hrvatski

Preliminarni pregled makrobentosa u okolici Nerezina (otok Lošinj, sjeverni Jadran)

Benthic communities were once investigated along three bottom transects in Artac Bay (Nerezine, Lošinj Island) during December 2003. Macrobenthos research was performed by a standard method of direct observation in situ and sampling using SCUBA diving equipment. A total of 24 species of macroalgae, one marine phanerogam and 84 animal species were recorded, and four benthic biocoenoses were established. The hard bottom in the research area is occupied by biocoenosis of photophilic seaweeds. Because of the dominance of sciaphilic elements in the shallow water, the community could be considered degraded. Brown algae of the Cystoseira genus, a basic element of the Mediterranean biocoenosis of photophilic seaweeds, do not form ordinary dense associations in the research area but are present as solitary individuals or small scarce clumps. The sedimentary bottom consists of detritic sand with a thin surface muddy layer and is occupied by the phanerogam Cymodocea nodosa. An increase of the phanerogam abundance and density in the southward direction was noticed despite the increase of depth in the area surveyed. A high abundance of deposit feeding sea-cucumbers (Holothuria spp.) is probably an evidence of a higher input of organic matter in the ecosystem. According to this preliminary survey conditions and state of benthos are partially in concordance with the available literature data. The general picture of macrobenthos, as well as composition of benthic communities are pointing to a recent worsening of environmental conditions. It has been found out afterwards that a direct outlet of untreated waste waters was placed in the northern part of the area surveyed, which caused the noticed degradation of macrobenthos. The recent closure of this pollution source enabled improvement of environmental conditions and benthic communities start to show signs of recovery.

bentos; flora; fauna; otok Lošinj; sjeverni Jadran

nije evidentirano

engleski

A macrobenthos preliminary survey in the vicinity of Nerezine (Lošinj Island, Northern Adriatic)

Benthic communities were once investigated along three bottom transects in Artac Bay (Nerezine, Lošinj Island) during December 2003. Macrobenthos research was performed by a standard method of direct observation in situ and sampling using SCUBA diving equipment. A total of 24 species of macroalgae, one marine phanerogam and 84 animal species were recorded, and four benthic biocoenoses were established. The hard bottom in the research area is occupied by biocoenosis of photophilic seaweeds. Because of the dominance of sciaphilic elements in the shallow water, the community could be considered degraded. Brown algae of the Cystoseira genus, a basic element of the Mediterranean biocoenosis of photophilic seaweeds, do not form ordinary dense associations in the research area but are present as solitary individuals or small scarce clumps. The sedimentary bottom consists of detritic sand with a thin surface muddy layer and is occupied by the phanerogam Cymodocea nodosa. An increase of the phanerogam abundance and density in the southward direction was noticed despite the increase of depth in the area surveyed. A high abundance of deposit feeding sea-cucumbers (Holothuria spp.) is probably an evidence of a higher input of organic matter in the ecosystem. According to this preliminary survey conditions and state of benthos are partially in concordance with the available literature data. The general picture of macrobenthos, as well as composition of benthic communities are pointing to a recent worsening of environmental conditions. It has been found out afterwards that a direct outlet of untreated waste waters was placed in the northern part of the area surveyed, which caused the noticed degradation of macrobenthos. The recent closure of this pollution source enabled improvement of environmental conditions and benthic communities start to show signs of recovery.

benthos; flora; fauna; Lošinj Island; Northern Adriatic

nije evidentirano