Utilização da análise dos componentes principais na caracterização dos sedimentos de superfície de fundo da Baía da Ilha Grande (RJ)

Mahiques, Michel Michaelovitch de; Furtado, Valdenir Veronese

doi:10.1590/s0373-55241989000100001

Cited by 9 publications

(6 citation statements)

References 3 publications

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“…This bay is divided into three main sectors, based on its oceanographic and physiographic characteristics, the eastern, central, and western sectors (Signorini, ). This study was conducted in the western sector, which is defined by a large number of microhabitats, such as rocky coasts, islands, mangroves, and sandy beaches, surrounded by the Serra do Mar Mountain Range and Atlantic Rain Forest (Mahiques & Furtado, ). The bay is relatively shallow, reaching depths of no more than 20 m, and has high rainfall levels during the austral spring and summer months, when there is a major allochthonous input from local rivers and organic matter from the Serra do Mar (Mahiques & Furtado, ).…”

Section: Methodsmentioning

confidence: 99%

“…This study was conducted in the western sector, which is defined by a large number of microhabitats, such as rocky coasts, islands, mangroves, and sandy beaches, surrounded by the Serra do Mar Mountain Range and Atlantic Rain Forest (Mahiques & Furtado, ). The bay is relatively shallow, reaching depths of no more than 20 m, and has high rainfall levels during the austral spring and summer months, when there is a major allochthonous input from local rivers and organic matter from the Serra do Mar (Mahiques & Furtado, ). Inside the bay, water circulates clockwise carrying saline water from the shelf of the western sector to the eastern sector, where salinity is lower.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Modelling habitat use by the Guiana dolphin, Sotalia guianensis, in south‐eastern Brazil: Effects of environmental and anthropogenic variables, and the adequacy of current management measures

Tardin

Maciel

Espécie

et al. 2020

Aquatic Conservation

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1. Species distribution modelling has been used to identify critical habitats for the delimitation of Marine Protected Areas. Although Marine Protected Areas may often overlap with the distribution of key marine species, illegal human activities often continue within these areas, causing negative impacts on the local biodiversity. 2. A generalized linear model with spatial eigenvector mapping was used to investigate, for the first time, the influence of environmental variables and anthropic activities on the number of Guiana dolphin, Sotalia guianensis sightings/grid, and to determine whether a Marine Reserve, in south-eastern Brazil, is adequate for the protection of the local population. Data were collected between May 2007 and October 2013 onboard a 7.5-m vessel with an inboard engine.3. The models for the different periods (annual, dry, and rainy seasons) all indicated that depth, the distance to seafood farms and fishing grounds, and mean sea surface temperatures influenced the distribution of the dolphins within the study area. The annual and seasonal models predicted that the dolphins prefer a continuous area between Cedro and Pico Islands, a large area that lies outside the limits of the Marine Reserve. 4. Although the habitat of Ilha Grande bay is still much less degraded than that inhabited by other nearby Guiana dolphin populations, the results of the present study indicate that anthropic activities in this area influence habitat use by the dolphins. Less than 30% of the area used by the dolphins is protected by the Tamoios Ecological Station (ESEC Tamoios). 5. Sotalia guianensis is classified as 'Vulnerable' in Brazil, although the marine reserve (ESEC Tamoios) does not protect the core area used by the local dolphin population. The results of the present study provide specific locations for the creation of a new multiple-use MPA, as suggested by the Brazilian National Action Plan for the Conservation of Small Cetaceans, or the inclusion of a special management programme for the area between Cedro and Pico islands to better protect the dolphins in the ESEC Tamoios buffer zone. The continuation of surveys to better

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Modelling habitat use by the Guiana dolphin, Sotalia guianensis, in south‐eastern Brazil: Effects of environmental and anthropogenic variables, and the adequacy of current management measures

Tardin

Maciel

Espécie

et al. 2020

Aquatic Conservation

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“…The study was carried out in Ilha Grande Bay (IGB), situated in the south of the state of Rio de Janeiro (23°06'S 44°00'W-23°18'S 44°30'W) covering the municipalities of Angra dos Reis, Paraty and a small portion of the municipality of Mangaratiba. It has a total area of 1,124 km2, being subdivided into three physiographic units, named: Western Portion (located between the mainland/Paraty and the west of Ilha Grande), Central Channel (located between Ilha Grande and the mainland/Angra dos Reis) and Eastern Portion (located east of Ilha Grande) (Mahiques andFurtado 1989, Lodi andHetzel 1998).…”

Section: Study Areamentioning

confidence: 99%

Voluntary scuba diving as a method for monitoring invasive exotic marine species

Mangelli¹,

Zapelini²,

Rocha³

et al. 2020

Ethnobio Conserv

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Monitoring surveys provide data needed to assess ecosystem conditions in places where bioinvasion occurs. The collection of data by volunteer researchers (citizen science) is an alternative for scientists and research agencies that lack information but do not have sufficient financial resources. The objective of the study was to evaluate the potential of volunteer divers with different diving experiences and the use (or not) of an invasive marine species identification guide at eight diving sites distributed between the north of Ilha Grande and the municipality of Angra dos Reis in the Central Channel of Ilha Grande Bay, Rio de Janeiro state. During the three months of study, 207 questionnaires were evaluated. The results showed that the group of volunteer divers with more experience identified a greater number of invasive exotic species compared to the group of divers with less experience. No statistical difference was found in the number of species identified between the groups of volunteer divers with and without a species identification chart. As a recommendation for the use of citizen science, it is necessary to use divers with greater diving experience. Developing stricter protocols for the identification of invasive exotic marine species is essential for the collection of quality data. The improvement of monitoring programs based on citizen science can provide useful information for research on biodiversity in marine environments, significantly reducing financial costs and time in the field, in addition to contributing to the ecological knowledge, awareness and environmental education of participants.

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“…IM is located in the Central Channel, and BP is located in the West Zone, two different areas of Ilha Grande Bay defined according to their physiographic and bathymetric features (MAHIQUES; FURTADO, 1989). IM has a perimeter of 1.43 km and a maximum depth of 25 m, and BP has a perimeter of 0.82 km and a maximum depth of 21 m; both islands are surrounded by granitic rocky shores.…”

Section: Study Areamentioning

confidence: 99%

The Structure of Subtidal Macroalgal Assemblages at the Tamoios Ecological Station, a Threatened Conservation Unit in Rio De Janeiro, Brazil

2015

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The structure of subtidal rocky bottom communities at Tamoios Ecological Station (TES), situated in Ilha Grande Bay, Rio de Janeiro State, as well as in other Brazilian marine protected areas, is insufficiently characterized. The present study describes the macroalgal assemblages of shallow subtidal rocky bottoms on two islands of the TES-Imboassica (IM) and Búzios Pequena (BP)adopting species and genera as observational units. Two sites were surveyed on each island in summer 2011. Random 30x30 cm quadrats (n=3) were scraped to collect all macroalgae except crustose species. The subtidal assemblages, in which 58 macroalgal species occurred, were characterized by the high frequency and percent cover of Sargassum vulgare C. Agardh (56.8±8.4%). The sites differed significantly in total number of species and Shannon-Weiner diversity index (PERMANOVA, p<0.05). According to SIMPER, the macroalgal genera that most contributed to the dissimilarities of cover between the sites (contribution >5%) were Sargassum, Laurencia, Wrangelia, Canistrocarpus, Asparagopsis, Hypnea, Ceratodictyon, Gayliella, Spyridia and Chondria.Dissimilarities within and between the islands, as shown by nMDS of the cover data, suggest that different spatial scales should be considered in monitoring the rocky bottom communities of Ilha Grande Bay.

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Utilização da análise dos componentes principais na caracterização dos sedimentos de superfície de fundo da Baía da Ilha Grande (RJ)

Cited by 9 publications

References 3 publications

Modelling habitat use by the Guiana dolphin, Sotalia guianensis, in south‐eastern Brazil: Effects of environmental and anthropogenic variables, and the adequacy of current management measures

Modelling habitat use by the Guiana dolphin, Sotalia guianensis, in south‐eastern Brazil: Effects of environmental and anthropogenic variables, and the adequacy of current management measures

Voluntary scuba diving as a method for monitoring invasive exotic marine species

The Structure of Subtidal Macroalgal Assemblages at the Tamoios Ecological Station, a Threatened Conservation Unit in Rio De Janeiro, Brazil

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