Impact of Inlet Management on the Resilience of a Coastal Lagoon: La Mancha, Veracruz, Mexico

Understanding the Dynamics of a Coastal Lagoon: Drivers, Exchanges, State of the Environment, Consequences and Responses

“…The study site is on the Gulf of Mexico in the state of Veracruz, between the coordinates 19 • 33 and 19 • 36 N and 96 • 22 and 96 • 24 W (Figure 1). Geologically, this area is a cumulative plain, formed by lacustrine, fluvial and biogenic sediments, occasionally combined with marine deposits [12]. The geomorphological evolution of the site is marked by long-term minimal marine sediment input and intense aeolian transport [15], which are both recorded during storm conditions related to northerly winds.…”

“…The lagoon of La Mancha is a brackish coastal lagoon, liable to siltation, with a surface of 126 ha, an average depth of 1.4 m and a maximum depth of 3 m [12,17]. The tides are mixed diurnal with a range of 0.69 m [18], and the lagoon is fed by two permanent river tributaries in the dry season (see Figure 1) and intermittently communicates with the sea [18].…”

“…The tides are mixed diurnal with a range of 0.69 m [18], and the lagoon is fed by two permanent river tributaries in the dry season (see Figure 1) and intermittently communicates with the sea [18]. The balance among sea water, rain and groundwater discharges regulates the hydrological variability of the lagoon [12]. The beach communicates with the lagoon in the lagoon inlet, and its natural opening and closing lead to modifications in the environment that alter the dynamics of the lagoon and cause changes in other surrounding ecosystems.…”

“…The opening and closing of the lagoon inlet determine the migration of sediments, fish species and nutrients into the lagoon body [18]: when the inlet of the lagoon is closed, the water level of the lagoon rises and the salinity decreases; when it is open, the water level decreases and there is greater salinity and sediment accumulation [15] (see Figure 2). The lagoon inlet is also opened by local fishermen about three times per year in the dry season, in order to increase their catch by altering the normal flooding regime [12]. The climate of the study area has three pronounced seasons: the rainy season, from June to October; a period of "Nortes", winter storms that occur in the western Gulf of Mexico, from November to March; and a dry season, in April and May [12].…”

“…In particular, the coastal lagoon of La Mancha (Figure 1), in the state of Veracruz, belongs to the municipality of Actopan. The lagoon has been on the Ramsar List of Wetlands of International Importance since 2004 [11] and was also established as a Priority Mangrove Conservation Site by CONABIO, the National Commission for the Knowledge and Use of Biodiversity [12]. Tourism in the vicinity of La Mancha is managed by a sustainable ecotourism company, called La Mancha en Movimiento S.S.S., where local fishermen, housewives, farmers and others have been trained to work as eco-guides [13].…”