ABSTRACT. Using a ternary gradlent s}istem, over 50 carotenoids, chlorophylls and their denvatives were separated from marine phytoplankton. Only 2 palrs of carotenoid pigments (19'-butanoyloxyfucoxanthin and siphonaxanthin, and 19'-hexanoyloxyfucoxanthin and 9'-cis-neoxanthln) and 3 chlorophylls (chlorophylls c , , c2 and Mg 2.4 divinyl pheoporphyrin a5 monomethyl ester [Mg2,4D]) were not resolved. Pigment chromatograms are presented for 12 uniaigal cultures from 10 algal classes important in the marine environment: Alnphidinlum cal-terae Hulbert (Dinophyceae), Chroomonas salina (Wislouch) Butcher (Cryptophyceae), Dunallella tertrolecta Butcher (Chlorophyceae); Emil~anla huxleyi (Lohmann) Hay et Mohler and Pavlova lutheri (Droop) Green (Prymnesiophyceae); Euglena gracllis Klebs (Euglenophyceae); Micl-omonas pusllla (Butcher) Manton et Parke and Pycnococcus provasohi Guillard (Praslnophyceae); Pelagococcus subv~ridis Norris (Chrysophyceae); Phaeodactylum tncornutum Bohlln (Baclllanophyceae); Porphyndlum cruentum (Bory) Drew et Ross (Rhodophyceae), and Synechococcus sp (Cyanophyceae). A chromatogram IS also given of a complex mixture of over 50 algal pigments such as might be found in a phytoplankton field sample This method is useful for analysis of phytoplankton plgments in seawater samples and other Instances where separations of complex pigment mixtures are required

Many parasitic Apicomplexa, such as Plasmodium falciparum, contain an unpigmented chloroplast remnant termed the apicoplast, which is a target for malaria treatment. However, no close relative of apicomplexans with a functional photosynthetic plastid has yet been described. Here we describe a newly cultured organism that has ultrastructural features typical for alveolates, is phylogenetically related to apicomplexans, and contains a photosynthetic plastid. The plastid is surrounded by four membranes, is pigmented by chlorophyll a, and uses the codon UGA to encode tryptophan in the psbA gene. This genetic feature has been found only in coccidian apicoplasts and various mitochondria. The UGA-Trp codon and phylogenies of plastid and nuclear ribosomal RNA genes indicate that the organism is the closest known photosynthetic relative to apicomplexan parasites and that its plastid shares an origin with the apicoplasts. The discovery of this organism provides a powerful model with which to study the evolution of parasitism in Apicomplexa.

Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed.

[1] Remote sensing of Southern Ocean chlorophyll concentrations is the most effective way to detect large-scale changes in phytoplankton biomass driven by seasonality and climate change. However, the current algorithms for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS, algorithm OC4v6), the Moderate Resolution Imaging Spectroradiometer (MODIS-Aqua, algorithm OC3M), and GlobColour significantly underestimate chlorophyll concentrations at high latitudes. Here, we use a long-term data set from the Southern Ocean (20 -160 E) to develop more accurate algorithms for all three of these products in southern high-latitude regions. These new algorithms improve in situ versus satellite chlorophyll coefficients of determination (r 2 ) from 0.27 to 0.46, 0.26 to 0.51, and 0.25 to 0.27, for OC4v6, OC3M, and GlobColour, respectively, while addressing the underestimation problem. This study also revealed that pigment composition, which reflects species composition and physiology, is key to understanding the reasons for satellite chlorophyll underestimation in this region. These significantly improved algorithms will permit more accurate estimates of standing stocks and more sensitive detection of spatial and temporal changes in those stocks, with consequences for derived products such as primary production and carbon cycling.

Sea ice and oceanic boundaries have a dominant effect in structuring Antarctic marine ecosystems. Satellite imagery and historical data have identified the southern boundary of the Antarctic Circumpolar Current as a site of enhanced biological productivity. Meso-scale surveys off the Antarctic peninsula have related the abundances of Antarctic krill (Euphausia superba) and salps (Salpa thompsoni) to inter-annual variations in sea-ice extent. Here we have examined the ecosystem structure and oceanography spanning 3,500 km of the east Antarctic coastline, linking the scales of local surveys and global observations. Between 80 degrees and 150 degrees E there is a threefold variation in the extent of annual sea-ice cover, enabling us to examine the regional effects of sea ice and ocean circulation on biological productivity. Phytoplankton, primary productivity, Antarctic krill, whales and seabirds were concentrated where winter sea-ice extent is maximal, whereas salps were located where the sea-ice extent is minimal. We found enhanced biological activity south of the southern boundary of the Antarctic Circumpolar Current rather than in association with it. We propose that along this coastline ocean circulation determines both the sea-ice conditions and the level of biological productivity at all trophic levels.

We conducted a scanning electron microscopic survey of morphological variations in the calcareous nanoplankton species Emiliania huxleyi in Southern Ocean surface water samples collected along a transect from 43 to 64°S and 141 to 145°E during

The pigment compositions of 37 species (65 strains) of cultured haptophytes were analysed using improved HPLC methods. We distinguished 8 pigment types based on the distribution of 9 chlorophyll c (chl c) pigments and 5 fucoxanthin derivatives. All types contained chl c 2 and Mg-2, 4-divinyl phaeoporphyrin a 5 monomethyl ester (MgDVP), fucoxanthin, diadinoxanthin and β,β-carotene. Pigment types were based on the following additional pigments: Type 1: chl c 1 ; Type 2: chl c 1 and chl c 2 -Pavlova gyrans-type; Type 3: chl c 1 and chl c 2 -monogalactosyl diacylglyceride ester (chl Type 5: Ochrosphaera spp.; Type 6: Nöelaerhabdaceae, notably Emiliania spp.; Type 7: Chrysochromulina spp.; Type 8: Phaeocystaceae, Prymnesiaceae and Isochrysidaceae. These pigment types showed a strong correlation with available phylogenetic trees, supporting a genetic basis for the pigment associations. The additional marker pigments offer oceanographers greater power for detecting haptophytes in mixed populations, while also distinguishing a greater proportion of them from diatoms. KEY WORDS: Haptophyta · HPLC · Chlorophylls c · Fucoxanthins · Pigment types · Phylogeny · Oceanography Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 270: [83][84][85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102] 2004 1995, Heimdal 1997), it is so time-consuming that oceanographers routinely use photosynthetic pigment profiles as chemotaxonomic markers of phytoplankton groups . In order to interpret pigment data from field samples, however, a thorough knowledge of the pigment composition of each of the likely species groups of the phytoplankton populations is necessary. Unfortunately very few wide-ranging pigment surveys of algal classes have been published, exceptions being for diatoms (Stauber & Jeffrey 1988) and haptophytes (Jeffrey & Wright 1994). Dominant species in field samples should always be assessed microscopically in representative samples (Andersen et al. 1996, Wright & van den Enden 2000.Knowledge of pigment characteristics of any group is always limited by the resolution of current separation methods. The haptophyte pigment study of Jeffrey & Wright (1994), which used the SCOR-UNESCO HPLC method of Wright et al. (1991), distinguished most of the marker carotenoids, but failed to resolve monovinyl and divinyl analogues of chlorophyll c (e.g. chlorophylls c 1 and c 2 ) and additional fucoxanthin derivatives such as 4-keto-19'-hexanoyloxyfucoxanthin (Egeland et al. 2000). Nevertheless 4 useful pigment subgroups of the class were determined. New advances in HPLC pigment technology in the past decade (Jeffrey et al. 1999 [review], Zapata et al. 2000) have allowed a new examination of the pigment composition of this important group of microalgae in the present work.The recent methods of Garrido & Zapata (1997) and Zapata et al. (2000), in which polymeric C 18 or monomeric C 8 columns were used with pyridine as solvent modifier, have allowed separation of 11 ch...

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