Submerged Park biology
The natural environment that characterizes the seabed of the MPA is unique in its extreme variety
of microhabitats, which are the result of the interaction of natural processes (bradyseism, marine
erosion, emissions from secondary volcanism) and anthropic activity (construction of buildings,
piers and fish ponds).

The rocky ridges of yellow tuff along the coast are followed by sandy and detrital bottoms that
alternate with submerged archaeological structures, which represent the planting substrate for
both photophilic (light lovers) and sciaphilous (shadow lovers) organisms. Generally, on the well-lit
summit of the submerged remains, a population dominated by vegetated organisms, such as
green and brown algae, is observed, while along the poorly lit walls a population consisting of
non-concretionary species settles, such as red algae, bryozoans, serpulids and polychrome
sponges .
In addition, octopuses and numerous rock fish, such as wrasse and sparidae, find shelter among
the submerged structures.
On the soft bottoms it is possible to observe specimens of Pinna nobllis, the largest
Mediterranean bivalve and currently protected species, and populations of sea truffles (Venus
verrucosa), particularly appreciated edible species, whose fishing can cause serious damage to
the archaeological finds.
An environment of considerable naturalistic importance is the Secca delle Fumose, located in
zone C of the submerged park in front of Lake Lucrino, consisting of a series of pillars (pilae) that
almost reach the surface of the sea; in the lower part of the piles, in some points, there are
sulphurous fumes that make the water particularly hot and allow the survival of sulphobacteria to
basis of a very peculiar food chain.
Going into detail, in the submerged park there are various biological associations of different
species of plants or animals (biocoenosis) that live in mutual relationship with the different marine
habitats present.
The biocoenosis of infralittoral algae is observed on the artificial pier of the former lido Augusto
(near zone B of Portus Julius), while a strong interdigitation between photophilic populations is
present on the nearby Roman artifacts, settling on the parts most exposed to light with instead
sciaphilic populations , observable in the cavities and on the shaded walls.
The biocenosis of the superficial muddy sands in a sheltered environment characterizes the soft
bottoms, which constitute the overall largest habitat of the submerged park: the presence of this
biocenosis, even up to a depth of about 15 m, is attributable to the conformation of the bay itself.
Pozzuoli, which looks like an inlet sheltered from the wave motion within the wider Gulf of Naples.
In proximity to the submerged structures this biocenosis is enriched with fragments coming from
the disintegration of the artifacts and from the carbonate exoskeletons of encrusting organisms.
The vegetal covers on a soft ground consist mainly of meadows of Caulerpa prolifera mixed with
Caulerpa racemosa. In some areas, such as in the port of Baia, the caulerpeti also settle on the
top part of the submerged Roman artefacts, accompanied by populations of photophilic algae,
mostly filamentous.
Altogether there are three large caulerpeti, one of which in the port of Baia, between 3 m and 12
m deep, and the other two in the area in front of Lake Lucrino, between 7 m and 11 m deep.
Cymodocea nodosa grasslands and semi-grasslands are observed where the hydrodynamism is
greater. An extensive grassland of Cymodocea nodosa is present in the area in front of Lake
Lucrino, between 3 m and 7 m deep. Isolated tufts of Posidonia oceanica have been found in
some areas, such as in front of Punta Epitaffio and the widening of Lake Lucrino.