8604 research outputs found
Sort by
Spatial and temporal variation in the diversity and structure of understorey macrofaunal assemblages within Laminaria hyperborea forests in the northeast Atlantic
No full textKelp species function as foundation organisms along almost one third of the world's coastlines, where they underpin diverse and productive forest habitats. The three-dimensional structure of the forest modifies local environmental conditions, which in some regions allows rich understorey macroalgal and macrofaunal assemblages to develop. These understorey assemblages, however, represent somewhat overlooked components of kelp forest ecosystems, with fundamental information on their structure and the processes that shape them often lacking. Here, we used an underwater suction sampler to characterize understorey macroalgal and macrofaunal assemblages within Laminaria hyperborea forests across the mid northeast Atlantic (United Kingdom). Specifically, we investigated spatial and temporal variation in the structure, abundance, diversity, and evenness of assemblages at twelve sites nested in four regions of the UK distributed along a 9° latitudinal gradient that encompassed a ∼ 2.5 °C gradient in mean sea surface temperature. Collectively, the samples comprised of 2.4 kg of understorey macroalgae from five functional groups, and 65,323 macrofaunal individuals from 179 taxa, demonstrating that understorey assemblages represent important repositories of biodiversity within coastal marine systems. Univariate assemblage metrics exhibited significant site-level variation, while the multivariate structure of assemblages exhibited both site and regional-level variation, and all metrics exhibited significant temporal variation. The observed variation was attributed in part to complex interactions between sea surface temperature, wave exposure and habitat structure, while the high site-level variation suggests that unquantified local-scale processes are also important influencers of understorey assemblages. Given that kelp forests are becoming increasingly threatened by multiple stressors, our results provide important evidence to support enhanced management of kelp forests, as well as baseline information that can serve as a benchmark to monitor, restore, and ultimately conserve these forests and their associated ecosystem service
South-West Marine Ecosystems in 2023 (The State of South-West Seas)
Get PDFA collation of observations made through the year from monitoring studies, harvested from social media,
publications etc. and recorded by the editors of section
Temporal variation in the structure, abundance, and composition of Laminaria hyperborea forests and their associated understorey assemblages over an intense storm season
No full textKelp species function as important foundation organisms in coastal marine ecosystems where they provide biogenic habitat and ameliorate environmental conditions, often facilitating the development of diverse understorey assemblages. The structure of kelp forests is influenced by a variety of environmental factors, changes in which can result in profound shifts in ecological structure and functioning. Intense storm-induced wave action in particular, can severely impact kelp forest ecosystems. Given that storms are anticipated to increase in frequency and intensity in response to anthropogenic climate change, it is critical to understand their potential impacts on kelp forest ecosystems. During the 2021/22 northeast Atlantic storm season, the United Kingdom (UK) was subject to several intense storms, of which the first and most severe was Storm Arwen. Due to the unusual northerly wind direction, the greatest impacts of Storm Arwen were felt along the northeast coast of the UK where wind gusts exceeded 90 km/h, and inshore significant wave heights of 7.2 m and wave periods of 9.3 s were recorded. Here, we investigated temporal and spatial variation in the structure of L. hyperborea forests and associated understorey assemblages along the northeast coast of the UK over the 2021/22 storm season. We found significant changes in the cover, density, length, biomass, and age structure of L. hyperborea populations and the composition of understorey assemblages following the storm season, particularly at our most north facing site. We suggest continuous monitoring of these systems to further our understanding of temporal variation and potential recovery trajectories, alongside enhanced management to promote resilience to future perturbation
Societal impacts of marine nitrogen pollution: rapid evidence assessment and future research
Get PDFNitrogen pollution is a global problem and to effects we need to understand both the ecological and societal impacts. Coral reefs are of particular concern, as they are a critical source of livelihoods, culture, and wellbeing for hundreds of millions of people. Yet they are rapidly
declining due to numerous pressures, with nitrogen pollution identified as a top-ranked non-climatic pressure. A Rapid Evidence Assessment was carried out to understand the societal impacts derived from marine nitrogen pollution on
coral reefs. The results highlight key research evidence gaps, such as unclear reporting of nitrogen pollution, not distinguishing impacts from nitrogen and other stressors, non-quantification of nitrogen-specific marine and societal
impacts, unstudied global regions with high nitrogen pressure, and the need for greater awareness on marine nitrogen pollution. Future research questions are
proposed to allow better understanding on how tropical coastal societies are being impacted by marine nitrogen pollution
Spatial distribution of the intertidal limpet Patella depressa Pennant, 1777: Patterns across wave exposure and season
No full textSpatial patterns of intertidal rocky shore gastropods depend on various environmental stresses and biological interactions. Understanding how and why these patterns arise can provide important insights into the ecology and behavior of ecologically key organisms. Here, we addressed the unexplored limpet aggregative behavior and the influence of wave action and season. We assessed intraspecific patterns of the spatial distribution of Patella depressa on rocky shores of contrasting wave exposure in seasons with different levels of storminess in central Portugal. We predicted that intraspecific spatial structure estimated through individual-to-individual nearest neighbor distances (NNDs) would be more aggregated on exposed sites than on sheltered sites and, if season-dependent, such aggregation would be greater during the stormier winter months. Two sheltered sites and two exposed sites were sampled three times in winter and in summer. On each sampling occasion, the mean NNDs were measured digitally in 20 replicated random quadrats (0.25 × 0.25 m). We showed that season and exposure significantly affect the spatial distribution of limpets, with an aggregated spatial structure on exposed sites during the stormy winter months. On sheltered sites, limpets were randomly distributed regardless of season. In contrast, on exposed sites, limpets which were randomly distributed during summer changed to an aggregated structure in the winter. This is the first report of seasonally modulated patterns of spatial distribution associated with wave exposure for P. depressa. Such behavior can influence resource availability and outcomes of competitive interactions, with implications for ecosystem functionin
Control of Vibrio vulnificus proliferation in the Baltic Sea through eutrophication and algal bloom management
No full textDue to climate change the pathogenic bacterium Vibrio vulnificus proliferates along brackish coastlines, posing risks to public health, tourism, and aquaculture. Here we investigated previously suggested regulation measures to reduce the prevalence of V. vulnificus, locally through seagrass and regionally through the reduction of eutrophication and consequential formation of algal blooms. Field samples collected in the summer of 2021 covered the salinity and eutrophication gradients of the Baltic Sea, one of the largest brackish areas worldwide. Physico-, biological- and hydrochemical parameters were measured and variables explaining V. vulnificus occurrence were identified by machine learning. The best V. vulnificus predictors were eutrophication-related features, such as particulate organic carbon and nitrogen, as well as occurrence of potential phytoplankton blooms and associated species. V. vulnificus abundance did not vary significantly between vegetated and non-vegetated areas. Thus, reducing nutrient inputs could be an effective method to control V. vulnificus populations in eutrophied brackish coast
Emerging Technologies for Remote Sensing of Floating and Submerged Plastic Litter
Get PDFMost advances in the remote sensing of floating marine plastic litter have been made using passive remote-sensing techniques in the visible (VIS) to short-wave-infrared (SWIR) parts of the
electromagnetic spectrum based on the spectral absorption features of plastic surfaces. In this paper, we present developments of new and emerging remote-sensing technologies of marine plastic litter such as passive techniques: fluid lensing, multi-angle polarimetry, and thermal infrared sensing (TIS); and active techniques: light detection and ranging (LiDAR), multispectral imaging detection and active reflectance (MiDAR), and radio detection and ranging (RADAR). Our review of the detection capabilities and limitations of the different sensing technologies shows that each has their own
weaknesses and strengths, and that there is not one single sensing technique that applies to all kinds of marine litter under every different condition in the aquatic environment. Rather, we should focus on the synergy between different technologies to detect marine plastic litter and potentially the use of proxies to estimate its presence. Therefore, in addition to further developing remote-sensing techniques, more research is needed in the composition of marine litter and the relationships between marine plastic litter and their proxies. In this paper, we propose a common vocabulary to help the
community to translate concepts among different disciplines and techniques
Physiology and functional biology of Rhizostomeae jellyfish
No full textRhizostomeae species attract our attention because of their distinctive body shape, their large size and because of blooms of some species in coastal areas around the world. The impacts of these blooms on human activities, and the interest in consumable species and those of biotechnological value have led to a significant expansion of research into the physiology and functional biology of Rhizostomeae jellyfish over the last years. This review brings together information generated over these last decades on rhizostome body composition, locomotion, toxins, nutrition, respiration, growth, among other functional parameters. Rhizostomes have more than double the carbon content per unit of biomass than jellyfish of Semaeostomeae. They swim about twice as fast, and consume more oxygen than other scyphozoans of the same size. Rhizostomes also have faster initial growth in laboratory and the highest body growth rates measured in nature, when compared to other medusae groups. Parameters such as body composition, nutrition and excretion are highly influenced by the presence of symbiotic zooxanthellae in species of the Kolpophorae suborder. These physiological and functional characteristics may reveal a wide range of adaptive responses, but our conclusions are still based on studies of a limited number of species. Available data indicates that Rhizosotomeae jellyfish have a higher energy demand and higher body productivity when compared to other jellyfish groups. The information gathered here can help ecologists better understand and make more assertive predictions on the role of these jellyfish in their ecosystem
Identification of copepod eggs, nauplii and copepodites, and facetotectan nauplii and cyprids - Occasional Publications of the MBA
Get PDFGlobal habitat predictions to inform spatiotemporal fisheries management: Initial steps within the framework
No full textTuna Regional Fishery Management Organizations (tRFMOs) are increasingly interested in spatiotemporal management as a tool to reduce interaction rates with vulnerable species. We use blue shark (Prionace glauca) as a case study to demonstrate the critical first steps in the implementation process, highlighting how predictions of global habitat for vulnerable life stages can be transformed into a publicly-accessible spatial bycatch mitigation tool. By providing examples of possible management goals and an associated threshold to identify essential habitats, we show how these key areas can represent a relatively low percentage of oceanic area on a monthly basis (16–24% between 50°S and 60°N), yet can have relatively high potential protection efficiency (∼ 42%) for vulnerable stages if fishing effort is redistributed elsewhere. While spatiotemporal management has demonstrable potential for blue sharks to effectively mitigate fishing mortality on sensitive life stages, we identify inherent challenges and sequential steps that require careful consideration by tRFMOs as work proceeds. We also discuss how our single-species framework could be easily extended to a multispecies approach by assigning relative conservation risk before layering habitat model predictions in an integrated analysis. Such broader application of our approach could address the goals of tRFMOs related to reducing the ecosystem effects of fishing and pave the way for efficient fisheries co-management using an ecosystem-based approac