Emerging technology has immense potential to increase the scale and efficiency of marine conservation. One such technology is large‐area imaging (LAI), which relies on structure‐from‐motion ...photogrammetry to create composite products, including 3‐dimensional (3‐D) environmental models, that are larger in spatial extent than the individual images used to create them. Use of LAI has become widespread in certain fields of marine science, primarily to measure the 3D structure of benthic ecosystems and track change over time. However, the use of LAI in the field of marine conservation appears limited. We conducted a review of the coral reef literature on the use of LAI to identify research themes and regional trends in applications of this technology. We also surveyed 135 coral reef scientists and conservation practitioners to determine community familiarity with LAI, evaluate barriers practitioners face in using LAI, and identify applications of LAI believed to be most exciting or relevant to coral conservation. Adoption of LAI was limited primarily to researchers at institutions based in advanced economies and was applied infrequently to conservation, although conservation practitioners and survey respondents from emerging economies indicated they expect to use LAI in the future. Our results revealed disconnect between current LAI research topics and conservation priorities identified by practitioners, highlighting the need for more diverse, conservation‐relevant research using LAI. We provide recommendations for how early adopters of LAI (typically Global North scientists from well‐resourced institutions) can facilitate access to this conservation technology. These recommendations include developing training resources, creating partnerships for data storage and analysis, publishing standard operating procedures for LAI workflows, standardizing methods, developing tools for efficient data extraction from LAI products, and conducting conservation‐relevant research using LAI.
Reducción de la brecha entre la investigación actual de imágenes de gran superficie y las necesidades de la conservación marina
Resumen
Las nuevas tecnologías tienen un enorme potencial para aumentar la escala y la eficiencia de la conservación marina. Una de ellas son las imágenes de gran superficie (IGS), que se basan en la fotogrametría de estructura a partir del movimiento para crear productos compuestos, incluidos modelos ambientales tridimensionales (3D), cuya extensión espacial es mayor que la de las imágenes individuales utilizadas para crearlos. El uso de las IGS se ha generalizado en determinados campos de las ciencias marinas, principalmente para medir la estructura tridimensional de los ecosistemas bentónicos y realizar un seguimiento de los cambios a lo largo del tiempo. Sin embargo, el uso de las IGS en el campo de la conservación marina parece limitado. Realizamos una revisión de la bibliografía sobre el uso de las IGS en los arrecifes de coral para identificar temas de investigación y tendencias regionales en las aplicaciones de esta tecnología. También encuestamos a 135 científicos de arrecifes de coral y profesionales de la conservación para determinar la familiaridad de la comunidad con las IGS, evaluar las barreras a las que se enfrentan los profesionales en el uso de las IGS e identificar sus aplicaciones consideradas como las más interesantes o relevantes para la conservación del coral. La adopción de las IGS se limitó principalmente a los investigadores de las instituciones con sede en las economías avanzadas y se aplicó con poca frecuencia a la conservación, aunque los profesionales de la conservación y los encuestados de las economías emergentes indicaron que esperan utilizar las IGS en el futuro. Nuestros resultados revelaron una desconexión entre los actuales temas de investigación de las IGS y las prioridades de conservación identificadas por los profesionales, lo que subraya la necesidad de una investigación más diversa y relevante para la conservación mediante el uso de las IGS.
The establishment of no-take marine protected areas (MPAs) on coral reefs is a common management strategy for conserving the diversity, abundance, and biomass of reef organisms. Generally, ...well-managed and enforced MPAs can increase or maintain the diversity and function of the enclosed coral reef, with some of the benefits extending to adjacent non-protected reefs. A fundamental question in coral reef conservation is whether these benefits arise within small MPAs (<1 km2), because larval input of reef organisms is largely decoupled from local adult reproduction. We examined the structure of fish assemblages, composition of fish feeding groups, benthic cover, and key ecosystem processes (grazing, macroalgal browsing, and coral replenishment) in three small (0.5-0.8 km2) no-take MPAs and adjacent areas where fisheries are allowed (non-MPAs) on coral reefs in Fiji. The MPAs exhibited greater species richness, density, and biomass of fishes than non-MPAs. Furthermore, MPAs contained a greater abundance and biomass of grazing herbivores and piscivores as well as a greater abundance of cleaners than fished areas. We also found differences in fish associations when foraging, with feeding groups being generally more diverse and having greater biomass within MPAs than adjacent non-MPAs. Grazing by parrotfishes was 3-6 times greater, and macroalgal browsing was 3-5 times greater in MPAs than in non-MPAs. On average, MPAs had 260-280% as much coral cover and only 5-25% as much macroalgal cover as their paired non-MPA sites. Finally, two of the three MPAs had three-fold more coral recruits than adjacent non-MPAs. The results of this study indicate that small MPAs benefit not only populations of reef fishes, but also enhance ecosystem processes that are critical to reef resilience within the MPAs.
Marine protected areas (MPAs) are widely utilized for conservation of the world’s marine resources. Yet, compliance with MPA regulations remains difficult to measure because of limits to human ...resources and a lack of affordable technologies to automate monitoring over time. The Marine Monitor, an autonomous vessel monitoring, recording, and reporting system leveraging commercial off-the-shelf X-band marine radar to detect and track vessels, was used to monitor five nearshore California MPAs simultaneously and continuously to identify and compare site-specific use patterns over one year. Vessel tracks were classified into two movement patterns to capture likely fishing activity, “focal” or “linear”, that corresponded with local targeted species. Some illegal fishing potentially occurred at all sites (7–17% of tracks depending on site) most frequently on weekends and at mid-day, but the majority of activity occurred just outside the MPAs and in the near vicinity suggesting both a high level of compliance with regulations and awareness of MPA boundaries. Time spent engaged in potential fishing activity compared to track counts suggests that unique vessels may spend more time fishing inside area boundaries at some sites than others. The spatial distribution of activity shows distinct concentrations near MPA boundaries at all sites which strongly suggests vessels purposefully target the narrow area at the MPA boundary or “fish the line”, a potential acknowledgement of successful spillover. This activity increased significantly during some local fishing seasons. Concentration of activity at MPA boundaries highlights the importance of continuous monitoring at a high spatial and temporal resolution. Reporting of vessel behavior at a fine-scale using radar can help resource managers target enforcement efforts and understand human use patterns near coastal MPAs.
Anthropogenic impacts on tropical and subtropical coastal environments are increasing at an alarming rate, compromising ecosystem functions, structures and services. Understanding the scale of marine ...population decline and diversity loss requires a long-term perspective that incorporates information from a range of sources. The Southern Atlantic Ocean represents a major gap in our understanding of pre-industrial marine species composition. Here we begin to fill this gap by performing an extensive review of the published data on Middle and Late Holocene marine fish remains along the southern coast of Brazil. This region preserves archaeological sites that are unique archives of past socio-ecological systems and pre-European biological diversity. We assessed snapshots of species compositions and relative abundances spanning the last 9500 years, and modelled differences in species' functional traits between archaeological and modern fisheries. We found evidence for both generalist and specialist fishing practices in pre-European times, with large body size and body mass caught regularly over hundreds of years. Comparison with modern catches revealed a significant decline in these functional traits, possibly associated with overfishing and escalating human impacts in recent times.
This paper presents an ethnographic case study of the design and revision of a decentralized marine management scheme implemented on the island of Moorea, French Polynesia named
Plan de Gestion de ...l’Espace Maritime
(PGEM). Drawing on an analysis of over 50 consultative workshops and meetings, held from 2018 to 2021 during the PGEM revision, we document the materials, discourses, and practices local stakeholders (e.g., fishers, cultural and environmental activists, government staff, and scientists) combine to build their interpretations of PGEM success or failure. We examine the diversity of domains these interpretations draw from (ecology, marine livelihoods, culture, religion, and politics) and how they are put into practice in people’s engagement with—or resistance to—the local marine management and governance design. Our results highlight how the controversies around the revision of Moorea’s PGEM overflowed the boundaries of ecology as construed by scientific experts. Stakeholders interpreted “marine resource management” as something well beyond just “marine resources” to include politics, identity, Polynesian cosmology, and livelihoods. Our findings provide generalizable patterns for understanding how natural-resource management policies are received and repurposed by local actors.
This article deals with the local conceptualisation of ‘conservation’ in the village Siviri in Vanuatu where villagers have established and maintain a small marine conservation area. Looking at ...villagers’ motivations, the aim is to carve out the local conceptualisation and practice of ‘conservation’, to show what conservation is for the villagers. The theoretical framework is a combination of two approaches, namely ‘assemblage’ and ‘world-making’. Conservation in Siviri is ontologically different from the concept of conservation used in Vanuatu national policy. It can be regarded as a creative engagement of villagers with their environment(s) to preserve the specific world-making assemblage consisting of humans and marine life for future generations.
•Proposing a framework to integrate advanced probabilistic modelling with hydrodynamic analysis of the marine floating structure.•Developing a Bayesian Network for reliability assessment and ...predicting optimum design point of the mooring system.•Considering the hydrodynamic response of the structure for failure modelling of the tensioned mooring system.•Proposing the Bayesian Approach for improving the safety of marine floating structures.
Marine floating structures are widely used in various fields of industry from oil and gas to renewable energy. The predominant dynamic responses of these structures are controlled by mooring lines. In recent years, a number of high-profile mooring failures have highlighted the high risk of this element in floating structures. A reliable design of mooring liness is necessary to improve the safety of offshore operations. This paper proposes a novel methodology to conduct reliability analysis of moored floating structures using Bayesian network (BN). The long-term distributions of extreme responses of the floating object are estimated using analytical frequency domain method, while mooring failure probability is estimated using limit state function in the proposed BN framework. Application of the methodology is demonstrated by estimating the failure probabilities of a floating cylinder with tensioned mooring system. The proposed study also explains how the hydrodynamic and reliability analysis could be integrated with BN to assess the overall safety of the offshore structures. The methodology presented can be employed to mitigate associated risk with marine structures brought about by stochastic hydrodynamic loads.
Marine reserves are being established worldwide to conserve and manage marine resources, and are also often assumed to conserve the evolutionary potential of marine populations. However, comparisons ...of genomic patterns inside and outside marine reserves in multiple species are scarce. Here, we aim to fill this gap by 1) comparing genomic variation in protected versus unprotected areas in a network of eight reserves in the Mediterranean Sea, and 2) disentangling the effect of seascape, space and marine reserves on this genomic variation in 1297 individuals from four species genotyped at more than 10 000 SNPs each. We report homogeneous patterns of local genetic diversity within and outside reserves in three of the four species (the white seabream Diplodus sargus, the striped red mullet Mullus surmuletus and the European spiny lobster Palinurus elephas). Surprisingly, the comber Serranus cabrilla shows lower genetic diversity in protected areas, highlighting an apparent conservation paradox that may be due to increased predation by protected fishes in the reserves. Multivariate analyses reveal that seascape factors (salinity, temperature and chlorophyll) and space exert a significant influence on genomic variation in some cases, while protection status has no detectable effect. Nevertheless, four marine reserves (Cabo de Palos, Cerbère‐Banyuls, Cap de Creus and Illes Columbretes) harbor singular genetic variation in one or two species. This pattern, observed in the four species, suggests that reserves contribute to preserve genetic variation locally. Our study illustrates that we can document key aspects of the genetic variation of marine species and their interaction with seascape factors, space and protection status in multiple species. It stresses the need for a multi‐species approach to inform marine conservation planning, opening up new perspectives at the community level.
Abstract
Although the management of fish spawning aggregations (FSAs) often requires a precautionary approach that initially emphasizes conservation, understanding the dynamics of spawning and ...interactions with fishing activities can help identify long-term management solutions that balance conservation with utilization. We designed a parsimonious, per-recruit model to evaluate the potential effects of seven time-closure scenarios implemented during the spawning season on egg production per recruit (EPR; a conservation metric) and yield per recruit (YPR; a fisheries metric) of Gulf corvina (Cynoscion othonopterus), a vulnerable marine fish that experiences persistent overfishing at its only known spawning grounds in the Gulf of California, Mexico. Three of the seven scenarios provided small-to-large increases in EPR (8–43%) accompanied by only small decreases in YPR (3–11%) that resulted in a sustainable fishery. Increased mortality of juveniles and small adults through targeted fishing or as bycatch in other fisheries, however, would erode the fisheries and conservation benefits of time closures. Our results demonstrate that information on spawning and fishing activities can be combined with stakeholder input to identify regulations that permit the sustainable harvesting of FSAs. Furthermore, the implementation of brief, temporal fishing effort restrictions can represent a viable, less restrictive alternative to marine protected areas for the management of FSAs.
Understanding the structure and connectivity of coral populations is fundamental for developing marine conservation policies, especially in patchy environments such as archipelagos. The Nansei ...Islands, extending more than 1000 km in southwestern Japan, are characterized by high levels of biodiversity and endemism, supported by coral reefs, which make this region ideal for assessing genetic attributes of coral populations. In this study, we conducted population genomic analyses based on genome‐wide, single‐nucleotide polymorphisms (SNPs) of Acropora digitifera, a common species in the Nansei Islands. By merging newly obtained genome resequencing data with previously published data, we identified more than 4 million genome‐wide SNPs in 303 colonies collected at 22 locations, with sequencing coverage ranging from 3.91× to 27.41×. While population structure analyses revealed genetic similarities between the southernmost and northernmost locations, separated by >1000 km, several subpopulations in intermediate locations suggested limited genetic admixture, indicating conflicting migration tendencies in the Nansei Islands. Although migration networks revealed a general tendency of northward migration along the Kuroshio Current, a substantial amount of southward migration was also detected, indicating important contributions of minor ocean currents to coral larval dispersal. Moreover, heterogeneity in the transition of effective population sizes among locations suggests different histories for individual subpopulations. The unexpected complexity of both past and present population dynamics in the Nansei Islands implies that heterogeneity of ocean currents and local environments, past and present, have influenced the population structure of this species, and similar unexpected population complexities may be expected for other marine species with similar reproductive modes.
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