ITRS 2025

A large-scale macro-predation experiment on stalked barnacles (Pollicipes pollicipes) reefs: effects on abundance, biomass and size

celine — 2025-04-27T12:55:39Z

Teresa Cruz¹, David Mateus¹, Gonzalo Macho^2,3, Katja J. Geiger⁴, Eric Thiébaut⁵, Joana N. Fernandes¹, Alba Aguión³, Julio Arrontes⁴, Caroline Broudin⁵, David Jacinto¹, Salvador Román³, Jorge Sostres⁴, Lucille Perrier⁵, Teresa Silva¹, Elsa Vásquez³, José Manuel Rico⁴, Dominique Davoult⁵, João J. Castro¹, Consolación Fernández⁴, Alina Sousa¹, José Luis Acuña⁴

¹University of Évora, Portugal - ²Fisherman's Cove, Mahé, Seychelles - ³Universidade de Vigo, Spain - ⁴Universidad de Oviedo, Spain - ⁵Sorbonne Université, CNRS, Station Biologique de Roscoff, France

Predation is a fundamental structuring process on intertidal temperate reefs. Among the predators acting in these environments, humans can play a crucial role, particularly in exploited resources. Most research on the relative role played by predators in structuring intertidal communities has not taken place on very wave-exposed shores. Stalked barnacles of the species Pollicipes pollicipes are exploited throughout their geographic range (SW England to Senegal), namely in France, Spain and Portugal. This species lives in highly wave-exposed rocky shores, and its exploitation is considered a high-risk activity. With the overall aim of studying the effect of human predation and other macropredators on the density, biomass and size-structure of P. pollicipes in Europe, a manipulative experiment was carried out in various sites in Brittany (France), Asturias and Galicia (Spain), and SW Portugal. At each site, 35 x 35 cm metal cages with a wide mesh size (5 cm) were installed to deter human predation and reduce macro-predation by other organisms. Control plots were also considered. At the start of the experiment, at each site, the cover of P. pollicipes did not differ between the two treatments (cage and control). With the additional objective of evaluating the effect of protection time from macropredators, the total density, total biomass and size-structure of the barnacles were independently measured two years (2017-2019) and one year (2018-2019) after the set up. At the end of the experiment, in each plot, we measured the percentage cover of P. pollicipes by image analysis (QGIS software); and we placed a 15 x 15 cm area over a group of P. pollicipes, photographed and scraped the area to count, measure and weight the barnacles. Data are being analysed in a univariate (total density and biomass) and multivariate way (size-structure of density and biomass) in relation to the factors site, region, predation and protection time, as well as using a meta-analytical approach.

Evaluating the effects of kelp harvesting and the impact on associated communities

celine — 2025-04-27T12:55:38Z

Catalina Ruz¹, Pippa Moore², Alejandro Pérez Matus¹

¹Pontificia Universidad Católica de Chile, Chile - ²Newcastle University, UK

Lessonia trabeculata forests play a crucial role as founder species in Chilean subtidal ecosystems, providing key ecosystem services. However, intensive extraction associated with the alginate industry significantly disturbs their resilience. In this study, we evaluated the recovery of L. trabeculata through a controlled experiment that considered different extraction intensities and scales.

The experiment was conducted in a management area (AMERB) in central Chile, where experimental blocks (n=4) were established at 12 m depth. In each block, five treatments were applied: total and partial removal (high: 100% and medium: 50% removal) in patches of 2 m and 4 m diameter, as well as a control without removal. For 18 months, the density of recruits, growth rates, and the effects on the sessile community of the subcanopy were monitored.

The results showed that the disturbance's intensity and scale influenced the forest recovery's speed. Patches with high removal and greater extension (4 m) showed a faster recovery in density and accumulated biomass. The growth rates of the remaining algae did not vary significantly between treatments, but not the growth of the recruits. However, as the extraction was more intense, the sub-canopy community showed a greater change, with increased cover of opportunistic species and a decrease in invertebrates.

These results highlight the importance of incorporating disturbance-specific characteristics into management plans, suggesting that reducing the intensity and scale of extraction can improve the resilience of these forests and ensure the sustainability of the L. trabeculata fishery.

Mapping mesophotic reefs along the coast of Chile (Southeastern Pacific) using fishers´ knowledge

celine — 2025-04-27T12:55:37Z

Miriam Fernandez¹, Valentina C. Romagnoli¹, Beatriz S. Murillo¹, Rodrigo Alarcón-Ireland¹, Mauro G. Zucconi¹, Mauricio F. Landaeta^1,2, Ricardo Beldade¹, Sergio A. Navarrete^1,3, , Pablo Saenz-Agudelo^1,4, Evie Wieters¹, Alejandro Perez-Matus¹

¹Universidad Católica de Chile, Chile - ²Universidad de Valparaíso, Chile - ³Universidad de Concepción, Chile - ⁴Universidad Austral de Chile, Chile

Mesophotic reef ecosystems are under significant human pressure (e.g., fisheries, climate change). Their remote location and depth present considerable logistical and technological challenges for study, limiting the understanding of their biodiversity, function, and conservation needs, both globally and particularly in temperate zones. Fishers' knowledge (FK) can offer valuable insights, contributing ecological, biological, and fisheries information on mesophotic reefs. Given the limited information available on mesophotic reefs in Chile, a study was conducted to map the location of mesophotic reefs and contribute to the assessment of biodiversity and exploitation, using FK. Along the coast of northern-central Chile, 29 fisher coves spanning 900 km were visited, and 196 fishers were interviewed. Using FK, it was possible to locate 1,274 fishing spots used by artisanal fishers on mesophotic reefs over the course of one year. The average depth and size were 49.4 m (± 26.5) and 1,619 km², respectively. The number of fishing spots exploited by fishers ranged from 14 to 27 among the fishing coves, while the area of use for fishing spots on mesophotic reefs varied substantially (between 21 km² and 1,842 km²). After fishers identified the location of fishing spots in mesophotic areas, 100 spots were randomly selected and visited, validating 98% of the sites reported. Fishers identified over 40 mesophotic reef species, dominated by Sebastes oculatus and Genypterus chilensis, two exploited species. Most fishers (76%) perceived a reduction in the abundance of the main target species exploited on mesophotic reefs. Chile has designated more than 40% of its Exclusive Economic Zone as marine protected areas. However, along the study area (a) only 92 of the fishing spots were within Marine Protected Areas of Multiple Use (7.2%), and (b) only one fishing spot overlapped with a no-take zone, suggesting the urgent need to focus conservation efforts on mesophotic ecosystems.

Generating ecologically relevant oxygen fluctuations using marine primary producers under laboratory conditions

celine — 2025-04-27T12:55:35Z

Aníbal Sánchez¹, Paula Celis-Plá², Marco Fusi³, Lucas Bravo^1,3, Simone Baldanzi^1,3

¹Universidad de Valparaíso, Chile - ²Universidad de Playa Ancha, Chile - ³Newcastle University, UK

Incorporating near-natural variation of the marine environmental variables into experimental designs is becoming imperative to make ecologically relevant inferences about ecophysiological responses to climate global change. Dissolved Oxygen (DO) is among the most important environmental variable in marine ecosystems and fluctuate strongly in coastal habitats, due to physical and biological phenomena. However, many technical challenges are still imposing high-cost equipment to ensure a complete mimicry of DO fluctuations in manipulative experiments. Here, we propose a simple and cost-effective methodology to simulate the oxygen fluctuations in laboratory through to marine primary producers as source of natural fluctuations. We tested the physiological status (Yield II and Fv/Fm) and photoprotective responses (phenolic production) of five different biomasses (200-400-600-800-1000g) of the macroalgae Lessonia spicata exposed to 7 days of artificial light (photoperiod of 12:12 hours day: night) within replicated aquaria. We showed that each biomass exhibited a unique fully functional oxygen fluctuating profile with different average DO saturations, harmonic oscillations and rates of DO Código de campo cambiado production/consumption. Biomasses <600g showed no significant changes in the physiological status of macroalgae (Yield II and Fv/Fm) and photoprotective responses (phenolic production) during the 7 days experiment, while effects of the environmental stress were found at greater biomasses (800 and 1000g). We successfully tested a method that can produce daily cycles of DO fluctuations in seawater trough to marine primary producers under controlled environment conditions. Our quantitative method provides cost-effective control the DO fluctuations in experimental set-ups with the use of a primary producers that can be replicated at low cost in virtually any laboratory worldwide using other species of marine algae, representing a highly effective method to control experimental settings that involve testing of fluctuating and ecologically relevant levels of dissolved oxygen.

Acclimation to daily fluctuations of dissolved oxygen improve oxygen regulation after stress exposure in the Kelp crab Taliepus dentatus

celine — 2025-04-27T12:55:34Z

Simone Baldanzi^1,2, Francisca Fernández¹, Lucas Bravo-Guzman¹, Anibal Sanchez¹, Miriam Fernández², Evie Weiters², Karen Diele³, Marco Fusi⁴

¹Universidad de Valparaíso, Chile - ²Pontificia Universidad Católica de Chile - ³Edinburgh Napier University, UK - ⁴Newcastle University, UK

Oxygen variability in coastal areas comprises both predictable patterns and stochastic fluctuations, creating a challenging signal-processing environment for marine species. In tropical habitats, due to strong photosynthetic activity of primary producers, daily fluctuations of dissolved oxygen (from oxygen-poor to supersaturated waters) can improve thermal tolerance of benthic species. Little is known, however, on the effects of dissolved oxygen fluctuations on temperate benthic species and there is a lack of experimental evidence worldwide. To begin to fill this gap, we exposed females of the kelp crab Taliepus dentatus to 10 days of acclimation to variable (daily fluctuations from hipo- to hyperoxia) vs constant conditions of dissolved oxygen, measuring animal metabolic activity (heartbeat), lactate and hemocyanin levels in the haemolymph. After acclimation, animals were exposed to 12 hours low temperature, hypoxia and low pH, simulating an upwelling event, and we determined their critical oxygen pressure (PO2crit) to test whether acclimation to daily fluctuations improved animal's oxygen regulation after stress. During acclimation, we found higher levels of lactate in those females experiencing Código de campo cambiado daily fluctuations of oxygen, but only after 4 days of acclimation. The heartbeat of females exposed to fluctuating oxygen conditions showed a significant increase of frequencies compared to the heartbeat of those females acclimated to constant values. After acclimation no differences in the PO2crit were found between females acclimated to constant vs fluctuating conditions of oxygen, while after stress exposure, females acclimated to fluctuating conditions were better able to regulate oxygen (lower PO2crit). The results show that acclimation to oxygen fluctuations improves kelp crabs' capacity to extract oxygen after experiencing an acute stress. We demonstrated that, for a temperate crab species, variability of oxygen can provide considerable physiological benefits, highlighting the importance of integrating ecologically relevant oxygen variability into experimental assessments of animal physiology.

Meandering artificial shorelines and their potential to enhance biodiversity

celine — 2025-04-27T12:55:33Z

Peter A. Todd¹, Janine Ledet¹, Kingsley J. Griffin¹, Yan Le Su¹

¹National University of Singapore, Singapore

Climate change has increased shoreline degradation, erosion, and inundation rates globally. This, together with urbanisation, has led to the acceleration of hard coastal modifications, such as the construction of coastal defences to protect shorelines, especially in urban areas. These hard engineered structures simplify, linearize, and homogenize the coast, leading to reduced biodiversity, ecological functioning, and ecosystem services. Conversely, increasing habitat complexity can lead to greater species richness. To date, efforts to actively manipulate and enhance habitat complexity have been restricted to relatively small scales (centimetres to meters), although there are some larger examples. Natural shorelines, however, are complex at multiple scales to the extent that their length is notoriously difficult to measure due to their fractal characteristics. Artificial coastal defences that integrate complex structures across scales from millimeters to 100s of meters will widen the variety of niches created. This ‘meandering shoreline' concept also replicates bays, headlands, reefs, and estuaries. To better understand the potential benefits of multi-scale complexity, we conducted two studies: 1. A meta-analysis on movement patterns, home ranges, and body size for a wide range of coastal marine species, and 2. A comparison of species richness between artificial hard defences with and without sandy bays. We found that, as mean body length of species increases, so does the general distance travelled, home range and core activity areas. We also found greater species richness in artificial shores that featured bays. These findings suggest that the design and planning of future coastal defences should consider incorporating habitat complexity across multiple scales to encourage colonisation and use by a wider range of species, thus reducing a key negative aspect of coastal infrastructure.

Be Limpet's Guest – A Tale of Algal Epibionts and Limpet Shells

celine — 2025-04-27T12:55:32Z

Louise B. Firth¹, Charlotte Clubley², Alex McGrath², Paul Gribben³, Stephen J. Hawkins^2,4, Antony M. Knights¹

¹University College Cork, Ireland - ²University of Plymouth, UK - ³University of New South Wales, Australia - ⁴University of Southampton, National Oceanography Centre Southampton, UK

Limpets are often recognised as important players in shaping benthic ecosystems through their grazing. However, their shells are much more than simple shelters—they serve as microhabitats for a diverse community of algae and other species. This poster explores how limpets, especially Patella ulyssiponensis, not only consume algae but also facilitate their growth by providing refuge for algae from their grazing competitors. In this "Beauty and the Beast" inspired poster, I reveal how the shells of limpets are island ecosystems for algal epibionts—essentially hosting guests that thrive in the protection of their "castle." When limpets are abundant on rocky shores, they often graze away the majority of algae, leaving only the most resistant species behind. However, in the presence of P. ulyssiponensis, algae flourish on their shells, as a result of aggressive behaviour by the limpet, which limits mutual grazing on their shells by other individuals - a form of associational defence. In contrast, other limpet species like Patella vulgata and Patella depressa are less important in facilitating algae, but shells of P. vulgata provide crucial refuge for smaller limpets from competitive pressures on the primary rock substrate. This creates unique "limpet islands" that support diverse algal communities. These findings challenge our understanding of limpets as mere grazers and instead position them as habitat-forming ecosystem engineers that host and protect diverse communities. The implications of these interactions go beyond theoretical ecology, shedding light on how habitat modifications by mobile organisms can shape ecosystems in unexpected ways, with potential impacts on wildlife management in a rapidly changing world.

Come visit my poster and discover the hidden life of limpet shells and the fascinating role they play on temperate reefs - just like the castle of a Disney classic, these shells are more than they appear!

Scaled-up approaches to eco-engineering in marine habitats

celine — 2025-04-27T12:55:31Z

Caoimhe Morris¹

¹University College Dublin, Ireland

Increased urbanisation along our coastlines has led to increased development of artificial structures that pose a significant threat to marine coastal ecosystems across the globe. Natural habitats are frequently replaced by infrastructure for shipment facilities or coastal defence structures. Artificial structures differ from natural rocky shorelines in both composition and configuration, and are typically vertical and featureless, lacking crevices and ridges formed organically on natural habitats. Such habitat characteristics are important in structuring marine assemblages, affecting key interactions and species distribution. Moreover, these structures can favour non-indigenous species and solutions to promote native over non-native species must be sought for.
Combining ecology and engineering, eco-engineering aims to fulfill the needs of both humans and marine organisms by incorporating features on artificial structures to support greater numbers of native biota. Surface complexity is the most evident difference between natural shores and artificial structures. The absence of these features are associated with lower species diversity on artificial substrates. As such, eco-engineering microhabitats during the construction of infrastructure or retrofitting them to existing structures can increase their value as habitats for marine biota.
Much of the eco-engineering research to date has been done at patch-scale while larger scale projects have involved designs of geometrically simplified microhabitats. Using approaches used in development of natural topography tiles we have designed large wall panels and habitat units that use natural topography to test if they can increase biodiversity in marine environments.
In particular, our research aims are to test the efficacy of scaled up eco-engineered structures to improve biodiversity on both intertidal seawalls and rock armour.
In order to address these aims, three replicate 180 x 150cm wall panels with incorporated natural topography were deployed on seawalls in Dublin Port, Kilmore Quay and Wexford Harbor. In addition, eight replicate habitat units (100x100x100cm) with integrated topography were deployed in two intertidal habitats in Dublin Port.
An overview of the approaches taken within this research will be presented along with preliminary findings on the efficacy of scaled up eco-engineered approaches to act as a solution for improving the diversity and abundance of species on artificial structures.
The predicted outcomes of this project will increase our understanding of eco-engineered habitats, building upon the evidence base for use in both future designs or for retrofitting existing artificial structures at larger scales to reduce the impact on biodiversity and ecosystem functioning.

A marine biogeographical transition zone is maintained by an eco-evolutionary driver

celine — 2025-04-27T12:55:30Z

Bernardo R. Broitman¹, Marco A. Lardies¹, Mauricio H. Oróstica², Nicolás I. Segovia³, Pilar A. Haye³

¹Universidad Adolfo Ibañez, Chile - ²Universidad Católica del Maule, Chile - ³Universidad Católica del Norte, Chile

A marine biogeographic and phylogeographic break located around 30°S on the shores of the southeastern Pacific coincides with a mesoscale change in coastal upwelling regime. Prior ecological and genetic evidence indicated that dispersal limitation was the leading mechanism maintaining the break. Mounting evidence of large between-site environmental heterogeneity along the transitional zone provides support for a niche-based mechanism as the underlying driver. To test this hypothesis, we examined patterns of phenotypic plasticity under contrasting thermal conditions for species belonging to multiple benthic taxa and different trophic levels, from multiple populations spanning the biogeographic break. We pooled our plasticity estimations with data from similar studies across the region and examined their joint spatial structure and its relationship with environmental heterogeneity. We observed that regardless of taxa and trophic level, individuals from populations within the biogeographic break showed higher phenotypic plasticity. Similarly, the spatial structure in neutral genetic markers for this diverse set of benthic species, which either spanned the transition zone or found the edge of their geographic ranges around it, hints at the presence of local adaptation. Our results suggest that evolutionary novel ecological interactions occur under environmental conditions that challenge species' physiological limits. The species that span the transition zone are likely to persist locally only through a net influx of propagules. The strong selective pressure identified by the spatial structure of phenotypical plasticity and phylogeographic patterns across multiple species suggest that the region may represent an area of special interest for future conservation efforts. Moreover, similar eco-evolutionary patterns may be a common feature in other coastal regions

Developing Standards for Marine Ecosystem Restoration

celine — 2025-04-27T12:55:29Z

Abel Zempleni¹, Sahar Stevenson-Jones²

¹Ifremer, France - ²Society for Ecological Restoration, Belgium

Marine ecosystem restoration is a critical component in mitigating biodiversity loss, enhancing ecosystem services, and improving coastal resilience. Whilst the SER Principles and Standards for Ecosystem exist to assist practitoners, there is a global call for adaptation to the marine space. Furthermore, as the global decline of marine ecosystems accelerates, the need for science-driven and adaptable restoration strategies has never been more urgent. The MRWG, a diverse network of scientists, conservationists, policymakers, and practitioners, will play a pivotal role in developing comprehensive and universally applicable restoration standards.

This presentation will highlight the MRWG's efforts in establishing this new set of guidelines and demonstrate how they provide a framework for effectively restoring marine habitats, ranging from seagrass meadows and oyster reefs to deep sea systems.

Finally, the presentation will discuss the broader implications of standards-based restoration and the network as a whole in advancing the Nature Restoration Regulation, with an emphasis on how consistent, scientifically-backed restoration methods can drive progress toward achieving the regulation's ambitious objectives. This collaborative approach ensures that restoration efforts are transparent, accountable, and measurable, setting the stage for large-scale, long-term success in marine conservation and recovery.