Lúcia S. Campos

Marine Biodiversity in the Atlantic and Pacific Coasts of South America: Knowledge and Gaps

The marine areas of South America (SA) include almost 30,000 km of coastline and encompass three different oceanic domains--the Caribbean, the Pacific, and the Atlantic--ranging in latitude from 12∘N to 55∘S. The 10 countries that border these coasts have different research capabilities and taxonomic traditions that affect taxonomic knowledge. This paper analyzes the status of knowledge of marine biodiversity in five subregions along the Atlantic and Pacific coasts of South America (SA): the Tropical East Pacific, the Humboldt Current,the Patagonian Shelf, the Brazilian Shelves, and the Tropical West Atlantic, and it provides a review of ecosystem threats and regional marine conservation strategies. South American marine biodiversity is least well known in the tropical subregions (with the exception of Costa Rica and Panama). Differences in total biodiversity were observed between the Atlantic and Pacific oceans at the same latitude. In the north of the continent, the Tropical East Pacific is richer in species than the Tropical West Atlantic, however, when standardized by coastal length, there is very little difference among them. In the south, the Humboldt Current system is much richer than the Patagonian Shelf. An analysis of endemism shows that 75% of the species are reported within only one of the SA regions, while about 22% of the species of SA are not reported elsewhere in the world. National and regional initiatives focusing on new exploration, especially to unknown areas and ecosystems, as well as collaboration among countries are fundamental to achieving the goal of completing inventories of species diversity and distribution.These inventories will allow accurate interpretation of the biogeography of its two oceanic coasts and latitudinal trends,and will also provide relevant information for science based policies.

Distribution of sewage input in marine sediments around a maritime Antarctic research station indicated by molecular geochemical indicators

Sediments from Admiralty Bay, Antarctica were collected during the austral summers of 2002/2003 and 2003/2004 in order to assess the distribution and concentration of sewage indicators originating from Comandante Ferraz Brazilian Antarctic Station. Fecal sterols (coprostanol+epicoprostanol) and linear alkylbenzenes (LABs) ranged from <0.01 to 0.95 microg g(-1) and <1.0 to 23 ng g(-1) dry weight, respectively. In general, the higher concentrations were found only locally in the vicinity of Ferraz station at Martel Inlet. Baseline values for fecal sterols and coprostanone were calculated as 0.19 and 0.40 microg g(-1), respectively. According to fecal sterols concentrations, sewage contribution to Martel Inlet has increased more than twice since 1997, as result of the increase in the number of researchers at the station especially during the last decade. A low correlation was found between total LABs and fecal steroids, which could be attributed to the contribution of the natural sources of steroids.

Latin America Echinoderm Biodiversity and Biogeography: Patterns and Affinities

We investigated the current patterns of diversity by country and by class of echinoderms, and analyzed their biogeographical, depth, and habitat or substratum affinities, using the database of the appendix of this book. Traditionally, the area has been divided into five biogeographical Regions and nine Provinces that cover a wide climate range. Currently, the echinoderm fauna of Latin America and Canary islands is constituted by 1,539 species, with 82 species of Crinoidea, 392 species of Asteroidea, 521 species of Ophiuroidea, 242 species of Echinoidea and 302 species of Holothuroidea. Species richness is highly variable among the different countries. The number of species for the countries is highly dependent on its coast length. The echinoderm fauna of the Panamic, Galapagos and the Chilean regions are biogeographically related. Other regions that are closely related are the Caribbean, West Indian, Lusitania and Brazilian. Cosmopolitan species are an important component in all the regions. Affinities between faunas are a consequence of the combination of climatic and trophic factors, connectivity as a function of distance, currents patterns and historical processes. Moreover, different environmental factors would be responsible for the faunal composition and species distribution at different spatial scales. The bathymetrical distribution of the echinoderm classes and the species richness varies according to the depth range and the ocean. Most species occurred at depths between 20 and 200 m. The Caribbean-Atlantic regions are richest in shallow depths, while the Pacific coast has higher values in deeper waters. The domination of each class in each substrate and habitat categories also varies differentially along each coast.

Echinoderm from Brazil: Historical Research and the Current State of Biodiversity Knowledge

This chapter aims to present historical development of echinoderm studies and current research in Brazil. Information about the important geographic and oceanographic features of the Brazilian coast is highlighted. Several aspects of taxonomy, distribution, reproduction, development, immunology, physiology and ecology of echinoderms found in both shallow and deep Brazilian waters are compiled and analyzed to show the current state of knowledge.

Environmental Processes, Biodiversity and Changes in Admiralty Bay, King George Island, Antarctica

The isolation of Antarctica from South America during the Oligocene (~35 mya) formed the Southern Ocean, generated the northward flow of the Atlantic Antarctic Bottom Water, and numerous unique geological and oceanic processes (e.g. an active spreading centre in the Bransfield Strait, ridge trench collision, gas hydrates on modern sediments, and complex circulation) along the northern end of the Antarctic Peninsula in particular (Barker and Burrell 1982; Pearse et al. 2001; Barker and Thomas 2004; Thomson 2004; Turner et al. 2009).

Anthropogenic impacts on sub-Antarctic and Antarctic islands and the adjacent marine environments

The impacts of human activities are more apparent at present in the sub-Antarctic than in the Antarctic. The sub-Antarctic islands, despite their physical isolation in the Southern Ocean, are generally more accessible, have less challenging climates, and a longer history of human presence than the more southern latitudes of the Peninsula and continent.

Macrostructure and evolution of the digestive system in Echinoida (Echinodermata)

The structure of the digestive system in Echinoida has long been puzzling since comparative studies have suggested that a derived structure, the siphon, has apparently evolved twice independently. New observations on the digestive system in five species of Cidaroida, four species of the Diadematoida and three species of Echinothurioida are presented. The results show that the four diadematoid species have a siphon and the three species of Echinothurioida have a siphonal groove, contrary to previous assertions. These observations make the macrostructure of the echinoid digestive system fully consistent with more recent phylogenetic hypotheses based on molecular and general morphological data, and support the idea that a siphon has evolved only once, in the stem lineage of the Acroechinoidea.

Environmental Assessment of Admiralty Bay, King George Island, Antarctica

Monitoring has been developed by Antarctic Programmes such as Antarctic New Zealand (www.antarcticanz.govt.nz) and the US Antarctic Programme (USAP) (http://www.usap.gov) considering expansion of human activities and inevitable environmental.

High Prevalence of Gammaproteobacteria in the Sediments of Admiralty Bay and North Bransfield Basin, Northwestern Antarctic Peninsula

Microorganisms dominate most Antarctic marine ecosystems, in terms of biomass and taxonomic diversity, and play crucial role in ecosystem functioning due to their high metabolic plasticity. Admiralty Bay is the largest bay on King George Island (South Shetland Islands, Antarctic Peninsula) and a combination of hydro-oceanographic characteristics (bathymetry, sea ice and glacier melting, seasonal entrance of water masses, turbidity, vertical fluxes) create conditions favoring organic carbon deposition on the seafloor and microbial activities. We sampled surface sediments from 15 sites across Admiralty Bay (100–502 m total depth) and the adjacent North Bransfield Basin (693–1147 m), and used the amplicon 454-sequencing of 16S rRNA gene tags to compare the bacterial composition, diversity, and microbial community structure across environmental parameters (sediment grain size, pigments and organic nutrients) between the two areas. Marine sediments had a high abundance of heterotrophic Gammaproteobacteria (92.4% and 83.8% inside and outside the bay, respectively), followed by Alphaproteobacteria (2.5 and 5.5%), Firmicutes (1.5 and 1.6%), Bacteroidetes (1.1 and 1.7%), Deltaproteobacteria (0.8 and 2.5%) and Actinobacteria (0.7 and 1.3%). Differences in alpha-diversity and bacterial community structure were found between the two areas, reflecting the physical and chemical differences in the sediments, and the organic matter input.

Shifts in microphytoplankton species and cell size at Admiralty Bay, Antarctica

Abstract Phytoplankton (>15 µm) was investigated in three shallow coastal areas at Admiralty Bay (AB) between the summers of 2002–03 and 2008–09. Phytoplankton abundance was low (103 cells l-1) and, over time, the prevailing cell size decreased due to a shift in phytoplankton dominant species from diatoms to dinoflagellates. In situ and remote sensing data showed that oscillations in sea surface temperature, precipitation, ice formation/melting, irradiance (cloud cover) and bottom circulation (indexed by the Antarctic Oscillation Index; AAO) were shown to govern the structure of the phytoplankton. Under negative AAO, diatoms prevailed, with the dominance of large (>80 µm) benthic diatoms (e.g. Corethron pennatum and Navicula directa) in periods of low production (102 cells l-1 in 2002–03), and medium-sized (31–80 µm) centrics (e.g. Thalassiosira spp. and Stellarima microtrias) when the abundance was higher (104 cells l-1 in 2003–04). Conversely, positive AAO led to the co-dominance of dinoflagellates and planktonic diatoms (e.g. Pseudo-nitzschia spp.) in the summers of 2007–08 and 2008–09. These results suggest that the AAO can be a good predictor of phytoplankton in coastal areas around the western Antarctic Peninsula, and may help our understanding of changes in other trophic levels of the food web.