Both whaling and whale-watching tourism occur in Iceland, but these activities are considered incompatible by many, and previous studies have suggested that whale-watch tourists would boycott whale-watch destinations where whaling takes place. This study assessed the perceptions of and attitudes towards ongoing whaling amongst whale-watch tourists in Iceland. A majority of whale-watching tourists in Iceland did not support whaling and did not think that whale-watching and whaling could exist side by side. However, 31% of respondents were unaware of Iceland's whaling before their visit and most of these indicated that prior knowledge of whaling activities would not have affected their choice of destination. More tourists had tried whale meat than either puffin or guillemot meat, suggesting that whale meat may be more strongly marketed to tourists visiting Iceland. These results suggest that not all tourists would consider boycotting travel to a whaling nation. The whale-watch industry is important to Iceland's economy, but given that the whaling industry can potentially negatively impact upon whale-watching activities, a careful analysis of the compatibility of these two industries is recommended.

Understanding the variables (biotic or abiotic) controlling coastal communities is the main goal of ecology research and it is crucial to predict how communities will evolve under the increasing pressure on coastal systems by human activities. The general aims of this study were to assess the variables affecting the distribution of the fast-growing sponge Hymeniacidon cf. perlevis, and to evaluate if physical stressful conditions have an influence in the relationship between Hymeniacidon and the sea lettuce Ulva lactuca. Specifically, the aims were to evaluate the abundance patterns of Hymeniacidon and Ulva and to assess the relationship of Ulva and physical variables on the abundance of Hymeniacidon at both intertidal and subtidal. Hymeniacidon and Ulva showed opposite abundance patterns. Hymeniacidon was more abundant in sites without Ulva, and negatively correlated with Ulva abundance at both heights. Intertidal Hymeniacidon abundance was not correlated with physical variables, but subtidal Hymeniacidon was.

Including a multi-year collection of samples (2004–2011) the present research fills 20 years of an information gap regarding the PCB burden in south-west Atlantic franciscana dolphins (Pontoporia blainvillei) while aiming to test the null hypothesis that PCBs congeners are increasingly bioaccumulating in south-west Atlantic specimens in relation to northern hemisphere records. In addition, the present survey analyses indicators of potential biological impairment associated to PCBs tissue burden. The results could associate each sampling area group of dolphins to one or two Aroclor® patterns and point to dominant regional diffuse sources entering PCBs mixtures to the marine environment with a possible regional/long-range atmospheric contribution. In addition, total PCB levels were from four to seven times lower than the closer precedents for the area (18–26 years ago) indicating a progress in the environmental release and biota exposure of PCBs and posing an objective indicator of success of the present international elimination programme. Further, when compared with regional and global bioaccumulation patterns, PCBs congeners in Argentinean specimens appeared to occur in a decreasing tendency. Finally, calculated TEQs TCDD levels raised a concern in regards to environmental safety, showing guideline values to be widely exceeded and the occasional occurrence of positive correlations between PCBs bioaccumulation vs. sexual immaturity.

Some excavating sponges are strong competitors for space on coral reefs, able to kill live coral tissue and to overgrow entire coral colonies. Stony corals with excavating sponges can die or become dislodged. To date no restoration efforts to eliminate excavating sponges from live corals have been considered. In this study we examined the effect and remedial potential of removal of the excavating sponge, Cliona delitrix, by monitoring tissue loss of the stony coral Montastrea cavernosa. Thirty-three corals colonized by the sponge were used: 11 as controls, and 22 as treatments in which sponges were removed using hammer and chisel. After sponge removal, resultant cavities in the coral skeletons were filled with common cement or epoxy. Standardized photos of each coral were taken immediately after sponge removal, and at 6 and 12 months afterwards. Results were similar between fill materials and showed a reduction in coral tissue loss in colonies where the sponge was removed. This study demonstrates that eliminating the bioeroding sponge enables potential recovery in affected stony corals after a year. However, 36% of experimental corals showed renewed presence of C. delitrix on the colony surface within a year after removal, demonstrating the extraordinary ability of this sponge to colonize corals. Although the technique used in this study is applicable to enhance modern coral restoration practices by slowing tissue loss, this method is costly, elaborate, and not suitable at a reef-wide scale. Further restoration alternatives and long-term measures to prevent over-colonization of corals by excavating sponges are encouraged.

Dredging activity poses an environmental risk to sponges as sediments from the dredge or disposal site may smother the sponge surface, potentially affecting water filtration and light penetration. Dredge-related sedimentation effects may also vary between sponge morphologies, potentially impacting community structure and functioning. To test this, 10 sponge species encompassing four different morphologies (massive, erect, cup and encrusting), were exposed to a single pulse treatment of three different sediment concentrations (0, 250 and 500 mg l−1) and followed over 2 weeks, in 1000 l tanks. Total suspended solids (TSS) and sedimentation rates (SR) were recorded throughout the study. A sharp decrease in TSS was recorded within the first 2–3 h and a total settlement of sediments occurred within the first 48 h of the pulse exposure (0, 8 and 16 mg cm−2 in the control, medium and high sediment treatments, respectively). The effects of high sedimentation included mortality of cup-shaped Callyspongia confoederata and small areas of tissue necrosis in other species, with massive, encrusting and wide cup morphologies particularly affected. However, the sediment concentrations tested in this experiment did not cause changes in the concentration of sponge pigments or the structure of the symbiotic microbial community in any species. These results indicate that a single pulse of sediments less than 16 mg cm−2 is not detrimental to most of the sponge species studied.

This is the first study estimating cetacean by-catch in the Turkish western Black Sea turbot fishery. One turbot fishing boat was observed during two fishing seasons, from April through July 2007 and April through mid-September 2008. During this time, 24 harbour porpoises and one bottlenose dolphin were caught in turbot trammel nets. The by-catch rate was found to be 0.18 for harbour porpoise and 0.01 for bottlenose dolphin individuals per kilometre in 2007, and 0.19 for harbour porpoise individuals in 2008. It is estimated that the total numbers of harbour porpoises killed in the Turkish western Black Sea during the legal fishing period (April and July) were 167 ± 153 (CV: 0.92) in 2007 and 329 ± 220 (CV: 0.67) in 2008, and the number killed during both legal and illegal periods of turbot fishing were 2011 ± 742 (CV: 0.37) in 2007 and 2294 ± 806 (CV: 0.35) in 2008. The estimated range of harbour porpoise by-catch in the turbot fishery on the Turkish western Black Sea coast is between these two estimates. The by-caught harbour porpoises were between 1–8 years of age. About half of them were within the age range of 4 (26%) and 5 (21%) years old, and 78% were physically immature individuals. Turbot fishing carried out with bottom nets, especially in May and June, when turbot fishing is banned, is a threat to the sustainability of harbour porpoise stocks.

In the present study, short-beaked common dolphins (Delphinus delphis L.) from the Bay of Gibraltar (GIB) and the Moray Firth (MF) were examined to document the relative frequency, distribution and shape of dorsal edge markings (DEMs) in the species and investigate potential causes for their occurrence. A dorsal fin layout system was used to map the relative positions and shapes of presenting DEMs along the anterior/posterior and upper/lower fin margin from 617 animals. A total of 1989 DEMs were extracted from the combined datasets, with individuals exhibiting between one and 11 nicks (median = 3). DEMs (in the form of tears, nicks, notches and indents) were primarily observed along the posterior trailing edges of fins, with the highest concentration being recorded in the upper region of the posterior fin (80.3%). Approximately 80% of all DEMs were round or rectangular in shape. Square (notched) and indented nick shapes were further recorded, but in significantly lower numbers. In contrast to all other nick shapes however, indented DEMs predominantly occurred along the anterior fin margin. Both natural and anthropogenic sources were implicated as causes of DEMs in the dataset. Interactions with fisheries were apparent in both GIB and MF animals and evidently present a threat to both populations. Indeed, the occurrence, prevalence and type of presenting DEM and/or fin injuries (e.g. missing fins or disfigurements) in the species may provide a useful measure of the type and intensity of fisheries interactions affecting different populations.

Being sessile filter feeders, sponges may be disadvantaged by sediments in many ways, e.g. through clogging and burial. However, in order to correctly recognize negative effects of sediments in the field, natural relationships of sponge taxa adapted to a life with sediments need to be understood. The present publication reviews available literature and provides observations on natural and beneficial interactions of sponges with sediments, distinguishing several strategies: (1) Saving energy through sediment incorporation, reducing or replacing spicule production commonly occurs in keratose, verongimorph, tethyid and poecilosclerid sponges, which often received scientific names referring to sediments. (2) Forming sediment crusts externally or embedded in surface tissues reinforces outer layers, provides shade, and for external crusts camouflage and shelter from spongivory and desiccation. External crusts often occur in the tethyids and axinellids, while surface armour is most common in keratose sponges. (3) Anchoring in soft sediments provides a selective advantage for space colonization. This is mainly achieved in the hexactinellid, polymastiid and spirophorine sponges by using spicules (predominantly in deeper water), commonly in endopsammic sponges by rootlets, basal agglutination and basal incorporation of particles, and in various groups by attachment to buried materials (shallow water). (4) Living at least partially embedded in sediments (psammobiosis) appears to be best developed in Oceanapia spp. and bioeroding sponges, generates shelter from various external conditions and reduces the risk of spongivory. Typical morphological characters of sediment-adapted sponges are thus sediment skeletons and surface crusts (reinforcement), stalks and fistules (elevation above sediments), spicule tufts and root-systems (anchoring).

Cliona delitrix is one of the most abundant and destructive coral-excavating sponges on Caribbean reefs. However, basic aspects of its reproductive biology, which largely determine the species propagation potential, remain unknown. A 2-year study (October 2009 to September 2011) was conducted to determine the reproductive cycle and gametogenesis of a C. delitrix population located in a shallow reef in Florida, USA. Mesohyl tissue collected from randomly chosen and tagged sponge individuals was sampled one to several times a month, and analysed by light and transmission electron microscopy (TEM). Cliona delitrix is oviparous and gonochoric, except for a few simultaneous hermaphroditic individuals. The C. delitrix reproductive cycle in Florida is from April to December, and is triggered by an increase in seawater temperature to 25°C. Oogenesis and spermatogenesis were asynchronous among individuals; with different cohorts of oocytes co-occurring in females, and spermatic cysts in males. Granulose cells acted as nurse cells, contributing to the growth and maturation of both female and male gametes. Spawning of gametes was not always synchronized with full moon phase. Unlike most other oviparous sponges, the reproductive cycle of C. delitrix is versatile and includes multiple spawning events during the summer of each year. This characteristic maximizes sponge propagation on coral reefs during the warmer months of the year, particularly when thermal stress induces coral mortality. This aspect, combined with its success on polluted areas, make C. delitrix a suitable bioindicator of coral reef health.

Although oogenesis is the best-known stage of development in sponges of the subclass Calcinea (Porifera, Calcarea), several aspects of this process await further investigation. In the present study, we examined by light and electron microscopy the oogenesis of three species of the order Clathrinida (Clathrina aurea, Borojevia aspina and B. brasiliensis) from the coast of Rio de Janeiro state (Brazil). Oogenesis in these species was a rare and not synchronized event, neither in the individual nor in the population level. Oocytes grew between the choanoderm and the pinacoderm. They did not form any special structure for nourishing the egg and phagocytosis of somatic cells was not observed. The vitellogenesis of B. aspina and B. brasiliensis was performed in a mixed pathway, while in C. aurea it was not possible to observe the vitellogenesis. In the Borojevias, the surrounding choanocytes provided small clear vesicles at the same time that oocytes modified phagosomes to produce fibrous yolk inclusions. The phylogenetic character mapping analysis indicated that egg development in the mesohyl is the ancestral state for Calcinea, while the ancestral condition of the vitellogenesis is still uncertain.

The biology and ecology of calcarean sponges are not as well understood as they are for demosponges. Here, in order to gain new insights, particularly about symbiotic relationships, the calcarean sponge Leucetta prolifera was sampled from south-western Australia and examined for its assumed photosymbionts. Pulse amplitude modulated fluorometry and extraction of photopigments established that the sponge was photosynthetic. Molecular analysis of the bacterial symbionts via sequencing of the V1–V3 region of the 16S rDNA gene confirmed that between 5 and 22% of all sequences belonged to the phylum Cyanobacteria, depending on the individual sample, with the most dominant strain aligning with Hormoscilla spongeliae, a widely distributed sponge symbiont. Analysis of fatty acids suggested that the sponge obtains nutrition through photosynthates from its symbionts. The relationship is assumed to be mutualistic, with the sponge receiving dietary support and the cyanobacteria sheltering in the sponge tissues. We list all Calcarea presently known to harbour photosymbionts.

Wounds caused by predation and/or physical disturbances to sessile marine animals are common. Consequently, these organisms had to develop strategies to endure such injuries and survive in such a dynamic environment. Sponges are known to possess one of the greatest capacities of regeneration among living metazoans, but this feature has been largely studied only in Demospongiae. In Calcarea, very few species have been investigated. Hence, we analysed the regeneration and speed rates from two regions (osculum and choanosome) of the body of a calcareous sponge: Ernstia sp. Only the osculum regenerated until the end of the experiment, while the choanosome simply cicatrized. Calcareous sponges seem to have a polarized regeneration closely related to their external morphology and level of individuality and integration. A brief review of the regeneration capacity in Calcarea is presented.

Many species of marine sponges on tropical reefs host abundant and diverse symbiont communities capable of varied metabolic pathways. While such communities may confer a nutritional benefit to some hosts (termed High Microbial Abundance (HMA) sponges), other sympatric species host only sparse symbiont communities (termed Low Microbial Abundance (LMA) sponges) and obtain a majority of their C and N from local sources. Sponge communities are widespread across large latitudinal gradients, however, and recent evidence suggests that these symbioses may also extend beyond the tropics. We investigated the role that symbionts play in the ecology of sponges from the temperate, hard-bottom reefs of Gray's Reef National Marine Sanctuary by calculating the niche size (as standard ellipse area (SEAc)) and assessing the relative placement of five HMA and four LMA sponge species within bivariate (δ13C and δ15N) isotopic space. Although photosymbiont abundance was low across most of these species, sponges were widespread across isotopic niche space, implying that microbial metabolism confers an ecological benefit to temperate sponges by expanding host metabolic capability. To examine how these associations vary across a latitudinal gradient, we also compared the relative placement of temperate and tropical conspecifics within isotopic space. Surprisingly, shifts in sponge δ13C and δ15N values between these regions suggest a reduced reliance on symbiont-derived nutrients in temperate sponges compared with their tropical conspecifics. Despite this, symbiotic sponges in temperate systems likely have a competitive advantage, allowing them to grow and compete for space within these habitats.

Symbionts in sponges must interact with the host immune system, and this can be mediated by immunomodulators. As the bases of the immune system in sponges resemble those of higher metazoans, it is possible that compounds from this microbiota show similar effects in other phyla. It is also known that several antibiotics, in special macrolides, can modulate many components of the immune response and sponges and their associated microorganisms are a rich source of these compounds. Therefore, we tested the immunosuppressive capacity of antibiotic substances produced by bacterial and fungal strains isolated from the Amazon freshwater sponge Metania reticulata. Fourteen bacterial and six fungal strains were obtained from samples of M. reticulata collected in the Negro River (Amazon Central Basin region), during the dry season. These cultures were monitored for natural antimicrobial activity, and two Bacillus strains (MERETb.761 and MERETb.762) and one fungus (MERETf.010) were selected. One Bacillus strain, MERETb.762, showed strong and specific antibiosis on Staphylococcus aureus and two fractions of its extract inhibited the degranulation of RBL–2H3 cells. The predicted formulas of these fractions were C12H6N4O8 and C25H4N2O6, both corresponding to nitroaromatic compounds.