Contrary to expectations based on the spectrochemical series, H 2 O is found to be a significantly weaker field ligand than OH -in the magnetochemical series ranking of ligand field strengths based on the spin states of iron(III) tetraphenylporphyrin complexes. The preparation and characterization of the [Fe(H 2 O)-(TPP)] + ion and the spectroscopic identification of Fe(OH)(TPP) have made this assessment possible. These two species were previously thought to be unattainable because of the facile formation of the well-known µ-oxo dimer, (TPP)Fe-O-Fe(TPP). However, the special characteristics of single equivalents of water under high acidity, relevant to metalloenzyme active sites and superacidity, make them accessible in benzene solution. Their 1 H NMR -pyrrole chemical shifts at -43 and +82 ppm indicate admixed-intermediate S ) 3 / 2 , 5 / 2 and high S ) 5 / 2 spin states for the aqua and hydroxo species, respectively. The X-ray crystal structure of the aqua complex has been determined for [Fe(H 2 O)(TPP)][CB 11 H 6 Cl 6 ] and is consistent with the high degree of S ) 3 / 2 character indicated by the NMR measurement, Mössbauer spectroscopy (∆E q ) 3.24 mm‚s -1 ), and magnetic susceptibility (µ eff ) 4.1 µ B ). The anhydrous precursor to these species is the "nearly bare" iron(III) porphyrin complex Fe(CB 11 H 6 Br 6 )(TPP). Judged by its magnetic parameters (δ pyrrole ) -62 ppm, ∆E q ) 3.68 mm‚s -1 , µ eff ) 4.0 µ B ) it attains the long sought essentially "pure" S ) 3 / 2 spin state. The magnetochemical ranking of ligand field strengths in five-coordinate high-spin and admixed-intermediate-spin iron(III) porphyrins is useful because it more closely reflects the intuitive field strengths of crystal field theory than does the usual spectrochemical ranking, which is controlled largely by π effects in octahedral low-spin d π 6 complexes.

In recent years, the use of intrinsic markers such as stable isotopes to link breeding and foraging grounds of migratory species has increased. Nevertheless, several assumptions still must be tested to interpret isotopic patterns found in the marine realm. We used a combination of satellite telemetry and stable isotope analysis to (i) identify key foraging grounds used by female loggerheads nesting in Florida and (ii) examine the relationship between stable isotope ratios and post-nesting migration destinations. We collected tissue samples for stable isotope analysis from 14 females equipped with satellite tags and an additional 57 untracked nesting females. Telemetry identified three post-nesting migratory pathways and associated non-breeding foraging grounds: (1) a seasonal continental shelf–constrained migratory pattern along the northeast U.S. coastline, (2) a non-breeding residency in southern foraging areas and (3) a residency in the waters adjacent to the breeding area. Isotopic variability in both δ13C and δ15N among individuals allowed identification of three distinct foraging aggregations. We used discriminant function analysis to examine how well δ13C and δ15N predict female post-nesting migration destination. The discriminant analysis classified correctly the foraging ground used for all but one individual and was used to predict putative feeding areas of untracked turtles. We provide the first documentation that the continental shelf of the Mid- and South Atlantic Bights are prime foraging areas for a large number (61%) of adult female loggerheads from the largest loggerhead nesting population in the western hemisphere and the second largest in the world. Our findings offer insights for future management efforts and suggest that this technique can be used to infer foraging strategies and residence areas in lieu of more expensive satellite telemetry, enabling sample sizes that are more representative at the population level.

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea, occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters.

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Migration of hawksbill turtlesEretmochelys imbricata from Tortuguero, Costa Rica. Á/ Ecography 28: 394 Á/402.The hawksbill turtle Eretmochelys imbricata is a widely distributed and critically endangered species that feeds on sponges and fills an important ecological role in the coral reef ecosystem. At Tortuguero, Costa Rica, trend analyses indicate considerable decline in nesting estimated at 77.2 Á/94.5% between 1956 and 2003, as a result of excessive turtle fishing. We analyzed flipper tag returns, satellite telemetry and genetic samples to determine movements and habitat use of adult female Tortuguero hawksbills. Tag returns and satellite telemetry show hawksbills migrate to foraging grounds in Nicaragua and Honduras. Genetic analysis indicates the hawksbills may also migrate to Cuban, Puerto Rican, and possibly Mexican waters. We conclude hawksbills represent an internationally shared resource. There is a close correlation between tag recapture sites, hawksbill foraging grounds and coral reef distribution. Caribbean coral reef decline may reduce food availability and negatively impact hawksbill turtles. Conversely, hawksbill decline may shift the balance on coral reefs by reducing predation pressure on sponges and hence make coral reefs less resilient to natural and anthropogenic threats. Strategies aiming to conserve hawksbills and coral reefs must consider both the extensive hawksbill migrations and the close relationship between the species and the coral reef ecosystem.S. Troëng (sebastian@cccturtle.org),

duction indicating destruction of the indacene structure. At an even higher negative potential reversible reduction of the phenylanthracene substructure can be observed. Apparently the substructures are electrochemically independent, too.Cyclic voltammetry of 4 a indicated that the oxidation of the dimethylamino group appears between the oxidation and the reduction of the indacene framework. This suggests that the lone electron pair at the amino group is energetically located between the HOMO and the LUMO of the indacene chromophore. The oxidation potential of the protonated dimethylamino group is considerably higher than that of the free base and beyond the accessible potentials in acetonitrile, which is reflected in the CV upon protonation by the disappearance of this peak. This increase of the oxidation potential makes a nonradiative deactivation process like the one described above impossible. The oxidation of the indacene chromophore in the protonated form occurs at the same potential as in the neutral form, where it appears as the second oxidation step. Apparently the indacene chromophore is influenced inductively by a positive charge on the dimethylamino group in the same way no matter how the charge is created, by protonation or oxidation.We have showed that by specific functionalization the electron donor and acceptor properties of the difluoroboradiaza-sindacene chromophore can be directed in a way that leads to electrogenerated luminescence or proton-dependent fluorescence. Presently we aim to incorporate the described dye compounds as active components in OLEDs and to test analytical applications in sensor chemistry. Experimental SectionCyclic voltammetry: Solvent acetonitrile: potentials reported [mV] vs ferrocene (FOC) as internal standard. Experimental conditions: reversible half-wave potentials El,,, room temperature, scan rate 250 mVs-', platinum disc working electrode. Ag, AgCl pseudo-reference electrode, platinum counterelectrode, supporting electrolyte 0 1 M tetrabutylammonium hexafluorophosphate. Spectroelectrochemistry : Solvent acetonitrile, transmission cell with a gold minigrid working electrode or reflection cell with a platinum disc working electrode. Optlcdl spectra: Concentrations IO-'M to 1 0 -6~ in chloroform filtered over basic alumina before use Emission spectra are corrected. ECL-measurements: The ECL spectrum was recorded by applying an alternating square wave with redox potentials determined by cyclic voltammetry (switching time 20 ms. solvent dichloromethane). Concentration: IO-'M, supporting electrolyte' 0.1 M tetrabutykammoniurn hexafluorophosphate. The emission is red-shifted because of reabsorption in more highly concentrated solutions.

BackgroundSea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns.Methodology/Principal FindingsUsing satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings.Conclusions/SignificanceIntra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly influenced by environmental conditions. This high degree of behavioural plasticity in Atlantic leatherback turtles makes species-targeted conservation strategies challenging and stresses the need for a larger dataset (>100 individuals) for providing general recommendations in terms of conservation.