On the right bank of the Gironde, the Barrails marsh occupies a depression of low land open to the coastal mudflats of Meschers while the Talmont marsh constitutes a 2nd entity separated by cultivated areas.
The landscape originality is very marked and offers strong contrasts between a coastal part occupied by brackish meadows, separated by tamarisk hedges and ditches with + or - salt water, and the internal zone, fed by springs and streams de Bardécille, de la Reine, where the halophilic influence fades to give way to a bocage marsh of humid plots limited by curtains or groves of ash trees.
Although the pastoral vocation is dominant, hunting activity is important and results in the presence of artificial ponds used for hunting water "fowl", whose ecological functioning brings them closer to certain natural habitats ("temporary ponds"). Mediterranean") from which they borrow part of their vegetation.
The entire site has been subjected over the last decades to strong pressures, particularly agricultural, which have led to the loss of nearly 100 hectares of natural meadows, while at the same time a strong decline is evident on certain plots which are not more grazed and are experiencing a decline in their biological quality.
Nevertheless, the area still presents biological interest as evidenced by the 12 animal species and 9 plant species with high heritage value present in the different natural environments.
In terms of flora, the most original habitat is represented by the hunting ponds which host the Prickly Crypsis and the 3-bract Loosestrife, 2 plants of Mediterranean origin of which the Charentais marshes constitute the northern limit of distribution in France then that on the other hand, the ash groves at the bottom of the marsh are home to the rare summer snowwort, protected at national level.
The area also plays a major role for avifauna: as a nesting site for various species of birds with unfavorable conservation status in France and as a migratory stopover area for small and large wading birds which use the west Atlantic route in their movements. between their wintering areas and their breeding areas. Finally, the important network of ditches and canals provides shelter to several rare or threatened aquatic mammals such as the Water Shrew or, above all, the European Otter.