Summary1. Identifying priority areas for marine vertebrate conservation is complex because species of conservation concern are highly mobile, inhabit dynamic habitats and are difficult to monitor. 2. Many marine vertebrates are known to associate with oceanographic fronts -physical interfaces at the transition between water masses -for foraging and migration, making them important candidate sites for conservation. Here, we review associations between marine vertebrates and fronts and how they vary with scale, regional oceanography and foraging ecology. 3. Accessibility, spatiotemporal predictability and relative productivity of front-associated foraging habitats are key aspects of their ecological importance. Predictable mesoscale (10s-100s km) regions of persistent frontal activity ('frontal zones') are particularly significant. 4. Frontal zones are hotspots of overlap between critical habitat and spatially explicit anthropogenic threats, such as the concentration of fisheries activity. As such, they represent tractable conservation units, in which to target measures for threat mitigation. 5. Front mapping via Earth observation (EO) remote sensing facilitates identification and monitoring of these hotspots of vulnerability. Seasonal or climatological products can locate biophysical hotspots, while near-real-time front mapping augments the suite of tools supporting spatially dynamic ocean management. 6. Synthesis and applications. Frontal zones are ecologically important for mobile marine vertebrates. We surmise that relative accessibility, predictability and productivity are key biophysical characteristics of ecologically significant frontal zones in contrasting oceanographic regions. Persistent frontal zones are potential priority conservation areas for multiple marine vertebrate taxa and are easily identifiable through front mapping via EO remote sensing. These insights are useful for marine spatial planning and marine biodiversity conservation, both within Exclusive Economic Zones and in the open oceans.

We present the findings of a 2-yr study of habitat use by bottlenose dolphins in the outer Shannon estuary on the west coast of Ireland. Data were collected during repeated, standardised, boat-based surveys of dolphins in a predefined 150 km 2 area of the outer estuary. Areas found to exceed a uniform-use pattern were termed 'critical areas' and delimited using the 50% contour derived from harmonic mean transformation of sighting locations. Dolphins exhibited preferential use of areas of the estuary with the greatest benthic slope and depth, highlighting the influence of environmental heterogeneity on habitat use by this species. Additionally, photo-identification was used to catalogue sightings of uniquely marked dolphins which provided distribution data at an individual level. Although the ranges of frequently sighted dolphins overlapped, a degree of partitioning was found in the use of up-river parts of the study area. The methods presented here could be applied at a range of spatial scales and we suggest that the identification of critical areas within a population's range is a priority when planning any conservation management strategy for marine mammals. KEY WORDS: Bottlenose dolphins · Habitat use · Critical areas · ConservationResale or republication not permitted without written consent of the publisher

A light and electron microscopical survey of spermatozoan gross morphology and ultrastructure in the Hymenoptera is presented. Details are provided for the first time for members of the families Xyelidae, Argidae, Tenthredinidae, Diprionidae, Cephidae, Figitidae, Proctotrupidae, Diaprii‐ dae, Heloridae, Eurytomidae, Leucospidae, Perilampidae, Torymidae, Braconidae, Dryinidae, Sphecidae, Pompilidae and Vespidae. Spermatozoan length ranged from 8 μm in some Braconidae to 500 μm in one chalcidoid. Considerable variation in gross morphology and ultrastructure were observed between taxa. Several phylogenetically informative characters were noted. Very small spermatozoa characterized most of the non‐cyclostome subfamilies of Braconidae; spirally twisted axoneme and mitochondrial derivatives occur in the Eulophidae, Eurytomidae and Pteromalidae; spermatozoa with virtually indistinguishable head (nucleus and acrosome) regions characterized the Vespinae and Polistinae. The presence of well‐developed spermatodesmata in the vas deferens and seminal vesicle characterize the Symphyta and were largely absent from other groups though they are occasionally present in some bees.

The morphology, function and phylogenetic significance of the hymenopterous ovipositor, as revealed by transverse sections, is explored. Ovipositors (including stings) of > 240 species belonging to some 69 families (representing all superfamilies) have been prepared and examined, and almost 180 are illustrated. Particular attention is paid to Ichneumonoidea. Sections show many new, phylogenetically informative characters as well as providing further insight into ovipositor function. Examples of synapomorphies are given which suggest various groupings at the family or subfamily levels. Functional interpretations are given for several characters, with particular reference to substrate penetration, passage of the egg along the ovipositor and stinging.

Experimental studies have highlighted the potential in£uence of contaminants on marine mammal immune function and anthropogenic contaminants are commonly believed to in£uence the development of diseases observed in the wild. However, estimates of the impact of contaminants on wild populations are constrained by uncertainty over natural variation in disease patterns under di¡erent environmental conditions. We used photographic techniques to compare levels of epidermal disease in ten coastal populations of bottlenose dolphins (Tursiops truncatus) exposed to a wide range of natural and anthropogenic conditions. Epidermal lesions were common in all populations (a¡ecting 460% of individuals), but both the prevalence and severity of 15 lesion categories varied between populations. No relationships were found between epidermal disease and contaminant levels across the four populations for which toxicological data were available. In contrast, there were highly signi¢cant linear relationships with oceanographic variables. In particular, populations from areas of low water temperature and low salinity exhibited higher lesion prevalence and severity. Such conditions may impact on epidermal integrity or produce more general physiological stress, potentially making animals more vulnerable to natural infections or anthropogenic factors. These results show that variations in natural environmental factors must be accounted for when investigating the importance of anthropogenic impacts on disease in wild marine mammals.