Marine sponges are the driver of many critical biological processes throughout various ecosystems. But anthropogenic and environmental pressures are rapidly compromising the diversity and abundance of Porifera worldwide. In our study, we reviewed the main experiences made on their cultivation to provide a roadmap of the best methodologies that could be applied to restore coastal sponge populations. We synthesized the results of experimental trials between 1950 and today to facilitate information on promising methods and materials. We detected a strong geographical imbalance between different ecoregions, as well as a shift of scientific effort from the investigation of “bath sponge” mariculture towards the rearing of bioactive compounds from sponges. Although sponge cultivation is arguably highly species-dependent, we further found that skeletal consistency in combination with taxonomy may be used to decide on appropriate techniques for future restoration initiatives.
Modular colonial benthic organisms exhibit high phenotypic plasticity, which is considered an effective strategy when faced with fluctuations in abiotic and biotic factors. However, when environmental changes occur abruptly, organisms’ adaptive capabilities can be limited, leading to the death of some colonies or to mass mortalities. Additionally, a decrease in body size has been proposed as one of the most common responses in both terrestrial and aquatic organisms to face global warming. Here, temperate corals’ response to thermal stress was documented using the precious red coral Corallium rubrum as a model species. The increased frequency of marine heat waves recorded in the north-western Mediterranean has led to a decrease in the total number of colonies of the analysed populations and reduced colony size in those that have survived, likely through fragmentation and branch loss. The laboratory analyses carried out on collected fragments showed an unexpected swelling, similar to resorption. Additionally, the occurrence of regular sclerite-like protuberances, typical of a normal skeleton surface, suggested a regeneration process. The documented phenomenon supports the hypothesis that C. rubrum exhibits an adaptive behaviour via the autotomy of branches, providing it with an unexpected resilience against climate anomalies thanks to phenotypic plasticity.
Although many animal species demonstrate individual personalities, studying these traits in wild sharks has proven challenging. Past research focused mainly on captive or juvenile sharks. Our ethological study of 31 wild adult bull sharks (Carcharhinus leucas) utilized an artificial provisioning site, amassing 2813 observations over 651 dives from October 2015 to January 2018 (27 months). Behavioural traits, including boldness-shyness and aggressiveness-placidity, were assessed using an ad hoc ethogram and an influencing factors table. This innovative approach not only allowed us to characterize individual shark behaviours but also to quantify their changes over time. Our findings suggest that adult bull sharks likely possess distinct personalities, spanning from extreme shyness to pronounced boldness, with varying levels of plasticity among individuals. Further exploration of shark personalities holds promise for advancing our comprehension of human–shark interactions and refining the management of potential aggressive behaviours exhibited by large shark species toward humans.
Corallium rubrum has been exploited by humankind for centuries. The long-term exploitation dynamics of this species make it even more important today to increase protection and restoration efforts as it provides a significant range of ecosystem services. This becomes even more important in areas where natural recovery is hindered or unlikely. So far, only very few experiments have been carried out in the past, investigating suitable techniques for the successful transplantation of this species. For this reason, a review was conducted in order to synthesize previous results and identify the most promising methodologies. Additionally, six different transplantation techniques were tested and discussed in the context of the review. Five techniques used fragments for transplantation, while one used newly settled larvae on PVC-tiles. Shallow C. rubrum colonies often grow upside down under crevices and rims as well as in caves, making the transplantation of fragments comparatively challenging. Here, C. rubrum was transplanted upside down under crevices using a PVC-grid in combination with epoxy putty to hold fragments in place, and the results indicated the potential benefits of this technique. In a novel approach, shallow colonies, and larvae on settling plates were also transferred to deeper areas, suggesting that mesophotic populations can be restored to reconstruct pre-exploitation conditions. Attaching the colonies to the roof of crevices provided a level of survivorship consistent with conventional erect transplantations of colonies on rock bottom but had the advantage of being more removed from sedimentation and anthropogenic disturbance. Future work must develop permanent grid-mounting methods for use in the crevices before this approach can be further explored for large-scale restoration efforts.