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Aim Sediment disturbances are important threats affecting marine biodiversity, but the variety of biological responses have not yet been synthesized. Here, we collate all available information to compare the extent of impacts across different taxonomic groups, habitat types, and pathways of impact (light attenuation, suspended sediment, and sedimentation). Location Global Time period Data collected from 1979 to 2017 Major taxa studied Coral, fish, seagrass, sponge, macroalgae, ascidian, bryozoan, crustacean, echinoderm, mollusc, polychaeta Methods We used meta-analyses to evaluate the effects of sediments across 842 observations found in 110 publications. We also evaluated some of the biological and methodological factors that could explain the variable effects observed in different studies. Results We found a significant negative effect of sediments on behavioural responses of species, reproduction and recruitment processes, organism’s morphology, physiology, community abundance and diversity, and species interactions. In contrast, the overall effect on abundance of individual species was statistically non-significant and there was a strong positive effect on abundance for sponge and polychaete species. Many individual studies described physiological effects on coral reefs, but effects on diversity of soft-bottom and coral reef communities were particularly detrimental. Phototrophic species were generally more negatively impacted by sediments than heterotrophs, driven by strong physiological responses in crustose coralline algae and seagrass. Additionally, species with limited mobility were more vulnerable to sediment disturbances than highly mobile species. Sedimentation alone triggered more consistently negative effects on most biological responses than light depletion and suspended sediments. We found evidence for increased impacts on community diversity when more than one pathway of impact was present, indicating that these disturbances can disrupt whole ecosystems. Main conclusions Our meta-analysis for the first time provided strong quantitative support of negative effects of sediments on marine biodiversity. Taxonomic groups, habitat types, and life history characteristics were most influential in determining biological responses to sediment disturbances, highlighting the importance of an ecosystem-based approach when fully accounting for the impacts of sediments.

Analysis that link hydrological processes with oceanographic dispersion offer a promising approach for assessing impacts of land-based activities on marine ecosystems. However, such an analysis has not yet been customised to quantify specific pressures from mining activities on marine biodiversity including those from spillages resulting from tailing dam failure. Here, using a Brazilian catchment in which a tailing dam collapsed (Doce river) as a case study, we provide a modelling approach to assess the impacts on key ecosystems and marine protected areas subjected to two exposure regimes: (i) a pulse disturbance event for the period 2015-2016, following the immediate release of sediments after dam burst, which witnessed an average increase of 88% in sediment exports; and (ii) a press disturbance phase for the period 2017-2029, when impacts are sustained over time by sediments along the river’s course. We integrated four components into impact assessments: hydrological modelling, coastal-circulation modelling, ecosystem mapping, and biological sensitivities. The results showed that pulse disturbance causes sharp increases in the amount of sediments entering the coastal area, exposing key sensitive ecosystems to pollution (e.g. rhodolith beds), highlighting an urgent need for developing restoration strategies for these areas. The intensity of impacts will diminish over time but the total area of sensitive ecosystems at risk are predicted to be enlarged. We determined monitoring and restoration priorities by evaluating and comparing the extent to which sensitive ecosystems within marine protected areas were exposed to disturbances. The information obtained in this study will allow the optimization of recovery efforts in the marine area affected, and valuation of ecosystem services lost.

Several countries, including Brazil, are making compelling case for historical progress towards achieving the targets for marine protection under the Convention on Biological Diversity. However, this can be done through the establishment of large marine protected areas (MPAs) in the open ocean, a conservation strategy that might be only tangential to the core ecological goal of MPA designation, i.e. biodiversity conservation. By using two newly-designated large MPAs in Brazil as an example, we outline three ways in which they indicate poor adherence to best practices in MPA planning: placing no-take MPAs in areas with limited potential for extractive uses, neglecting the need to account for spatial dependencies among areas to maintain populations over time, and the inadequacy of the MPAs to regulate fishing of mobile pelagic species.

Made available in DSpace on 2016-07-07T12:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2010. Added 1 bitstream(s) on 2016-07-07T12:43:07Z : No. of bitstreams: 1 ISSN0104-6497-2010-18-02-129-135.pdf: 7174503 bytes, checksum: a3ef5ad79d0aac2de439037ecfcc5fdc (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Crustacean species from Brazil were evaluated to define their conservation status under the Categories and Criteria of the IUCN Red List of Threatened Species at the regional level. This study represents an effort of the Chico Mendes Institute for Biodiversity Conservation (ICMBio), the Brazilian agency for conservation of biodiversity, and the Brazilian Crustacean Society (SBC) to systematically collate specific data for these species and to determine their risks of extinction. The IUCN Red List Categories and Criteria were applied to 130 candidate species, following IUCN Red List Guidelines. Assessments to determine the risk of extinction were conducted during a three-day workshop held in Brasília in September 2010, which brought together about 30 experts to share information about species and threats. A total of 14 species (11.6%), 12 of them endemic to Brazil, qualified for one of the three Red List categories of threat (CR, EN, or VU). Twenty-five species (20.8%) were listed as Data Deficient, and because of this lack of data the extinction risk for crustaceans may be under-estimated. IUCN Criterion B was most often used during the assessments (85%), and the main threats identified are associated with removal of riparian forest causing siltation, and discharge of domestic, urban, industrial, and agricultural effluents, degrading water quality, as well as uncontrolled fishery activities. The South Atlantic hydrological basin contains the largest number of threatened species, which indicates that increased attention from agencies, institutions, and researchers is needed to develop appropriate strategies and regulations to aid in their conservation. Universidade Estadual Paulista, Departamento de Ciências Biológicas, Instituto de Biociências de São Vicente