The area in question has been greatly affected by changes in the course of the centuries, by periods of erosion and deposition of material by the river and the sea and by the man-made drainage and canalization work. In the recent past some of the land was given over to grazing and agriculture, whilst the seaward area survived relatively intact from a natural history perspective. Beginning in the early 1990's work was undertaken to create a seasonal freshwater marsh called “il Ripristino” (“the Restoration”): the new conditions have dramatically increased the number of wetland habitat species, of which the birdlife is the most obvious element.

The area of the reserve is now a site frequented by humans and wildlife alike. It is an area in which various habitats have been recreated and are maintained to encourage the presence of a large number of animal and plant species.

In addition, a number of structures have been created specifically to blend with the local environment and facilitate the observation of wildlife in the area. Comfortable and easily accessible for anyone wishing to get to know and experience an interesting and rich natural environment, the area is great for anyone wishing to relax in a natural setting but also for those wishing to study nature and learn.

The main aims of this project are:
•  Conservation of reedbeds, sand dunes, mudflats and saltmarshes in their current state
•  Restoration of an experimental area as a freshwater marsh, with temporary wetlands and flooded meadows
•  Recreation and conservation of an example of Plains Woodland
•  Management of the area with the aim of increasing diversity using herbivores, such as Camargue horses and Greylag geese, to control vegetation, reproducing the natural sequence of summer droughts and winter flooding
•  Education of visitors in the recently built Wetland Centre
•  Creation of the "Stazione Biologica della Cona" with the aim of promoting field research, covering topics such as: wetland ecology, restoration and management of recreated habitats, biodiversity and biogeography, bird populations and migration, compatibility between conservation and human activities, management, planning etc.
•  Increasing awareness about wildlife conservation.

The biodiversity of the area, already great for a number of reasons including its position at the northernmost point of Mediterranean, increased enormously from the first flooding of the experimental pool (October 1989), the introduction of horses (1991) and, more recently, the extension of a hunting ban to cover the whole reserve (1994).
The slight decrease of wintering waterfowl registered in the western side of the Marano and Grado lagoon was counterbalanced by a parallel increase, in the east, within the Isonzo Nature Reserve, contributing to the maintenance of a fairly high waterbird population in the region, a fact which shows the importance of a network of well distributed and safe day-roosts for conservation and wise management of wildfowl populations.