A Simple and Low-Cost Method for Analyzing Microphytobenthos from Marine Sediments

Kappaphycus alvarezii which is endemic to the Indo-Pacific region is the main raw material for kappa carrageenan production. A seedling that was cultivated in Japan (originally from the Philippines) was introduced in a trial, for aquaculture purpose, in 1995, in Sao Paulo State, southeastern region of Brazil. It was later introduced in Santa Catarina State, in Southern Brazil. In 1998, another seedling that was brought from Venezuela, also originally from the Philippines, was commercially introduced at Ilha Grande Bay and later on at Sepetiba Bay, both in Rio de Janeiro State. The aim of this study was to characterize 21 samples from different farms (Rio de Janeiro and Santa Catarina States) and verify if they are K. alvarezii or other species. Based on the intergenic spacer cox2-3 sequences, phylogenetic relationships were inferred through neighbor joining, maximum likelihood, and Bayesian analyses. The topology of the trees suggests that all samples from the different farms form a monophyletic group of K. alvarezii. Statistical analysis of the cox2-3 marker calculated with median-joining network showed 38 variable positions defining 15 haplotypes for the studied samples of Kappaphycus. The most frequent K. alvarezii haplotype grouped the samples cultivated worldwide with the Brazilian samples. These results are important for better productivity and are environmentally desirable for introduction purposes since the species introduced is known and will help focusing the research on this species. This knowledge can be of assistance to the government in setting up environmental and cultivation protocols to achieve sustainability in macroalgae aquaculture.

The reef-building vermetid Petaloconchus varians occurs in the western Atlantic Ocean, from the Caribbean Sea to the southern coast of Brazil. The present study evaluated the abundance of P. varians on intertidal rocky shores in Ilha Grande Bay (Rio de Janeiro State), and characterized their reefs, describing the species density, besides the weight and the belt width of the reefs. Petaloconchus varians reefs were recorded at 25 sites, with rocky shores exposed to different wave action (very sheltered, sheltered, semi-exposed and exposed) and slopes (10° to 46°). Clusters of individuals constructed large reefs along the middle intertidal zone, creating a wide belt (38 cm to 2 m). The density of P. varians and the weight of the reefs ranged from 620 to 2,559 ind.100 cm-2 and from 100 to 1,500 g.100 cm-2, respectively. Considering that the species was last reported from the area in the mid-20th century, the present study suggests that P. varians reefs are becoming dominant in the intertidal zone of rocky shores in Ilha Grande Bay. This is a contribution to knowledge of this ecosystem in Ilha Grande Bay, in view of local or global ecological changes.

The reef-building vermetid Petaloconchus varians is a dominant species on the intertidal zone of rocky shores at Ilha Grande Bay (Rio de Janeiro State, Brazil). On August 2010, subtidal vermetid reefs were collected in the nuclear power plant discharge area at Ilha Grande Bay. The characteristics of the subtidal reefs were investigated, being described their formation, density and range extension. These are monospecific reefs formed by dense clusters of P. varians, developing mainly by peripheral growth on the rims of most of the bottom rocks resembling “microatolls”. The reefs were recorded spreading over about 1,000 m2, restricted to the nuclear power plant discharge area, under continuous influence of waterflow currents (30 cm.s−1), high temperature (>36 °C) and chlorine inputs. It is a unique subtidal P. varians reef formation in the nuclear power plant discharge area at Ilha Grande Bay, with unprecedented records in the Brazilian coast.

In the present study, we describe a new species belonging to the genus Chalinula from Ilha Grande Bay, Rio de Janeiro state, off Southeast Brazil. Chalinula tamoiensis sp. nov. is thinly to thickly encrusting, purple or pink coloured in life, with oscules raised in volcano shaped projections or more commonly flush with the surface, in thinly encrusting specimens. Skeleton typically anisotropic, with variable amounts of spongin and oxeas ranging from 59 to 90 m long. Maximum likelihood analyses of large ribosomal subunit DNA (28S rRNA) recovered Chalinula polyphyletic. Chalinula tamoiensis sp. nov. clustered with a subset of species from other ocean basins and was distantly related to Chalinula molitba, from the Tropical Western Atlantic and Chalinula nematifera, from the Central Western Pacific, with which it shares a series of traits. A summary of morphological characters of all species belonging to the genus and new sequences of the larger ribosomal subunit DNA are also provided.

The Ilha Grande Bay is considered an area of extreme biological importance for the conservation of Brazilian biodiversity. While monitoring the macroinvertebrate ascidian-dwellers around Ilha Grande Bay, an undescribed commensal species of the amphipod family Leucothoidae was discovered. In this paper, we describe the new species of Leucothoe, associated with the ascidiacean Phallusia nigra. http://www.zoobank.org/urn:lsid:zoobank.org:pub:5F1F321C-D4B7-4C2D-A91B-AFB18E54C5E0

In general, mercury (Hg) undergoes biomagnification in aquatic systems. The absence of Hg biomagnification in a certain aquatic environment constitutes an exceptional finding and this seems to be the case for Sepetiba Bay, in Rio de Janeiro state (RJ), Brazil. There are three distinct ecological populations of Guiana dolphins in the Sepetiba Bay (SB)-Ilha Grande Bay (IGB) Complex, inhabiting: (1) the inner part of SB; (2) SB entrance; and (3) IGB. In addition, there are two other delphinid species, rough-toothed dolphin and Atlantic spotted dolphin, that feed on the SB-IGB Complex. Considering the widely employed use of cetaceans as sentinels of environmental contamination by bioaccumulative toxicants, we have biopsy sampled individuals of the abovementioned ecological populations/species for measuring skin Hg concentrations. Two Bryde's whales and one humpback whale were biopsied in the SB-IGB Complex as well. Skin Hg concentrations [μgg-1 dry weight (dw)] of Guiana dolphins were the highest in IGB, followed by SB entrance and the inner part of SB (0.99-5.47; 0.09-6.00; 0.08-2.22). Considering all species investigated in the present study, skin Hg concentrations were found in the following order: humpback whale < Bryde's whale < Guiana dolphins from SB inner part < Guiana dolphins from SB entrance < Guiana dolphins IGB = Atlantic spotted dolphins < rough-toothed dolphins. The skin Hg concentrations found in Guiana dolphins from the inner part of Sepetiba Bay (0.08-2.22) and rough-toothed dolphins from the SB-IGB Complex (1.26-20.0) are among the lowest and highest ever reported for dolphins worldwide, respectively.

Two new records of sponges are registered from Ilha Grande Bay (Rio de Janeiro, Brazil), which is an important area in Angra dos Reis for its tourist, economic and environmental contributions. Two species are redescribed in order to elucidate their morphological variations in relation to the known Caribbean specimens: Iotrochota arenosa, a new record to Brazil; and Echinodictyum dendroides, which have now been recorded on the south-east coast of Brazil for the first time. Furthermore, the genus Echinodictyum is redefined.

The Potential Ecological Risk Index (PERI) was proposed by Håkan-son in 1980 to be used as a diagnostic tool for water pollution. The aim of this study was to apply the PERI for tropical conditions, proposing modifications. The metal contamination of 15 areas, including five bays, from the coastal systems of the Rio de Janeiro State, Brazil, which pre-sent different pollution degrees and trophic status, was assessed. For environment sensitivity assessment through bioproduction estimation, the ratio of total phosphorus (in mg/g)/organic matter in sediment (in %) ×100 was used, instead of the correlation between total nitrogen and organic matter as used in the original index calculation. The results for environment sensitivity were correlated with the concentration of acid volatile sulfides in sediments and with chlorophyll-a of the water column, showing a compatible relationship between water trophic status and se-diment anoxia. The highest degree of contamination (DC) was found for the N-NW sector of the Guanabara bay (60.21 – classified as very high), followed by the Sepetiba bay stations, which showed DC values classified as moderate. The Ilha Grande bay and Paraty (Mamanguá) showed low DC values. The station of the Guanabara bay was the only one classified by the index as of very high ecological risk (PERI=697), followed by three stations classified as of moderate risk (Mouth of Guanabara bay; Garsas, Sepetiba bay; and Angra, Ribeira bay). All the other stations present low risk associated with metal exposure. As mercury is the metal of highest toxicity factor in the Håkanson formulation, a control test was applied to observe the relationship between PERI and mercury concentrations in fish and its bioconcentration factors, which are related to mercury bioavailability in the system. The results of the modified PERI were fully satisfactory for ranking areas of contamination.

Pyrethroid insecticides along the Southwestern Atlantic coast: Guiana dolphin (Sotalia guianensis) as a bioindicator

The present study evaluates mercury (Hg) toxicokinetics in Perna perna (L.) mussels from tropical bays through transplantation experiments. The mussels were transplanted from Guanabara Bay (GB) to Ilha Grande Bay (IGB). The experiments were carried out in December 2008 (experiment 1) and June 2009 (experiment 2). Both experiments lasted one month. In the experiment 2, the transplanted animals (77±8 µg.kg -1 ) showed a significant increase in Hg concentrations and exhibited significantly higher Hg concentrations than the animals that remained in GB (41±4 µg.kg -1 ). Despite this increase in mercury levels, the transplanted animals have not achieved the Hg concentrations of IGB resident animals (100±11 µg.kg -1 ). These results suggest that individuals of this species rapidly incorporated Hg in tropical estuaries. DOI: http://dx.doi.org/10.17807/orbital.v10i4.1069

Understanding trophic transference role in mercury biomagnification and bioaccumulation in the Atlantic spotted dolphin (Stenella frontalis)

Bivalve mollusks may be affected by numerous infectious diseases, which cause high mortality rates and economic burdens for producers. Another challenge for bivalve aquaculture is the protection of farms from human contamination, such as sewage and stormwater discharges. Ilha Grande Bay (IGB), located in Rio de Janeiro state, is the largest Brazilian producer of scallops (Nodipecten nodosus). This region has recently suffered a mass mortality of mollusks, and several environmental contaminants have been reported in the area. To contribute to the elucidation of scallop collapse and better characterize the human impacts, this study assessed the circulation of mollusk (Ostreid herpesvirus-1 [OsHV-1]) and human (mastadenovirus [HAdV] and norovirus GII) viral pathogens in waters and animals produced at IGB. Neither water nor animals were positive for OsHV-1. However, of the 7 points analyzed, 5 points showed contamination by HAdV or norovirus. HAdV and norovirus were detected in 5.5 and 6.9% of the analyzed water samples, respectively, in concentrations ranging from 2.39 × 103 to 1 × 105 genome copies/L. One scallop sample was positive for norovirus (4.5%). These results demonstrate human contamination in the region, presenting a risk of consumer contamination, and a non-association between OsHV-1 and the mass mortality described in scallops.

The spread of invasive species in marine ecosystems is a growing global concern, particularly in regions with high economic and ecological importance. Sun corals (Tubastraea spp.) are native scleractinians from the Pacific Ocean that have spread along most of the Brazilian coast. This invasive species initially established populations in Rio de Janeiro state, SE Brazil, reaching high levels of abundance. Although the ecological aspects and impacts caused by this organism have been studied in detail, the natural mechanisms that drive its dispersal have attracted little attention. In this research, we focus on the coastal dispersion of sun coral larvae between Cabo de São Tomé and Ilha Grande Bay, and the offshore transport of sun coral larvae, investigating how submesoscale oceanographic features such as filaments, fronts and eddies influence connectivity among different sites. A high-resolution numerical model was used to simulate the coastal dynamics, incorporating the influence of the Brazil Current, wind-driven circulation, and submesoscale structures. Larval dispersal was examined under different wind scenarios, including northeasterly winds that drive southward currents and enhance offshore transport via submesoscale filaments. Results show that submesoscale features, particularly filaments emerged from upwelling regions, play a significant role on sun coral larvae dispersion. These features act as pathways that connect larvae from coastal to offshore oil exploration areas, highlighting the importance of both natural and anthropogenic processes for the dispersal of this invasive species. This research provides critical insights into the mechanisms governing the spread of invasive marine species, emphasizing the need for integrated coastal management strategies. Understanding how physical processes drive larval transport is essential for developing targeted control measures to mitigate the impact of invasive species like sun coral on native ecosystems and local economies. Furthermore, the study underscores the importance of monitoring both natural and anthropogenic influences on marine bioinvasions, particularly in regions with significant offshore industrial activities.

Este trabalho trata das capturas da cavalinha, Scomber japonicus Houttuyn, no Estado do Rio de Janeiro (Brasil), realizadas por traineiras, durante as pescarias da sardinha-verdadeira, Sardinella brasiliensis (Steindachner, 1879), nos anos de 1993-1997, espécies que são encontradas nos mesmos cardumes. As pescarias da cavalinha têm mais importância nos meses de março a agosto, com maiores capturas no outono (cerca de 50% da produção anual). A produtividade das pescarias da cavalinha decresce ao longo do ano, com o máximo de 0,8 t/lance no verão. Em geral, a produção da cavalinha não ultrapassa os 10% daquela que corresponde à sardinha-verdadeira. Os principais pesqueiros da cavalinha estão situados na baía da Ilha Grande e adjacências, que contribuem com 84% da produção anual da espécie no Estado. Em tais pesqueiros, mais de 90% das capturas da cavalinha se realizam entre o verão e o inverno, quando também são mais elevados os índices de produtividade. A cavalinha é capturada desde superfície até 60 m de profundidade, concentrando-se entre 11 – 40 m, com maior frequência na faixa de 21 – 30 m de profundidade.

The high diversity of species in the marine environment gives rise to compounds with unique structural patterns not found as natural products in other systems and with great potential for pharmacological, cosmetic and nutritional use. The genus Tubastraea (Class Anthozoa, Order Scleractinia, Family Dendrophylliidae) is characterized as a hard coral without the presence of zooxanthellae. In species of this genus alkaloids derived from the compound aplysinopsin with pharmacological activity are known. In Brazil T. coccinea and T. tagusensis are characterized as non-indigenous and invasive and are currently found along the Brazilian coast, from Santa Catarina to Bahia states. This study aims to analyze the mutagenic, cytotoxic and genotoxic potential of methanolic and ethanolic extracts from T. coccinea and T. tagusensis collected in Ilha Grande Bay, Rio de Janeiro state, Brazil. Bacterial reverse mutation assay on the standard strains TA97, TA98, TA100, TA102 and TA104, in vitro micronucleus formation test and colorimetric assays for cytotoxic signals on the cell lines HepG2 and RAW264.7 were used. We also synthesized an oxoaplysinopsin derivate alkaloid (APL01) for comparative purposes. No mutagenic (250; 312.5; 375; 437.5 and 500μg/plate) or genotoxic (0.05; 0.5; 5.0; 50 and 500μg/mL) effects were observed in any sample tested for all measured concentrations. Cytotoxic responses were observed for eukaryotic cells in all tested samples at 500 and 5000μg/mL concentrations. Cytotoxicity found in the WST-1 assay was independent of the metabolism of substances present in samples compositions. The cytotoxicity observed in the LDH release assay depended on metabolism.