Otoliths are an excellent tool for analysing the pattern of habitat use between adults and juveniles and connectivity between fish populations. Larimus breviceps is a species belonging to the family Sciaenidae, which has an important role in the marine food chain, as it is one of the most abundant and frequent species in the bycatch of coastal shrimp fisheries in Brazil. The present study aimed at comparing the otolith shape of specimens collected in three different Brazilian coastal areas: Sergipe (SE), northeastern region; São Paulo (SP), southeastern region; and Paraná (PR), southern region. In a laboratory, 88 otoliths were extracted, photographed, and the contour was analysed by the wavelet method (32 from SE, 28 from SP, and 28 from PR). The otolith contours varied between sampling sites. Linear discriminant analysis correctly reclassified 60.23% otoliths by the sampled sites, with the best reclassifications occurring in SE (62.5%), followed by PR (60.71%) and SP (57.14%). Multivariate analysis of variance also evidenced significant differences in contours among the sampling sites (F = 2.3; P < 0.005). Thus, two morphotypes of otoliths were found for L. breviceps: one from Sergipe (northeastern Brazil) and the second one from southeastern–southern Brazil, indicating connectivity between the populations off São Paulo and Paraná, to be confirmed by future genetic studies.

Progressive salinization of water and soil will be increasingly severe in low-lying coastal areas as climate change proceeds. Thus, understanding the economic impacts of salinity intrusion will be essential for effective adaptation planning. This paper uses econometric analysis to predict the impact of climate-induced increases in soil salinity on high-yielding-variety rice production in coastal Bangladesh. Findings indicate an output decline of 15.6 percent in nine subdistricts where soil salinity will exceed 4 deciSiemens per meter before 2050. Without new adaptation strategies, the predicted changes will result in 7.7 and 5.6 percent losses in the Barisal and Chittagong regions, respectively.

Interview surveys of 116 coastal residents and fishermen and surveys by motorboat were conducted in 2000 and 2001 in French Guiana in order to assess the distribution, habitats and conservation status of the West Indian manatee Trichechus manatus. There were 72 reported sightings of manatees, and we made 10 sightings during river surveys. Interviews suggested that manatees may be less abundant than in the recent past, but are still present and regularly sighted all along the coast and in estuaries up to 80 km inland. The main reason for any recent decline is probably hunting for meat, pressures from development and, in some areas, pollution from maritime traffic. Although only opportunistically caught, manatees are still poached. In some areas they are killed for cultural beliefs, but only on a small scale. The main habitat for the manatee in French Guiana is estuarine mangroves. A survey at Coswine, an area where manatees have been sighted year-round, indicated that this mangrove area is characterized by biotic and abiotic factors within the range known to provide suitable habitat for the species. However, habitats for manatees in French Guiana are limited and receive little formal protection, and the species' status is based more on fortuitous protection than on any active conservation. Public awareness programmes for the manatee are currently being developed by local NGOs, but a regional conservation programme is also required.