Niño, the Pacific decadal oscillation phase, and the incidence of mesoscale phenomena such as meanders and eddies.The great biodiversity of the California Current System area off Punta Eugenia is supported by high phytoplankton production (PP) caused by coastal upwelling. Satellite imagery was used to characterize the sea surface temperature (SST), phytoplankton biomass (Chlsat), and PP variation in this area during 1997-2012, and to generate a first approximation to its climatology, or an average year. Chlsat and PP had higher values inshore (0-120 km from shore) than offshore. SST had minima inshore and maxima offshore from January through October, with a gradient reversal at the end of autumn. SST often presented spatial distributions with minima and maxima suggesting mesoscale phenomena, such as meanders and eddies. These affected Chlsat and PP inshore. In general, inshore Chlsat and PP were high in March-August (up to >5 mg m-3, and >3.5 g C m-2 d-1), and low in September-February (up to ~1.2 mg m-3, and ~1.2 g C m-2 d-1). Offshore (120-240 km), Chlsat and PP presented similar and relatively low values throughout the whole year, ~0.3 mg m-3 and ~0.5 g C m-2 d-1. Most Chlsat and PP variation was in the annual and interannual periods. Chlsat data from 1998 (El Niño year) and those of 2000 presented significant differences for the inshore region. But, when comparing other El Niño years, there were no significant differences, suggesting that the local impact of ENSO events depend on the type of El Niño, the Pacific decadal oscillation phase, and the incidence of mesoscale phenomena such as meanders and eddies

Ps19, a novel chitin binding protein from Pteria sterna capable to mineralize aragonite plates in vitro.

Mollusk shell is composed of two CaCO3 polymorphs (calcite and aragonite) and an organic matrix that consists of acetic acid- or ethylenediaminetetraacetic acid (EDTA)-soluble and insoluble proteins and other biomolecules (polysaccharides, β-chitin). However, the shell matrix proteins involved in nacre formation are not fully known. Thus, the aim of this study was to identify and characterize a novel protein from the acetic acid-insoluble fraction from the shell of Pteria sterna, named in this study as Ps19, to have a better understanding of the biomineralization process. Ps19 biochemical characterization showed that it is a glycoprotein that exhibits calcium- and chitin-binding capabilities. Additionally, it is capable of inducing aragonite plate crystallization in vitro. Ps19 partial peptide sequence showed similarity with other known shell matrix proteins, but it displayed similarity with proteins from Crassostrea gigas, Mizuhopecten yessoensis, Biomphalaria glabrata, Alpysia californica, Lottia gigantea and Elysia chlorotica. The results obtained indicated that Ps19 might play an important role in nacre growth of mollusk shells