ImplicaÃÃes de fatores ambientais na deposiÃÃo de plÃsticos no ambiente praial de um ecossistema estuarino

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Marine debris are materials from anthropogenic sources, such as plastics, paper, glass, wood and others, that enter the marine and coastal environments from multiple sources, and are considered as one of the most important marine pollutants by the turn of the XXI Century. Sandy beaches are usually more studied because they are relatively easy to be monitored, but estuarine beaches are rarely the focus of systematic works. An estuarine beach on the Goiana River estuary (PE/PB) was monitored from April 2006 to March 2007. Three 20m wide replicate transects divided into two strata, foreshore and backshore, were individually monitored. Monthly, transects were monitored and cleaned, being registered quantities, composition, size categories (1- 10cmÂ, 11-100cmÂ, 101-1000cmÂ, >1001cmÂ) and, the most probable sources were estimated. Meteorological, morphological and physico-chemical parameters were registered. A rainy season (April to September 2006) and a dry season (October 2006 to March 2007) were defined. In rainy season, the beach was significantly more contaminated by marine debris. Plastics were the prevalent type of item in all monitored months. Identified sources were the Goiana River estuary (63.2%) and fishing activities (37.5%), and significant differences in the number of fishing-related items were registered between the lobster fishing months (May to August) and the other months. In spite of the neutral sedimentary balance in a one year cycle, there is deposition and erosion of the beach in different months. The most common category was 11- 100cm with 56% of the total items, followed by 1-10cm (26%), 101-1000cm (15%) e >1001cm (3%). There were significant differences between the Goiana River source and >1001 cm size category, and between mixed sources and 101-1000 e >1001 cm categories. There were significant differences, in the total number of items, between foreshore and backshore, the rainy and dry months and the size categories sampled. Prevalent items were fragments and soft packaging, polystyrene fragments, fragments of cups, fragments and rigid plastic containers and plastic bags on the foreshore and backshore for each size categories. Soft plastics from the Goiana River and from mixed sources were more sampled on the foreshore, while rigid plastics from the Goiana River and from fishing activities were more sampled on the backshore. The most sampled items were individually analyzed and the potential risk of each one was estimated to both the biota (ingestion, entanglement, fouling) and the riverine population (scenic quality, boating and fishing, human health). For this particular size, plastic bags and soft packaging with >1001cm are considered the most dangerous items. In general, ingestion and degradation of the scenic quality were the most important impacts. It is recommended, as priority actions to the reduction of this type of marine pollution in the estuary, the introduction of alternatives to the collection of solid wastes and sewage from fishing boats and from the riverine population from Acaà and Carne de Vaca

ASSUNTO(S)

nordeste do brasil northeast brazil goiana river estuary marine debris estuÃrio do rio goiana lixo marinho oceanografia

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