Catálogo de publicaciones - libros

Lagoons and coastal wetlands are among the most common environments in the transitional zone located between terrestrial ecosystems and adjacent seas. Their persistence and ecosystem processes are controlled by complex interactions among stressors and fluxes of material between land, ocean and atmosphere. As a result, coastal zones are among the most changeable and vulnerable environments on Earth. Among other, natural factors that have the largest impact on coastal lagoons and wetlands are sea-level rise, precipitation and river runoff, and storminess (; ). Natural stressors are interconnected in many ways and are often associated with human impact. In recent decades, most coastal ecosystems have experienced strong anthropogenic pressures, due to progressive human migration from continental areas. At present, nearly 40–50% of the population lives within 100 km of the coastline, including some of the world’s largest cities ().

A Wetland Change Model has been developed to identify the vulnerability of coastal wetlands at broad spatial (regional to global (mean spatial resolution of 85 km)) and temporal scales (modelling period of 100 years). The model provides a dynamic and integrated assessment of wetland loss, and a means of estimating the transitions between different vegetated wetland types and open water under a range of scenarios of sea-level rise and changes in accommodation space from human intervention. This paper is an overview of key issues raised in the process of quantifying broad-scale vulnerabilities of coastal wetlands to forcing from sea-level rise discussing controlling factors of tidal range, sediment availability and accommodation space, identification of response lags and defining the threshold for wetland loss and transition.

Coastal wetland stability and structure can be significantly affected by littoral processes when they are close to the shoreline. Thus, under certain conditions, the combination of shoreline dynamics and direct wave action during storms can influence the stability of marshes and vegetation community composition. This interaction between littoral dynamics and coastal wetlands is illustrated by analysing processes taking place in the Buda Island (Ebro delta, NW Spain), where a coastal lagoon very close to a retreating shoreline exists. Two main time scales have been found to be relevant for interaction of coastal processes with ecosystem dynamics, the decadal and episodic scales. The decadal scale determines the average trend in beach width and directly controls the potential loss of wetland surface. The episodic scale is linked to the occurrence of wave and storm surge events and it determines a pulsing stress in the ecosystem through flooding, being key parameters to determine their direct influence the intensity and repetition of these events.

Application of ecological risk assessment to coastal and estuarine systems is accelerating although it initially lagged behind applications to land and freshwaters. Broader spatial and temporal scales, and multiple stressor integration are appropriately being considered more frequently in all risk assessment activities. This expansion and integration is essential for coastal risk assessment. Because coastal assessments must deal with co-occurrence of several candidate stressors manifesting within broad spatial and temporal scales, wider use of formal methods for assessing causal linkages is needed. Simple Bayesian inference techniques are discussed here to demonstrate their utility in quantifying the belief warranted by available information. The applicability of Bayesian techniques is illustrated with two examples, possible causes of fish kills on the Mid-Atlantic US coast and possible causes of hepatic lesions in fish of Puget Sound (Washington, US).

‘Venice is sinking while the sea level is rising’ is a common statement in issues concerning the future of the Venice lagoon. The search for a reliable interpretative tool for measured sea-level changes has taken on more urgency since the sea-level rise was indexed as the consequence of global warming—with catastrophic scenarios for both the ecotone and the city, linked to increasing lagoon erosion, sudden modifications of biological equilibriums, loss of wetlands, salt aggression and an increasing frequency of exceptional high tide events. However, the peculiar hydrodynamics of the northern Adriatic Sea, made more complex by the freshwater inflow from the Po River, and the conceptual limits of existing long-term predictive systems, would suggest a more cautious approach to the scenarios yet proposed for the next century.

The detection, attribution and prediction of global and large scale regional change are goals for the Global Observing Systems of the United Nations. Coastal areas are particularly sensitive to global change, but there is a variety of limitations to universal coverage of observations. The coastal module of the Global Terrestrial Observing System (C-GTOS) considers sentinel ecosystems to address these goals for the terrestrial, wetland and freshwater ecosystems of the coast. Sentinel ecosystems for observing systems are a limited number of well understood systems that have substantial datasets and are observed in a sustained fashion, forming an early warning and core system for broader regional and global change. A necessary step in the development of C-GTOS is the examination of current definitions of coastal areas by anticipated users and information providers, and identification of potential coastal networks and sites. We applied the sentinel system framework to the selection of C-GTOS observation sites from several international programs using various global delineations of coastal areas. Delineations were based on the most common definitions of the coast adopted by potential C-GTOS users and information providers, and included mapped areas of various distance from the coastline, coastal areas of low elevation, and a seaward boundary matching the Economic Exclusive Zone (EEZ). Decreases in the number of sites within each international program occurred with each definition marking area closer to the coastline. The Ramsar Convention on Wetlands demonstrates the greatest percentage of coastal sites by any definition. The process of choosing specific sentinel sites for C-GTOS continues from this initial screening, and is the next step towards the development of an in situ site network supporting the observation of global and large scale change.

This paper aims at comparing inedited maps of macrophytes and phytoplankton distribution in the lagoon of Venice in 1980 and 2003. The macrophyte distribution is displayed with reference to different biomass intervals which allow the calculation of the occupied surface, standing crop (SC), net (NPP) and gross (GPP) production. In 1980 the total macroalgal SC was ca. 841 ktonnes whereas the annual NPP and GPP were estimated to be ca. 2912 and 18498 ktonnes, respectively. In 2003 macroalgae displayed a marked regression and the SC, NPP and GPP decreased to ca. 89, 471 and 2336 ktonnes. Maps of the seagrass distribution date back to 1990 but their biomass and production have been quantified only in 2003. On the whole, in 2003, on a surface of ca. 56 km the three species living in the lagoon accounted for a SC and a NPP of ca. 209 and 821 ktonnes, whereas the GPP estimated according to literature was about twice as high as the NPP. was the most abundant phanerogam in the lagoon. Its SC was higher than the total of the macroalgae, although the latter were more productive. covered the highest surface in the lagoon but its biomass and production were a little lower than that of , which was common and widespread in the past, displayed an evident regression trend which was mainly due to the increase of the water turbidity and the disruptions of its habitat. Similarly, phytoplankton, underwent a descending trend, although data quoted in the present paper display its distribution only in the summer period.

The alga is an invasive pest species in many parts of the world and has recently become established in several estuaries in south eastern Australia. A major infestation has occurred in Lake Conjola, an intermittently open and closed coastal lagoon in southern NSW. Short term (1 week) laboratory experiments were carried out to investigate growth and survival of fragments of collected from this outbreak, under a range of salinities (15–30 ppt) and water temperatures (15–30°C). Fronds, stolons and thalli of the alga all displayed similar responses. Many of the algal fragments doubled in size over the week and a maximum growth rate of 174 mm/week was recorded. Fragments showed good growth (>20 mm/week) at salinities >20 ppt and temperatures >20°C. Almost total mortality occurred at salinities lower than 20 ppt and temperatures less than 20°C. Historical records of water quality demonstrate that prior to entrance manipulation in 2001, salinities in Lake Conjola had often dropped to below 17 ppt for extended periods (up to 2 years). This suggests that management of the alga may be improved if the lake was allowed to undergo its normal cycles of opening and closing to the ocean, and that entrance manipulation may be one factor that has influenced the success of this invasive species.

The Darß-Zingst Lagoon, a coastal inlet of the southern Baltic Sea, was subject to extended monitoring. The biomass data of zooplankton from 1969 to 2001 were used to analyze long-term trends and to correlate zooplankton biomass with abiotic factors. The dominant species in the lagoon were the calanoid copepods and , and the rotifer f. . In the longterm trend, two pronounced changes in zooplankton biomass and species composition were observed. They are discussed in connection with a shift in dominance from macrophytes to phytoplankton and the invasion of a polychaet species into the lagoon. Significant relations between zooplankton data and abiotic parameters were found. While temperature, precipitation and NAO winter index correlated positively with copepods and negatively with rotifers, the relationships were inversely for pH-value and duration of ice cover.

In this study, 40 Atlanto-Mediterranean coastal lagoons were analyzed in order to evaluate the extent to which their ecological characteristics depend on hydrographic, trophic or geomorphologic features. Fish species richness increases with lagoon volume and the openness parameter, which characterizes the potential influence of the sea on general lagoon hydrology and is related to the total transversal area of the inlets, which connect the lagoon to the sea. On the other hand, the number of species decreases exponentially with the phosphate concentration in water. The fishing yield increases with the chlorophyll concentration in the water column and exponentially with shoreline development. With respect to the fish assemblage composition, geomorphologic features alone explain 22% of the variance in the canonical analyses and an additional 75% when including the hydrographic and trophic characteristics of the lagoon, the latter on its own explaining only 3% of the observed differences.