Predicting the impact of sea-level (SL) rise on coral reefs requires reliable models of reef accretion. Most assume that accretion results from vertical growth of coralgal framework, but recent studies show that reefs exposed to hurricanes consist of layers of coral gravel rather than in-place corals. New models are therefore needed to account for hurricane impact on reef accretion over geological timescales. To investigate this geological impact, we report the configuration and development of a 4-km-long fringing reef at Punta Maroma along the northeast Yucatan Peninsula. Satellite-derived bathymetry shows the crest is set-back a uniform distance of 315 ±15 m from a mid-shelf slope break, and the reef-front decreases 50% in width and depth along its length. A 12-core drill transect constrained by multiple 230Th ages shows the reef is composed of an ~ 2-m thick layer of coral clasts that has retrograded 100 m over its back-reef during the last 5.5 ka. These findings are consistent with a hurricane-control model of reef development where large waves trip and break over the mid-shelf slope break, triggering rapid energy dissipation and thus limiting how far upslope individual waves can fragment corals and redistribute clasts. As SL rises and water depth increases, energy dissipation during wave-breaking is reduced, extending the clast-transport limit, thus leading to reef retrogradation. This hurricane model may be applicable to a large sub-set of fringing reefs in the tropical Western-Atlantic necessitating a reappraisal of their accretion rates and response to future SL rise.

This paper aims to highlight the prevailing experiences of Latin America and to clarify what ‘green infrastructure’ entails in addition to describing seven case studies from a range of coastal ecosystems (wetlands, coastal dunes, beaches and coral reefs) at scales varying from local to regional. The case studies are categorised according to their degree of naturalness (nature-based, engineered ecosystems, soft engineering, ecologically enhanced hard infrastructure and de-engineering). Generally, the implementation of green infrastructure projects aims to increase resilience, enhance the provision of ecosystem services, recover biodiversity, reduce the negative effects of hard infrastructure and implement corrective measures. The greatest benefits of these projects relate to the creation of multi-functional spaces, which often combine the above advantages with improved opportunities for recreation and/or economic activities. It is hoped that this paper will disseminate the experience in green infrastructure among academics and practitioners and stimulate wider adoption of green infrastructure projects and good practices.

Sustainable energy is needed globally, and Ocean Thermal Energy Conversion (OTEC) is a possible way to diversify the energy matrix. This article suggests a preliminary selection process to find optimal sites for OTEC deployment on the Mexican coastline. The method comprises the (1) evaluation of the thermal power potential, using daily data (16 years) of sea surface temperature, and the percentage of available time of the power thresholds; (2) assessment of feasibility using a decision matrix, fed by technical, environmental and socioeconomic criteria; (3) identification of four potential sites; and (4) comparison of OTEC competitiveness with other technologies through the levelized cost of energy. Multi-criteria decision analysis was applied to select optimal sites, using the technique for ordering performance by the similarity to the ideal solution. The best sites were (1) Puerto Angel and (2) Cabo San Lucas; with power production of > 50 MW and a persistence of > 40%. As yet there is no evidence from operational OTEC plants that could alter the environmental and socioeconomic criteria weightings. More in situ studies on pilot plants should help to determine their possible environmental impact and socio-economic consequences before any larger-scale projects are implemented.

Bahia Magdalena is a coastal lagoon with an enormous biological and fishing wealth; it is located in the Pacific coast of Baja California (Mexico), a transitional zone between tropical and temperate regions which is strongly affected by the global-scale climate phenomena. The objective of this work was to determine the impact of the unusual and consecutive warming events known as The Blob (TB2013–2015) and the 2015–2016 El Niño on the hydrological characteristics and plankton communities, the lower levels of the trophic web, from January 2015 to December 2017. This coastal lagoon lacks river runoff and primary producers depend on the upwelling’s nutrient supply. The environmental variables analyzed were the upwelling index (PFEL-NOAA), the air and sea temperature, salinity, nutrients, and chlorophyll-a. The species composition, species richness and the Shannon-Weiner diversity index were used to describe some aspects of the phytoplankton community structure and its phenology. The biomass and mortality of zooplankton also were analyzed. The seasonal pattern of hydrology was described with data collected in nine sampling stations. An alternative approach used with both biological and environmental datasets was to select representative sampling stations located in the vicinity of the inlet and in the interior of the lagoon. Chla-fluorescence imagery collected by the MODIS-Aqua satellite was used as an indicator of phytoplankton abundance. Statistical analyses included bi- and multivariate parametric and non-parametric tests. Principal component analysis was used to describe the seasonality of hydrological data and the canonical correlation analysis to relate environmental and biological datasets. The increase of temperature at a global and local scale in 2015 had as consequence an atypical increase in the water temperature in the fall of 2015, coincident with the abrupt diminishing of upwelling strength and input of nutrients advected from the ocean. A recovery of these two variables was recorded in 2016 at the end of the El Niño. The most abundant group of phytoplankton species were diatoms. Algal blooms were composed by species adapted to high temperatures and nutrients depletion in 2015, while in 2016 and 2017 were composed by ruderal-strategist species and they were boosted by the nutrient pulses associated with the spring upwellings. The fall algal bloom, typical of subtropical coastal lagoons, was observed only in 2016 and it was confined to the interior of the lagoon where there are local inputs of nutrients. In 2015 and 2016 there was a succession of diatoms and dinoflagellates related to the rising of temperature while in 2017 this pattern changed because of the strong upwellings. The relationships of water temperature and silicate with a ratio of diatoms’ cell abundance, was analyzed using generalized additive models (GAMs), showing significant correlations but different trends in some years. The species richness of diatom blooms was high; on the other hand, species diversity increased at the end of spring and early summer. The seasonal pattern of zooplankton biomass showed changes along the 3 years, but the most noticeable was an increase during winter and early spring 2015 and the lack of the usual high values of June–July in 2017. The seasonal pattern of the phytoplankton abundance was different in comparison with the 1982–1983 El Niño while the zooplankton was similar among the three strongest El Niño. The changes we observed strongly suggest that the warming caused by those phenomena highly affected the upwelling strength, the length of the temperate and warm seasons and the hydrology. Phenology of phytoplankton and zooplankton changed after the strong perturbation under the El Niño, and possibly The Blob. The recovery of phytoplankton biomass began in 2017, but its taxonomic composition was not adequate to support the zooplankton recovery.