The Ocean and Cryosphere in a Changing Climate - April 2022

Damaging and accelerated anthropization in coastal areas, as well as the need to adapt to climate change, means we must concentrate on improving management plans based on the diagnoses provided by coastal studies. Among these studies is the vulnerability assessment, obtained from evaluating a set of variables or indicators, which contribute to sustainable development. Since there is no single list of variables to consider in determining coastal vulnerability, 60 vulnerability studies from a period of 29 years (1994–2023), from across the globe, were consulted, and through a statistical mode method, the variables most used by multidisciplinary authors were identified. These studies were organized into groups: ecological, geomorphological, maritime climate, socioeconomic and legislative; creating sets categorized as the minimum indispensable, acceptable, and ideal variables. The results showed that most studies use between six and seven variables from only the maritime climate and geomorphological information groups. The number of variables used by individual studies, on the other hand, was not directly related to the scales (global, national, regional, local), but to the risks, such as flooding and erosion, it resolved. Only two studies included the minimum essential information for the legislative group, which is the presence of protected natural areas. Coastline displacements was the variable most used (43 studies), followed by the geoform type and the rate of sea level change (36), the wave regime (35) and the tidal range (33). The DSSs (Decision Support Systems) for coastal management were also reviewed, showing that these systems focus on a topic with a greater number of variables.

La reserva de carbono en los manglares que bordean el sistema estuarino de San Blas-laguna Grande de Mexcaltitán, Nayarit, México en el periodo de 1980-2015, definió 3 zonas ambientales con base en las diferentes presiones antrópicas y cantidad de carbono almacenado en la biomasa arbórea y en el suelo. Estas zonas muestran diferenciascon respecto a los comportamientos en amplitud y tiempo de residencia del agua intersticial. La biomasa y carbono (aéreo y subterráneo), así como el secuestro de carbono en el suelo a 20 cm de profundidad se incrementó de la zona sur a la norte. Estos parámetros indican valores bajos, comparados con reportes de diversos autores en manglares de tipo primario. Lo anterior, causado por la pérdida de la estructura y función del ecosistema, se define como bosques secundarios, con desplazamiento de Rhizophora mangle por Avicennia germinans y Laguncularia racemosa. Razón por la cual es fundamental generar información que permita confirmar el estado de conservación del ecosistema, considerando la capacidad de captura y secuestro de carbono, así como su valor monetario y pérdida. Se calcula, para esta investigación, un valor monetario por almacén de carbono arbóreo del manglar de $4,431,826.7 dólares americanos por ton CO2 ha-1; con pérdidas de $132,414.3 dólares americanos por ton CO2 ha-1 en 1980-2015.

Here, we review the functioning and importance of deltaic coastal systems in the northern and southern Gulf of Mexico and how petroleum activities have impacted these two important systems. The Mississippi and Usumacinta-Grijalva Deltas are areas of high biological productivity and biodiversity that support the two largest fisheries in the Gulf. The north central Gulf receives inflow from the Mississippi river, the largest discharge in North America. The Mississippi Delta covers about 10,000 km². The Usumacinta-Grijalva River is the second highest freshwater input to the Gulf and discharges to the Usumacinta-Grijalva/Laguna de Terminos deltaic complex. These two areas are the largest petroleum producing regions in the Gulf, involving both inshore and offshore production. Petroleum activities impact coastal ecosystems in two important ways. In inshore areas dominated by coastal wetlands, there has been enormous physical disruption of the natural environment that affected hydrology and system functioning. In both inshore and offshore areas, spilled oil and release of high salinity produced water has led to widespread toxic pollution. Documentation of petroleum activity impacts on coastal marine ecosystems is much more advanced in the Mississippi Delta. Here, we describe how petroleum production impacts coastal ecosystems and discuss how restoration and management can restore the functioning of impacted coastal ecosystems.

Fiscal economic instruments (FEI) are indirect regulation mechanisms that generate public revenue for the state through rights to use, charges, and concessions. In Mexico, some of these instruments can be used in the surveillance, administration, and preservation of the environment. In this paper, we analyze the changes in Federal and State growth rates of expenditure budgets in critical areas of the Yucatan Peninsula coast to describe their contribution to sustainable development during the last 12 years. We present an adaptation of the methodological guide of economic instruments for environmental management from CEPAL, with 2013 as the base year for the Gross Domestic Product (GDP) deflator and the use of the Protocol of Nagoya year as an international compromise signed by Mexico. The results obtained show that the expenditure budgets respond to economic, political, and short-term security attention without expectations for sustainability. However, alarming evidence of severe environmental deterioration in the coast is diminishing natural attraction, from tourism, for example, which is the main source of income in the region. The effective use of FEI by local governments may be useful to addressing environmental challenges from a decentralization process with better awareness of the importance of coastal areas for regional sustainability.