The importance of a long-term ecological perspective is well documented, yet long-term data are not widely available. This paper represents the first quantitative description of sublittoral sponge assemblages over long temporal scales (6 years) along the coast of the East Pacific Ocean (Mazatlan Bay), with the goal of describing their levels of intra-and inter-annual variability, and their relationship to changing environmental conditions. It was possible to detect an apparent short-term pattern (intra-annual), with a highly diverse and stable structure, usually in the drought season, which was consistent most of the years. However, only a few species showed regular (predictable) seasonal cycles. The species per square meter (from 0.1 to 0.5), total species per sampling (14-21), and H' diversity using log e (1.4-2) also fluctuated greatly between years, suggesting that although a consistent short-term pattern was found most of the years, the inter-annual variability was also high. The univariate and multivariate results and regression models indicated that local winds played a key role in this shortterm pattern (intra-annual). During the rainy season, or during the transition between the drought and rainy season, the winds coming from the southwest (WSW) produced an increase in the net sediment movement, which was an important factor for diversity. The long-term fluctuations (annual pattern of diversity) also correlated positively with wind speed (88% of the variance observed) and with sediment deposition (69% of the variance observed). In addition, the results indicated the existence of large-scale structuring factors, as the annual pattern of diversity also was correlated positively with the Southern Oscillation (SOI) and Multivariate ENSO (MEI) indices (82% and 88% of the observed variance, for MEI and SOI, respectively). In conclusion, this study suggests that sponge assemblages in Mazatlán Bay are extremely dynamic, and changes in this community are associated with processes that occur over the short-and long-time scales (several months to several years). The significant positive relationship between wind speed and sediment deposition showed that the main factors controlling the diversity in these shallow rocky ecosystems are the winds and the swell. A high proportion of coarse sand also indicated a very high energy in the environment, which, combined with the effect of silting, abraded and removed sponges and other organisms. These features contribute to the instability of the community by producing dramatic fluctuations in species abundance and preventing competitive processes from producing a more stable community.

Scutellastra mexicana is the largest known patellid limpet species and probably is one of the most endangered marine invertebrates. The species was once distributed along the American Pacific coast from Mexico to Peru, but their large size (up to 35 cm long) and easy accessibility (shallow sublittoral), made it very vulnerable to human collection and now is extinct on most of the mainland Mexican coast. In August 2017, a large population of this species was found on María Cleofas island, off the coast of west‐central Mexico (Marías Archipelago, Pacific Ocean). This constitutes the only report of a population of this species since 1988. A total of 808 adult individuals of up to 26 cm in length and 20 cm in width were estimated, together with the presence of juveniles, suggesting that it is a self‐sustaining population. The population was monitored in August 2017 and August 2018. Although the species is under the category ‘Special Protection’ in the General Mexican Wild Law, and that María Cleofas island is a Biosphere Reserve, fishermen that operate with impunity in the area decimated the limpet population within a year of its discovery. Abundance in the shallowest area decreased significantly from 120 individuals per transect (65 m long and 2.75 m wide) in August 2017 to 48 individuals in August 2018, and the estimated adult population decreased from 808 to 304 limpets. Neither passive national conservation policies nor local practices have reduced current threats to biodiversity and resource depletion in Marías Archipelago. Protected areas like this are ‘paper parks’—parks in name only—because there is no active conservation strategy or protection of marine species.

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Natural products with promising biomedical properties have been described from sponges, but the problem of supply is usually a limiting factor for their pharmacological evaluation. Mycale cecilia produces an array of metabolites containing a pyrrole-2-carbaldehyde moiety (e.g., mycalazals and mycalenitriles) that have shown activity as growth inhibitors of the human prostate carcinoma cell line LNcaP. This study shows that the culture of M. cecilia is a viable method to supply mycalazals while protecting the wild population. Small implants were bound to ceramic tiles, and after 3 to 4 days, the tissue samples formed a secure attachment. Subsequently, these explants were simultaneously cultured in their natural environment and in small tanks for 60 days. Sponges in the tanks were fed a diet consisting of a mixture of two microalgae (Tetraselmis sp. and Isochrysis sp.) and powdered yeast Saccharomyces cerevisiae. The final survival of the explants differed significantly between the two farming methods: It was higher in the natural environment (95 ± 7.07%; overall mean ± standard error) than in the enclosed system (65 ± 21.21%). Growth was also higher than in the tanks, and after 60 days, it increased to 207% in the sea and 65% in the tanks, which represented a daily increase of 3.5% and 1.5%, respectively. At the end of the trial, both the explants cultured in the sea and in the tanks retained the production of bioactive metabolites. The mean concentration of pyrrole-2-carbaldehyde derivatives in wild and cultured sponges was determined by (1)H-NMR. These results demonstrate that in-sea aquaculture of M. cecilia is a viable method for supplying the amounts of mycalazal-type compounds needed to advance the studies on their bioactivity.

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