Macrobrachium amazonicum is the most frequently consumed freshwater crustacean by river communities of the Amazon. Despite its relative abundance and vast knowledge on the species from data on cultivated specimens, little is known regarding its biology in the natural environment, especially its use of creeks that are strongly influenced by the tide. Specimens of Macrobrachium amazonicum were collected in September 2006 (dry season) and March 2007 (rainy season) from two perennial creeks of the Guajará Bay in the state of Pará (northern Brazil), using traps similar to the matapis used by local fishermen to identify the spatial distribution of the species. Shrimps of all sizes use the tidal creeks in both seasons, including for breeding purposes. The greatest abundance of the species occurred in headwater areas and in the dry season. It is suggested that abundant allochthonous organic matter and the preference for protected areas may explain the abundance and breeding activity of this species in the headwaters of the creeks.Keywords: creek, Macrobrachium, Amazon River prawn, estuary.Distribuição espacial do camarão-da-amazônia -Macrobrachium Amazonicum (Heller, 1862) (Decapoda, Caridea, Palaemonidae) em dois canais perenes de um estuário da costa norte do Brasil (Baía do Guajará -Belém, Pará, Brasil) ResumoMacrobrachium amazonicum é o crustáceo dulcícola mais frequentemente consumido pelas populações ribeirinhas da Amazônia. Entretanto, apesar de sua relativa abundância e vasto conhecimento da espécie a partir de dados de cultivo, pouco se conhece sobre sua biologia no ambiente natural, especialmente quanto à forma de utilização de canais fortemente influenciados pelas marés. Amostras desse camarão foram coletadas em setembro/06 (período seco) e março/07 (período chuvoso), em dois canais perenes da Baía do Guajará, Pará, utilizando armadilhas (matapis) como as utilizadas pelos pescadores locais para identificar a distribuição espacial dos organismos. Os canais de maré são utilizados por camarões de todos os tamanhos nas duas estações do ano, inclusive para a reprodução. A maior abundância de indivíduos da espécie foi encontrada no período seco, nas áreas a montante dos canais . Postula-se que a abundante matéria orgânica alóctone e a busca de locais protegidos podem ser os fatores que explicam a concentração da abundância e da atividade reprodutiva nas áreas a montante dos canais.Palavra-chave: canais de maré, Macrobrachium, camarão-da-amazônia, estuário.

The performance of 20 fishery production systems off the state of Para´in the northern region of Brazil was compared using the ÔRAPFISHÕ methodology, with 57 identified attributes distributed among five evaluation fields: economics, sociology, ecology, technology and politics. The results indicated the existence of three large groups of fishery sectors: (i) industrial (red snapper with traps, the Laulao catfish, shrimp trawl) and semi-industrial (lobster) fisheries; (ii) large-scale artisanal fisheries (acoupa weakfish, red snapper with lines, king mackerel, Spanish mackerel, coco sea catfish); and (iii) smallscale artisanal fisheries (shellfish, crab, estuarine longline, fish traps, etc.). While the industrial and large-scale artisanal systems demonstrated greater sustainability from an economic and social standpoint, small-scale fisheries appeared to be more ecologically sustainable. Based on the results, a reduction in industrial fishing efforts is recommended, along with the establishment of licensing quotas for fishing vessels, as well as an increased investment in research on proper guidance and management of the semi-industrial and large-scale artisanal fisheries sectors. For small-scale artisanal fisheries, economic incentives are suggested for the aggregate value of the products and to assist fishers in the development of an appropriate social organization. Finally, it is believed that a greater stakeholder involvement in the decision-making process would improve management actions for all modalities.

Artisanal fishing on the northern coast of Brazil is characterized by a set of different fishery modalities. Using a multidisciplinary approach, 20 fishery production systems were identified, with distinct characteristics regarding technology and purpose. The characteristics of each system were classified into five dimensions (ecological, economic, social, technological and political). Multidimensional scaling revealed that some of these 20 systems have greater similarities. Thus, a total of 10 groups were identified.

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Landing data are the most basic information used to manage fisheries, although they are often unavailable or incomplete. The objective of this work was to reconstruct the national database of marine commercial landings for the Brazilian industrial and artisanal fisheries, from 1950 to 2015. Total landings increased strongly from 1950 to mid-1980s and suffered sharp decline in the early 1990s, mainly associated to the collapse of sardine fisheries. After that, another period of increasing landings was observed, but at a much lower rate. Industrial landings always surpassed artisanal landings in Brazilian waters, except for the beginning of the time series, when many industrial fleets had not started yet, and in the early 2000s, when a change in the methodology for collecting landing statistics was implemented in the state of Pará leading to an overestimation of artisanal landings. Artisanal fisheries have been declining since 2005, which is worrisome due to the social impact it may have on local income and food security. Regional differences were also observed, with industrial landings being always higher than artisanal landings in southeastern-southern Brazil, while the opposite was true for the northern-northeastern regions. Higher landings were observed in the southeastern-southern regions when both artisanal and industrial fleets were combined. Sardine and demersal fishes were the main resources landed by industrial fishers. Artisanal fishers caught more species than their industrial counterpart, featuring Xiphopenaeus kroyeri, Cynoscion acoupa, and Ucides cordatus. Although the fishing of Epinephelus itajara was banned in Brazil, it continues to be landed. Yet, catches of this species and others under some threat status are still not properly registered, including: Carcharhinus longimanus, Galeorhinus galeus, Sphyrna lewini, Sphyrna mokarran, Pristis pectinata, and Pseudobatos horkelii. Fishing resources not identified in previous landing reconstruction efforts, such as sea urchins and sea cucumbers, have now been reported. The database presented here should be continuously updated and improved. It is of paramount importance to resume the collection of landing statistics, including information on fishing effort, to assess the relative impact of fisheries and environmental factors on the main Brazilian fishing stocks.

-This study aimed to describe the population structure of the Amazon shrimp Macrobrachium amazonicum, as well as their relative growth between the length of the cephalothorax and the total length, and between the length of the cephalothorax and the total mass of shrimps of a fluvial-estuarine plain in the State of Pará. Shrimps were sampled monthly from August 2006 to July 2007, using trawl nets, taking three replicates at each site (Arapiranga and Mosqueiro) per month, totaling 72 replicates. We caught 5,510 specimens, being 90.90% from Arapiranga Island and 9.1% from Mosqueiro Island. The highest densities occurred in July (1.33 individuals/m²), at the beginning of the dry season and in December (1.66 individuals/m²), at the beginning of the rainy season. The morphometric analysis for separate and grouped sexes resulted in negative and positive allometric growth. Ovigerous females were observed in all months, indicating continuous reproduction and the majority (67.81%) was caught during the less rainy season. The abundance and continuous reproduction of M. amazonicum show that this estuary offers conditions for the proper development of this population.

The Southern red snapper, Lutjanus purpureus, is a valuable economic resource, especially in international market. However, no recent data are available on the reproductive biology of this species in Brazilian waters, in particular, the stock found on the Amazon reef. The present study evaluated the population structure and reproductive biology of L. purpureus, and the volume of the catch of juveniles taken by the local commercial fisheries. A total of 923 specimens were analyzed, of which, 577 were female and 346 male (sex ratio: 0.6:1; p < 0.05). The analysis of the gonadosomatic index (GSI) and the distribution of maturation stages indicated that the males and females are able to reproduce throughout the year, however the reproductive peak occurs simultaneously with the increase in the water discharge of the Amazon River. The spawning females were registered in the study area, indicating that L. purpureus does not perform long distance reproductive migrations, different from the previously proposed. The Fork length at first sexual maturation (FL50) was estimated to be 35.2 cm in the males and 32.1 cm in the females. The high frequency of juveniles (< FL50) captured by the commercial snapper fleet using longlines (33.67% of the total catch) and traps (42.1%) indicates the poor selectivity of the fishing gear used by the snapper fleet, which may contribute to the accelerated depletion of the L. purpureus stock. Although the results of this study show a catch percentage of juveniles >50%, it is still a significant percentage of juveniles that are being caught due to little or no guidance and enforcement of fishing gear to ensure compliance with current legislation. Considering the data presented in this study and the current situation of declining fish stocks of L. purpureus, an assessment is recommended for the inclusion of the species in the IUCN Red List of Threatened Species, which is currently a species categorized as “vulnerable” in the Brazilian Red List.

Macrobrachium amazonicum is a freshwater prawn endemic to South America with wide distribution in Brazilian Amazon rivers. In estuary and freshwater streams of the Pará State, they are captured with different types of traps locally know matapi. This study evaluated the efficiency of traps of different sizes (large, medium and small) and baits (babassu coconut and fish) for sampling this shrimp. Samplings were conducted with 24 traps with different treatments (trap size and bait). We captured 909 specimens. Higher mean catches were observed in traps baited with babassu coconut. Interactions between babassu coconut bait and medium matapi (BM-M), and fish bait and large matapi (FISH-L) were significant. Carapace length (CL) varied significantly between sites (F = 12.74, p < 0.01). The total maximum length was 13.65 cm. Medium traps baited with babassu coconut were the most successful in the tested combinations, however, there was a clear correlation between size trap and size of shrimp, for both body weight and carapace length.