http://www.aprh.pt/rgci/rgci451.html

Pedro Henrique P. Belarmino, Sarah Mariana da Silva, Marie-Christine
Rufener, Maria Christina B. de Araújo
Solid waste in mangrove in the Potengi River (Natal, RN, Brazil):
relation to the location and uses
Journal of Integrated Coastal Zone Management, 14(3):447-457 (2014)
DOI: 10.5894/rgci451

ABSTRACT
Mangroves are one of the most important ecosystems on Earth; however,
its potential is affected by intense human activities and urban sprawl.
The increase of the populations in localities near the coast has been
pressing this and other natural biological systems. One of the main
impacts on mangroves is solid waste disposal from anthropogenic origin.
Studies on the impact of solid waste in coastal regions are quite
widespread and well known, but are generally made with a focus on the
beaches or in the marine environment, while research on mangroves are
quite scarce. The estuary of Potengi river (Natal-RN) has a great
environmental and socio-economic importance; in its mangroves, about
1,200 families survive by collecting crustacean and shellfish. According
to local studies, the estuary is affected by intense changes that
occurred during the last century, mainly due to disorderly growth of
Natal city. The objective of this work was to carry out an assessment of
solid waste pollution in two mangrove areas associated with the estuary
of the Potengi River, establishing its relationship with the location
and levels of use and exploitation of these areas. A diagnosis of the
areas was carried out through monthly observation, to determine their
main characteristics and types of use. For a detailed survey of the main
uses were made contacts and informal interviews with local residents,
fishermen, tourists, traders and government agencies. For evaluation of
solid waste were demarcated three transects of 50m2 each in each area.
Samples were taken monthly for 06 months (three of the rainy season:
May, June and July, and three of the dry season: September, October and
November); the abundance and location in the environment (sediment or
suspended), were analyzed. The classification according to the
constitution (plastic, metal, glass, paper, wood, fabric and organic)
and when possible, their most likely source (local users, domestic,
mixed and fishing) also were determined. The areas showed environmental
characteristics and use completely different. In the Area 1 the access
is difficult because it is done through a dirt road that enters a very
narrow trail bordered by thick vegetation and with erosion process. The
mangrove presents good condition, with vegetation preserved and used
only by locals. In the Area 2 there is only a narrow strip of mangrove
totally limited in their faces west and south by urban structures.
Besides the paved lanes that allow the arrival to the area, providing
parking and stalls for selling crafts and food, the place has an access
that was opened with the removal of mangroves, and built on a high rock
allowing the arrival of hundreds of tourists to Reis Magos Fort. In the
six months of sampling, was recorded a total of 1,381 items of solid
waste, 77 for Area 1 and 1304 for Area 2. Area 2 had approximately 17
times more items than Area 1, however, in both areas, the most frequent
category of litter was plastic. Also, in both areas, litter on the
sediment was majority. In the area 1 the predominant source was mixed
contributing 49% of the total items, while in area 2, 57% of the
residues identified, probably originated in the local users. The large
amount of residues found in the area 2, demonstrates that the area needs
planning and infrastructure to receive tourists, with the installation
of bins for collect solid wastes in sufficient quantities and
environmental education with tradespeople, users and tour guides.

Keywords: Environmental pollution; rivers; plastics; environmental
monitoring.